MATLAB: How to implement Drag and Drop functionality in MATLAB

annotation;dragdwhhgwaitfigureguiguideImage Processing ToolboxinterfacelineMATLABmoveuicontroluserwindow

I would like to be able to drag and drop a graphic object (Eg : TEXTBOX) across a figure window.

Best Answer

In Image Processing Toolbox, there are some functions which provides draggable object such as imrect and impoly etc.
For details, please refer the following documentation:
https://www.mathworks.com/help/images/building-guis-with-modular-interactive-tools.html
Also, this feature can be implemented using a combination of the Figure Properties and the graphic object properties. The figure properties to be used are:
WindowButtonUpFcn
WindowButtonMotionFcn
CurrentPoint
The property of the graphic object to be used is:
ButtonDownFcn
The following example implements drag and drop functionality for a text box that is displayed on a Figure Window. This example function is also attached as a MATLAB-file:
function drag_drop
dragging = [];
orPos = [];
f = figure('WindowButtonUpFcn',@dropObject,'units','normalized','WindowButtonMotionFcn',@moveObject);
a = annotation('textbox','position',[0.2 0.2 0.2 0.2],'String','Hello','ButtonDownFcn',@dragObject);
    function dragObject(hObject,eventdata)
        dragging = hObject;
        orPos = get(gcf,'CurrentPoint');
    end
    function dropObject(hObject,eventdata)
        if ~isempty(dragging)
            newPos = get(gcf,'CurrentPoint');
            posDiff = newPos - orPos;
            set(dragging,'Position',get(dragging,'Position') + [posDiff(1:2) 0 0]);
            dragging = [];
        end
    end
    function moveObject(hObject,eventdata)
        if ~isempty(dragging)
            newPos = get(gcf,'CurrentPoint');
            posDiff = newPos - orPos;
            orPos = newPos;
            set(dragging,'Position',get(dragging,'Position') + [posDiff(1:2) 0 0]);
        end
    end
end
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