class DrtGlueDemo(object):
def __init__(self, examples):
# Set up the main window.
self._top = Tk()
self._top.title('DRT Glue Demo')
# Set up key bindings.
self._init_bindings()
# Initialize the fonts.self._error = None
self._init_fonts(self._top)
self._examples = examples
self._readingCache = [None for example in examples]
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Set the data to None
self._curExample = -1
self._readings = []
self._drs = None
self._drsWidget = None
self._error = None
self._init_glue()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_exampleListbox(self._top)
self._init_readingListbox(self._top)
self._init_canvas(self._top)
# Resize callback
self._canvas.bind('<Configure>', self._configure)
#########################################
## Initialization Helpers
#########################################
def _init_glue(self):
tagger = RegexpTagger([
('^(David|Mary|John)$', 'NNP'),
('^(walks|sees|eats|chases|believes|gives|sleeps|chases|persuades|tries|seems|leaves)$',
'VB'), ('^(go|order|vanish|find|approach)$', 'VB'),
('^(a)$', 'ex_quant'), ('^(every)$', 'univ_quant'),
('^(sandwich|man|dog|pizza|unicorn|cat|senator)$', 'NN'),
('^(big|gray|former)$', 'JJ'), ('^(him|himself)$', 'PRP')
])
depparser = MaltParser(tagger=tagger)
self._glue = DrtGlue(depparser=depparser, remove_duplicates=False)
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = Font(family='helvetica',
weight='bold',
size=self._size.get())
self._font = Font(family='helvetica', size=self._size.get())
if self._size.get() < 0: big = self._size.get() - 2
else: big = self._size.get() + 2
self._bigfont = Font(family='helvetica', weight='bold', size=big)
def _init_exampleListbox(self, parent):
self._exampleFrame = listframe = Frame(parent)
self._exampleFrame.pack(fill='both', side='left', padx=2)
self._exampleList_label = Label(self._exampleFrame,
font=self._boldfont,
text='Examples')
self._exampleList_label.pack()
self._exampleList = Listbox(self._exampleFrame,
selectmode='single',
relief='groove',
background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._exampleList.pack(side='right', fill='both', expand=1)
for example in self._examples:
self._exampleList.insert('end', (' %s' % example))
self._exampleList.config(height=min(len(self._examples), 25), width=40)
# Add a scrollbar if there are more than 25 examples.
if len(self._examples) > 25:
listscroll = Scrollbar(self._exampleFrame, orient='vertical')
self._exampleList.config(yscrollcommand=listscroll.set)
listscroll.config(command=self._exampleList.yview)
listscroll.pack(side='left', fill='y')
# If they select a example, apply it.
self._exampleList.bind('<<ListboxSelect>>', self._exampleList_select)
def _init_readingListbox(self, parent):
self._readingFrame = listframe = Frame(parent)
self._readingFrame.pack(fill='both', side='left', padx=2)
self._readingList_label = Label(self._readingFrame,
font=self._boldfont,
text='Readings')
self._readingList_label.pack()
self._readingList = Listbox(self._readingFrame,
selectmode='single',
relief='groove',
background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._readingList.pack(side='right', fill='both', expand=1)
# Add a scrollbar if there are more than 25 examples.
listscroll = Scrollbar(self._readingFrame, orient='vertical')
self._readingList.config(yscrollcommand=listscroll.set)
listscroll.config(command=self._readingList.yview)
listscroll.pack(side='right', fill='y')
self._populate_readingListbox()
def _populate_readingListbox(self):
# Populate the listbox with integers
self._readingList.delete(0, 'end')
for i in range(len(self._readings)):
self._readingList.insert('end', (' %s' % (i + 1)))
self._readingList.config(height=min(len(self._readings), 25), width=5)
# If they select a example, apply it.
self._readingList.bind('<<ListboxSelect>>', self._readingList_select)
def _init_bindings(self):
# Key bindings are a good thing.
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Escape>', self.destroy)
self._top.bind('n', self.next)
self._top.bind('<space>', self.next)
self._top.bind('p', self.prev)
self._top.bind('<BackSpace>', self.prev)
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom', padx=3, pady=2)
Button(
buttonframe,
text='Prev',
background='#90c0d0',
foreground='black',
command=self.prev,
).pack(side='left')
Button(
buttonframe,
text='Next',
background='#90c0d0',
foreground='black',
command=self.next,
).pack(side='left')
def _configure(self, event):
self._autostep = 0
(x1, y1, x2, y2) = self._cframe.scrollregion()
y2 = event.height - 6
self._canvas['scrollregion'] = '%d %d %d %d' % (x1, y1, x2, y2)
self._redraw()
def _init_canvas(self, parent):
self._cframe = CanvasFrame(
parent,
background='white',
#width=525, height=250,
closeenough=10,
border=2,
relief='sunken')
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
# Initially, there's no tree or text
self._tree = None
self._textwidgets = []
self._textline = None
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Exit',
underline=1,
command=self.destroy,
accelerator='q')
menubar.add_cascade(label='File', underline=0, menu=filemenu)
actionmenu = Menu(menubar, tearoff=0)
actionmenu.add_command(label='Next',
underline=0,
command=self.next,
accelerator='n, Space')
actionmenu.add_command(label='Previous',
underline=0,
command=self.prev,
accelerator='p, Backspace')
menubar.add_cascade(label='Action', underline=0, menu=actionmenu)
optionmenu = Menu(menubar, tearoff=0)
optionmenu.add_checkbutton(label='Remove Duplicates',
underline=0,
variable=self._glue.remove_duplicates,
command=self._toggle_remove_duplicates,
accelerator='r')
menubar.add_cascade(label='Options', underline=0, menu=optionmenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_radiobutton(label='Tiny',
variable=self._size,
underline=0,
value=10,
command=self.resize)
viewmenu.add_radiobutton(label='Small',
variable=self._size,
underline=0,
value=12,
command=self.resize)
viewmenu.add_radiobutton(label='Medium',
variable=self._size,
underline=0,
value=14,
command=self.resize)
viewmenu.add_radiobutton(label='Large',
variable=self._size,
underline=0,
value=18,
command=self.resize)
viewmenu.add_radiobutton(label='Huge',
variable=self._size,
underline=0,
value=24,
command=self.resize)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0, command=self.about)
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
#########################################
## Main draw procedure
#########################################
def _redraw(self):
canvas = self._canvas
# Delete the old DRS, widgets, etc.
if self._drsWidget is not None:
self._drsWidget.clear()
if self._drs:
self._drsWidget = DrsWidget(self._canvas, self._drs)
self._drsWidget.draw()
if self._error:
self._drsWidget = DrsWidget(self._canvas, self._error)
self._drsWidget.draw()
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
self._autostep = 0
if self._top is None: return
self._top.destroy()
self._top = None
def prev(self, *e):
selection = self._readingList.curselection()
readingListSize = self._readingList.size()
# there are readings
if readingListSize > 0:
# if one reading is currently selected
if len(selection) == 1:
index = int(selection[0])
# if it's on (or before) the first item
if index <= 0:
self._select_previous_example()
else:
self._readingList_store_selection(index - 1)
else:
#select its first reading
self._readingList_store_selection(readingListSize - 1)
else:
self._select_previous_example()
def _select_previous_example(self):
#if the current example is not the first example
if self._curExample > 0:
self._exampleList_store_selection(self._curExample - 1)
else:
#go to the last example
self._exampleList_store_selection(len(self._examples) - 1)
def next(self, *e):
selection = self._readingList.curselection()
readingListSize = self._readingList.size()
# if there are readings
if readingListSize > 0:
# if one reading is currently selected
if len(selection) == 1:
index = int(selection[0])
# if it's on (or past) the last item
if index >= (readingListSize - 1):
self._select_next_example()
else:
self._readingList_store_selection(index + 1)
else:
#select its first reading
self._readingList_store_selection(0)
else:
self._select_next_example()
def _select_next_example(self):
#if the current example is not the last example
if self._curExample < len(self._examples) - 1:
self._exampleList_store_selection(self._curExample + 1)
else:
#go to the first example
self._exampleList_store_selection(0)
def about(self, *e):
ABOUT = (
"NLTK Discourse Representation Theory (DRT) Glue Semantics Demo\n"
+ "Written by Daniel H. Garrette")
TITLE = 'About: NLTK DRT Glue Demo'
try:
from six.moves.tkinter_messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def postscript(self, *e):
self._autostep = 0
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle(): return
self._top.mainloop(*args, **kwargs)
def resize(self, size=None):
if size is not None: self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
self._bigfont.configure(size=-(abs(size + 2)))
self._redraw()
def _toggle_remove_duplicates(self):
self._glue.remove_duplicates = not self._glue.remove_duplicates
self._exampleList.selection_clear(0, 'end')
self._readings = []
self._populate_readingListbox()
self._readingCache = [None for ex in self._examples]
self._curExample = -1
self._error = None
self._drs = None
self._redraw()
def _exampleList_select(self, event):
selection = self._exampleList.curselection()
if len(selection) != 1: return
self._exampleList_store_selection(int(selection[0]))
def _exampleList_store_selection(self, index):
self._curExample = index
example = self._examples[index]
self._exampleList.selection_clear(0, 'end')
if example:
cache = self._readingCache[index]
if cache:
if isinstance(cache, list):
self._readings = cache
self._error = None
else:
self._readings = []
self._error = cache
else:
try:
self._readings = self._glue.parse_to_meaning(example)
self._error = None
self._readingCache[index] = self._readings
except Exception as e:
self._readings = []
self._error = DrtVariableExpression(
Variable('Error: ' + str(e)))
self._readingCache[index] = self._error
#add a star to the end of the example
self._exampleList.delete(index)
self._exampleList.insert(index, (' %s *' % example))
self._exampleList.config(height=min(
len(self._examples), 25),
width=40)
self._populate_readingListbox()
self._exampleList.selection_set(index)
self._drs = None
self._redraw()
def _readingList_select(self, event):
selection = self._readingList.curselection()
if len(selection) != 1: return
self._readingList_store_selection(int(selection[0]))
def _readingList_store_selection(self, index):
reading = self._readings[index]
self._readingList.selection_clear(0, 'end')
if reading:
self._readingList.selection_set(index)
self._drs = reading.simplify().normalize().resolve_anaphora()
self._redraw()
class RecursiveDescentApp(object):
"""
A graphical tool for exploring the recursive descent parser. The tool
displays the parser's tree and the remaining text, and allows the
user to control the parser's operation. In particular, the user
can expand subtrees on the frontier, match tokens on the frontier
against the text, and backtrack. A "step" button simply steps
through the parsing process, performing the operations that
``RecursiveDescentParser`` would use.
"""
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingRecursiveDescentParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Recursive Descent Parser Application')
# Set up key bindings.
self._init_bindings()
# Initialize the fonts.
self._init_fonts(self._top)
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animation_frames = IntVar(self._top)
self._animation_frames.set(5)
self._animating_lock = 0
self._autostep = 0
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# Initialize the parser.
self._parser.initialize(self._sent)
# Resize callback
self._canvas.bind('<Configure>', self._configure)
#########################################
## Initialization Helpers
#########################################
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = Font(family='helvetica', weight='bold',
size=self._size.get())
self._font = Font(family='helvetica',
size=self._size.get())
if self._size.get() < 0: big = self._size.get()-2
else: big = self._size.get()+2
self._bigfont = Font(family='helvetica', weight='bold',
size=big)
def _init_grammar(self, parent):
# Grammar view.
self._prodframe = listframe = Frame(parent)
self._prodframe.pack(fill='both', side='left', padx=2)
self._prodlist_label = Label(self._prodframe, font=self._boldfont,
text='Available Expansions')
self._prodlist_label.pack()
self._prodlist = Listbox(self._prodframe, selectmode='single',
relief='groove', background='white',
foreground='#909090', font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._prodlist.pack(side='right', fill='both', expand=1)
self._productions = list(self._parser.grammar().productions())
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
self._prodlist.config(height=min(len(self._productions), 25))
# Add a scrollbar if there are more than 25 productions.
if len(self._productions) > 25:
listscroll = Scrollbar(self._prodframe,
orient='vertical')
self._prodlist.config(yscrollcommand = listscroll.set)
listscroll.config(command=self._prodlist.yview)
listscroll.pack(side='left', fill='y')
# If they select a production, apply it.
self._prodlist.bind('<<ListboxSelect>>', self._prodlist_select)
def _init_bindings(self):
