Cell select callback on uitable

I have a uitable that I want to be able to select a cell with a mouse, and the value in that cell be put in an edit box. Under the CellSelectionCallback, I have the following code.

However, it attempts to run (and crash) when the contents of the uitable change. How can I only implement this when the mouse selects that cell?

function uitable1_CellSelectionCallback(hObject, eventdata, handles)
% hObject    handle to uitable1 (see GCBO)
% eventdata  structure with the following fields (see MATLAB.UI.CONTROL.TABLE)
%  Indices: row and column indices of the cell(s) currently selecteds
% handles    structure with handles and user data (see GUIDATA)

%handles=guidata(source);
handles.currentCell=eventdata.Indices;
guidata(gcf,handles);
handles=guidata(gcf);
Indices=handles.currentCell;
data=get(handles.uitable1,'Data');
data=data(Indices(1),Indices(2));
set(handles.editNum,'String', data);

[Geoff Hayes]

Jason - why is the code crashing? What is the error message? Put a breakpoint at the line

 handles.currentCell=eventdata.Indices;

and observe (i.e. step through the code to see) what happens when the contents of the eatable changes.

The crash could be related to eventdata.Indices being empty and so the calls to Indices(1) and Indices(2) produce the errors. Guard against this case by doing something like

 if ~isempty(eventdata.Indices)
    handles.currentCell=eventdata.Indices;
    guidata(hObject,handles);
    Indices=handles.currentCell;
    data=get(handles.uitable1,'Data');
    data=data(Indices(1),Indices(2));
    set(handles.editNum,'String', data);
 end

Note the call to handles=guidata(gcf); is unnecessary and so can be removed, and the switch from gcf to hObject (see the documentation of guidata to understand why this is possible).

[Jason]

Oh I see, I thought the function was more like on "onclick" callback. It seems once you have selected a cell it forever watches that for a change. As the function uses the idnex of the cell to refer back to the underlying "data" that was used, when it changes, there are occurances when this is empty and causes an error:

Attempted to access data(1,1); index out of bounds because size(data)=[0,0].

Error in OpenFile>uitable1_CellSelectionCallback (line 1282)
    data=data(Indices(1),Indices(2));

Is there a way to switch off this monitoring of the selected cell once it has updated the edit box ("editNum"). This will prevent all future errors??

[Geoff Hayes]

Given your error message, I don't understand why there is no data. Is it because you have deleted all elements from the table?

A problem with the code may be because the selected cell retains focus and so you may have to shift the focus to some other control, or just guard against the problem you are experiencing.

[Jason]

Thankyou Geoff, I've included another check before executing this:

if ~isempty(eventdata.Indices)&&~isempty(data)

[Geoff Hayes]

Cool, Jason. Consider making your solution (in the above comment) as an answer to your question.

Answer 1

[Jason]

Thankyou Geoff for the help, I've included another check before executing this:

if ~isempty(eventdata.Indices)&&~isempty(data)

if ~isempty(eventdata.Indices)
    handles.currentCell=eventdata.Indices;
    guidata(hObject,handles);
    Indices=handles.currentCell;
    data=get(handles.uitable1,'Data');
    data=data(Indices(1),Indices(2));
    set(handles.editNum,'String', data);
 end

[Julius Rinaldi Simanungkalit]

this method does work, but only to display one cell only. can you help me how to display one table row, by just clicking. Please help me :)