Dragable rectangle with text

Hi, im trying to make a rectangle that is labelled which can be dragged. However i only managed to do it with annotations, and want to change it to dragging with a rectangle. How do i do it?

This is my code:

function drag_drop 
dragging = [];
orPos = [];
f = figure('WindowButtonUpFcn',@dropObject,'units','normalized','WindowButtonMotionFcn',@moveObject);
a = annotation('textbox','position',[0.1, 0.1, 0.1, 0.1],'String','StudyTable','ButtonDownFcn',@dragObject);
a = annotation('textbox','position',[0.1, 0.1, 0.1, 0.1],'String','CoffeeTable','ButtonDownFcn',@dragObject);
a = annotation('textbox','position',[0.35, 0.35, 0.35, 0.35],'String','Room','ButtonDownFcn',@dragObject);
rectangle('textbox','position',[0.35, 0.35, 0.35, 0.35],'String','Room','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

[Rik]

You forgot to format your code as code. Apart from that, I don't see why your code would not work for other objects if it works for annotation objects.

[J. Alex Lee]

there's no communication between the entrant callback "dragObject" and anything else

[Rik]

It only seems that way because of the lack of proper indentation. All functions are nested functions within the main function, so they actually share some variables. I would prefer a more explicit method of sharing handles, but this should work.

[J. Alex Lee]

well, i actually tried to run the code...the problem is not implementation of drag-and-drop...the problem is about endowing a rectangle class with some text. [edit] removed code that doesn't answer the OP, and made answer below.

Answer 1

[J. Alex Lee]

Ugly, but minimal changes to original code:

function drag_drop
close all
dragging = [];
orPos = [];
f = figure('WindowButtonUpFcn',@dropObject,'units','normalized','WindowButtonMotionFcn',@moveObject);
% a = annotation('textbox','position',[0.1, 0.1, 0.1, 0.1],'String','StudyTable','ButtonDownFcn',@dragObject);
% a = annotation('textbox','position',[0.1, 0.1, 0.1, 0.1],'String','CoffeeTable','ButtonDownFcn',@dragObject);
% a = annotation('textbox','position',[0.35, 0.35, 0.35, 0.35],'String','Room','ButtonDownFcn',@dragObject);

tmp =  text(0.35,0.35,'Room','VerticalAlignment','bottom');
a = rectangle('position',[0.35, 0.35, 0.35, 0.35],'EdgeColor','r','ButtonDownFcn',@dragObject,'UserData',tmp);

tmp =  text(0.1,0.1,'StudyTable','VerticalAlignment','bottom');
b = rectangle('position',[0.1, 0.1, 0.1, 0.1],'EdgeColor','r','ButtonDownFcn',@dragObject,'UserData',tmp);

tmp =  text(0.1,0.1,'CoffeeTable','VerticalAlignment','bottom');
c = rectangle('position',[0.1, 0.1, 0.1, 0.1],'EdgeColor','r','ButtonDownFcn',@dragObject,'UserData',tmp);

set(gca,'XLim',[0,1],'YLim',[0,1])

	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;
			
			rectpos = get(dragging,'Position') + [posDiff(1:2) 0 0];
			set(dragging,'Position',rectpos);
			set(dragging.UserData,'Position',rectpos(1:3));
			dragging = [];
		end
	end
	function moveObject(hObject,eventdata)
		if ~isempty(dragging)
			newPos = get(gcf,'CurrentPoint');
			posDiff = newPos - orPos;
			orPos = newPos;
			
			rectpos = get(dragging,'Position') + [posDiff(1:2) 0 0];
			set(dragging,'Position',rectpos);
			set(dragging.UserData,'Position',rectpos(1:3));
		end
	end
end

[keith tan]

Hi, thx for the help, it works. I have one more question if it isnt pushing it. How do i make it so that you can rotate the rectangles.

[J. Alex Lee]

hmm, you ran the above code and it failed? what version of matlab are you running? i ran on 2020b.

By the way you have to grab the edge of the rectangles. I just confirmed that if you specify a FaceColor, you can grab anywhere in the rectangle.

[J. Alex Lee]

I think to do anything more sophisticated you will want to organize your box+labels into some class and treat the thing as an "app", which will draw on OOP concepts.

WIth rectangles I bet you can only rotate 90 degress at a time, which would amount to just inverting the height/width, but then you need to make decisions like which corner of the box wil be your reference point for positioning.

If you want general angles, look into patch() or fill() maybe