# Key bindings are a good thing.
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Escape>', self.destroy)
self._top.bind('e', self.expand)
#self._top.bind('<Alt-e>', self.expand)
#self._top.bind('<Control-e>', self.expand)
self._top.bind('m', self.match)
self._top.bind('<Alt-m>', self.match)
self._top.bind('<Control-m>', self.match)
self._top.bind('b', self.backtrack)
self._top.bind('<Alt-b>', self.backtrack)
self._top.bind('<Control-b>', self.backtrack)
self._top.bind('<Control-z>', self.backtrack)
self._top.bind('<BackSpace>', self.backtrack)
self._top.bind('a', self.autostep)
#self._top.bind('<Control-a>', self.autostep)
self._top.bind('<Control-space>', self.autostep)
self._top.bind('<Control-c>', self.cancel_autostep)
self._top.bind('<space>', self.step)
self._top.bind('<Delete>', self.reset)
self._top.bind('<Control-p>', self.postscript)
#self._top.bind('<h>', self.help)
#self._top.bind('<Alt-h>', self.help)
self._top.bind('<Control-h>', self.help)
self._top.bind('<F1>', self.help)
#self._top.bind('<g>', self.toggle_grammar)
#self._top.bind('<Alt-g>', self.toggle_grammar)
#self._top.bind('<Control-g>', self.toggle_grammar)
self._top.bind('<Control-g>', self.edit_grammar)
self._top.bind('<Control-t>', self.edit_sentence)
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom', padx=3, pady=2)
Button(buttonframe, text='Step',
background='#90c0d0', foreground='black',
command=self.step,).pack(side='left')
Button(buttonframe, text='Autostep',
background='#90c0d0', foreground='black',
command=self.autostep,).pack(side='left')
Button(buttonframe, text='Expand', underline=0,
background='#90f090', foreground='black',
command=self.expand).pack(side='left')
Button(buttonframe, text='Match', underline=0,
background='#90f090', foreground='black',
command=self.match).pack(side='left')
Button(buttonframe, text='Backtrack', underline=0,
background='#f0a0a0', foreground='black',
command=self.backtrack).pack(side='left')
# Replace autostep...
# self._autostep_button = Button(buttonframe, text='Autostep',
# underline=0, command=self.autostep)
# self._autostep_button.pack(side='left')
def _configure(self, event):
self._autostep = 0
(x1, y1, x2, y2) = self._cframe.scrollregion()
y2 = event.height - 6
self._canvas['scrollregion'] = '%d %d %d %d' % (x1,y1,x2,y2)
self._redraw()
def _init_feedback(self, parent):
self._feedbackframe = feedbackframe = Frame(parent)
feedbackframe.pack(fill='x', side='bottom', padx=3, pady=3)
self._lastoper_label = Label(feedbackframe, text='Last Operation:',
font=self._font)
self._lastoper_label.pack(side='left')
lastoperframe = Frame(feedbackframe, relief='sunken', border=1)
lastoperframe.pack(fill='x', side='right', expand=1, padx=5)
self._lastoper1 = Label(lastoperframe, foreground='#007070',
background='#f0f0f0', font=self._font)
self._lastoper2 = Label(lastoperframe, anchor='w', width=30,
foreground='#004040', background='#f0f0f0',
font=self._font)
self._lastoper1.pack(side='left')
self._lastoper2.pack(side='left', fill='x', expand=1)
def _init_canvas(self, parent):
self._cframe = CanvasFrame(parent, background='white',
#width=525, height=250,
closeenough=10,
border=2, relief='sunken')
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
# Initially, there's no tree or text
self._tree = None
self._textwidgets = []
self._textline = None
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Reset Parser', underline=0,
command=self.reset, accelerator='Del')
filemenu.add_command(label='Print to Postscript', underline=0,
command=self.postscript, accelerator='Ctrl-p')
filemenu.add_command(label='Exit', underline=1,
command=self.destroy, accelerator='Ctrl-x')
menubar.add_cascade(label='File', underline=0, menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(label='Edit Grammar', underline=5,
command=self.edit_grammar,
accelerator='Ctrl-g')
editmenu.add_command(label='Edit Text', underline=5,
command=self.edit_sentence,
accelerator='Ctrl-t')
menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
rulemenu = Menu(menubar, tearoff=0)
rulemenu.add_command(label='Step', underline=1,
command=self.step, accelerator='Space')
rulemenu.add_separator()
rulemenu.add_command(label='Match', underline=0,
command=self.match, accelerator='Ctrl-m')
rulemenu.add_command(label='Expand', underline=0,
command=self.expand, accelerator='Ctrl-e')
rulemenu.add_separator()
rulemenu.add_command(label='Backtrack', underline=0,
command=self.backtrack, accelerator='Ctrl-b')
menubar.add_cascade(label='Apply', underline=0, menu=rulemenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_checkbutton(label="Show Grammar", underline=0,
variable=self._show_grammar,
command=self._toggle_grammar)
viewmenu.add_separator()
viewmenu.add_radiobutton(label='Tiny', variable=self._size,
underline=0, value=10, command=self.resize)
viewmenu.add_radiobutton(label='Small', variable=self._size,
underline=0, value=12, command=self.resize)
viewmenu.add_radiobutton(label='Medium', variable=self._size,
underline=0, value=14, command=self.resize)
viewmenu.add_radiobutton(label='Large', variable=self._size,
underline=0, value=18, command=self.resize)
viewmenu.add_radiobutton(label='Huge', variable=self._size,
underline=0, value=24, command=self.resize)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
animatemenu = Menu(menubar, tearoff=0)
animatemenu.add_radiobutton(label="No Animation", underline=0,
variable=self._animation_frames,
value=0)
animatemenu.add_radiobutton(label="Slow Animation", underline=0,
variable=self._animation_frames,
value=10, accelerator='-')
animatemenu.add_radiobutton(label="Normal Animation", underline=0,
variable=self._animation_frames,
value=5, accelerator='=')
animatemenu.add_radiobutton(label="Fast Animation", underline=0,
variable=self._animation_frames,
value=2, accelerator='+')
menubar.add_cascade(label="Animate", underline=1, menu=animatemenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0,
command=self.about)
helpmenu.add_command(label='Instructions', underline=0,
command=self.help, accelerator='F1')
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
#########################################
## Helper
#########################################
def _get(self, widget, treeloc):
for i in treeloc: widget = widget.subtrees()[i]
if isinstance(widget, TreeSegmentWidget):
widget = widget.label()
return widget
#########################################
## Main draw procedure
#########################################
def _redraw(self):
canvas = self._canvas
# Delete the old tree, widgets, etc.
if self._tree is not None:
self._cframe.destroy_widget(self._tree)
for twidget in self._textwidgets:
self._cframe.destroy_widget(twidget)
if self._textline is not None:
self._canvas.delete(self._textline)
# Draw the tree.
helv = ('helvetica', -self._size.get())
bold = ('helvetica', -self._size.get(), 'bold')
attribs = {'tree_color': '#000000', 'tree_width': 2,
'node_font': bold, 'leaf_font': helv,}
tree = self._parser.tree()
self._tree = tree_to_treesegment(canvas, tree, **attribs)
self._cframe.add_widget(self._tree, 30, 5)
# Draw the text.
helv = ('helvetica', -self._size.get())
bottom = y = self._cframe.scrollregion()[3]
self._textwidgets = [TextWidget(canvas, word, font=self._font)
for word in self._sent]
for twidget in self._textwidgets:
self._cframe.add_widget(twidget, 0, 0)
twidget.move(0, bottom-twidget.bbox()[3]-5)
y = min(y, twidget.bbox()[1])
# Draw a line over the text, to separate it from the tree.
self._textline = canvas.create_line(-5000, y-5, 5000, y-5, dash='.')
# Highlight appropriate nodes.
self._highlight_nodes()
self._highlight_prodlist()
# Make sure the text lines up.
self._position_text()
def _redraw_quick(self):
# This should be more-or-less sufficient after an animation.
self._highlight_nodes()
self._highlight_prodlist()
self._position_text()
def _highlight_nodes(self):
# Highlight the list of nodes to be checked.
bold = ('helvetica', -self._size.get(), 'bold')
for treeloc in self._parser.frontier()[:1]:
self._get(self._tree, treeloc)['color'] = '#20a050'
self._get(self._tree, treeloc)['font'] = bold
for treeloc in self._parser.frontier()[1:]:
self._get(self._tree, treeloc)['color'] = '#008080'
def _highlight_prodlist(self):
# Highlight the productions that can be expanded.
# Boy, too bad tkinter doesn't implement Listbox.itemconfig;
# that would be pretty useful here.
self._prodlist.delete(0, 'end')
expandable = self._parser.expandable_productions()
untried = self._parser.untried_expandable_productions()
productions = self._productions
for index in range(len(productions)):
if productions[index] in expandable:
if productions[index] in untried:
self._prodlist.insert(index, ' %s' % productions[index])
else:
self._prodlist.insert(index, ' %s (TRIED)' %
productions[index])
self._prodlist.selection_set(index)
else:
self._prodlist.insert(index, ' %s' % productions[index])
def _position_text(self):
# Line up the text widgets that are matched against the tree
numwords = len(self._sent)
num_matched = numwords - len(self._parser.remaining_text())
leaves = self._tree_leaves()[:num_matched]
xmax = self._tree.bbox()[0]
for i in range(0, len(leaves)):
widget = self._textwidgets[i]
leaf = leaves[i]
widget['color'] = '#006040'
leaf['color'] = '#006040'
widget.move(leaf.bbox()[0] - widget.bbox()[0], 0)
xmax = widget.bbox()[2] + 10
# Line up the text widgets that are not matched against the tree.
for i in range(len(leaves), numwords):
widget = self._textwidgets[i]
widget['color'] = '#a0a0a0'
widget.move(xmax - widget.bbox()[0], 0)
xmax = widget.bbox()[2] + 10
# If we have a complete parse, make everything green :)
if self._parser.currently_complete():
for twidget in self._textwidgets:
twidget['color'] = '#00a000'
# Move the matched leaves down to the text.
for i in range(0, len(leaves)):
widget = self._textwidgets[i]
leaf = leaves[i]
dy = widget.bbox()[1] - leaf.bbox()[3] - 10.0
dy = max(dy, leaf.parent().label().bbox()[3] - leaf.bbox()[3] + 10)
leaf.move(0, dy)
def _tree_leaves(self, tree=None):
if tree is None: tree = self._tree
if isinstance(tree, TreeSegmentWidget):
leaves = []
for child in tree.subtrees(): leaves += self._tree_leaves(child)
return leaves
else:
return [tree]
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
self._autostep = 0
if self._top is None: return
self._top.destroy()
self._top = None
def reset(self, *e):
self._autostep = 0
self._parser.initialize(self._sent)
self._lastoper1['text'] = 'Reset Application'
self._lastoper2['text'] = ''
self._redraw()
def autostep(self, *e):
if self._animation_frames.get() == 0:
self._animation_frames.set(2)
if self._autostep:
self._autostep = 0
else:
self._autostep = 1
self._step()
def cancel_autostep(self, *e):
#self._autostep_button['text'] = 'Autostep'
self._autostep = 0
# Make sure to stop auto-stepping if we get any user input.
def step(self, *e): self._autostep = 0; self._step()
def match(self, *e): self._autostep = 0; self._match()
def expand(self, *e): self._autostep = 0; self._expand()
def backtrack(self, *e): self._autostep = 0; self._backtrack()
def _step(self):
if self._animating_lock: return
# Try expanding, matching, and backtracking (in that order)
if self._expand(): pass
elif self._parser.untried_match() and self._match(): pass
elif self._backtrack(): pass
else:
self._lastoper1['text'] = 'Finished'
self._lastoper2['text'] = ''
self._autostep = 0
# Check if we just completed a parse.
if self._parser.currently_complete():
self._autostep = 0
self._lastoper2['text'] += ' [COMPLETE PARSE]'
def _expand(self, *e):
if self._animating_lock: return
old_frontier = self._parser.frontier()
rv = self._parser.expand()
if rv is not None:
self._lastoper1['text'] = 'Expand:'
self._lastoper2['text'] = rv
self._prodlist.selection_clear(0, 'end')
index = self._productions.index(rv)
self._prodlist.selection_set(index)
self._animate_expand(old_frontier[0])
return True
else:
self._lastoper1['text'] = 'Expand:'
self._lastoper2['text'] = '(all expansions tried)'
return False
def _match(self, *e):
if self._animating_lock: return
old_frontier = self._parser.frontier()
rv = self._parser.match()
if rv is not None:
self._lastoper1['text'] = 'Match:'
self._lastoper2['text'] = rv
self._animate_match(old_frontier[0])
return True
else:
self._lastoper1['text'] = 'Match:'
self._lastoper2['text'] = '(failed)'
return False
def _backtrack(self, *e):
if self._animating_lock: return
if self._parser.backtrack():
elt = self._parser.tree()
for i in self._parser.frontier()[0]:
elt = elt[i]
self._lastoper1['text'] = 'Backtrack'
self._lastoper2['text'] = ''
if isinstance(elt, Tree):
self._animate_backtrack(self._parser.frontier()[0])
else:
self._animate_match_backtrack(self._parser.frontier()[0])
return True
else:
self._autostep = 0
self._lastoper1['text'] = 'Finished'
self._lastoper2['text'] = ''
return False
def about(self, *e):
ABOUT = ("NLTK Recursive Descent Parser Application\n"+
"Written by Edward Loper")
TITLE = 'About: Recursive Descent Parser Application'
try:
from six.moves.tkinter_messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def help(self, *e):
