NAME

 
 RtdImageZoomView - itcl widget managing the RtdImage zoom window

NAMESPACE

 
 rtd

PARENT CLASS

 
 util::FrameWidget

SYNOPSIS

 
 RtdImageZoomView <path> ?options?

DESCRIPTION

 
 This [incr Tk] widget class can be used to display a magnified portion
 of the image while tracking mouse motion events in the image window.
 There are two versions of this widget, see RtdImageZoom(n) for the
 other one. This version uses an rtdimage "view" of the main image and
 changes the x and y offsets as needed. This has the advantage that it
 always displays the correct pixels, even when the main image is
 "subsampled" and there are no restrictions on the size or shape of the
 zoom window. The main part of this widget is implemented in C++ by the
 rtdimage subcommand "zoomview".  This widget is a subclass of
 FrameWidget, so it inherits its methods and options. In addition the
 options and methods below are defined.

ITK COMPONENTS

 
 check
        Checkbutton to turn zooming on/off.

 f
        Frame with on/off button and scale menu.

 image
        RtdImage(n) widget for zoom.

 label
        Optional label for zoom factor.

 larger
        Optional button to increase zoom factor.

 smaller
        Optional button to decrease zoom factor.

STANDARD OPTIONS

 
 -background -height -labelfont -width

WIDGET OPTIONS

 
 -command
        Optional command to evaluate when the zoom factor changes.

 -factor
        Zoom magnification factor.

 -height
        Height of zoom frame.

 -labelfont
        Fonts used.

 -propagate
        Flag: if true, make scale of zoom window relative to target
        window.

 -shelp
        Help text displayed when mouse enters widget.

 -target_image
        Target (main) RtdImage itcl widget.

 -usexshm
        X shared memory option.

 -usexsync
        X synchronisation option.

 -verbose
        Flag: if true, print diagnostic messages.

 -width
        Width of zoom frame.

PUBLIC METHODS

 
 enter_image {image}
        This method is called when the mouse ptr enters an RtdImage.  Set
        the target scale factor from the given rtdimage.

 inc_zoom {inc}
        Increment or decrement the zoom factor.

 leave_image {image}
        This method is called when the mouse ptr leaves an RtdImage.
        clear out the zoom image.

 scale {}
        Called when the main image is scaled to draw a box around the
        center pixel.

 zoom {{clear 0}}
        Called when the zoom checkbutton is pressed.

PROTECTED VARIABLES

 
 canvas_
        Internal canvas widget.

 image_
        Internal rtd image.

 target_image_
        Internal target image.

 target_scale_
        Scale of the target (or current target) image.

SEE ALSO

 
 FrameWidget(n)

 


- - - - - -
Last change: 07 May 99