Pan Window

The pan window, implemented by the RtdImagePan widget, displays a view of the main image at a smaller magnification and a rectangle indicating the size and position of the visible portion of the image. The pan window is given a maximum size at start-up and always tries to fit the image in the window by shrinking it by integer factors. The rectangle can be dragged around in the pan window with the left mouse button to pan or move the image. The panning rectangle is implemented using the same class as the main image uses for line graphics: class CanvasDraw.

Here is an example, taken from the RtdImageCtrl class, demonstrating how to create a pan window:

 
pack [RtdImagePan $this.pan \ 
    -target_image $this \ 
    -width $pan_width \ 
    -height $pan_height \ 
    -usexshm $usexshm \ 
    -verbose $verbose \ 
    -bd 3 \ 
    -relief groove] \ 
    -side right -in $panel

See RtdImagePan(n) for more details.