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Jim
Jim

Reputation: 5960

Matlab GUI Callback Start and Completion

Is there a general purpose way to determine when a Matlab GUI callback function begins and then has returned to the dispatcher?

I want to lock out user interaction while callbacks are running to completion and also show busy status while callbacks are running. Is there a dispatcher accessible where I can insert this code, or do I have to put it into every callback function.

I am aware of the modal waitbar but I want to avoid using that as much as possible. (They can't be killed gracefully.)

Upvotes: 0

Views: 182

Answers (2)

Rotem
Rotem

Reputation: 32084

I suggest to add a wrapper function, that wraps all original UIControl callback functions.
The wrapper function does the following:

  • Locks (disables) all GUI UIControl objects.
  • Executes original callback function.
  • Enables all GUI UIControl after original callback returns.

You can also start a timer before original callback, and stop the timer when callback returns (the timer can simulate a wait bar using an image built int to the main GUI [image inside a small axes]).

Example (assuming GUI was created using guide tool): 

% --- Executes just before untitled1 is made visible.
function untitled1_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to untitled1 (see VARARGIN)

% Choose default command line output for untitled1
handles.output = hObject;

%Add wrapper function to each UIControl callback.
A = findall(hObject.Parent, 'Type', 'UIControl');
for i = 1:length(A)
    set(A(i), 'Callback', {@wrapper, A(i).Callback});
end

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes untitled1 wait for user response (see UIRESUME)
% uiwait(handles.figure1);


function wrapper(ObjH, EventData, origCallback)
disp('Do somthing before callback begins...');
%You can also start a timer.

%Disable all UIControl objects, before executing original callback
A = findall(ObjH.Parent, 'Type', 'UIControl');
for i = 1:length(A)
    set(A(i), 'Enable', 'off');
end

%Execute original callback.
feval(origCallback, ObjH, EventData);

disp('Do somthing after callback ends...');
%You can also stop the timer.

%Enable all UIControl objects, after executing original callback
for i = 1:length(A)
    set(A(i), 'Enable', 'on');
end


% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
pause(1);
set(handles.pushbutton1, 'BackgroundColor', [rand(1,1), rand(1,1), rand(1,1)]);

Upvotes: 1

Tasos Papastylianou
Tasos Papastylianou

Reputation: 22215

You can generally lock user interaction with the waitfor command. It is designed to do exactly what you ask.

You can make your callback function update a handle property when it's finished, which can cause waitfor to exit. If that handle property you're updating also happens to hold the result of a tic / toc operation timing the duration of your callback function, then you kill two birds with one stone :)

Upvotes: 0

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