self._autostep = 0
# The default font's not very legible; try using 'fixed' instead.
try:
ShowText(self._top, 'Help: Recursive Descent Parser Application',
(__doc__ or '').strip(), width=75, font='fixed')
except:
ShowText(self._top, 'Help: Recursive Descent Parser Application',
(__doc__ or '').strip(), width=75)
def postscript(self, *e):
self._autostep = 0
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle(): return
self._top.mainloop(*args, **kwargs)
def resize(self, size=None):
if size is not None: self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
self._bigfont.configure(size=-(abs(size+2)))
self._redraw()
#########################################
## Expand Production Selection
#########################################
def _toggle_grammar(self, *e):
if self._show_grammar.get():
self._prodframe.pack(fill='both', side='left', padx=2,
after=self._feedbackframe)
self._lastoper1['text'] = 'Show Grammar'
else:
self._prodframe.pack_forget()
self._lastoper1['text'] = 'Hide Grammar'
self._lastoper2['text'] = ''
# def toggle_grammar(self, *e):
# self._show_grammar = not self._show_grammar
# if self._show_grammar:
# self._prodframe.pack(fill='both', expand='y', side='left',
# after=self._feedbackframe)
# self._lastoper1['text'] = 'Show Grammar'
# else:
# self._prodframe.pack_forget()
# self._lastoper1['text'] = 'Hide Grammar'
# self._lastoper2['text'] = ''
def _prodlist_select(self, event):
selection = self._prodlist.curselection()
if len(selection) != 1: return
index = int(selection[0])
old_frontier = self._parser.frontier()
production = self._parser.expand(self._productions[index])
if production:
self._lastoper1['text'] = 'Expand:'
self._lastoper2['text'] = production
self._prodlist.selection_clear(0, 'end')
self._prodlist.selection_set(index)
self._animate_expand(old_frontier[0])
else:
# Reset the production selections.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.expandable_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
#########################################
## Animation
#########################################
def _animate_expand(self, treeloc):
oldwidget = self._get(self._tree, treeloc)
oldtree = oldwidget.parent()
top = not isinstance(oldtree.parent(), TreeSegmentWidget)
tree = self._parser.tree()
for i in treeloc:
tree = tree[i]
widget = tree_to_treesegment(self._canvas, tree,
node_font=self._boldfont,
leaf_color='white',
tree_width=2, tree_color='white',
node_color='white',
leaf_font=self._font)
widget.label()['color'] = '#20a050'
(oldx, oldy) = oldtree.label().bbox()[:2]
(newx, newy) = widget.label().bbox()[:2]
widget.move(oldx-newx, oldy-newy)
if top:
self._cframe.add_widget(widget, 0, 5)
widget.move(30-widget.label().bbox()[0], 0)
self._tree = widget
else:
oldtree.parent().replace_child(oldtree, widget)
# Move the children over so they don't overlap.
# Line the children up in a strange way.
if widget.subtrees():
dx = (oldx + widget.label().width()/2 -
widget.subtrees()[0].bbox()[0]/2 -
widget.subtrees()[0].bbox()[2]/2)
for subtree in widget.subtrees(): subtree.move(dx, 0)
self._makeroom(widget)
if top:
self._cframe.destroy_widget(oldtree)
else:
oldtree.destroy()
colors = ['gray%d' % (10*int(10*x/self._animation_frames.get()))
for x in range(self._animation_frames.get(),0,-1)]
# Move the text string down, if necessary.
dy = widget.bbox()[3] + 30 - self._canvas.coords(self._textline)[1]
if dy > 0:
for twidget in self._textwidgets: twidget.move(0, dy)
self._canvas.move(self._textline, 0, dy)
self._animate_expand_frame(widget, colors)
def _makeroom(self, treeseg):
"""
Make sure that no sibling tree bbox's overlap.
"""
parent = treeseg.parent()
if not isinstance(parent, TreeSegmentWidget): return
index = parent.subtrees().index(treeseg)
# Handle siblings to the right
rsiblings = parent.subtrees()[index+1:]
if rsiblings:
dx = treeseg.bbox()[2] - rsiblings[0].bbox()[0] + 10
for sibling in rsiblings: sibling.move(dx, 0)
# Handle siblings to the left
if index > 0:
lsibling = parent.subtrees()[index-1]
dx = max(0, lsibling.bbox()[2] - treeseg.bbox()[0] + 10)
treeseg.move(dx, 0)
# Keep working up the tree.
self._makeroom(parent)
def _animate_expand_frame(self, widget, colors):
if len(colors) > 0:
self._animating_lock = 1
widget['color'] = colors[0]
for subtree in widget.subtrees():
if isinstance(subtree, TreeSegmentWidget):
subtree.label()['color'] = colors[0]
else:
subtree['color'] = colors[0]
self._top.after(50, self._animate_expand_frame,
widget, colors[1:])
else:
widget['color'] = 'black'
for subtree in widget.subtrees():
if isinstance(subtree, TreeSegmentWidget):
subtree.label()['color'] = 'black'
else:
subtree['color'] = 'black'
self._redraw_quick()
widget.label()['color'] = 'black'
self._animating_lock = 0
if self._autostep: self._step()
def _animate_backtrack(self, treeloc):
# Flash red first, if we're animating.
if self._animation_frames.get() == 0: colors = []
else: colors = ['#a00000', '#000000', '#a00000']
colors += ['gray%d' % (10*int(10*x/(self._animation_frames.get())))
for x in range(1, self._animation_frames.get()+1)]
widgets = [self._get(self._tree, treeloc).parent()]
for subtree in widgets[0].subtrees():
if isinstance(subtree, TreeSegmentWidget):
widgets.append(subtree.label())
else:
widgets.append(subtree)
self._animate_backtrack_frame(widgets, colors)
def _animate_backtrack_frame(self, widgets, colors):
if len(colors) > 0:
self._animating_lock = 1
for widget in widgets: widget['color'] = colors[0]
self._top.after(50, self._animate_backtrack_frame,
widgets, colors[1:])
else:
for widget in widgets[0].subtrees():
widgets[0].remove_child(widget)
widget.destroy()
self._redraw_quick()
self._animating_lock = 0
if self._autostep: self._step()
def _animate_match_backtrack(self, treeloc):
widget = self._get(self._tree, treeloc)
node = widget.parent().label()
dy = ((node.bbox()[3] - widget.bbox()[1] + 14) /
max(1, self._animation_frames.get()))
self._animate_match_backtrack_frame(self._animation_frames.get(),
widget, dy)
def _animate_match(self, treeloc):
widget = self._get(self._tree, treeloc)
dy = ((self._textwidgets[0].bbox()[1] - widget.bbox()[3] - 10.0) /
max(1, self._animation_frames.get()))
self._animate_match_frame(self._animation_frames.get(), widget, dy)
def _animate_match_frame(self, frame, widget, dy):
if frame > 0:
self._animating_lock = 1
widget.move(0, dy)
self._top.after(10, self._animate_match_frame,
frame-1, widget, dy)
else:
widget['color'] = '#006040'
self._redraw_quick()
self._animating_lock = 0
if self._autostep: self._step()
def _animate_match_backtrack_frame(self, frame, widget, dy):
if frame > 0:
self._animating_lock = 1
widget.move(0, dy)
self._top.after(10, self._animate_match_backtrack_frame,
frame-1, widget, dy)
else:
widget.parent().remove_child(widget)
widget.destroy()
self._animating_lock = 0
if self._autostep: self._step()
def edit_grammar(self, *e):
CFGEditor(self._top, self._parser.grammar(), self.set_grammar)
def set_grammar(self, grammar):
self._parser.set_grammar(grammar)
self._productions = list(grammar.productions())
self._prodlist.delete(0, 'end')
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
def edit_sentence(self, *e):
sentence = " ".join(self._sent)
title = 'Edit Text'
instr = 'Enter a new sentence to parse.'
EntryDialog(self._top, sentence, instr, self.set_sentence, title)
def set_sentence(self, sentence):
self._sent = sentence.split() #[XX] use tagged?
self.reset()
class RecursiveDescentApp(object):
"""
A graphical tool for exploring the recursive descent parser. The tool
displays the parser's tree and the remaining text, and allows the
user to control the parser's operation. In particular, the user
can expand subtrees on the frontier, match tokens on the frontier
against the text, and backtrack. A "step" button simply steps
through the parsing process, performing the operations that
``RecursiveDescentParser`` would use.
"""
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingRecursiveDescentParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Recursive Descent Parser Application')
# Set up key bindings.
self._init_bindings()
# Initialize the fonts.
self._init_fonts(self._top)
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animation_frames = IntVar(self._top)
self._animation_frames.set(5)
self._animating_lock = 0
self._autostep = 0
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# Initialize the parser.
self._parser.initialize(self._sent)
# Resize callback
self._canvas.bind('<Configure>', self._configure)
#########################################
## Initialization Helpers
#########################################
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = Font(family='helvetica', weight='bold', size=self._size.get())
self._font = Font(family='helvetica', size=self._size.get())
if self._size.get() < 0:
big = self._size.get() - 2
else:
big = self._size.get() + 2
self._bigfont = Font(family='helvetica', weight='bold', size=big)
def _init_grammar(self, parent):
# Grammar view.
self._prodframe = listframe = Frame(parent)
self._prodframe.pack(fill='both', side='left', padx=2)
self._prodlist_label = Label(
self._prodframe, font=self._boldfont, text='Available Expansions'
)
self._prodlist_label.pack()
self._prodlist = Listbox(
self._prodframe,
selectmode='single',
relief='groove',
background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0',
)
self._prodlist.pack(side='right', fill='both', expand=1)
self._productions = list(self._parser.grammar().productions())
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
self._prodlist.config(height=min(len(self._productions), 25))
# Add a scrollbar if there are more than 25 productions.
if len(self._productions) > 25:
listscroll = Scrollbar(self._prodframe, orient='vertical')
self._prodlist.config(yscrollcommand=listscroll.set)
listscroll.config(command=self._prodlist.yview)
listscroll.pack(side='left', fill='y')
# If they select a production, apply it.
self._prodlist.bind('<<ListboxSelect>>', self._prodlist_select)
def _init_bindings(self):
# Key bindings are a good thing.
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Escape>', self.destroy)
self._top.bind('e', self.expand)
# self._top.bind('<Alt-e>', self.expand)
# self._top.bind('<Control-e>', self.expand)
self._top.bind('m', self.match)
self._top.bind('<Alt-m>', self.match)
self._top.bind('<Control-m>', self.match)
self._top.bind('b', self.backtrack)
self._top.bind('<Alt-b>', self.backtrack)
self._top.bind('<Control-b>', self.backtrack)
self._top.bind('<Control-z>', self.backtrack)
self._top.bind('<BackSpace>', self.backtrack)
self._top.bind('a', self.autostep)
# self._top.bind('<Control-a>', self.autostep)
self._top.bind('<Control-space>', self.autostep)
self._top.bind('<Control-c>', self.cancel_autostep)
self._top.bind('<space>', self.step)
self._top.bind('<Delete>', self.reset)
self._top.bind('<Control-p>', self.postscript)
# self._top.bind('<h>', self.help)
# self._top.bind('<Alt-h>', self.help)
self._top.bind('<Control-h>', self.help)
self._top.bind('<F1>', self.help)
# self._top.bind('<g>', self.toggle_grammar)
# self._top.bind('<Alt-g>', self.toggle_grammar)
# self._top.bind('<Control-g>', self.toggle_grammar)
self._top.bind('<Control-g>', self.edit_grammar)
self._top.bind('<Control-t>', self.edit_sentence)
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom', padx=3, pady=2)
Button(
buttonframe,
text='Step',
background='#90c0d0',
foreground='black',
command=self.step,
).pack(side='left')
Button(
buttonframe,
text='Autostep',
background='#90c0d0',
foreground='black',
command=self.autostep,
).pack(side='left')
Button(
buttonframe,
text='Expand',
underline=0,
background='#90f090',
foreground='black',
command=self.expand,
).pack(side='left')
Button(
buttonframe,
text='Match',
underline=0,
background='#90f090',
foreground='black',
command=self.match,
).pack(side='left')
Button(
buttonframe,
text='Backtrack',
underline=0,
background='#f0a0a0',
foreground='black',
command=self.backtrack,
).pack(side='left')
