MATLAB Answers

Walter Roberson

controlling background color of selected uicontrol popup?

Asked by Walter Roberson
on 28 Jan 2011

I can create a uicontrol('Style','popup') with a 'backgroundcolor'. This works and the color is the one I chose. However, as soon as I select any value, the background color goes to a grayish, with the text in the foreground color I have set. The selected pop-up entry does not use the background color.

Is there a way to control the background color of a selected pop-up entry?

(I am trying to color-code my uicontrols according to the major class of functionality they have within the terms of my program. Although I could in theory do so just by adjusting their text foreground colors, the area of the text compared to the area of the control is relatively small and the color coding of the text is not nearly as distinguishable as color coding the background.)


Dang. Jan's technique worked for popups, but not for a list box. I had to force it to unrender (by setting max to 1 on a multivalued list) and rerender. That emits a warning each time, so I don't want to handle things that way. Oh yes, changing the box size massively wasn't enough of a re-rendering!

Jan Simon
on 15 Feb 2011

Does REFRESH(FigHandle) help?

Alas, refresh() doesn't do a thing. It doesn't even cause the figure to flash momentarily if I'm stepping in debug mode.

2 Answers

Jan Simon
Answer by Jan Simon
on 28 Jan 2011
Edited by Jan Simon
on 30 Jan 2013
 Accepted answer

The selected pop-up gets the different color as long as the UICONTROL has the focus. Although Matlab's documentation claims that "figure(gcf)" gives the focus to the figure, this does not work from at least Matlab 5.3 to 2009a. Therefore I usually insert a call to a function named "FocusToFig" in the UICONTROL's callback function:

function FocusToFig(ObjH, EventData)  %#ok<INUSD>
% Move focus to figure
% FocusToFig(ObjH, [DummyEventData])
%   ObjH: Handle of a graphics object. It is tried to move the focus to the
%         parent figure and making it the CurrentFigure of the root object.
%   DummyEventData: The 2nd input is optional and ignored.
% Tested: Matlab 6.5, 7.7, 7.8, WinXP
% Author: Jan Simon, Heidelberg, (C) 2009-2011
if any(ishandle(ObjH))   % Catch no handle and empty ObjH
   FigH = ancestor(ObjH, 'figure');
   if strcmpi(get(ObjH, 'Type'), 'uicontrol')
      set(ObjH, 'enable', 'off');
      set(ObjH, 'enable', 'on');
     % Methods according to the documentation (does not move the focus for
     % keyboard events under Matlab 5.3, 6.5, 2008b, 2009a):
     set(0, 'CurrentFigure', FigH);

This moves the keyboard focus also to the figure, such that the KeyPressFcn is called again.


The grayish color is retained even when focus moves elsewhere. A uicontrol popup that has focus has a single-pixel rectangle of color drawn around the outside of it (it looks orange-y at least with the controls I tested on.)

Jan Simon
on 29 Jan 2011

The main task of my function for your purpose is not to move the focus, but to disable the UICONTROL temporarily, what forces a redraw.
Because the moving of the focus does not work correctly under Windows for 10 years, I expect there could be corresponding problems for a Ubuntu64 server displayed to a Linux32 client...

Answer by Matt Fig
on 28 Jan 2011

Things seem to work here as you wish, unless I misunderstand you.

uicontrol('Style','popup','backgroundcol',[.9 .7 .3],'string',{'P';'Y';'F'})

This creates a popupmenu with an orange-ish bgc. After I select any of the three strings, the bgc is the same.



(We need a commented editor!)

Aggh. We need a *comment* editor!

Jan Simon
on 29 Jan 2011

Fine. Is your problem solved then?

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