procedure :canvas name Creates a canvas widget within the current panel frame for the TCL interpreter. name is used to generate the path name of the window to be created. It should have the format of a widget name (e.g. :canvas CVS) and should be unique within this interpreter. The name will be lower-cased (using the string tolower command) in order to generate the path name used to create the window. Currently the canvas widget is non interactive and thus no click procedure is invoked. The :canvas procedure may also be used directly within a frame window (i.e. before any panel window has been created). The :canvas procedure may have a number of arguments however none of these is mandatory. arguments :x number number is the x-co-ordinate within the current panel of the canvas widget in pixels e.g. :x 400 :y number number is the y-co-ordinate within the current panel of the canvas widget in pixels e.g. :y 200 The :x and :y parameters may be omitted in which case the packer geometry manager will be used and the position of the window will be determined by the contents of the master (panel) window. If however the :x and :y parameters are supplied then the placer geometry manager will be used to position the window within the master (panel) window. Warning: Note that it is not possible to mix use of the packer and placer geometry managers within the same window. Thus all windows within a panel must request or imply that the same geometry manager is used. :w number number is the width of the canvas widget in pixels e.g. :w 400 :h number number is the height of the canvas widget in pixels e.g. :y 200 The :canvas procedure creates an empty window into which objects can be created using the :draw procedure.