Synchronize scroll bars of two uitables

Hello,

In a GUI, I created two (large) uitables. I need to synchronize scrollbars (horizontal and vertical), so when the user browses (scrolls down, up, left, right...) in one uitable, the view of the other uitable follows and keeps synchronized (same rows/columns are shown).

Is there a way to do that?

Thank you,

Antoine

Answer 1

[Walter Roberson]

There is no documented way to affect the scrolling of even one uitable.

You may be able to work at the Java level; see http://undocumentedmatlab.com/

[Antoine Luijkx]

Thanks Walter. Indeed, that's what I feared.

I built up some code based on the Java level (see below). However, I have visual bugs after uitable update and I have to refresh manually the uitables.

Moreover, it works well when navigating through uitables with mouse-clicking on scroll bars, but when I try to navigate with keyboard (right, left, page down, etc...), that becomes messy, because the selected cell goes from one uitable to the other one.

Finally, I have to use try/cach, because I receive some java errors (Exception in thread "AWT-EventQueue-0" java.util.ConcurrentModificationException)

Any thought on this?

function temp_to_delete()

figure(1);
tab1 = uitable('Parent',gcf,'Data',magic(400),'Units','normalized','Position',[.05 .2 .4 .4]);
tab2 = uitable('Parent',gcf,'Data',magic(400),'Units','normalized','Position',[.55 .2 .4 .4]);
jhEdit1 = findjobj(tab1);
jhEdit2 = findjobj(tab2);
set(jhEdit1,'AdjustmentValueChangedCallback',{@slider_callback});
set(jhEdit2,'AdjustmentValueChangedCallback',{@slider_callback});

function slider_callback(~,e)

      try        
          val=get(get(e,'Source'),'Value');
          if get(e,'Source')== get(jhEdit1,'HorizontalScrollBar')
              set(get(jhEdit2,'HorizontalScrollBar'),'Value',val);            
              set(tab2,'Visible','off');pause(0.01);set(tab2,'Visible','on');
          elseif get(e,'Source')== get(jhEdit1,'VerticalScrollBar')
              set(get(jhEdit2,'VerticalScrollBar'),'Value',val);
              set(tab2,'Visible','off');pause(0.01);set(tab2,'Visible','on');
          elseif get(e,'Source')== get(jhEdit2,'HorizontalScrollBar')
              set(get(jhEdit1,'HorizontalScrollBar'),'Value',val);
              set(tab1,'Visible','off');pause(0.01);set(tab1,'Visible','on');
          elseif get(e,'Source')== get(jhEdit2,'VerticalScrollBar')
              set(get(jhEdit1,'VerticalScrollBar'),'Value',val);
              set(tab1,'Visible','off');pause(0.01);set(tab1,'Visible','on');
          end
      catch
      end

end

end

Thanks again,

Antoine

Answer 2

[John Anderson]

Thanks for this answer, very useful. There may well be better ways of doing this now. However, to avoid having to play around with the visibility of the matlab uitable objects using the lines

set(tab1,'Visible','off');pause(0.01);set(tab1,'Visible','on');

you can simply invoke the repaint method of the javacomponent. This reduces the flicker and makes the operation run a little smoother.

jhEdit2.repaint
jhEdit1.repaint