MATLAB: How to detect a buttonup event on a uicontrol

button-upbuttonupMATLABmousereleaseuicontrolwindowbuttonupfcn

I would like to have an option so that I know when a uicontrol of style 'pushbutton' is pressed or released.

Best Answer

The ability to detect a buttonup event on a uicontrol is not available in MATLAB.

To work around this issue, you can use either of the following options:

1. Use a uicontrol of style 'togglebutton' instead of a push button and perform two different actions depending on the 'Value' property of the toggle button uicontrol. The following example shows the 'Callback' function for such a toggle button uicontrol:

function togglebutton1_Callback(hObject, eventdata, handles)
button_state = get(hObject,'Value');
if button_state == get(hObject,'Max')
      % toggle button is pressed, perform action1
elseif button_state == get(hObject,'Min')
      % toggle button is not pressed, perform action2
end

2. Alternatively, you can create a push button uicontrol with its 'Enable' property set to 'inactive'. Then, you can set the 'ButtonDownFcn' property on the uicontrol and the 'WindowButtonUpFcn' property on the parent figure. This can be done as shown in the example code below:

h = uicontrol('Style', 'pushbutton', 'String', 'My_pushbutton',...
      'Position', [20 150 100 70], 'Enable', 'inactive','ButtonDownFcn','disp(''The button is pressed'')');
set(gcf,'WindowButtonUpFcn','disp(''The button is released'')');

Note that the second approach will not work when the figure is in a mode that uses the ‘WindowButtonUpFcn’ property, like Zoom, Pan, etc.

Related Solutions

MATLAB: How to make a push button respond to clicking with the right mouse button

There are two properties which can be used in conjunction to accomplish this.

One is the button's 'ButtonDownFcn' callback function. This callback function executes when pressing a mouse button on or near a UICONTROL object -- including when pressing the right mouse button.

The other property is the figure's 'SelectionType' property. This property indicates which kind of click was registered in the figure window -- including clicks on controls within the figure.

Putting these two together, you can define a 'ButtonDownFcn' callback for a push button which checks the figure's 'SelectionType' property to detect a right-click. An example is shown below. (In that example, the ANCESTOR function is used to get the figure's handle. If this is being done in a GUIDE-created GUI, this is unnecessary as the 'handles' structure already provides access to the figure's handle.)

function test
      uicontrol('Style', 'pushbutton', ...
                'ButtonDownFcn', @myCallback);
end
function myCallback(src, evt)
      figHandle = ancestor(src, 'figure');
      clickType = get(figHandle, 'SelectionType');
      if strcmp(clickType, 'alt')
          disp('right click action goes here!');
      end
end

MATLAB: How to toggle: Making uicontrols (in)visible

% you've written 'Edit1' instead of 'handles.Edit1'

button_state = get(hObject,'Value');
if button_state == get(hObject,'Max')
set(handles.Edit1,'Visible','off')
elseif button_state == get(hObject,'Min')
set(handles.Edit1,'Visible','on')  
end

Best Answer

Related Solutions

MATLAB: How to make a push button respond to clicking with the right mouse button

MATLAB: How to toggle: Making uicontrols (in)visible

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