You almost have it - you just need to assign the handle of the crop area to the handles object and then store this updated (handles) application data so that it will be there the next time the user presses the button.
If the user has pressed the Crop button, chosen Yes, and selected an area within the image then the code
plot(handles.x,handles.y);
becomes
% save the handle to the rectangle that surrounds the area of the image
% that is to be cropped
handles.hCropRect = plot(handles.x,handles.y);
% store the updated app data
guidata(hObject,handles);
So we have a handle for the rectangle of the area to be cropped. You want this rectangle to be removed whenever the user presses the Crop button again, so we can do the following as the first line in the button callback (right before your above if statement, or as the first line within the if block)
% check to see if the handles object has the hCropRect field
if isfield(handles,'hCropRect');
% delete only if not empty
if ~isempty(handles.hCropRect)
delete(handles.hCropRect);
% clear the handle to denote that it has been deleted
handles.hCropRect = [];
% clear x and y
handles.x = [];
handles.y = [];
% store the updated app data
guidata(hObject,handles);
end
end
Try the above and see what happens!
I noticed that your code didn't have the guidata(hObject,handles) command - how were you able to access the handles.x, handles.y, and handles.finalRect outside of this function?
