GUI handles in classes problem

Hello,

I'm writing an OO gui program and I'm having issues trying to use the set() function to change GUI element properties. I'm simply trying to change a buttons enable property from off to on. I have attached abridged code showing the same problem below. My world is c++ programming and the way matlab handles classes etc feels rather strange so the problem might simply be caused by my misunderstanding of the system. Anyway, when I attempt to use the set() function on the handle AD.buttonExit, it works as expected when I execute the command in the initUI() function. If I try to do the same in a different function, it fails. I checked the stacks by simply printing the contens of AD. In the initUI function it clearly shows a handle value for buttonExit, it doesn't in the constructor function (or any other class-member-function). I feel like I'm making a elementary mistake, however I don't see it and I hope someone might be able to assist me.

Kind regards, Ruben Higler

code (abridged for clarity):

classdef test

      properties 
          AppUI;
          buttonExit;
      end

      methods 
          function AD = test()
              %draws UI
              AD.initUI(); 
              set(AD.buttonExit, 'Enable', 'on')
              AD.test2()
          end
          function initUI(AD)
              AD.AppUI = figure('Visible','off','Position',[520,321,695,482], 'MenuBar', 'none', 'Name', '3D Particle Tracking',...
                  'NumberTitle', 'off', 'Resize', 'off', 'Color', [0.94,0.94,0.94]);
              AD.buttonExit = uicontrol('Enable', 'off', 'Style', 'pushbutton', 'Visible', 'on', 'Position', [35,29,181,31], 'String', 'Exit');
              set(AD.AppUI, 'Visible', 'on');
              %1 set(AD.buttonExit, 'Enable', 'on')
          end
          function test2(AD)
              set(AD.buttonExit, 'Enable', 'on')
          end
      end
  end

Answer 1

[per isakson]

In Matlab the connection between "handle" in "Handle Graphic" and handle classes in the OO-system is that both are "references" to objects, however objects of quite different kinds.

In the Matlab OO-system there are value and handle classes. The former is immutable and the latter mutable.

Your class, test, need to inherit from handle to behave the way you expect. Change the first line of the code to

    classdef test < handle

[Jette]

Does this mean that all GUI-classes need to be handle classes? Do you know a documentation or tutorial dealing with GUIs using OOP?

[per isakson]

No.

No, however, these three FEX submissions are worth looking at.

A ScrollPanel object that can contain lightweight Handle Graphics objects.

An extension of the handle graphics set/get class HGSETGET.

ANIMATOR - animate data