# Replace autostep...
# self._autostep_button = Button(buttonframe, text='Autostep',
# underline=0, command=self.autostep)
# self._autostep_button.pack(side='left')
def _configure(self, event):
self._autostep = 0
(x1, y1, x2, y2) = self._cframe.scrollregion()
y2 = event.height - 6
self._canvas['scrollregion'] = '%d %d %d %d' % (x1, y1, x2, y2)
self._redraw()
def _init_feedback(self, parent):
self._feedbackframe = feedbackframe = Frame(parent)
feedbackframe.pack(fill='x', side='bottom', padx=3, pady=3)
self._lastoper_label = Label(
feedbackframe, text='Last Operation:', font=self._font
)
self._lastoper_label.pack(side='left')
lastoperframe = Frame(feedbackframe, relief='sunken', border=1)
lastoperframe.pack(fill='x', side='right', expand=1, padx=5)
self._lastoper1 = Label(
lastoperframe, foreground='#007070', background='#f0f0f0', font=self._font
)
self._lastoper2 = Label(
lastoperframe,
anchor='w',
width=30,
foreground='#004040',
background='#f0f0f0',
font=self._font,
)
self._lastoper1.pack(side='left')
self._lastoper2.pack(side='left', fill='x', expand=1)
def _init_canvas(self, parent):
self._cframe = CanvasFrame(
parent,
background='white',
# width=525, height=250,
closeenough=10,
border=2,
relief='sunken',
)
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
# Initially, there's no tree or text
self._tree = None
self._textwidgets = []
self._textline = None
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(
label='Reset Parser', underline=0, command=self.reset, accelerator='Del'
)
filemenu.add_command(
label='Print to Postscript',
underline=0,
command=self.postscript,
accelerator='Ctrl-p',
)
filemenu.add_command(
label='Exit', underline=1, command=self.destroy, accelerator='Ctrl-x'
)
menubar.add_cascade(label='File', underline=0, menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(
label='Edit Grammar',
underline=5,
command=self.edit_grammar,
accelerator='Ctrl-g',
)
editmenu.add_command(
label='Edit Text',
underline=5,
command=self.edit_sentence,
accelerator='Ctrl-t',
)
menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
rulemenu = Menu(menubar, tearoff=0)
rulemenu.add_command(
label='Step', underline=1, command=self.step, accelerator='Space'
)
rulemenu.add_separator()
rulemenu.add_command(
label='Match', underline=0, command=self.match, accelerator='Ctrl-m'
)
rulemenu.add_command(
label='Expand', underline=0, command=self.expand, accelerator='Ctrl-e'
)
rulemenu.add_separator()
rulemenu.add_command(
label='Backtrack', underline=0, command=self.backtrack, accelerator='Ctrl-b'
)
menubar.add_cascade(label='Apply', underline=0, menu=rulemenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_checkbutton(
label="Show Grammar",
underline=0,
variable=self._show_grammar,
command=self._toggle_grammar,
)
viewmenu.add_separator()
viewmenu.add_radiobutton(
label='Tiny',
variable=self._size,
underline=0,
value=10,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Small',
variable=self._size,
underline=0,
value=12,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Medium',
variable=self._size,
underline=0,
value=14,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Large',
variable=self._size,
underline=0,
value=18,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Huge',
variable=self._size,
underline=0,
value=24,
command=self.resize,
)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
animatemenu = Menu(menubar, tearoff=0)
animatemenu.add_radiobutton(
label="No Animation", underline=0, variable=self._animation_frames, value=0
)
animatemenu.add_radiobutton(
label="Slow Animation",
underline=0,
variable=self._animation_frames,
value=10,
accelerator='-',
)
animatemenu.add_radiobutton(
label="Normal Animation",
underline=0,
variable=self._animation_frames,
value=5,
accelerator='=',
)
animatemenu.add_radiobutton(
label="Fast Animation",
underline=0,
variable=self._animation_frames,
value=2,
accelerator='+',
)
menubar.add_cascade(label="Animate", underline=1, menu=animatemenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0, command=self.about)
helpmenu.add_command(
label='Instructions', underline=0, command=self.help, accelerator='F1'
)
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
#########################################
## Helper
#########################################
def _get(self, widget, treeloc):
for i in treeloc:
widget = widget.subtrees()[i]
if isinstance(widget, TreeSegmentWidget):
widget = widget.label()
return widget
#########################################
## Main draw procedure
#########################################
def _redraw(self):
canvas = self._canvas
# Delete the old tree, widgets, etc.
if self._tree is not None:
self._cframe.destroy_widget(self._tree)
for twidget in self._textwidgets:
self._cframe.destroy_widget(twidget)
if self._textline is not None:
self._canvas.delete(self._textline)
# Draw the tree.
helv = ('helvetica', -self._size.get())
bold = ('helvetica', -self._size.get(), 'bold')
attribs = {
'tree_color': '#000000',
'tree_width': 2,
'node_font': bold,
'leaf_font': helv,
}
tree = self._parser.tree()
self._tree = tree_to_treesegment(canvas, tree, **attribs)
self._cframe.add_widget(self._tree, 30, 5)
# Draw the text.
helv = ('helvetica', -self._size.get())
bottom = y = self._cframe.scrollregion()[3]
self._textwidgets = [
TextWidget(canvas, word, font=self._font) for word in self._sent
]
for twidget in self._textwidgets:
self._cframe.add_widget(twidget, 0, 0)
twidget.move(0, bottom - twidget.bbox()[3] - 5)
y = min(y, twidget.bbox()[1])
# Draw a line over the text, to separate it from the tree.
self._textline = canvas.create_line(-5000, y - 5, 5000, y - 5, dash='.')
# Highlight appropriate nodes.
self._highlight_nodes()
self._highlight_prodlist()
# Make sure the text lines up.
self._position_text()
def _redraw_quick(self):
# This should be more-or-less sufficient after an animation.
self._highlight_nodes()
self._highlight_prodlist()
self._position_text()
def _highlight_nodes(self):
# Highlight the list of nodes to be checked.
bold = ('helvetica', -self._size.get(), 'bold')
for treeloc in self._parser.frontier()[:1]:
self._get(self._tree, treeloc)['color'] = '#20a050'
self._get(self._tree, treeloc)['font'] = bold
for treeloc in self._parser.frontier()[1:]:
self._get(self._tree, treeloc)['color'] = '#008080'
def _highlight_prodlist(self):
# Highlight the productions that can be expanded.
# Boy, too bad tkinter doesn't implement Listbox.itemconfig;
# that would be pretty useful here.
self._prodlist.delete(0, 'end')
expandable = self._parser.expandable_productions()
untried = self._parser.untried_expandable_productions()
productions = self._productions
for index in range(len(productions)):
if productions[index] in expandable:
if productions[index] in untried:
self._prodlist.insert(index, ' %s' % productions[index])
else:
self._prodlist.insert(index, ' %s (TRIED)' % productions[index])
self._prodlist.selection_set(index)
else:
self._prodlist.insert(index, ' %s' % productions[index])
def _position_text(self):
# Line up the text widgets that are matched against the tree
numwords = len(self._sent)
num_matched = numwords - len(self._parser.remaining_text())
leaves = self._tree_leaves()[:num_matched]
xmax = self._tree.bbox()[0]
for i in range(0, len(leaves)):
widget = self._textwidgets[i]
leaf = leaves[i]
widget['color'] = '#006040'
leaf['color'] = '#006040'
widget.move(leaf.bbox()[0] - widget.bbox()[0], 0)
xmax = widget.bbox()[2] + 10
# Line up the text widgets that are not matched against the tree.
for i in range(len(leaves), numwords):
widget = self._textwidgets[i]
widget['color'] = '#a0a0a0'
widget.move(xmax - widget.bbox()[0], 0)
xmax = widget.bbox()[2] + 10
# If we have a complete parse, make everything green :)
if self._parser.currently_complete():
for twidget in self._textwidgets:
twidget['color'] = '#00a000'
# Move the matched leaves down to the text.
for i in range(0, len(leaves)):
widget = self._textwidgets[i]
leaf = leaves[i]
dy = widget.bbox()[1] - leaf.bbox()[3] - 10.0
dy = max(dy, leaf.parent().label().bbox()[3] - leaf.bbox()[3] + 10)
leaf.move(0, dy)
def _tree_leaves(self, tree=None):
if tree is None:
tree = self._tree
if isinstance(tree, TreeSegmentWidget):
leaves = []
for child in tree.subtrees():
leaves += self._tree_leaves(child)
return leaves
else:
return [tree]
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
self._autostep = 0
if self._top is None:
return
self._top.destroy()
self._top = None
def reset(self, *e):
self._autostep = 0
self._parser.initialize(self._sent)
self._lastoper1['text'] = 'Reset Application'
self._lastoper2['text'] = ''
self._redraw()
def autostep(self, *e):
if self._animation_frames.get() == 0:
self._animation_frames.set(2)
if self._autostep:
self._autostep = 0
else:
self._autostep = 1
self._step()
def cancel_autostep(self, *e):
# self._autostep_button['text'] = 'Autostep'
self._autostep = 0
# Make sure to stop auto-stepping if we get any user input.
def step(self, *e):
self._autostep = 0
self._step()
def match(self, *e):
self._autostep = 0
self._match()
def expand(self, *e):
self._autostep = 0
self._expand()
def backtrack(self, *e):
self._autostep = 0
self._backtrack()
def _step(self):
if self._animating_lock:
return
# Try expanding, matching, and backtracking (in that order)
if self._expand():
pass
elif self._parser.untried_match() and self._match():
pass
elif self._backtrack():
pass
else:
self._lastoper1['text'] = 'Finished'
self._lastoper2['text'] = ''
self._autostep = 0
# Check if we just completed a parse.
if self._parser.currently_complete():
self._autostep = 0
self._lastoper2['text'] += ' [COMPLETE PARSE]'
def _expand(self, *e):
if self._animating_lock:
return
old_frontier = self._parser.frontier()
rv = self._parser.expand()
if rv is not None:
self._lastoper1['text'] = 'Expand:'
self._lastoper2['text'] = rv
self._prodlist.selection_clear(0, 'end')
index = self._productions.index(rv)
self._prodlist.selection_set(index)
self._animate_expand(old_frontier[0])
return True
else:
self._lastoper1['text'] = 'Expand:'
self._lastoper2['text'] = '(all expansions tried)'
return False
def _match(self, *e):
if self._animating_lock:
return
old_frontier = self._parser.frontier()
rv = self._parser.match()
if rv is not None:
self._lastoper1['text'] = 'Match:'
self._lastoper2['text'] = rv
self._animate_match(old_frontier[0])
return True
else:
self._lastoper1['text'] = 'Match:'
self._lastoper2['text'] = '(failed)'
return False
def _backtrack(self, *e):
if self._animating_lock:
return
if self._parser.backtrack():
elt = self._parser.tree()
for i in self._parser.frontier()[0]:
elt = elt[i]
self._lastoper1['text'] = 'Backtrack'
self._lastoper2['text'] = ''
if isinstance(elt, Tree):
self._animate_backtrack(self._parser.frontier()[0])
else:
self._animate_match_backtrack(self._parser.frontier()[0])
return True
else:
self._autostep = 0
self._lastoper1['text'] = 'Finished'
self._lastoper2['text'] = ''
return False
def about(self, *e):
ABOUT = (
"NLTK Recursive Descent Parser Application\n" + "Written by Edward Loper"
)
TITLE = 'About: Recursive Descent Parser Application'
try:
from six.moves.tkinter_messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def help(self, *e):
self._autostep = 0
# The default font's not very legible; try using 'fixed' instead.
try:
ShowText(
self._top,
'Help: Recursive Descent Parser Application',
(__doc__ or '').strip(),
width=75,
font='fixed',
)
except:
ShowText(
self._top,
'Help: Recursive Descent Parser Application',
(__doc__ or '').strip(),
width=75,
)
def postscript(self, *e):
self._autostep = 0
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle():
return
self._top.mainloop(*args, **kwargs)
def resize(self, size=None):
if size is not None:
self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
self._bigfont.configure(size=-(abs(size + 2)))
self._redraw()
#########################################
## Expand Production Selection
#########################################
def _toggle_grammar(self, *e):
if self._show_grammar.get():
self._prodframe.pack(
fill='both', side='left', padx=2, after=self._feedbackframe
)
self._lastoper1['text'] = 'Show Grammar'
else:
self._prodframe.pack_forget()
self._lastoper1['text'] = 'Hide Grammar'
self._lastoper2['text'] = ''
# def toggle_grammar(self, *e):
# self._show_grammar = not self._show_grammar
# if self._show_grammar:
# self._prodframe.pack(fill='both', expand='y', side='left',
# after=self._feedbackframe)
# self._lastoper1['text'] = 'Show Grammar'
# else:
# self._prodframe.pack_forget()
# self._lastoper1['text'] = 'Hide Grammar'
# self._lastoper2['text'] = ''
def _prodlist_select(self, event):
selection = self._prodlist.curselection()
if len(selection) != 1:
return
index = int(selection[0])
old_frontier = self._parser.frontier()
production = self._parser.expand(self._productions[index])
if production:
self._lastoper1['text'] = 'Expand:'
self._lastoper2['text'] = production
self._prodlist.selection_clear(0, 'end')
self._prodlist.selection_set(index)
self._animate_expand(old_frontier[0])
else:
# Reset the production selections.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.expandable_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
#########################################
## Animation
#########################################
def _animate_expand(self, treeloc):
oldwidget = self._get(self._tree, treeloc)
oldtree = oldwidget.parent()
top = not isinstance(oldtree.parent(), TreeSegmentWidget)
tree = self._parser.tree()
for i in treeloc:
tree = tree[i]
widget = tree_to_treesegment(
self._canvas,
tree,
node_font=self._boldfont,
leaf_color='white',
tree_width=2,
tree_color='white',
node_color='white',
leaf_font=self._font,
)
widget.label()['color'] = '#20a050'
(oldx, oldy) = oldtree.label().bbox()[:2]
(newx, newy) = widget.label().bbox()[:2]
widget.move(oldx - newx, oldy - newy)
if top:
self._cframe.add_widget(widget, 0, 5)
widget.move(30 - widget.label().bbox()[0], 0)
self._tree = widget
else:
oldtree.parent().replace_child(oldtree, widget)
# Move the children over so they don't overlap.
# Line the children up in a strange way.
if widget.subtrees():
dx = (
oldx
+ widget.label().width() / 2
- widget.subtrees()[0].bbox()[0] / 2
- widget.subtrees()[0].bbox()[2] / 2
)
for subtree in widget.subtrees():
subtree.move(dx, 0)
self._makeroom(widget)
if top:
self._cframe.destroy_widget(oldtree)
else:
oldtree.destroy()
colors = [
'gray%d' % (10 * int(10 * x / self._animation_frames.get()))
for x in range(self._animation_frames.get(), 0, -1)
]
# Move the text string down, if necessary.
dy = widget.bbox()[3] + 30 - self._canvas.coords(self._textline)[1]
if dy > 0:
for twidget in self._textwidgets:
twidget.move(0, dy)
self._canvas.move(self._textline, 0, dy)
self._animate_expand_frame(widget, colors)
def _makeroom(self, treeseg):
"""
Make sure that no sibling tree bbox's overlap.
