NAME

 
 RtdImageFrame - itcl widget for displaying a section of an rtdimage

NAMESPACE

 
 rtd

PARENT CLASS

 
 util::FrameWidget

SYNOPSIS

 
 RtdImageFrame <path> ?options?

DESCRIPTION

 
 This widget is used to display rapid frames for an RtdImage widget. A
 rapid frame is an instance of a RtdImage widget that displays a small
 section of the main image and can be updated faster with real-time
 images because it is smaller than the main image.

 The area in the main image being used for the rapid frame is marked
 with one black and one white dashed rectangle. The rapid frame can be
 moved or resized in in the same way as any other graphic objects by
 dragging with the left mouse button over it or on one of the 8 resize
 handles displayed around it when it is selected. One of the dashed
 rectangles shows the current position of the rapid frame while the
 other one shows the new position and size being set.

 Two types of rapid frames are supported.  The first type is an RtdImage
 "view" of the main image embedded into its canvas window at a given x,y
 offset, so that it appears that main image is being updated more
 frequently inside the dashed box. In this case, the rapid frame is a
 separate rtdimage canvas image item in the same canvas with the main
 image, but at a different offset.  The second type of rapid frame is
 displayed in a popup window and is implemented by the class
 RtdImagePopup(n).

 Creating and manipulating a rapid frame usually involves communication
 with the rtdServer and camera, to tell the camera to start sending
 images at the given rate from the given area. Since this is very
 application specific, you can arrange to have your own Tcl command
 evaluated whenever a rapid frame is created, moved, resized or deleted.
 See the RtdImage(n) -rapid_frame_command option for how to do this.

 Note that currently, only one rapid frame is allowed at a time.
 Creating a second one automatically deletes the first. This may be
 changed in a future release.

WIDGET OPTIONS

 
 -command
        Tcl command to be evaluated whenever the frame is created moved,
        resized or deleted: 7 args will be appended:

         frameId = unique rapid frame id for use with rtdServer

         name = unique name for the frame

         op  = {move,resize or delete}

         x, y = coords of upper left corner of frame in image

         width, height = dimensions of frame.

 -height
        Height of image frame.

 -region_id
        Canvas id of the (region) object used to position and move the
        image in the canvas.

 -subsample
        Flag: if true, pan image is "subsampled" when shrinking, otherwise
        the pixels are averaged.

 -target_image
        Target rtdimage.

 -usexshm
        X shared memory option.

 -usexsync
        X synchronisation option.

 -verbose
        Flag: if true, print diagnostic messages.

 -width
        Width of image frame.

 -xoffset
        X offset of image frame.

 -yoffset
        Y offset of image frame.

PUBLIC METHODS

 
 get_image {}
        Return the name of the underlying rtdimage object.

 notify_cmd {op args}
        This method is called (from the main image's CanvasDraw(n) widget)
        whenever an embedded rapid frame is moved, resized or deleted.  If
        the "-command" option was given to this class, then that tcl
        command is evaluated with the frameId, operation name (move,
        resize, delete) the x, y coords and the width and height of the
        frame.

PROTECTED METHODS

 
 init {}
        This method is called from the base class (FrameWidget) after all
        the options have been evaluated.

PROTECTED VARIABLES

 
 canvas_
        Canvas window containing rapid frame image .

 draw_
        CanvasDraw object, for setting up move, resize operations on
        embedded image.

 frameId_
        Rapid frame Id, needed to communicate with rtdServer.

 imageId_
        Canvas image id.

 image_
        Internal rtdimage for rapid frame.

 rectId_
        Canvas id of rectangle used to get events for moving/resizing
        image.

 target_image_
        Target internal rtdimage.

SEE ALSO

 
 FrameWidget(n)

 


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Last change: 07 May 99