When in the workspace I type e.g. “plot(” or “corrcoef(” and wait a second, I am presented with a context sensitive help showing a number of ways to use the “plot” or “corrcoef” functions. Where is this context sensitive help stored? I have tried to look at different functions to see how the help-section is written, and made a similar setup:

function testHelp(x,varargin)
% TESTHELP   See how context help is defined
%   TESTHELP(X)
%
%   TESTHELP(X,Y)

but it does not present me with a “similar” context sensitive help…

Cheers Henrik

You might already be aware of this and probably have a reason for not using it.
To check for version of MATLAB have you tried the verLessThan function?

if ~verLessThan('matlab','7.6')
    % Do something here that that works in newer version
else
    % Do something here that works in the older version
end

Regards .. Varun

For any newly-created object, simply pass this object through javaObjectEDT once to save you the trouble of using javaMethodEDT on each of its subsequent method invocations. As Matt noted in the article, javaObjectEDT’s overhead is slight and its benefits far outweigh the negligible performance penalty (on R2008b+, that is…).

AFAIK, set does not automatically use EDT if the object was not auto-delegated using javaObjectEDT. Note to set the callback on handle(jObject,’CallbackProperties’) rather than directly on the Java object jObject, in order to prevent a memory leak.

first thanks for all the code and insights you are sharing with us. I have to admit that you inspired me to use a lot of Java functionality in my GUIs. They are looking much better now;-) I was never much concerned with the threading problems in smaller GUIs.

But now I’ve rewrote a complete Matlab GUI with Java Swing and Netbeans and running into some serious threading trouble. With findjobj() I look for the java handles in Matlab and assign the existing Matlab functions as callbacks and change the elements content from Matlab.

I’m not sure if I understood the usage of javaObjectEDT correctly. If I could use javaObjectEDT to create the GUI from MATLAB, there would be no problems, occuring in the subsequent calls to the objects methods. But each time the return value is a new object I have to use javaMethodEDT?

Another question: Does the Matlab set() function dispatch all its calls automatically to the EDT? Should it be used if possible to change properties?

Thanks a lot for your time and keep up the great work. I don’t know what I would do without all your available examples and scripts.

Thanks a lot
Mark

if str2double(v(1:3)) > 7.6

problematic on the upcoming version 7.10?

classdef impoly_vertex < impoly
 
    properties (GetAccess = public, SetAccess = private)
        vertexCrossSize;
        vertexDotSize;
    end %properties
 
    methods
        function obj =  impoly_vertex(crossSize,dotSize,varargin)
            if nargin < 2
                error('impoly_vertex:InsufficientArguments','Both the cross and dot size must be passed as constructor arguments');
            end %if
            obj = obj@impoly(varargin{:});
            obj.parseSizeInputs(crossSize,dotSize);
            obj.setVertexSize;
        end %impoly_vertex
 
        function setVertexSize(obj)
            crossChildren = findobj(obj.h_group,'Type','line','Marker','+');
            dotChildren = findobj(obj.h_group,'Type','line','Marker','O');
            set(crossChildren,'MarkerSize',obj.vertexCrossSize);
            set(dotChildren,'MarkerSize',obj.vertexDotSize);
        end
 
        function setCrossSize(obj,cs)
            obj.parseSizeInputs(cs,obj.vertexDotSize);
            obj.setVertexSize;
        end %setCrossSize
 
        function setDotSize(obj,ds)
            obj.parseSizeInputs(obj.vertexCrossSize,ds);
            obj.setVertexSize;
        end %setCrossSize
    end
 
    methods (Access = protected)
        function parseSizeInputs(obj,cs,ds)
            validateattributes(cs,{'numeric'},{'scalar','nonnegative','real'});
            validateattributes(ds,{'numeric'},{'scalar','nonnegative','real'});
            obj.vertexCrossSize = cs;
            obj.vertexDotSize = ds;
        end %parseSizeInputs
    end %private Methods    
 
end %impoly_vertex

Here we let it draw the polygon then find the vertices and change the marker size of the lines that make them up. Usage as follows:

figure, imshow('gantrycrane.png');
%about half the regular vertex size
h = impoly_vertex(4.5,2.25,gca, [188,30; 189,142; 93,141; 13,41; 14,29]);
setColor(h,'yellow');
h.setVertexSize; %need to reset manually for this version
addNewPositionCallback(h,@(p) title(mat2str(p,3)));
fcn = makeConstrainToRectFcn('impoly',get(gca,'XLim'),...
get(gca,'YLim'));
setPositionConstraintFcn(h,fcn);

A couple more points:

I really try to avoid editing any of the supplied code as it becomes a maintenance headache when you change versions.

Also a useful detective tool is the metaclass class

So mc = ?impoly gives you all sorts of useful info to help design you subclass.

Hope this Helps
Matt W

Also see the following related CSSM threads here and here.

In your toolbox, try modifying TC.xml, with a graceful degradation in case this fails. Something like this:

try
   tabcomplete(...);
catch
   oldFname = fullfile(matlabroot, 'toolbox/local/TC.xml');
   newFname = fullfile(pwd,'TC.xml');
   msgbox(['Please ask your sysadmin to replace ' oldFname ' with ' newFname]);
end