MATLAB Creating Graphical User Interfaces

9 Examples of GUIDE UIs

UI was saved. For more information on setting tags, see “Identify the Axes” on page 9- 23

in the previous example.

The handles.Strings data is used in the spinstopbutton_Callback function,

which includes the following code for changing the label of the button:

str = get(hObject,'String');

state = find(strcmp(str,handles.Strings));

set(hObject,'String',handles.Strings{3-state});

The find function returns the index of the string that matches the button's current

label. The call to set switches the label to the alternative string. If state is 1 , 3-state

sets it to 2. If state is 2 , it sets it to 1.

Interrupt the Spin Callback

If you click the Spin/Stop button when its label is Stop, its callback is looping through

code that updates the display by advancing the rotation of the surface objects. The

spinstopbutton_Callback contains code that listens to such events, but it does not

use the events structure to accomplish this. Instead, it uses this piece of code to exit the

display loop:

if find(strcmp(get(hObject,'String'),handles.Strings)) == 1

handles.azimuth = az;

guidata(hObject,handles);

break

end

Entering this block of code while spinning the view exits the while loop to stop the

animation. First, however, it saves the current azimuth of rotation for initializing the

next spin. (The handles structure can store any variable, not just handles.) If you click

the (now) Spin button, the animation resumes at the place where it halted, using the

cached azimuth value.

When you click Quit, the UI destroys the figure, exiting immediately. To avoid errors due

to quitting while the animation is running, the while loop must know whether the axes

object still exists:

while ishandle(handles.axes1)

% plotting code

...

end

You can write the spinstopbutton_Callback function without a while loop, which

avoids you having to test that the figure still exists. You can, for example, create a timer