canvas_zoom man page
canvas::zoom — Zoom control for canvas::sqmap
package require Tcl 8.4
package require Tk 8.4
package require canvas::zoom ?0.1?
::canvas::zoom pathName ?options?
This package provides a widget to enable the user of a map display to control the zoom level.
- ::canvas::zoom pathName ?options?
Creates the zoom control widget pathName and configures it. The methods and options supported by the new widget are described in the following sections.
The result of the command is pathName.
The value for this option is either vertical, or horizontal, specifying the orientation of the major axis of the widget. The default is vertical.
The value for this option is a non-negative integer. It specifies the number of zoom levels to support.
The value for this option is the name of a global or namespaced variable which is connected with the widget. changes to the zoom level made the widget are propagated to this variable, and in turn changes to the variable are imported into the widget.
This option specifies a command prefix. This callback will be invoked whenever the zoom level is changed. It is called with two additional arguments, the zoom control widget, and the new zoom level, in this order.
The widget supports no methods beyond the standard (configure, cget, etc.).