MATLAB Creating Graphical User Interfaces

8 Programming a GUIDE UI

Panel

Make the Panel Respond to Button Clicks

You can create a callback function that executes when the end user right-clicks or left-

clicks on the panel. If you are working in GUIDE, then right-click the panel in the layout

and select View Callbacks > ButtonDownFcn to create the callback function.

This code is an example of a ButtonDownFcn callback in GUIDE.

function uipanel1_ButtonDownFcn(hObject, eventdata, handles)

% hObject handle to uipanel1 (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

display('Mouse button was pressed');

When the end user clicks on the panel, this function displays the text, 'Mouse button

was pressed', in the Command Window.

Resize the Window and Panel

By default, GUIDE UIs cannot be resized, but you can override this behavior by selecting

Tools > GUI Options and setting Resize behavior to Proportional.

Programmatic UIs can be resized by default, and you can change this behavior by setting

the Resize property of the figure on or off.

When your UI is resizable, the position of components in the window adjust as the user

resizes it. If you have a panel in your UI, then the panel’s size will change with the

window’s size. Use the panel’s SizeChangedFcn callback to make your UI perform specific

tasks when the panel resizes.

This code is an example of a panel’s SizeChangedFcn callback in a GUIDE UI. When the

end user resizes the window, this function modifies the font size of static text inside the

panel.

function uipanel1_SizeChangedFcn(hObject, eventdata, handles)

% hObject handle to uipanel1 (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

set(hObject,'Units','Points')

panelSizePts = get(hObject,'Position');

panelHeight = panelSizePts(4);