Output class object inherits the property/value pairs of a figure

I am trying to write a simple class. The purpose of the class is to create a figure. What I do is:

classdef myFig < handle
        properties
            Parent
        end
    methods
        function obj = myFig
            obj.Parent = figure;
        end
    end
end

My question is:

What should I do, in order any object that belongs to myFig class inherits the properties of the figure?

Ultimately, I would like to call a get method and view all the property/value pairs of the figure created.

Thank you

Answer 1

[Sean de Wolski]

Giorgos, rather than writing a figure class, write two classes for the vertical and horizontal scrollbars. Then add them to the figures as you need them. I have a bunch of utilities like this that I call my "Components"

For example:

figure
ColorPanel('Units','normalized','Position',[0 0 1 0.3], 'Color1',[1 0 0], 'Color2',[0 0 1])

The ColorPanel class is attached.

Answer 2

[Guillaume]

Assuming 2014b, as figure is not a class in earlier version:

For class A to inherit the properties of class B, class A has to derive from class B. Hence if you want to inherit the properties of the figure class (aka matlab.ui.Figure), myFig needs to derive from it:

classdef myFig < matlab.ui.Figure

Unfortunately for you, matlab.ui.Figure is sealed, which means you're not allowed to derive from it. So no inheritance for you.

What you'll have to do then, is hold the figure as a member variable and recreate all the properties of the figure:

classdef myFig < handle 
    properties (Access = private)
        hfig
    end

      properties (Dependent)
          Position;
          %... and so on for all the properties of figure
      end

      methods
          function this = myFig(hfig)
              validateattributes(hfig, {'matlab.ui.Figure'}, {'scalar'});
              this.hfig = hfig;
          end

          function varargout = get.Position(this)
              varargout{:} = this.hfig.Position;            
          end

          %... and so on for all the properties of figure
      end
  end

It's going to be tedious...

The last option is to override subsref in your class and implement some sort of dynamic properties. That is probably even more work and overriding subsref has some nasty side effects.

[Giorgos Papakonstantinou]

Thank you very much Guillaume. I can imagine that this has a lot of work. The reason why I would like to do something like this, is because I often write a big GUI which has a vertical and a horizontal slider that helps me to navigate through it (something like Auto scroll GUI of FEX). Additionally, I am using a WindowScrollWheelFcn which also helps to navigate through the GUI.

So I thought maybe I write a class which "enhances" the default figure of Matlab. However, still inherits all its properties.

All these because I find it very tedious to write lengthy ResizeFcn which serve the same purpose.

Is there any other hint or practice that I can follow to implement what I have just described?

[Guillaume]

Actually, I didn't think that the dynamicprop class allowed you to create dependent dynamic properties, but it does. That makes it much easier to implement the myFig class:

classdef myFig < dynamicprops 
    properties (Access = private)
        hfig
    end

    methods
        function this = myFig(hfig)
            validateattributes(hfig, {'matlab.ui.Figure'}, {'scalar'});
            this.hfig = hfig;
            %create all the figure properties as dependent dynamic properties:
            for propname = properties(hfig)'
                metaprop = addprop(this, propname{1});
                metaprop.Dependent = true;
                metaprop.SetMethod = @(this, varargin) SetDispatch(this, propname{1}, varargin{:});
                metaprop.GetMethod = @(this) GetDispatch(this, propname{1});
            end
        end        
    end

    methods (Access = private)
        function SetDispatch(this, propname, varargin)
            %called whenever a dependent dynamic property is set.
            %just dispatch to the figure property
            this.hfig.(propname) = varargin{:};
        end

        function varargout = GetDispatch(this, propname)
            %called whenever a dependent dynamic property is read.
            %just dispatch to the figure property
            varargout{:} = this.hfig.(propname);
        end
    end
end

Still not as neat as inheriting from the class itself but not too bad.

[Guillaume]

Note that as written, it only dispatches to non-hidden properties of the figure class. If you wanted to also access the hidden properties (if any exists), you would have to use a meta.properties object on the class to get them.

At the same time, this would allow you to check for read-only properties.

Doing so is left as an exercise to the reader...