Tag: tree	Creates a tree widget, and is also used for individual nodes in the tree.
Attrib Name	Type	Possible Values	Description
_height	integer	null	Get total height of widget in pixels.
_width	integer	null	Get total width of widget in pixels.
border	integer	0,*	Set size of border.
default-widget	boolean	null	Whether this widget is the 'default' for the window.
dragdata-text	string	null	Specify the text data to be given as drag data.
dragdata-url	string	null	Specify the URL to be given as drag data.
expandable	boolean	null	Specify whether this tree item should be allowed to expand or not.
expanded	boolean	false,true	Tree item is expanded or not.
focused	boolean	null	Whether this widget has focus or not.
font	font	null	Specify font used in widget.
height	integer	-1,*	Set total height of widget in pixels. -1 specifies natural height.
label	string	null	Add a label the the widgets's bottom level box.
onbuttonpress	function	(node, button_number, x_coordinate, y_coordinate)	Specify function called on a button press event.
onbuttonrelease	function	(node, button_number, x_coordinate, y_coordinate)	Specify function called on a button release event.
ondeselect	function	(deselected_node)	Specify function to call when a sub item is 'deselected'.
ondoubleclick	function	(node, button_number, x_coordinate, y_coordinate)	Specify function called on a doubleclick event.
ondrag	function	(source_node)	Makes widget a drag source, and calls specified function when drag starts
ondrop	function	(target_node, drag_data, suggested_action)	Makes widget accept drag events, and calls specified function on a drop.
onexpand	function	(expanding_node)	Specify function to call when a tree item is expanded.
onfocus	function	(event_node)	Specify function called on a focus in event.
onkeypress	function	(event_node, key_name, key_value)	Specify function called on a keypress event.
onkeyrelease	function	(event_node, key_name, key_value)	Specify function called on a keyrelease event.
onmousemotion	function	(node, button_mask, x_coordinate, y_coordinate)	Specify function called when the mouse is moved on this widget.
onselect	function	(selected_node)	Specify function to call when a sub item is 'selected'.
ontripleclick	function	(node, button_number, x_coordinate, y_coordinate)	Specify function called on a tripleclick event.
selected	boolean	true,false	Item is highlighted or not.
selection-type	choice	single,multiple,browse,extended	The mode of the selection.
sensitive	boolean	true,false	Toggle widget sensitivity. Will propogate through widget tree.
style	string	Comma seperated style rules.	The look and color of this widget.
tooltip	string	null	Specify tooltip for widget.
visible	boolean	true,false	Toggle if the widget is to be visible on the screen.
width	integer	-1,*	Set total width of widget in pixels. -1 specifies natural width.