"""
parent = treeseg.parent()
if not isinstance(parent, TreeSegmentWidget):
return
index = parent.subtrees().index(treeseg)
# Handle siblings to the right
rsiblings = parent.subtrees()[index + 1 :]
if rsiblings:
dx = treeseg.bbox()[2] - rsiblings[0].bbox()[0] + 10
for sibling in rsiblings:
sibling.move(dx, 0)
# Handle siblings to the left
if index > 0:
lsibling = parent.subtrees()[index - 1]
dx = max(0, lsibling.bbox()[2] - treeseg.bbox()[0] + 10)
treeseg.move(dx, 0)
# Keep working up the tree.
self._makeroom(parent)
def _animate_expand_frame(self, widget, colors):
if len(colors) > 0:
self._animating_lock = 1
widget['color'] = colors[0]
for subtree in widget.subtrees():
if isinstance(subtree, TreeSegmentWidget):
subtree.label()['color'] = colors[0]
else:
subtree['color'] = colors[0]
self._top.after(50, self._animate_expand_frame, widget, colors[1:])
else:
widget['color'] = 'black'
for subtree in widget.subtrees():
if isinstance(subtree, TreeSegmentWidget):
subtree.label()['color'] = 'black'
else:
subtree['color'] = 'black'
self._redraw_quick()
widget.label()['color'] = 'black'
self._animating_lock = 0
if self._autostep:
self._step()
def _animate_backtrack(self, treeloc):
# Flash red first, if we're animating.
if self._animation_frames.get() == 0:
colors = []
else:
colors = ['#a00000', '#000000', '#a00000']
colors += [
'gray%d' % (10 * int(10 * x / (self._animation_frames.get())))
for x in range(1, self._animation_frames.get() + 1)
]
widgets = [self._get(self._tree, treeloc).parent()]
for subtree in widgets[0].subtrees():
if isinstance(subtree, TreeSegmentWidget):
widgets.append(subtree.label())
else:
widgets.append(subtree)
self._animate_backtrack_frame(widgets, colors)
def _animate_backtrack_frame(self, widgets, colors):
if len(colors) > 0:
self._animating_lock = 1
for widget in widgets:
widget['color'] = colors[0]
self._top.after(50, self._animate_backtrack_frame, widgets, colors[1:])
else:
for widget in widgets[0].subtrees():
widgets[0].remove_child(widget)
widget.destroy()
self._redraw_quick()
self._animating_lock = 0
if self._autostep:
self._step()
def _animate_match_backtrack(self, treeloc):
widget = self._get(self._tree, treeloc)
node = widget.parent().label()
dy = (node.bbox()[3] - widget.bbox()[1] + 14) / max(
1, self._animation_frames.get()
)
self._animate_match_backtrack_frame(self._animation_frames.get(), widget, dy)
def _animate_match(self, treeloc):
widget = self._get(self._tree, treeloc)
dy = (self._textwidgets[0].bbox()[1] - widget.bbox()[3] - 10.0) / max(
1, self._animation_frames.get()
)
self._animate_match_frame(self._animation_frames.get(), widget, dy)
def _animate_match_frame(self, frame, widget, dy):
if frame > 0:
self._animating_lock = 1
widget.move(0, dy)
self._top.after(10, self._animate_match_frame, frame - 1, widget, dy)
else:
widget['color'] = '#006040'
self._redraw_quick()
self._animating_lock = 0
if self._autostep:
self._step()
def _animate_match_backtrack_frame(self, frame, widget, dy):
if frame > 0:
self._animating_lock = 1
widget.move(0, dy)
self._top.after(
10, self._animate_match_backtrack_frame, frame - 1, widget, dy
)
else:
widget.parent().remove_child(widget)
widget.destroy()
self._animating_lock = 0
if self._autostep:
self._step()
def edit_grammar(self, *e):
CFGEditor(self._top, self._parser.grammar(), self.set_grammar)
def set_grammar(self, grammar):
self._parser.set_grammar(grammar)
self._productions = list(grammar.productions())
self._prodlist.delete(0, 'end')
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
def edit_sentence(self, *e):
sentence = " ".join(self._sent)
title = 'Edit Text'
instr = 'Enter a new sentence to parse.'
EntryDialog(self._top, sentence, instr, self.set_sentence, title)
def set_sentence(self, sentence):
self._sent = sentence.split() # [XX] use tagged?
self.reset()
class ShiftReduceApp(object):
"""
A graphical tool for exploring the shift-reduce parser. The tool
displays the parser's stack and the remaining text, and allows the
user to control the parser's operation. In particular, the user
can shift tokens onto the stack, and can perform reductions on the
top elements of the stack. A "step" button simply steps through
the parsing process, performing the operations that
``nltk.parse.ShiftReduceParser`` would use.
"""
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingShiftReduceParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Shift Reduce Parser Application')
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animating_lock = 0
self._animate = IntVar(self._top)
self._animate.set(10) # = medium
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Initialize fonts.
self._init_fonts(self._top)
# Set up key bindings.
self._init_bindings()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# A popup menu for reducing.
self._reduce_menu = Menu(self._canvas, tearoff=0)
# Reset the demo, and set the feedback frame to empty.
self.reset()
self._lastoper1['text'] = ''
#########################################
## Initialization Helpers
#########################################
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = Font(family='helvetica', weight='bold', size=self._size.get())
self._font = Font(family='helvetica', size=self._size.get())
def _init_grammar(self, parent):
# Grammar view.
self._prodframe = listframe = Frame(parent)
self._prodframe.pack(fill='both', side='left', padx=2)
self._prodlist_label = Label(
self._prodframe, font=self._boldfont, text='Available Reductions'
)
self._prodlist_label.pack()
self._prodlist = Listbox(
self._prodframe,
selectmode='single',
relief='groove',
background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0',
)
self._prodlist.pack(side='right', fill='both', expand=1)
self._productions = list(self._parser.grammar().productions())
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
self._prodlist.config(height=min(len(self._productions), 25))
# Add a scrollbar if there are more than 25 productions.
if 1: # len(self._productions) > 25:
listscroll = Scrollbar(self._prodframe, orient='vertical')
self._prodlist.config(yscrollcommand=listscroll.set)
listscroll.config(command=self._prodlist.yview)
listscroll.pack(side='left', fill='y')
# If they select a production, apply it.
self._prodlist.bind('<<ListboxSelect>>', self._prodlist_select)
# When they hover over a production, highlight it.
self._hover = -1
self._prodlist.bind('<Motion>', self._highlight_hover)
self._prodlist.bind('<Leave>', self._clear_hover)
def _init_bindings(self):
# Quit
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Alt-q>', self.destroy)
self._top.bind('<Alt-x>', self.destroy)
# Ops (step, shift, reduce, undo)
self._top.bind('<space>', self.step)
self._top.bind('<s>', self.shift)
self._top.bind('<Alt-s>', self.shift)
self._top.bind('<Control-s>', self.shift)
self._top.bind('<r>', self.reduce)
self._top.bind('<Alt-r>', self.reduce)
self._top.bind('<Control-r>', self.reduce)
self._top.bind('<Delete>', self.reset)
self._top.bind('<u>', self.undo)
self._top.bind('<Alt-u>', self.undo)
self._top.bind('<Control-u>', self.undo)
self._top.bind('<Control-z>', self.undo)
self._top.bind('<BackSpace>', self.undo)
# Misc
self._top.bind('<Control-p>', self.postscript)
self._top.bind('<Control-h>', self.help)
self._top.bind('<F1>', self.help)
self._top.bind('<Control-g>', self.edit_grammar)
self._top.bind('<Control-t>', self.edit_sentence)
# Animation speed control
self._top.bind('-', lambda e, a=self._animate: a.set(20))
self._top.bind('=', lambda e, a=self._animate: a.set(10))
self._top.bind('+', lambda e, a=self._animate: a.set(4))
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom')
Button(
buttonframe,
text='Step',
background='#90c0d0',
foreground='black',
command=self.step,
).pack(side='left')
Button(
buttonframe,
text='Shift',
underline=0,
background='#90f090',
foreground='black',
command=self.shift,
).pack(side='left')
Button(
buttonframe,
text='Reduce',
underline=0,
background='#90f090',
foreground='black',
command=self.reduce,
).pack(side='left')
Button(
buttonframe,
text='Undo',
underline=0,
background='#f0a0a0',
foreground='black',
command=self.undo,
).pack(side='left')
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(
label='Reset Parser', underline=0, command=self.reset, accelerator='Del'
)
filemenu.add_command(
label='Print to Postscript',
underline=0,
command=self.postscript,
accelerator='Ctrl-p',
)
filemenu.add_command(
label='Exit', underline=1, command=self.destroy, accelerator='Ctrl-x'
)
menubar.add_cascade(label='File', underline=0, menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(
label='Edit Grammar',
underline=5,
command=self.edit_grammar,
accelerator='Ctrl-g',
)
editmenu.add_command(
label='Edit Text',
underline=5,
command=self.edit_sentence,
accelerator='Ctrl-t',
)
menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
rulemenu = Menu(menubar, tearoff=0)
rulemenu.add_command(
label='Step', underline=1, command=self.step, accelerator='Space'
)
rulemenu.add_separator()
rulemenu.add_command(
label='Shift', underline=0, command=self.shift, accelerator='Ctrl-s'
)
rulemenu.add_command(
label='Reduce', underline=0, command=self.reduce, accelerator='Ctrl-r'
)
rulemenu.add_separator()
rulemenu.add_command(
label='Undo', underline=0, command=self.undo, accelerator='Ctrl-u'
)
menubar.add_cascade(label='Apply', underline=0, menu=rulemenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_checkbutton(
label="Show Grammar",
underline=0,
variable=self._show_grammar,
command=self._toggle_grammar,
)
viewmenu.add_separator()
viewmenu.add_radiobutton(
label='Tiny',
variable=self._size,
underline=0,
value=10,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Small',
variable=self._size,
underline=0,
value=12,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Medium',
variable=self._size,
underline=0,
value=14,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Large',
variable=self._size,
underline=0,
value=18,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Huge',
variable=self._size,
underline=0,
value=24,
command=self.resize,
)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
animatemenu = Menu(menubar, tearoff=0)
animatemenu.add_radiobutton(
label="No Animation", underline=0, variable=self._animate, value=0
)
animatemenu.add_radiobutton(
label="Slow Animation",
underline=0,
variable=self._animate,
value=20,
accelerator='-',
)
animatemenu.add_radiobutton(
label="Normal Animation",
underline=0,
variable=self._animate,
value=10,
accelerator='=',
)
animatemenu.add_radiobutton(
label="Fast Animation",
underline=0,
variable=self._animate,
value=4,
accelerator='+',
)
menubar.add_cascade(label="Animate", underline=1, menu=animatemenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0, command=self.about)
helpmenu.add_command(
label='Instructions', underline=0, command=self.help, accelerator='F1'
)
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
def _init_feedback(self, parent):
self._feedbackframe = feedbackframe = Frame(parent)
feedbackframe.pack(fill='x', side='bottom', padx=3, pady=3)
self._lastoper_label = Label(
feedbackframe, text='Last Operation:', font=self._font
)
self._lastoper_label.pack(side='left')
lastoperframe = Frame(feedbackframe, relief='sunken', border=1)
lastoperframe.pack(fill='x', side='right', expand=1, padx=5)
self._lastoper1 = Label(
lastoperframe, foreground='#007070', background='#f0f0f0', font=self._font
)
self._lastoper2 = Label(
lastoperframe,
anchor='w',
width=30,
foreground='#004040',
background='#f0f0f0',
font=self._font,
)
self._lastoper1.pack(side='left')
self._lastoper2.pack(side='left', fill='x', expand=1)
def _init_canvas(self, parent):
self._cframe = CanvasFrame(
parent,
background='white',
width=525,
closeenough=10,
border=2,
relief='sunken',
)
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
self._stackwidgets = []
self._rtextwidgets = []
self._titlebar = canvas.create_rectangle(
0, 0, 0, 0, fill='#c0f0f0', outline='black'
)
self._exprline = canvas.create_line(0, 0, 0, 0, dash='.')
