nltk.draw.util.SymbolWidget

class documentation

class SymbolWidget(TextWidget): (source)

Constructor: SymbolWidget(canvas, symbol, **attribs)

A canvas widget that displays special symbols, such as the negation sign and the exists operator. Symbols are specified by name. Currently, the following symbol names are defined: neg, disj, conj, lambda, merge, forall, exists, subseteq, subset, notsubset, emptyset, imp, rightarrow, equal, notequal, epsilon.

Attributes:

color: the color of the text.
draggable: whether the text can be dragged by the user.

Static Method	`symbolsheet`	Open a new Tkinter window that displays the entire alphabet for the symbol font. This is useful for constructing the `SymbolWidget.SYMBOLS` dictionary.
Method	`__init__`	Create a new symbol widget.
Method	`__repr__`	No summary
Method	`set_symbol`	Change the symbol that is displayed by this symbol widget.
Method	`symbol`	No summary
Constant	`SYMBOLS`	A dictionary mapping from symbols to the character in the `symbol` font used to render them.
Instance Variable	`_symbol`	Undocumented

Inherited from TextWidget:

Method	`__getitem__`	No summary
Method	`__setitem__`	Set the value of the attribute `attr` to `value`. See the class documentation for a list of attributes supported by this canvas widget.
Method	`set_text`	Change the text that is displayed by this text widget.
Method	`text`	No summary
Method	`_tags`	No summary
Instance Variable	`_tag`	Undocumented
Instance Variable	`_text`	Undocumented

Inherited from CanvasWidget (via TextWidget):

Method	`bbox`	No summary
Method	`bind_click`	Register a new callback that will be called whenever this `CanvasWidget` is clicked on.
Method	`bind_drag`	Register a new callback that will be called after this `CanvasWidget` is dragged. This implicitly makes this `CanvasWidget` draggable.
Method	`canvas`	No summary
Method	`child_widgets`	No summary
Method	`destroy`	Remove this `CanvasWidget` from its `Canvas`. After a `CanvasWidget` has been destroyed, it should not be accessed.
Method	`height`	No summary
Method	`hidden`	No summary
Method	`hide`	Temporarily hide this canvas widget.
Method	`manage`	Arrange this canvas widget and all of its descendants.
Method	`move`	Move this canvas widget by a given distance. In particular, shift the canvas widget right by `dx` pixels, and down by `dy` pixels. Both `dx` and `dy` may be negative, resulting in leftward or upward movement.
Method	`moveto`	Move this canvas widget to the given location. In particular, shift the canvas widget such that the corner or side of the bounding box specified by `anchor` is at location (`x`, `y`).
Method	`parent`	No summary
Method	`show`	Show a hidden canvas widget.
Method	`tags`	No summary
Method	`unbind_click`	Remove a callback that was registered with `bind_click`.
Method	`unbind_drag`	Remove a callback that was registered with `bind_drag`.
Method	`update`	Update the graphical display of this canvas widget, and all of its ancestors, in response to a change in one of this canvas widget's children.
Method	`width`	No summary
Method	`__click`	If this `CanvasWidget` has a drag callback, then call it; otherwise, find the closest ancestor with a click callback, and call it. If no ancestors have a click callback, do nothing.
Method	`__drag`	If this `CanvasWidget` has a drag callback, then call it; otherwise, find the closest ancestor with a drag callback, and call it. If no ancestors have a drag callback, do nothing.
Method	`__motion_cb`	move this object to the new location
Method	`__press_cb`	record the button press event in `self.__press`
Method	`__release_cb`	unregister motion & button release callbacks.
Method	`__start_drag`	register a motion callback
Method	`_add_child_widget`	Register a hierarchical child widget. The child will be considered part of this canvas widget for purposes of user interaction. `_add_child_widget` has two direct effects:
Method	`_manage`	Arrange the child widgets of this canvas widget. This method is called when the canvas widget is initially created. It is also called if the user calls the `manage` method on this canvas widget or any of its ancestors.
Method	`_remove_child_widget`	Remove a hierarchical child widget. This child will no longer be considered part of this canvas widget for purposes of user interaction. `_add_child_widget` has two direct effects:
Method	`_update`	Update this canvas widget in response to a change in one of its children.
Instance Variable	`__callbacks`	Registered callbacks. Currently, four keys are used: `1`, `2`, `3`, and `'drag'`. The values are callback functions. Each callback function takes a single argument, which is the `CanvasWidget` that triggered the callback.
Instance Variable	`__canvas`	This `CanvasWidget`'s canvas.
Instance Variable	`__children`	This `CanvasWidget`'s hierarchical child widgets.
Instance Variable	`__drag_x`	Where it's been moved to (to find dx)
Instance Variable	`__drag_y`	Where it's been moved to (to find dy)
Instance Variable	`__draggable`	Is this canvas widget draggable?
Instance Variable	`__hidden`	Undocumented
Instance Variable	`__parent`	This `CanvasWidget`'s hierarchical parent widget.
Instance Variable	`__press`	The ButtonPress event that we're currently handling.
Instance Variable	`__updating`	Is this canvas widget currently performing an update? If it is, then it will ignore any new update requests from child widgets.

@staticmethod
def symbolsheet(size=20): (source) ¶

Open a new Tkinter window that displays the entire alphabet for the symbol font. This is useful for constructing the SymbolWidget.SYMBOLS dictionary.

def __init__(self, canvas, symbol, **attribs): (source) ¶

overrides nltk.draw.util.TextWidget.__init__

Create a new symbol widget.

Parameters
canvas:Tkinter.Canvas	This canvas widget's canvas.
symbol:str	The name of the symbol to display.
**attribs	The new canvas widget's attributes.

def __repr__(self): (source) ¶

overrides nltk.draw.util.TextWidget.__repr__

Returns
str	a string representation of this canvas widget.

def set_symbol(self, symbol): (source) ¶

Change the symbol that is displayed by this symbol widget.

Parameters
symbol:str	The name of the symbol to display.

def symbol(self): (source) ¶

Returns
str	the name of the symbol that is displayed by this symbol widget.

SYMBOLS = (source) ¶

A dictionary mapping from symbols to the character in the symbol font used to render them.

Value

{'neg': 'Ø',
 'disj': 'Ú',
 'conj': 'Ù',
 'lambda': 'l',
 'merge': 'Ä',
 'forall': '"',
 'exists': '$',
...

_symbol = (source) ¶

Undocumented