Get a GUI to update while a loop is running
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I have a GUI with a "Run" button that runs a filter on a continuous stream of images. The "Run" button callback function is "interruptible" = "on" and the "BusyAction" is "queue". I then adjust a slider which adjusts the filter that the "Run" loop is using and updates the GuiData handles variable. The problem is that the filter update is not recognised, until I stop the "Run" loop, and repress the "Run" button. Does anyone know how to get a running loop to use the latest version of a variable in the GuiData handles structure?
For example, the Run Function
function run_pushbutton_Callback(hObject, eventdata, handles)
if get(handles.run_pushbutton,'UserData')==1, return; end
set(handles.run_pushbutton,'UserData',1);
while (get(handles.run_pushbutton,'UserData') ~= 0)
% Increment the image number
handles.curImgNum = handles.curImgNum + 1;
guidata(hObject,handles); % Save the data
tempFiltWgt = handles.temporalFiltWeight/100
% Run the filter weight on the images...
% ...
end
Stop Function
function stop_pushbutton_Callback(hObject, eventdata, handles)
disp('STOP pressed.')
set(handles.run_pushbutton,'UserData',0);
Slider Function
function temporal_slider_Callback(hObject, eventdata, handles)
%obtains the slider value from the slider component
handles.temporalFiltWeight = get(handles.temporal_slider,'Value');
% Update handles structure
guidata(hObject, handles);
I have taken out all of the non-essentials to make the code clear. I am constantly updating the GuiData handles structure to try to keep everything up to date, but it won't seem to be updated in a function that has been interrupted. Is there any solution?
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采纳的回答
Teja Muppirala
2011-3-31
Instead of having this
%obtains the slider value from the slider component
handles.temporalFiltWeight = get(handles.temporal_slider,'Value');
in the slider callback, you could put this code as the first line inside the while loop in the run_pushbutton callback. Would that work?
更多回答(2 个)
Titus Edelhofer
2011-3-31
Try to put a drawnow into the loop to allow the event queue to be processed.
Titus
3 个评论
Lance Darragh
2018-4-20
I had a similar issue as in this post. Adding the drawnow command as the second line (the first being the one suggested as the original solution) fixed the problem, both were needed. Neither one by itself fixed the problem. Thank you all for your suggestions. By the way, it doesn't hurt to keep the statement in the slider callback function as well, in case it is needed outside of this while loop.
Robert Cumming
2011-3-31
As well as the drawnow command you could try putting a pause (0.1) in - this can help refresh graphics in the queue.
2 个评论
Jan
2011-3-31
Some Java updates are performed after PAUSE(0.02) only, e.g. to get the contents of UICONTROLs by GETFRAME. But in the OP's problem 0.1 sec would mean a remarkable slowdown, so I'd prefer DRAWNOW.
Robert Cumming
2011-3-31
To be honest I didn't examine the OP code, only the general problem - and my answer was to complement the drawnow if it didn;t do it (for whatever reason), and do agree that it could cause a slow down if called a lot!
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