def reset_workspace(self):
c = self._workspace.canvas()
fontsize = int(self._size.get())
node_font = ("helvetica", -(fontsize + 4), "bold")
leaf_font = ("helvetica", -(fontsize + 2))
# Remove the old tree
if self._tree is not None:
self._workspace.remove_widget(self._tree)
# The root of the tree.
start = self._grammar.start().symbol()
rootnode = TextWidget(c, start, font=node_font, draggable=1)
# The leaves of the tree.
leaves = []
for word in self._text:
leaves.append(TextWidget(c, word, font=leaf_font, draggable=1))
# Put it all together into one tree
self._tree = TreeSegmentWidget(c, rootnode, leaves, color="white")
# Add it to the workspace.
self._workspace.add_widget(self._tree)
# Move the leaves to the bottom of the workspace.
for leaf in leaves:
leaf.move(0, 100)
def tree_to_widget(s, canvas):
"""
Parse a tree string, and return a corresponding widget. See the
module docstring for the format of C{s}.
"""
WORD = r'(\\\\|\\[^\\\n]|[^\\\s()<>])+'
TOKEN_RE = re.compile(r'\(\s*%s|<\s*%s|\)|>|%s|\s+' % (WORD, WORD, WORD))
stack = [[]]
for tok in tokenize(s.strip(), TOKEN_RE):
if tok.strip() == '':
pass
elif tok[:1] in '(<':
label = word_to_widget(tok[1:].strip(),
canvas,
color='#004080',
bold=True)
roof = (tok[:1] == '<')
stack[-1].append(dict(canvas=canvas, label=label, roof=roof))
stack.append([])
elif tok[:1] in ')>':
subtrees = stack.pop()
node_kwargs = stack[-1][-1]
stack[-1][-1] = TreeSegmentWidget(subtrees=subtrees, **node_kwargs)
else:
leaf = word_to_widget(tok.strip(), canvas, color='#008040')
stack[-1].append(leaf)
if not len(stack) == 1 and len(stack[0]) == 1:
raise ValueError('unbalanced parens?')
return stack[0][0]