def _selectprod_cb(self, production):
canvas = self._treelet_canvas
self._prodlist.highlight(production)
if self._treelet is not None: self._treelet.destroy()
# Convert the production to a tree.
rhs = production.rhs()
for (i, elt) in enumerate(rhs):
if isinstance(elt, Nonterminal): elt = Tree(elt)
tree = Tree(production.lhs().symbol(), *rhs)
# Draw the tree in the treelet area.
fontsize = int(self._size.get())
node_font = ('helvetica', -(fontsize+4), 'bold')
leaf_font = ('helvetica', -(fontsize+2))
self._treelet = tree_to_treesegment(canvas, tree,
node_font=node_font,
leaf_font=leaf_font)
self._treelet['draggable'] = 1
# Center the treelet.
(x1, y1, x2, y2) = self._treelet.bbox()
w, h = int(canvas['width']), int(canvas['height'])
self._treelet.move((w-x1-x2)/2, (h-y1-y2)/2)
# Mark the places where we can add it to the workspace.
self._markproduction(production)
def _selectprod_cb(self, production):
canvas = self._treelet_canvas
self._prodlist.highlight(production)
if self._treelet is not None:
self._treelet.destroy()
# Convert the production to a tree.
rhs = production.rhs()
for (i, elt) in enumerate(rhs):
if isinstance(elt, Nonterminal):
elt = Tree(elt)
tree = Tree(production.lhs().symbol(), *rhs)
# Draw the tree in the treelet area.
fontsize = int(self._size.get())
node_font = ("helvetica", -(fontsize + 4), "bold")
leaf_font = ("helvetica", -(fontsize + 2))
self._treelet = tree_to_treesegment(canvas,
tree,
node_font=node_font,
leaf_font=leaf_font)
self._treelet["draggable"] = 1
# Center the treelet.
(x1, y1, x2, y2) = self._treelet.bbox()
w, h = int(canvas["width"]), int(canvas["height"])
self._treelet.move((w - x1 - x2) / 2, (h - y1 - y2) / 2)
# Mark the places where we can add it to the workspace.
self._markproduction(production)
def write_tree_stream(self, nltk_tree):
"""
Draws and outputs in PNG for ipython.
PNG is used instead of PDF, since it can be displayed in the qt console and
has wider browser support.
"""
import os
import base64
import subprocess
import tempfile
from nltk.draw.tree import tree_to_treesegment
from nltk.draw.util import CanvasFrame
from nltk.internals import find_binary
_canvas_frame = CanvasFrame()
# widget = tree_to_treesegment(_canvas_frame.canvas(), self)
widget = tree_to_treesegment(_canvas_frame.canvas(), nltk_tree)
_canvas_frame.add_widget(widget)
x, y, w, h = widget.bbox()
# print_to_file uses scrollregion to set the width and height of the pdf.
_canvas_frame.canvas()["scrollregion"] = (0, 0, w, h)
with tempfile.NamedTemporaryFile() as file:
in_path = "{0:}.ps".format(file.name)
out_path = "{0:}.png".format(file.name)
_canvas_frame.print_to_file(in_path)
_canvas_frame.destroy_widget(widget)
try:
subprocess.call([
find_binary(
"gs",
binary_names=["gswin32c.exe", "gswin64c.exe"],
env_vars=["PATH"],
verbose=False,
)
] + "-q -dEPSCrop -sDEVICE=png16m -r90 -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -dSAFER -dBATCH -dNOPAUSE -sOutputFile={0:} {1:}"
.format(out_path, in_path).split())
except LookupError:
pre_error_message = str(
"The Ghostscript executable isn't found.\n"
"See http://web.mit.edu/ghostscript/www/Install.htm\n"
"If you're using a Mac, you can try installing\n"
"https://docs.brew.sh/Installation then `brew install ghostscript`"
)
print(pre_error_message, file=sys.stderr)
raise LookupError
with open(out_path, "rb") as sr:
res = sr.read()
b = bytearray(res)
# b0 = b[0]
os.remove(in_path)
os.remove(out_path)
# return base64.b64encode(res).decode()
# return base64.b64encode(res)
# return b0
return b
def to_ps(self, filename):
"""Export as a PostScript image.
This function is used by `_repr_png_`.
"""
_canvas_frame = CanvasFrame()
# WIP customization of visual appearance
# NB: conda-provided python and tk cannot access most fonts on the
# system, thus it currently falls back on the default font
widget = tree_to_treesegment(_canvas_frame.canvas(), self,
tree_yspace=35,
node_font=('Verdana', -18, 'bold'),
leaf_font=('Verdana', -18))
_canvas_frame.add_widget(widget)
x, y, w, h = widget.bbox()
# print_to_file uses scrollregion to set the width and height of the
# pdf
_canvas_frame.canvas()['scrollregion'] = (0, 0, w, h)
# print to file
_canvas_frame.print_to_file(filename)
_canvas_frame.destroy_widget(widget)
def to_ps(self, filename):
"""Export as a PostScript image.
This function is used by `_repr_png_`.
"""
_canvas_frame = CanvasFrame()
# WIP customization of visual appearance
# NB: conda-provided python and tk cannot access most fonts on the
# system, thus it currently falls back on the default font
widget = tree_to_treesegment(_canvas_frame.canvas(),
self,
tree_yspace=35,
node_font=('Verdana', -18, 'bold'),
leaf_font=('Verdana', -18))
_canvas_frame.add_widget(widget)
x, y, w, h = widget.bbox()
# print_to_file uses scrollregion to set the width and height of the
# pdf
_canvas_frame.canvas()['scrollregion'] = (0, 0, w, h)
# print to file
_canvas_frame.print_to_file(filename)
_canvas_frame.destroy_widget(widget)
