Photoshop area selection info

Question

Hello,
  I'd like to get information about the current selected area in the opened image, as a rect (top, left, bottom, right). I succeeded to select an area with the following code, but now I need to get the info if user changes it:
SPErr SelectArea ( const double inTop,
                             const double inLeft,
                             const double inBottom,
                             const double inRight)
    ASSERT(sPSActionControl);
    SPErr error = kSPNoError;
    PIActionDescriptor result = NULL;
    PIActionDescriptor saveAsDescriptor = NULL;
    // We have to construct a saveAsDescriptor of classRectangle because
    // that is what the selection key is:
    PIActionDescriptor rectangle = NULL;
    PIActionReference reference = NULL;
    error = sPSActionDescriptor->Make(&saveAsDescriptor);
    if (error) goto returnError;
    error = sPSActionReference->Make(&reference);
    if (error) goto returnError;
    error = sPSActionReference->PutProperty(reference,
                                            // Normally this would be classProperty, but a selection is
                                            // actually an alpha channel:
                                            classChannel,
                                            keySelection);
    if (error) goto returnError;
    error = sPSActionDescriptor->Make(&rectangle);
    if (error) goto returnError;
    error = sPSActionDescriptor->PutUnitFloat(    rectangle, keyTop, unitDistance, inTop);
    if (error) goto returnError;               
    error = sPSActionDescriptor->PutUnitFloat(    rectangle, keyLeft, unitDistance, inLeft);
    if (error) goto returnError;
    error = sPSActionDescriptor->PutUnitFloat(    rectangle, keyBottom, unitDistance, inBottom);
    if (error) goto returnError;
    error = sPSActionDescriptor->PutUnitFloat(    rectangle, keyRight, unitDistance, inRight);
    if (error) goto returnError;
    error = sPSActionDescriptor->Make(&saveAsDescriptor);
    if (error) goto returnError;
    // "keyTarget" should always be the first key in, if there is one, which
    // there is in this case because we are doing the command:
    // "set selection to <rect>".
    error = sPSActionDescriptor->PutReference( saveAsDescriptor, keyTarget, reference );
    if (error) goto returnError;
    // Now we put the new, changed information, which is an object
    // of classRectangle, using the key "keyTo":
    sPSActionDescriptor->PutObject( saveAsDescriptor, keyTo, classRectangle, rectangle );
    if (error) goto returnError;
    error = sPSActionControl->Play(&result, eventSet, saveAsDescriptor, plugInDialogSilent);
    if (error) goto returnError;
    returnError:
        if (result != NULL) sPSActionDescriptor->Free(result);
        if (rectangle != NULL) sPSActionDescriptor->Free(rectangle);
        if (reference != NULL) sPSActionReference->Free(reference);
        if (saveAsDescriptor != NULL) sPSActionDescriptor->Free(saveAsDescriptor);
    return error;
Thanx.
Ale

Answer 1

If you break it down it might help to figure out where it's not working as expected.
Make sure your "Info" button is toggled until your rear LCD display shows the camera's mode, shutter speed, f-stop, ISO, etc. etc.  This wont impact the ability to change AF mode selection, but at least you can see that the camera is responding to your next button press.
When you press the rear AF selection button, it should be the button in the extreme top right corner of the back of the camera.   After pressing this button (but before pressing the M-Fn button) the rear-display should change.  The top of the rear display should read:  "AF point selection", the row below should show which AF mode is currently selected.  The row below that should display each of the available modes but at the extreme right you should see the "M-Fn" signifying that pressing that button will cause it to toggle to the next mode.
When you initially press the rear AF selection button, do you see the rear LCD display update  to show that you can either select new AF modes -or- alter the selected point within your current mode?  
Tim Campbell
5D II, 5D III, 60Da