-background -selectbackground -takefocus -borderwidth -selectborderwidth -xscrollcommand -relief -selectforeground -yscrollcommand
Canvas widgets implement structured graphics. A canvas displays any number of items, which may be things like rectangles, circles, lines, and text. Items may be manipulated (e.g. moved or re-coloured) and commands may be associated with items in much the same way that the bind command allows commands to be bound to widgets. For example, a particular command may be associated with the <Button-1> event so that the command is invoked whenever button 1 is pressed with the mouse cursor over an item. This means that items in a canvas can have behaviours defined by the Tk scripts bound to them.
Each item may also have any number of tags associated with it. A tag is just a string of characters, and it may take any form except that of an integer. For example, ``x123'' is OK but ``123'' isn't. The same tag may be associated with many different items. This is commonly done to group items in various interesting ways; for example, all selected items might be given the tag ``selected''.
The tag all is implicitly associated with every item in the canvas; it may be used to invoke operations on all the items in the canvas.
The tag current is managed automatically by Tk; it applies to the current item, which is the topmost item whose drawn area covers the position of the mouse cursor. If the mouse is not in the canvas widget or is not over an item, then no item has the current tag.
When specifying items in canvas widget commands, if the specifier is an integer then it is assumed to refer to the single item with that id. If the specifier is not an integer, then it is assumed to refer to all of the items in the canvas that have a tag matching the specifier. The symbol tagOrId is used below to indicate that an argument specifies either an id that selects a single item or a tag that selects zero or more items. Some widget commands only operate on a single item at a time; if tagOrId is specified in a way that names multiple items, then the normal behaviour is for the command to use the first (lowest) of these items in the display list that is suitable for the command. Exceptions are noted in the widget command descriptions below.
Individual items may be moved or scaled using widget commands described below, but they may not be rotated.
pathName option ?arg arg ...?
The only events for which bindings may be specified are those related to the mouse and keyboard, such as Enter, Leave, ButtonPress, Motion, and KeyPress. The handling of events in canvases uses the current item defined in ITEM IDS AND TAGS above. Enter and Leave events trigger for an item when it becomes the current item or ceases to be the current item; note that these events are different than Enter and Leave events for windows. Mouse-related events are directed to the current item, if any. Keyboard-related events are directed to the focus item, if any (see the focus widget command below for more on this).
It is possible for multiple bindings to match a particular event. This could occur, for example, if one binding is associated with the item's id and another is associated with one of the item's tags. When this occurs, all of the matching bindings are invoked. A binding associated with the all tag is invoked first, followed by one binding for each of the item's tags (in order), followed by a binding associated with the item's id. If there are multiple matching bindings for a single tag, then only the most specific binding is invoked. A continue command in a binding script terminates that script, and a break command terminates that script and skips any remaining scripts for the event, just as for the bind command.
If bindings have been created for a canvas window using the bind command, then they are invoked in addition to bindings created for the canvas's items using the bind widget command. The bindings for items will be invoked before any of the bindings for the window as a whole.
Once the focus has been set to an item, the item will display the insertion cursor and all keyboard events will be directed to that item. The focus item within a canvas and the focus window on the screen (set with the focus command) are totally independent: a given item doesn't actually have the input focus unless (a) its canvas is the focus window and (b) the item is the focus item within the canvas. In most cases it is advisable to follow the focus widget command with the focus command to set the focus window to the canvas (if it wasn't there already).
Note that the canvas grab item, as set by this command, and the tk grab item, as set by grab(9) are totally independent; a canvas item doesn't actually grab the mouse unless a) the canvas itself has grabbed the mouse or b) the mouse events are being delivered to the canvas as a matter of course.
pathName create arc x1 y1 x2 y2 ?option value option value ...?
pathName create bitmap x y ?option value option value ...?
pathName create image x y ?option value option value ...?
pathName create line x1 y1... xn yn ?option value option value ...?
pathName create oval x1 y1 x2 y2 ?option value option value ...?
pathName create polygon x1 y1 ... xn yn ?option value option value ...?
Polygon items are different from other items such as rectangles, ovals and arcs in that interior points are considered to be ``inside'' a polygon (e.g. for purposes of the find closest and find overlapping widget commands) even if it is not filled. For most other item types, an interior point is considered to be inside the item only if the item is filled or if it has neither a fill nor an outline. If you would like an unfilled polygon whose interior points are not considered to be inside the polygon, use a line item instead.
pathName create rectangle x1 y1 x2 y2 ?option value option value ...?
pathName create text x y ?option value option value ...?
pathName create window x y ?option value option value ...?
|CANVAS(9 )||Rev: Thu Feb 15 14:44:05 GMT 2007|