canvas::zoom (3)
NAME
canvas::zoom - Zoom control for canvas::sqmapSYNOPSIS
package require Tcl 8.4package require Tk 8.4
package require snit
package require uevent::onidle
package require canvas::zoom ?0.2.1?
::canvas::zoom pathName ?options?
DESCRIPTION
This package provides a widget to enable the user of a map display to control the zoom level.API
- ::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.
OPTIONS
- -orient
- The value for this option is either vertical, or horizontal, specifying the orientation of the major axis of the widget. The default is vertical.
- -levels
- The value for this option is a non-negative integer. It specifies the number of zoom levels to support.
- -variable
- 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.
- -command
- 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.