MATLAB: GUI: how to call callback function from keyboard using ‘windowkeypressfcn’

Question

Hi all,

I've pushbutton callback function as below:

function movefront_Callback(hObject, eventdata, handles)
handles.speed.String = num2str(str2double(handles.speed.String) +1);

And I would like to call this function from the keyboard, so I've this:

function figure1_WindowKeyPressFcn(hObject, eventdata, handles)
switch eventdata.Key
    case 'a'
        handles.speed.String = num2str(str2double(handles.speed.String) + 1);  
    case 'b'
        handles.speed.String = num2str(str2double(handles.speed.String) - 1);
end

The above code works but I called it directly from the handles structure. How do I call the callback function from the windowskeypress function?

e.g

switch eventdata.Key
      case 'a'
          @movefront_Callback(); %not working obviously

thanks in advance.

Answer 1

James - all you need to do is to just call the callback directly and ensure that you pass the correct inputs. Since your callback signature is

 function movefront_Callback(hObject, eventdata, handles)

then you need to pass the handle to the movefront control (this is hObject), the event data (which can be empty as it seems to be only valid for key presses and other events like that) and the handles structure. So your key press callback can become

 function figure1_WindowKeyPressFcn(hObject, eventdata, handles)
 switch eventdata.Key
    case 'a'
        movefront_Callback(handles.movefront, [], handles); 
    case 'b'
        moveback_Callback(handles.moveback, [], handles); 
 end

Try the above and see what happens!