GUI flickers when customly resized

When I select the checkbox "Show stats" the GUI is resized w/o any flicker, whereas selecting "Show buttons" causes the GUI to flicker due to the custom resize. How can I eliminate the flicker?

Run the following example GUI (any other best-practice advises are really welcome):

function example

% Figure Window
S.fh = figure('Units','pixels','Pos',[600 500 370 225],...
              'Menubar','none','Resize','off');

% Uipanel for buttons
S.upB = uipanel('Title','Show buttons','Units','pixels','Pos',[10 90 351 65]);
% Buttons check box
S.cbB = setdiff(findall(S.upB),S.upB);
        set(S.cbB,'Style','checkbox','Parent',S.fh,'Visible','on',...
            'Value',1,'Pos',[20 148 90 15],'Callback',{@cb_call,S.upB});

% Uipanel for stats
S.upS = uipanel('Title','Show stats','Units','pixels','Pos',[10 10 351 65]);
% Stats check box
S.cbS = setdiff(findall(S.upS),S.upS);
        set(S.cbS,'Style','checkbox','Parent',S.fh,'Visible','on',...
            'Value',1,'Pos',[20 68 90 15],'Callback',{@cb_call,S.upS});

% textbox
S.txDisp  = uicontrol('Style','text','Pos',[10 170 200 55]);
S.txComp  = uicontrol('Style','text','Pos',[225 178 115 33]); 

% cb_call -----------------------------------------------------------------
    function cb_call(varargin)
        if get(varargin{1},'Value')
            resizeFig(get(varargin{3},'Pos') - 5,...
                      unique([varargin{1},S.cbB]),S.upB,S.txComp,S.txDisp,S.fh)
            set(varargin{3},'Visible','on');
        else
            set(varargin{3},'Visible','off');
            resizeFig(-get(varargin{3},'Pos') + 5,...
                      unique([varargin{1},S.cbB]),S.upB,S.txComp,S.txDisp,S.fh)
        end

          setFocusFig(varargin{1})
      end
% resizeFig ---------------------------------------------------------------
    function resizeFig(height,varargin)
    set(varargin{end},'Pos', get(varargin{end},'Pos') + [0 -height(end) 0 height(end)])
        for h = [varargin{1:end-1}]
            set(h,'Pos', get(h,'Pos') + [0 height(end) 0 0])
        end
    end

% setFocusFig -------------------------------------------------------------
    function setFocusFig(hObject)
        % Workaround to set focus to figure
        set(hObject, 'Enable', 'off');
        drawnow;
        set(hObject, 'Enable', 'on'); 
    end

end

Answer 1

[Matt Fig]

I think your approach looks like what I have done in the past. I tried to do a couple of things which I think might make a slight difference in speed, but perhaps not. (Some things I changed just to help me understand the code.)

One thing I did notice was this setFocusFig function. When I comment out the call to that, the GUI does seem to resize smoother. I wonder what the purpose of this function is? The only thing that I can see it doing is making the callback object lose focus after the resize. Anyway, I doubt this will help, but give it a try. It is difficult for me to do much without seeing the flickering that you are.

function S = example3()

% Figure Window
S.fh = figure('Units','pixels','Pos',[600 500 370 225],...
              'Menubar','none','Resize','off');

% Uipanel for buttons
S.upB = uipanel('Title','Show buttons','Units','pixels','Pos',[10 90 351 65]);

% Buttons check box
S.cbB = findall(S.upB,'style','text');
set(S.cbB,'Style','checkbox','Parent',S.fh,'Visible','on','userd',S.upB,...
            'Value',1,'Pos',[20 148 90 15],'Callback',{@cb_call});

% Uipanel for stats
S.upS = uipanel('Title','Show stats','Units','pixels','Pos',[10 10 351 65]);
% Stats check box
S.cbS = findall(S.upS,'style','text');
set(S.cbS,'Style','checkbox','Parent',S.fh,'Visible','on','userd',S.upS,...
            'Value',1,'Pos',[20 68 90 15],'Callback',{@cb_call});

% textbox
S.txDisp  = uicontrol('Style','text','Pos',[10 170 200 55]);
S.txComp  = uicontrol('Style','text','Pos',[225 178 115 33]); 

% cb_call -----------------------------------------------------------------
    function cb_call(varargin)
        H = varargin{1};
        P = get(H,'userd');  % The uipanel it is connected to.
        if get(H,'Value')
            resizeFig(get(P,'Pos') - 5,H,S.cbB,S.upB,S.txComp,S.txDisp)
            set(P,'Visible','on');
        else
            resizeFig(5 - get(P,'Pos'),H,S.cbB,S.upB,S.txComp,S.txDisp)
            set(P,'Visible','off');            
        end
%           setFocusFig(H)  % What is this for??
      end

% resizeFig ---------------------------------------------------------------
    function resizeFig(varargin)
        H = varargin{1}(4);
        set(S.fh,'Pos', get(S.fh,'Pos') + [0 -H 0 H])
        for h = unique([varargin{2:end}])
            set(h,'Pos', get(h,'Pos') + [0 H 0 0])
        end
    end

% setFocusFig -------------------------------------------------------------
    function setFocusFig(hObject)
        % Workaround to set focus to figure
        set(hObject, 'Enable', 'off');
        drawnow;
        set(hObject, 'Enable', 'on'); 
    end
end

[Oleg Komarov]

I appreciate the effort, unfortunately it still resizes with the same flickering.

The GUI is a countdown clock with pushbuttons and KeyPressFcn. I want to be able to start and stop teh clock with the spacebar even after the check/uncheck of the panels. The only way I found is the setFocusFig method...

Answer 2

[Matt Fig]

No flicker here. What renderer are you using? I am using painters.

[Oleg Komarov]

Painters as well. How would you approach the resizing?