MATLAB: How to implement singleton behavior for a programmtically created GUI

MATLAB

I am creating a GUI programmatically. However I require the singleton GUI behavior for my project. (i.e. if the user tries to run a second instance of my program it only brings the current singleton into focus and does not destroy any objects).

Best Answer

The singleton behavior can be implemented by querying for the tag of the GUI under the root object. If the GUI has been launched , the GUI will be a child of the root object. If the GUI has not been launched, it will not be found and the GUI can be launched.

The following code demonstrates this

function my_gui()
%Search if the figure exists
h = findall(0,'tag','my_gui');
if (isempty(h))
      %Launch the figure
      figHandle = figure('tag','my_gui');
      plot(rand(4,4));
      set(figHandle,'handlevisibility','callback');
else
      %Figure exists so bring Figure to the focus
      figure(h);
end;

Related Solutions

MATLAB: Does the execution of the callback function cause another figure to be opened instead of acting on the GUI in MATLAB

This can occur if you are using GCF in your callback function. GCF is a convenience function that returns the handle of the root object's "CurrentFigure" property. This property can only hold a figure whose handle is visible, i.e. the HandleVisibility is "on" (or "callback" while a callback is executing). If the figure's "HandleVisibility" is "off", then its handle will not be stored in the root object's "CurrentFigure" property. In this case, GCF will return either another figure (whose "HandleVisibility" is "on") or a new figure (if there are no figures with the appropriate "HandleVisibility" value).

Instead of GCF, you should use either GCBF, or the handle of the figure from the "handles" structure. GCBF will return the handle of the figure that contains the current callback object, i.e. the last object interacted with. The "handles" structure should contain the handle for the figure automatically, unless its Tag was modified and can not be used as a fieldname.

For instructions on plotting into axes in your GUI, see the Related Solution listed below:

MATLAB: Making structure arrays programmtically.

If you have the stats TB you can import a file directly as a dataset object.

It is very convenient and easy to use.

EDIT

I have created the following xlsx file:

Now to create programmatically the structure (independently on the number of columns):

[data,text] = xlsread('test.xlsx');
In = [text;num2cell(data,1)];
S  = struct(In{:});

Or if you want a non-scalar structure create first In as:

In = [text;num2cell(num2cell(data),1)];

Best Answer

Related Solutions

MATLAB: Does the execution of the callback function cause another figure to be opened instead of acting on the GUI in MATLAB

MATLAB: Making structure arrays programmtically.

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