self._stacktop = canvas.create_line(0, 0, 0, 0, fill='#408080')
size = self._size.get() + 4
self._stacklabel = TextWidget(
canvas, 'Stack', color='#004040', font=self._boldfont
)
self._rtextlabel = TextWidget(
canvas, 'Remaining Text', color='#004040', font=self._boldfont
)
self._cframe.add_widget(self._stacklabel)
self._cframe.add_widget(self._rtextlabel)
#########################################
## Main draw procedure
#########################################
def _redraw(self):
scrollregion = self._canvas['scrollregion'].split()
(cx1, cy1, cx2, cy2) = [int(c) for c in scrollregion]
# Delete the old stack & rtext widgets.
for stackwidget in self._stackwidgets:
self._cframe.destroy_widget(stackwidget)
self._stackwidgets = []
for rtextwidget in self._rtextwidgets:
self._cframe.destroy_widget(rtextwidget)
self._rtextwidgets = []
# Position the titlebar & exprline
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2 - y1 + 10
self._canvas.coords(self._titlebar, -5000, 0, 5000, y - 4)
self._canvas.coords(self._exprline, 0, y * 2 - 10, 5000, y * 2 - 10)
# Position the titlebar labels..
(x1, y1, x2, y2) = self._stacklabel.bbox()
self._stacklabel.move(5 - x1, 3 - y1)
(x1, y1, x2, y2) = self._rtextlabel.bbox()
self._rtextlabel.move(cx2 - x2 - 5, 3 - y1)
# Draw the stack.
stackx = 5
for tok in self._parser.stack():
if isinstance(tok, Tree):
attribs = {
'tree_color': '#4080a0',
'tree_width': 2,
'node_font': self._boldfont,
'node_color': '#006060',
'leaf_color': '#006060',
'leaf_font': self._font,
}
widget = tree_to_treesegment(self._canvas, tok, **attribs)
widget.label()['color'] = '#000000'
else:
widget = TextWidget(self._canvas, tok, color='#000000', font=self._font)
widget.bind_click(self._popup_reduce)
self._stackwidgets.append(widget)
self._cframe.add_widget(widget, stackx, y)
stackx = widget.bbox()[2] + 10
# Draw the remaining text.
rtextwidth = 0
for tok in self._parser.remaining_text():
widget = TextWidget(self._canvas, tok, color='#000000', font=self._font)
self._rtextwidgets.append(widget)
self._cframe.add_widget(widget, rtextwidth, y)
rtextwidth = widget.bbox()[2] + 4
# Allow enough room to shift the next token (for animations)
if len(self._rtextwidgets) > 0:
stackx += self._rtextwidgets[0].width()
# Move the remaining text to the correct location (keep it
# right-justified, when possible); and move the remaining text
# label, if necessary.
stackx = max(stackx, self._stacklabel.width() + 25)
rlabelwidth = self._rtextlabel.width() + 10
if stackx >= cx2 - max(rtextwidth, rlabelwidth):
cx2 = stackx + max(rtextwidth, rlabelwidth)
for rtextwidget in self._rtextwidgets:
rtextwidget.move(4 + cx2 - rtextwidth, 0)
self._rtextlabel.move(cx2 - self._rtextlabel.bbox()[2] - 5, 0)
midx = (stackx + cx2 - max(rtextwidth, rlabelwidth)) / 2
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
(x1, y1, x2, y2) = self._stacklabel.bbox()
# Set up binding to allow them to shift a token by dragging it.
if len(self._rtextwidgets) > 0:
def drag_shift(widget, midx=midx, self=self):
if widget.bbox()[0] < midx:
self.shift()
else:
self._redraw()
self._rtextwidgets[0].bind_drag(drag_shift)
self._rtextwidgets[0].bind_click(self.shift)
# Draw the stack top.
self._highlight_productions()
def _draw_stack_top(self, widget):
# hack..
midx = widget.bbox()[2] + 50
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
def _highlight_productions(self):
# Highlight the productions that can be reduced.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
if self._top is None:
return
self._top.destroy()
self._top = None
def reset(self, *e):
self._parser.initialize(self._sent)
self._lastoper1['text'] = 'Reset App'
self._lastoper2['text'] = ''
self._redraw()
def step(self, *e):
if self.reduce():
return True
elif self.shift():
return True
else:
if list(self._parser.parses()):
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Success'
else:
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Failure'
def shift(self, *e):
if self._animating_lock:
return
if self._parser.shift():
tok = self._parser.stack()[-1]
self._lastoper1['text'] = 'Shift:'
self._lastoper2['text'] = '%r' % tok
if self._animate.get():
self._animate_shift()
else:
self._redraw()
return True
return False
def reduce(self, *e):
if self._animating_lock:
return
production = self._parser.reduce()
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
return production
def undo(self, *e):
if self._animating_lock:
return
if self._parser.undo():
self._redraw()
def postscript(self, *e):
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle():
return
self._top.mainloop(*args, **kwargs)
#########################################
## Menubar callbacks
#########################################
def resize(self, size=None):
if size is not None:
self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
# self._stacklabel['font'] = ('helvetica', -size-4, 'bold')
# self._rtextlabel['font'] = ('helvetica', -size-4, 'bold')
# self._lastoper_label['font'] = ('helvetica', -size)
# self._lastoper1['font'] = ('helvetica', -size)
# self._lastoper2['font'] = ('helvetica', -size)
# self._prodlist['font'] = ('helvetica', -size)
# self._prodlist_label['font'] = ('helvetica', -size-2, 'bold')
self._redraw()
def help(self, *e):
# The default font's not very legible; try using 'fixed' instead.
try:
ShowText(
self._top,
'Help: Shift-Reduce Parser Application',
(__doc__ or '').strip(),
width=75,
font='fixed',
)
except:
ShowText(
self._top,
'Help: Shift-Reduce Parser Application',
(__doc__ or '').strip(),
width=75,
)
def about(self, *e):
ABOUT = "NLTK Shift-Reduce Parser Application\n" + "Written by Edward Loper"
TITLE = 'About: Shift-Reduce Parser Application'
try:
from six.moves.tkinter_messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def edit_grammar(self, *e):
CFGEditor(self._top, self._parser.grammar(), self.set_grammar)
def set_grammar(self, grammar):
self._parser.set_grammar(grammar)
self._productions = list(grammar.productions())
self._prodlist.delete(0, 'end')
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
def edit_sentence(self, *e):
sentence = " ".join(self._sent)
title = 'Edit Text'
instr = 'Enter a new sentence to parse.'
EntryDialog(self._top, sentence, instr, self.set_sentence, title)
def set_sentence(self, sent):
self._sent = sent.split() # [XX] use tagged?
self.reset()
#########################################
## Reduce Production Selection
#########################################
def _toggle_grammar(self, *e):
if self._show_grammar.get():
self._prodframe.pack(
fill='both', side='left', padx=2, after=self._feedbackframe
)
self._lastoper1['text'] = 'Show Grammar'
else:
self._prodframe.pack_forget()
self._lastoper1['text'] = 'Hide Grammar'
self._lastoper2['text'] = ''
def _prodlist_select(self, event):
selection = self._prodlist.curselection()
if len(selection) != 1:
return
index = int(selection[0])
production = self._parser.reduce(self._productions[index])
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
else:
# Reset the production selections.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
def _popup_reduce(self, widget):
# Remove old commands.
productions = self._parser.reducible_productions()
if len(productions) == 0:
return
self._reduce_menu.delete(0, 'end')
for production in productions:
self._reduce_menu.add_command(label=str(production), command=self.reduce)
self._reduce_menu.post(
self._canvas.winfo_pointerx(), self._canvas.winfo_pointery()
)
#########################################
## Animations
#########################################
def _animate_shift(self):
# What widget are we shifting?
widget = self._rtextwidgets[0]
# Where are we shifting from & to?
right = widget.bbox()[0]
if len(self._stackwidgets) == 0:
left = 5
else:
left = self._stackwidgets[-1].bbox()[2] + 10
# Start animating.
dt = self._animate.get()
dx = (left - right) * 1.0 / dt
self._animate_shift_frame(dt, widget, dx)
def _animate_shift_frame(self, frame, widget, dx):
if frame > 0:
self._animating_lock = 1
widget.move(dx, 0)
self._top.after(10, self._animate_shift_frame, frame - 1, widget, dx)
else:
# but: stacktop??
# Shift the widget to the stack.
del self._rtextwidgets[0]
self._stackwidgets.append(widget)
self._animating_lock = 0
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
def _animate_reduce(self):
# What widgets are we shifting?
numwidgets = len(self._parser.stack()[-1]) # number of children
widgets = self._stackwidgets[-numwidgets:]
# How far are we moving?
if isinstance(widgets[0], TreeSegmentWidget):
ydist = 15 + widgets[0].label().height()
else:
ydist = 15 + widgets[0].height()
# Start animating.
dt = self._animate.get()
dy = ydist * 2.0 / dt
self._animate_reduce_frame(dt / 2, widgets, dy)
def _animate_reduce_frame(self, frame, widgets, dy):
if frame > 0:
self._animating_lock = 1
for widget in widgets:
widget.move(0, dy)
self._top.after(10, self._animate_reduce_frame, frame - 1, widgets, dy)
else:
del self._stackwidgets[-len(widgets) :]
for widget in widgets:
self._cframe.remove_widget(widget)
tok = self._parser.stack()[-1]
if not isinstance(tok, Tree):
raise ValueError()
label = TextWidget(
self._canvas, str(tok.label()), color='#006060', font=self._boldfont
)
widget = TreeSegmentWidget(self._canvas, label, widgets, width=2)
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2 - y1 + 10
if not self._stackwidgets:
x = 5
else:
x = self._stackwidgets[-1].bbox()[2] + 10
self._cframe.add_widget(widget, x, y)
self._stackwidgets.append(widget)
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
# # Delete the old widgets..
# del self._stackwidgets[-len(widgets):]
# for widget in widgets:
# self._cframe.destroy_widget(widget)
#
# # Make a new one.
# tok = self._parser.stack()[-1]
# if isinstance(tok, Tree):
# attribs = {'tree_color': '#4080a0', 'tree_width': 2,
# 'node_font': bold, 'node_color': '#006060',
# 'leaf_color': '#006060', 'leaf_font':self._font}
# widget = tree_to_treesegment(self._canvas, tok.type(),
# **attribs)
# widget.node()['color'] = '#000000'
# else:
# widget = TextWidget(self._canvas, tok.type(),
# color='#000000', font=self._font)
# widget.bind_click(self._popup_reduce)
# (x1, y1, x2, y2) = self._stacklabel.bbox()
# y = y2-y1+10
# if not self._stackwidgets: x = 5
# else: x = self._stackwidgets[-1].bbox()[2] + 10
# self._cframe.add_widget(widget, x, y)
# self._stackwidgets.append(widget)
# self._redraw()
self._animating_lock = 0
#########################################
## Hovering.
#########################################
def _highlight_hover(self, event):
# What production are we hovering over?
index = self._prodlist.nearest(event.y)
if self._hover == index:
return
# Clear any previous hover highlighting.
self._clear_hover()
# If the production corresponds to an available reduction,
# highlight the stack.
selection = [int(s) for s in self._prodlist.curselection()]
if index in selection:
rhslen = len(self._productions[index].rhs())
for stackwidget in self._stackwidgets[-rhslen:]:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = '#00a000'
else:
stackwidget['color'] = '#00a000'
# Remember what production we're hovering over.
self._hover = index
def _clear_hover(self, *event):
# Clear any previous hover highlighting.
if self._hover == -1:
return
self._hover = -1
for stackwidget in self._stackwidgets:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = 'black'
else:
stackwidget['color'] = 'black'
class DrtGlueDemo(object):
def __init__(self, examples):
# Set up the main window.
self._top = Tk()
self._top.title('DRT Glue Demo')
# Set up key bindings.
self._init_bindings()
# Initialize the fonts.self._error = None
self._init_fonts(self._top)
self._examples = examples
self._readingCache = [None for example in examples]
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Set the data to None
self._curExample = -1
self._readings = []
self._drs = None
self._drsWidget = None
self._error = None
self._init_glue()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_exampleListbox(self._top)
self._init_readingListbox(self._top)
self._init_canvas(self._top)
# Resize callback
self._canvas.bind('<Configure>', self._configure)
#########################################
## Initialization Helpers
#########################################
def _init_glue(self):
tagger = RegexpTagger(
[('^(David|Mary|John)$', 'NNP'),
('^(walks|sees|eats|chases|believes|gives|sleeps|chases|persuades|tries|seems|leaves)$', 'VB'),
('^(go|order|vanish|find|approach)$', 'VB'),
('^(a)$', 'ex_quant'),
('^(every)$', 'univ_quant'),
('^(sandwich|man|dog|pizza|unicorn|cat|senator)$', 'NN'),
('^(big|gray|former)$', 'JJ'),
('^(him|himself)$', 'PRP')
])
depparser = MaltParser(tagger=tagger)
self._glue = DrtGlue(depparser=depparser, remove_duplicates=False)
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = Font(family='helvetica', weight='bold',
size=self._size.get())
self._font = Font(family='helvetica',
size=self._size.get())
if self._size.get() < 0: big = self._size.get()-2
else: big = self._size.get()+2
self._bigfont = Font(family='helvetica', weight='bold',
size=big)
def _init_exampleListbox(self, parent):
self._exampleFrame = listframe = Frame(parent)
self._exampleFrame.pack(fill='both', side='left', padx=2)
self._exampleList_label = Label(self._exampleFrame, font=self._boldfont,
text='Examples')
self._exampleList_label.pack()
self._exampleList = Listbox(self._exampleFrame, selectmode='single',
relief='groove', background='white',
foreground='#909090', font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._exampleList.pack(side='right', fill='both', expand=1)
for example in self._examples:
self._exampleList.insert('end', (' %s' % example))
self._exampleList.config(height=min(len(self._examples), 25), width=40)
# Add a scrollbar if there are more than 25 examples.
if len(self._examples) > 25:
listscroll = Scrollbar(self._exampleFrame,
orient='vertical')
self._exampleList.config(yscrollcommand = listscroll.set)
listscroll.config(command=self._exampleList.yview)
listscroll.pack(side='left', fill='y')
# If they select a example, apply it.
self._exampleList.bind('<<ListboxSelect>>', self._exampleList_select)
def _init_readingListbox(self, parent):
self._readingFrame = listframe = Frame(parent)
self._readingFrame.pack(fill='both', side='left', padx=2)
self._readingList_label = Label(self._readingFrame, font=self._boldfont,
text='Readings')
self._readingList_label.pack()
self._readingList = Listbox(self._readingFrame, selectmode='single',
relief='groove', background='white',
foreground='#909090', font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._readingList.pack(side='right', fill='both', expand=1)
# Add a scrollbar if there are more than 25 examples.
listscroll = Scrollbar(self._readingFrame,
orient='vertical')
self._readingList.config(yscrollcommand = listscroll.set)
listscroll.config(command=self._readingList.yview)
listscroll.pack(side='right', fill='y')
self._populate_readingListbox()
def _populate_readingListbox(self):
# Populate the listbox with integers
self._readingList.delete(0, 'end')
for i in range(len(self._readings)):
self._readingList.insert('end', (' %s' % (i+1)))
self._readingList.config(height=min(len(self._readings), 25), width=5)
# If they select a example, apply it.
self._readingList.bind('<<ListboxSelect>>', self._readingList_select)
def _init_bindings(self):
