live updating edit field when slider value is changing - matlab

Question

I have a slider and a edit field, which are defined as
uicontrol(fig,'Style','Slider','Units','characters','Position',[17.1+f*iwidth 10.5 4 28.6],'Min',0,'Max',1000,'Value',500,'SliderStep', [1/500 , 10/500 ],'Callback','evaluation_callbacks(''results'',guidata(gcbo))','Tag',['slider' int2str(f)]);
uicontrol(fig,'Style','Edit','Enable','inactive','Units','characters','Position',[14+f*iwidth 8.2 9 1.6],'FontSize',10,'String',500,'Tag',['rating' int2str(f)]);
With the following Callback functions:
function evaluation_callbacks(varargin)
% EVALUATION_CALLBACKS Callback functions for the evaluation interface
%
% evaluation_callbacks(fname,varargin) executes the callback function
% fname_callback with various parameters
fname=[varargin{1},'_callback'];
feval(fname,varargin{2:end});
%%%saving the rating results and proceeding to the next experiment or exiting
function results_callback(handles)
% stop audio
clear sound
%getting the ratings for all files
for f=1:handles.nbfile
handles.ratings(handles.expe_order(handles.expe),handles.file_order(f))=get(getfield(handles,['slider' int2str(f)]),'Value');
end
%saving the whole results (to avoid losing data if the program terminates early)
results='';
fid=fopen(handles.resultfile,'w');
for e=1:handles.nbexpe
for f=1:handles.nbfile
fprintf(fid,'%d\n',handles.ratings(e,f));
end
end
fclose(fid);
if handles.expe<handles.nbexpe
handles.expe=handles.expe+1;
% updating title
set(handles.experiment,'String',handles.parameter{handles.expe});
% update evaluation parameters
set(handles.scale90,'String',handles.high{handles.expe});
set(handles.scale10,'String',handles.low{handles.expe});
if handles.expe==handles.nbexpe
pos=get(handles.results,'Position');
pos(1)=pos(1)+2.5;
pos(3)=19;
set(handles.results,'Position',pos,'String','Save and exit');
end
%moving all the sliders back to 50
for f=1:handles.nbfile
shandle=getfield(handles,['slider' int2str(f)]);
set(shandle,'Value',500);
rhandle=getfield(handles,['rating' int2str(f)]);
set(rhandle,'String',500);
end
%randomizing the order of the tested files for the next experiment
handles.file_order=randperm(handles.nbfile);
%testing whether a break is needed before the next experiment
if etime(clock,handles.time) > 20*60
wfig=warndlg(['You have been working for ' int2str(round(etime(clock,handles.time)/60)) 'minutes. It is recommended that you take a break of at least the same duration before starting the next experiment. Click on OK when you are ready.'],'Warning');
uiwait(wfig);
end
handles.time=clock;
% Start next audio sample
play_callback(handles,1)
guidata(gcbf,handles);
else
%exiting
close(gcbf);
end
%%%rounding and displaying the values of the sliders
function slider_callback(handles,f)
shandle=getfield(handles,['slider' int2str(f)]);
set(shandle,'Value',round(get(shandle,'Value')));
rhandle=getfield(handles,['rating' int2str(f)]);
set(rhandle,'String',get(shandle,'Value'));
As it is right now, the edit field value are not live updated if. The value of the edit field are only updated if the slider is moved and the mouse button is released.
I have tried to add a listener to the slider, but I cannot make it work. So far I have followed the following guides/posts without any luck.
http://undocumentedmatlab.com/blog/continuous-slider-callback
and
https://se.mathworks.com/matlabcentral/answers/140706-use-slider-for-live-updating-of-threshold-on-2d-contour-plot
Can anybody help?

Answer 1

Add a listener in the myGUI_OpeningFcn. Note you need to change myGUI to match your GUI script filename.
addlistener(handles.slider1,'ContinuousValueChange',#(hObject,eventdata)myGUI('updateText',hObject,eventdata,guidata(hObject)));
Then, add the following function in your GUI script.
function updateText(hObject, eventdata, handles)
set(handles.text2,'String',get(hObject,'Value'));
guidata(hObject,handles);
More specifically, in your case, you need to add a bunch of listeners:
for i=1:handles.nbfile
addlistener(getfield(handles,['slider' int2str(i)]),'ContinuousValueChange',#(hObject,eventdata)myGUI('updateText',hObject,eventdata,guidata(hObject)));
end
Then add:
function updateText(hObject, eventdata, handles)
f = hObject.Tag(7:end);
set(getfield(handles,['rating' f]),'String',get(hObject,'Value'));
guidata(hObject,handles);
Update
In your GUI script, add listeners in the OpeningFcn (which is the second function automatically generated by Matlab when your GUI was created):
for i=1:handles.nbfile
addlistener(getfield(handles,['slider' int2str(i)]),'ContinuousValueChange',#(hObject,eventdata)myCallBackFileName('updateText',hObject,eventdata,guidata(hObject)));
You will need to change myCallBackFileName to match the filename of your callback script. Then add the updateText function.