# Key bindings are a good thing.
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Escape>', self.destroy)
self._top.bind('n', self.next)
self._top.bind('<space>', self.next)
self._top.bind('p', self.prev)
self._top.bind('<BackSpace>', self.prev)
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom', padx=3, pady=2)
Button(buttonframe, text='Prev',
background='#90c0d0', foreground='black',
command=self.prev,).pack(side='left')
Button(buttonframe, text='Next',
background='#90c0d0', foreground='black',
command=self.next,).pack(side='left')
def _configure(self, event):
self._autostep = 0
(x1, y1, x2, y2) = self._cframe.scrollregion()
y2 = event.height - 6
self._canvas['scrollregion'] = '%d %d %d %d' % (x1,y1,x2,y2)
self._redraw()
def _init_canvas(self, parent):
self._cframe = CanvasFrame(parent, background='white',
#width=525, height=250,
closeenough=10,
border=2, relief='sunken')
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
# Initially, there's no tree or text
self._tree = None
self._textwidgets = []
self._textline = None
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Exit', underline=1,
command=self.destroy, accelerator='q')
menubar.add_cascade(label='File', underline=0, menu=filemenu)
actionmenu = Menu(menubar, tearoff=0)
actionmenu.add_command(label='Next', underline=0,
command=self.next, accelerator='n, Space')
actionmenu.add_command(label='Previous', underline=0,
command=self.prev, accelerator='p, Backspace')
menubar.add_cascade(label='Action', underline=0, menu=actionmenu)
optionmenu = Menu(menubar, tearoff=0)
optionmenu.add_checkbutton(label='Remove Duplicates', underline=0,
variable=self._glue.remove_duplicates,
command=self._toggle_remove_duplicates,
accelerator='r')
menubar.add_cascade(label='Options', underline=0, menu=optionmenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_radiobutton(label='Tiny', variable=self._size,
underline=0, value=10, command=self.resize)
viewmenu.add_radiobutton(label='Small', variable=self._size,
underline=0, value=12, command=self.resize)
viewmenu.add_radiobutton(label='Medium', variable=self._size,
underline=0, value=14, command=self.resize)
viewmenu.add_radiobutton(label='Large', variable=self._size,
underline=0, value=18, command=self.resize)
viewmenu.add_radiobutton(label='Huge', variable=self._size,
underline=0, value=24, command=self.resize)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0,
command=self.about)
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
#########################################
## Main draw procedure
#########################################
def _redraw(self):
canvas = self._canvas
# Delete the old DRS, widgets, etc.
if self._drsWidget is not None:
self._drsWidget.clear()
if self._drs:
self._drsWidget = DrsWidget( self._canvas, self._drs )
self._drsWidget.draw()
if self._error:
self._drsWidget = DrsWidget( self._canvas, self._error )
self._drsWidget.draw()
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
self._autostep = 0
if self._top is None: return
self._top.destroy()
self._top = None
def prev(self, *e):
selection = self._readingList.curselection()
readingListSize = self._readingList.size()
# there are readings
if readingListSize > 0:
# if one reading is currently selected
if len(selection) == 1:
index = int(selection[0])
# if it's on (or before) the first item
if index <= 0:
self._select_previous_example()
else:
self._readingList_store_selection(index-1)
else:
#select its first reading
self._readingList_store_selection(readingListSize-1)
else:
self._select_previous_example()
def _select_previous_example(self):
#if the current example is not the first example
if self._curExample > 0:
self._exampleList_store_selection(self._curExample-1)
else:
#go to the last example
self._exampleList_store_selection(len(self._examples)-1)
def next(self, *e):
selection = self._readingList.curselection()
readingListSize = self._readingList.size()
# if there are readings
if readingListSize > 0:
# if one reading is currently selected
if len(selection) == 1:
index = int(selection[0])
# if it's on (or past) the last item
if index >= (readingListSize-1):
self._select_next_example()
else:
self._readingList_store_selection(index+1)
else:
#select its first reading
self._readingList_store_selection(0)
else:
self._select_next_example()
def _select_next_example(self):
#if the current example is not the last example
if self._curExample < len(self._examples)-1:
self._exampleList_store_selection(self._curExample+1)
else:
#go to the first example
self._exampleList_store_selection(0)
def about(self, *e):
ABOUT = ("NLTK Discourse Representation Theory (DRT) Glue Semantics Demo\n"+
"Written by Daniel H. Garrette")
TITLE = 'About: NLTK DRT Glue Demo'
try:
from six.moves.tkinter_messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def postscript(self, *e):
self._autostep = 0
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle(): return
self._top.mainloop(*args, **kwargs)
def resize(self, size=None):
if size is not None: self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
self._bigfont.configure(size=-(abs(size+2)))
self._redraw()
def _toggle_remove_duplicates(self):
self._glue.remove_duplicates = not self._glue.remove_duplicates
self._exampleList.selection_clear(0, 'end')
self._readings = []
self._populate_readingListbox()
self._readingCache = [None for ex in self._examples]
self._curExample = -1
self._error = None
self._drs = None
self._redraw()
def _exampleList_select(self, event):
selection = self._exampleList.curselection()
if len(selection) != 1: return
self._exampleList_store_selection(int(selection[0]))
def _exampleList_store_selection(self, index):
self._curExample = index
example = self._examples[index]
self._exampleList.selection_clear(0, 'end')
if example:
cache = self._readingCache[index]
if cache:
if isinstance(cache, list):
self._readings = cache
self._error = None
else:
self._readings = []
self._error = cache
else:
try:
self._readings = self._glue.parse_to_meaning(example)
self._error = None
self._readingCache[index] = self._readings
except Exception as e:
self._readings = []
self._error = DrtVariableExpression(Variable('Error: ' + str(e)))
self._readingCache[index] = self._error
#add a star to the end of the example
self._exampleList.delete(index)
self._exampleList.insert(index, (' %s *' % example))
self._exampleList.config(height=min(len(self._examples), 25), width=40)
self._populate_readingListbox()
self._exampleList.selection_set(index)
self._drs = None
self._redraw()
def _readingList_select(self, event):
selection = self._readingList.curselection()
if len(selection) != 1: return
self._readingList_store_selection(int(selection[0]))
def _readingList_store_selection(self, index):
reading = self._readings[index]
self._readingList.selection_clear(0, 'end')
if reading:
self._readingList.selection_set(index)
self._drs = reading.simplify().normalize().resolve_anaphora()
self._redraw()
class ShiftReduceApp(object):
"""
A graphical tool for exploring the shift-reduce parser. The tool
displays the parser's stack and the remaining text, and allows the
user to control the parser's operation. In particular, the user
can shift tokens onto the stack, and can perform reductions on the
top elements of the stack. A "step" button simply steps through
the parsing process, performing the operations that
``nltk.parse.ShiftReduceParser`` would use.
"""
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingShiftReduceParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Shift Reduce Parser Application')
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animating_lock = 0
self._animate = IntVar(self._top)
self._animate.set(10) # = medium
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Initialize fonts.
self._init_fonts(self._top)
# Set up key bindings.
self._init_bindings()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# A popup menu for reducing.
self._reduce_menu = Menu(self._canvas, tearoff=0)
# Reset the demo, and set the feedback frame to empty.
self.reset()
self._lastoper1['text'] = ''
#########################################
## Initialization Helpers
#########################################
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = Font(family='helvetica', weight='bold', size=self._size.get())
self._font = Font(family='helvetica', size=self._size.get())
def _init_grammar(self, parent):
# Grammar view.
self._prodframe = listframe = Frame(parent)
self._prodframe.pack(fill='both', side='left', padx=2)
self._prodlist_label = Label(
self._prodframe, font=self._boldfont, text='Available Reductions'
)
self._prodlist_label.pack()
self._prodlist = Listbox(
self._prodframe,
selectmode='single',
relief='groove',
background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0',
)
self._prodlist.pack(side='right', fill='both', expand=1)
self._productions = list(self._parser.grammar().productions())
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
self._prodlist.config(height=min(len(self._productions), 25))
# Add a scrollbar if there are more than 25 productions.
if 1: # len(self._productions) > 25:
listscroll = Scrollbar(self._prodframe, orient='vertical')
self._prodlist.config(yscrollcommand=listscroll.set)
listscroll.config(command=self._prodlist.yview)
listscroll.pack(side='left', fill='y')
# If they select a production, apply it.
self._prodlist.bind('<<ListboxSelect>>', self._prodlist_select)
# When they hover over a production, highlight it.
self._hover = -1
self._prodlist.bind('<Motion>', self._highlight_hover)
self._prodlist.bind('<Leave>', self._clear_hover)
def _init_bindings(self):
# Quit
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Alt-q>', self.destroy)
self._top.bind('<Alt-x>', self.destroy)
# Ops (step, shift, reduce, undo)
self._top.bind('<space>', self.step)
self._top.bind('<s>', self.shift)
self._top.bind('<Alt-s>', self.shift)
self._top.bind('<Control-s>', self.shift)
self._top.bind('<r>', self.reduce)
self._top.bind('<Alt-r>', self.reduce)
self._top.bind('<Control-r>', self.reduce)
self._top.bind('<Delete>', self.reset)
self._top.bind('<u>', self.undo)
self._top.bind('<Alt-u>', self.undo)
self._top.bind('<Control-u>', self.undo)
self._top.bind('<Control-z>', self.undo)
self._top.bind('<BackSpace>', self.undo)
# Misc
self._top.bind('<Control-p>', self.postscript)
self._top.bind('<Control-h>', self.help)
self._top.bind('<F1>', self.help)
self._top.bind('<Control-g>', self.edit_grammar)
self._top.bind('<Control-t>', self.edit_sentence)
# Animation speed control
self._top.bind('-', lambda e, a=self._animate: a.set(20))
self._top.bind('=', lambda e, a=self._animate: a.set(10))
self._top.bind('+', lambda e, a=self._animate: a.set(4))
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom')
Button(
buttonframe,
text='Step',
background='#90c0d0',
foreground='black',
command=self.step,
).pack(side='left')
Button(
buttonframe,
text='Shift',
underline=0,
background='#90f090',
foreground='black',
command=self.shift,
).pack(side='left')
Button(
buttonframe,
text='Reduce',
underline=0,
background='#90f090',
foreground='black',
command=self.reduce,
).pack(side='left')
Button(
buttonframe,
text='Undo',
underline=0,
background='#f0a0a0',
foreground='black',
command=self.undo,
).pack(side='left')
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(
label='Reset Parser', underline=0, command=self.reset, accelerator='Del'
)
filemenu.add_command(
label='Print to Postscript',
underline=0,
command=self.postscript,
accelerator='Ctrl-p',
)
filemenu.add_command(
label='Exit', underline=1, command=self.destroy, accelerator='Ctrl-x'
)
menubar.add_cascade(label='File', underline=0, menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(
label='Edit Grammar',
underline=5,
command=self.edit_grammar,
accelerator='Ctrl-g',
)
editmenu.add_command(
label='Edit Text',
underline=5,
command=self.edit_sentence,
accelerator='Ctrl-t',
)
menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
rulemenu = Menu(menubar, tearoff=0)
rulemenu.add_command(
label='Step', underline=1, command=self.step, accelerator='Space'
)
rulemenu.add_separator()
rulemenu.add_command(
label='Shift', underline=0, command=self.shift, accelerator='Ctrl-s'
)
rulemenu.add_command(
label='Reduce', underline=0, command=self.reduce, accelerator='Ctrl-r'
)
rulemenu.add_separator()
rulemenu.add_command(
label='Undo', underline=0, command=self.undo, accelerator='Ctrl-u'
)
menubar.add_cascade(label='Apply', underline=0, menu=rulemenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_checkbutton(
label="Show Grammar",
underline=0,
variable=self._show_grammar,
command=self._toggle_grammar,
)
viewmenu.add_separator()
viewmenu.add_radiobutton(
label='Tiny',
variable=self._size,
underline=0,
value=10,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Small',
variable=self._size,
underline=0,
value=12,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Medium',
variable=self._size,
underline=0,
value=14,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Large',
variable=self._size,
underline=0,
value=18,
command=self.resize,
)
viewmenu.add_radiobutton(
label='Huge',
variable=self._size,
underline=0,
value=24,
command=self.resize,
)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
animatemenu = Menu(menubar, tearoff=0)
animatemenu.add_radiobutton(
label="No Animation", underline=0, variable=self._animate, value=0
)
animatemenu.add_radiobutton(
label="Slow Animation",
underline=0,
variable=self._animate,
value=20,
accelerator='-',
)
animatemenu.add_radiobutton(
label="Normal Animation",
underline=0,
variable=self._animate,
value=10,
accelerator='=',
)
animatemenu.add_radiobutton(
label="Fast Animation",
underline=0,
variable=self._animate,
value=4,
accelerator='+',
)
menubar.add_cascade(label="Animate", underline=1, menu=animatemenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0, command=self.about)
helpmenu.add_command(
label='Instructions', underline=0, command=self.help, accelerator='F1'
)
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
def _init_feedback(self, parent):
self._feedbackframe = feedbackframe = Frame(parent)
feedbackframe.pack(fill='x', side='bottom', padx=3, pady=3)
self._lastoper_label = Label(
feedbackframe, text='Last Operation:', font=self._font
)
self._lastoper_label.pack(side='left')
lastoperframe = Frame(feedbackframe, relief='sunken', border=1)
lastoperframe.pack(fill='x', side='right', expand=1, padx=5)
self._lastoper1 = Label(
lastoperframe, foreground='#007070', background='#f0f0f0', font=self._font
)
self._lastoper2 = Label(
lastoperframe,
anchor='w',
width=30,
foreground='#004040',
background='#f0f0f0',
font=self._font,
)
self._lastoper1.pack(side='left')
self._lastoper2.pack(side='left', fill='x', expand=1)
def _init_canvas(self, parent):
self._cframe = CanvasFrame(
parent,
background='white',
width=525,
closeenough=10,
border=2,
relief='sunken',
)
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
self._stackwidgets = []
self._rtextwidgets = []
self._titlebar = canvas.create_rectangle(
0, 0, 0, 0, fill='#c0f0f0', outline='black'
)
self._exprline = canvas.create_line(0, 0, 0, 0, dash='.')
self._stacktop = canvas.create_line(0, 0, 0, 0, fill='#408080')
size = self._size.get() + 4
self._stacklabel = TextWidget(
canvas, 'Stack', color='#004040', font=self._boldfont
)
self._rtextlabel = TextWidget(
canvas, 'Remaining Text', color='#004040', font=self._boldfont
)
self._cframe.add_widget(self._stacklabel)
self._cframe.add_widget(self._rtextlabel)
#########################################
## Main draw procedure
#########################################
def _redraw(self):
scrollregion = self._canvas['scrollregion'].split()
(cx1, cy1, cx2, cy2) = [int(c) for c in scrollregion]
# Delete the old stack & rtext widgets.
for stackwidget in self._stackwidgets:
self._cframe.destroy_widget(stackwidget)
self._stackwidgets = []
for rtextwidget in self._rtextwidgets:
self._cframe.destroy_widget(rtextwidget)
self._rtextwidgets = []
# Position the titlebar & exprline
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2 - y1 + 10
self._canvas.coords(self._titlebar, -5000, 0, 5000, y - 4)
self._canvas.coords(self._exprline, 0, y * 2 - 10, 5000, y * 2 - 10)
# Position the titlebar labels..
(x1, y1, x2, y2) = self._stacklabel.bbox()
self._stacklabel.move(5 - x1, 3 - y1)
(x1, y1, x2, y2) = self._rtextlabel.bbox()
self._rtextlabel.move(cx2 - x2 - 5, 3 - y1)
# Draw the stack.
stackx = 5
for tok in self._parser.stack():
if isinstance(tok, Tree):
attribs = {
'tree_color': '#4080a0',
'tree_width': 2,
'node_font': self._boldfont,
'node_color': '#006060',
'leaf_color': '#006060',
'leaf_font': self._font,
}
widget = tree_to_treesegment(self._canvas, tok, **attribs)
widget.label()['color'] = '#000000'
else:
widget = TextWidget(self._canvas, tok, color='#000000', font=self._font)
widget.bind_click(self._popup_reduce)
self._stackwidgets.append(widget)
self._cframe.add_widget(widget, stackx, y)
stackx = widget.bbox()[2] + 10
# Draw the remaining text.
rtextwidth = 0
for tok in self._parser.remaining_text():
widget = TextWidget(self._canvas, tok, color='#000000', font=self._font)
self._rtextwidgets.append(widget)
self._cframe.add_widget(widget, rtextwidth, y)
rtextwidth = widget.bbox()[2] + 4
# Allow enough room to shift the next token (for animations)
if len(self._rtextwidgets) > 0:
stackx += self._rtextwidgets[0].width()
# Move the remaining text to the correct location (keep it
# right-justified, when possible); and move the remaining text
# label, if necessary.
stackx = max(stackx, self._stacklabel.width() + 25)
rlabelwidth = self._rtextlabel.width() + 10
if stackx >= cx2 - max(rtextwidth, rlabelwidth):
cx2 = stackx + max(rtextwidth, rlabelwidth)
for rtextwidget in self._rtextwidgets:
rtextwidget.move(4 + cx2 - rtextwidth, 0)
self._rtextlabel.move(cx2 - self._rtextlabel.bbox()[2] - 5, 0)
midx = (stackx + cx2 - max(rtextwidth, rlabelwidth)) / 2
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
(x1, y1, x2, y2) = self._stacklabel.bbox()
# Set up binding to allow them to shift a token by dragging it.
if len(self._rtextwidgets) > 0:
def drag_shift(widget, midx=midx, self=self):
if widget.bbox()[0] < midx:
self.shift()
else:
self._redraw()
self._rtextwidgets[0].bind_drag(drag_shift)
self._rtextwidgets[0].bind_click(self.shift)
# Draw the stack top.
self._highlight_productions()
def _draw_stack_top(self, widget):
# hack..
midx = widget.bbox()[2] + 50
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
def _highlight_productions(self):
# Highlight the productions that can be reduced.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
if self._top is None:
return
self._top.destroy()
self._top = None
def reset(self, *e):
self._parser.initialize(self._sent)
self._lastoper1['text'] = 'Reset App'
self._lastoper2['text'] = ''
self._redraw()
def step(self, *e):
if self.reduce():
return True
elif self.shift():
return True
else:
if list(self._parser.parses()):
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Success'
else:
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Failure'
def shift(self, *e):
if self._animating_lock:
return
if self._parser.shift():
tok = self._parser.stack()[-1]
self._lastoper1['text'] = 'Shift:'
self._lastoper2['text'] = '%r' % tok
if self._animate.get():
self._animate_shift()
else:
self._redraw()
return True
return False
def reduce(self, *e):
if self._animating_lock:
return
production = self._parser.reduce()
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
return production
def undo(self, *e):
if self._animating_lock:
return
if self._parser.undo():
self._redraw()
def postscript(self, *e):
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle():
return
self._top.mainloop(*args, **kwargs)
#########################################
## Menubar callbacks
#########################################
def resize(self, size=None):
if size is not None:
self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
# self._stacklabel['font'] = ('helvetica', -size-4, 'bold')
# self._rtextlabel['font'] = ('helvetica', -size-4, 'bold')
# self._lastoper_label['font'] = ('helvetica', -size)
# self._lastoper1['font'] = ('helvetica', -size)
# self._lastoper2['font'] = ('helvetica', -size)
# self._prodlist['font'] = ('helvetica', -size)
# self._prodlist_label['font'] = ('helvetica', -size-2, 'bold')
self._redraw()
def help(self, *e):
# The default font's not very legible; try using 'fixed' instead.
try:
ShowText(
self._top,
'Help: Shift-Reduce Parser Application',
(__doc__ or '').strip(),
width=75,
font='fixed',
)
except:
ShowText(
self._top,
'Help: Shift-Reduce Parser Application',
(__doc__ or '').strip(),
width=75,
)
def about(self, *e):
ABOUT = "NLTK Shift-Reduce Parser Application\n" + "Written by Edward Loper"
TITLE = 'About: Shift-Reduce Parser Application'
try:
from six.moves.tkinter_messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def edit_grammar(self, *e):
CFGEditor(self._top, self._parser.grammar(), self.set_grammar)
def set_grammar(self, grammar):
self._parser.set_grammar(grammar)
self._productions = list(grammar.productions())
self._prodlist.delete(0, 'end')
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
def edit_sentence(self, *e):
sentence = " ".join(self._sent)
title = 'Edit Text'
instr = 'Enter a new sentence to parse.'
EntryDialog(self._top, sentence, instr, self.set_sentence, title)
def set_sentence(self, sent):
self._sent = sent.split() # [XX] use tagged?
self.reset()
#########################################
## Reduce Production Selection
#########################################
def _toggle_grammar(self, *e):
if self._show_grammar.get():
self._prodframe.pack(
fill='both', side='left', padx=2, after=self._feedbackframe
)
self._lastoper1['text'] = 'Show Grammar'
else:
self._prodframe.pack_forget()
self._lastoper1['text'] = 'Hide Grammar'
self._lastoper2['text'] = ''
def _prodlist_select(self, event):
selection = self._prodlist.curselection()
if len(selection) != 1:
return
index = int(selection[0])
production = self._parser.reduce(self._productions[index])
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
else:
# Reset the production selections.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
def _popup_reduce(self, widget):
# Remove old commands.
productions = self._parser.reducible_productions()
if len(productions) == 0:
return
self._reduce_menu.delete(0, 'end')
for production in productions:
self._reduce_menu.add_command(label=str(production), command=self.reduce)
self._reduce_menu.post(
self._canvas.winfo_pointerx(), self._canvas.winfo_pointery()
)
#########################################
## Animations
#########################################
def _animate_shift(self):
# What widget are we shifting?
widget = self._rtextwidgets[0]
# Where are we shifting from & to?
right = widget.bbox()[0]
if len(self._stackwidgets) == 0:
left = 5
else:
left = self._stackwidgets[-1].bbox()[2] + 10
# Start animating.
dt = self._animate.get()
dx = (left - right) * 1.0 / dt
self._animate_shift_frame(dt, widget, dx)
def _animate_shift_frame(self, frame, widget, dx):
if frame > 0:
self._animating_lock = 1
widget.move(dx, 0)
self._top.after(10, self._animate_shift_frame, frame - 1, widget, dx)
else:
# but: stacktop??
# Shift the widget to the stack.
del self._rtextwidgets[0]
self._stackwidgets.append(widget)
self._animating_lock = 0
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
def _animate_reduce(self):
# What widgets are we shifting?
numwidgets = len(self._parser.stack()[-1]) # number of children
widgets = self._stackwidgets[-numwidgets:]
# How far are we moving?
if isinstance(widgets[0], TreeSegmentWidget):
ydist = 15 + widgets[0].label().height()
else:
ydist = 15 + widgets[0].height()
# Start animating.
dt = self._animate.get()
dy = ydist * 2.0 / dt
self._animate_reduce_frame(dt / 2, widgets, dy)
def _animate_reduce_frame(self, frame, widgets, dy):
if frame > 0:
self._animating_lock = 1
for widget in widgets:
widget.move(0, dy)
self._top.after(10, self._animate_reduce_frame, frame - 1, widgets, dy)
else:
del self._stackwidgets[-len(widgets) :]
for widget in widgets:
self._cframe.remove_widget(widget)
tok = self._parser.stack()[-1]
if not isinstance(tok, Tree):
raise ValueError()
label = TextWidget(
self._canvas, str(tok.label()), color='#006060', font=self._boldfont
)
widget = TreeSegmentWidget(self._canvas, label, widgets, width=2)
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2 - y1 + 10
if not self._stackwidgets:
x = 5
else:
x = self._stackwidgets[-1].bbox()[2] + 10
self._cframe.add_widget(widget, x, y)
self._stackwidgets.append(widget)
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
# # Delete the old widgets..
# del self._stackwidgets[-len(widgets):]
# for widget in widgets:
# self._cframe.destroy_widget(widget)
#
# # Make a new one.
# tok = self._parser.stack()[-1]
# if isinstance(tok, Tree):
# attribs = {'tree_color': '#4080a0', 'tree_width': 2,
# 'node_font': bold, 'node_color': '#006060',
# 'leaf_color': '#006060', 'leaf_font':self._font}
# widget = tree_to_treesegment(self._canvas, tok.type(),
# **attribs)
# widget.node()['color'] = '#000000'
# else:
# widget = TextWidget(self._canvas, tok.type(),
# color='#000000', font=self._font)
# widget.bind_click(self._popup_reduce)
# (x1, y1, x2, y2) = self._stacklabel.bbox()
# y = y2-y1+10
# if not self._stackwidgets: x = 5
# else: x = self._stackwidgets[-1].bbox()[2] + 10
# self._cframe.add_widget(widget, x, y)
# self._stackwidgets.append(widget)
# self._redraw()
self._animating_lock = 0
#########################################
## Hovering.
#########################################
def _highlight_hover(self, event):
# What production are we hovering over?
index = self._prodlist.nearest(event.y)
if self._hover == index:
return
# Clear any previous hover highlighting.
self._clear_hover()
# If the production corresponds to an available reduction,
# highlight the stack.
selection = [int(s) for s in self._prodlist.curselection()]
if index in selection:
rhslen = len(self._productions[index].rhs())
for stackwidget in self._stackwidgets[-rhslen:]:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = '#00a000'
else:
stackwidget['color'] = '#00a000'
# Remember what production we're hovering over.
self._hover = index
def _clear_hover(self, *event):
# Clear any previous hover highlighting.
if self._hover == -1:
return
self._hover = -1
for stackwidget in self._stackwidgets:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = 'black'
else:
stackwidget['color'] = 'black'