background of editable cells UITABLE
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Hi !
I created an uitable with guide and I would like to change the background of editable cells.
I tried to use the HTML code with the method https://www.mathworks.com/matlabcentral/answers/25038-how-to-change-each-cell-color-in-a-uitable , it works for the background, but I can't change the value of my cell anymore.
Any ideas ?
12 Comments
Adam Danz
on 29 Jul 2019
Check the "ColumnEditable" property values.
Reeny
on 29 Jul 2019
Adam Danz
on 29 Jul 2019
So the ColumnEditable property has changed and you didn't make that change?
Reeny
on 29 Jul 2019
My bet is that "data" is empty
data = {};
data{1,1}
% ERROR: Index in position 1 exceeds array bounds. (r2019a)
Reeny
on 29 Jul 2019
Reeny
on 29 Jul 2019
Have you verified that 'data' isn't empty? One way of doing that is to put a break at the 3rd line within the conditional (at data{1,1}...) and to see the value of 'data' when the code gets to the break.
Another way of doing that is by printing out the value of 'data' just before that line.
if column == 1
colergen = @(color, text) ['<html><table border=0 width=400 bgcolor=',color,'><TR><TD>',text,'</TD></TR></table></html>'];
data = getappdata(handles.uitable1, 'data')
data %will print to command window
data{1,1} = colergen('#33ffff',(data{1,1}))
set(handles.uitable1, 'data', data);
end
If your error message is "Index exceeds the number of array elements (0)." and that error is comming from the line data{1,1} = colergen..., then either "data" is empty or something's going wrong in your colergen() function.
Reeny
on 29 Jul 2019
Adam Danz
on 29 Jul 2019
Something's not lining up, could you show the full copy-pasted error message?
From the partial error message you shared, it looks like the error is happening on row=eventdata.... but that line is before the set(handles...) line so that doesn't make sense.
Reeny
on 29 Jul 2019
Adam Danz
on 29 Jul 2019
Bingo! See answer. Let me know how that turns out.
Accepted Answer
[Continued from comments section under the question]
Summary of the problem
"when the [callback function] is over, the first line is executes once again. I don't understand why."
This is an unfortunate, known problem in GUIDE GUIs. The 2nd invocation of the callback function is the result of changing the object focus which is inevitable.
Solution
To get around this, at the top of your callback function write a conditional that escapes the callback function if the indices are empty.
if isempty(eventdata.Indices)
return
end
15 Comments
Reeny
on 29 Jul 2019
Adam Danz
on 29 Jul 2019
Glad we got there!
Reeny
on 30 Jul 2019
Adam Danz
on 30 Jul 2019
This will be difficult to trouble shoot without being able to working with the code that produces the problem. Could you make a small block of code that I can run independently that produces the problem? If you can, also let me know the version of matlab you're running.
I created my uitable with GUIDE, with the parameters you can see in the following picture. 
My code is the following :
function Table_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 Table (see VARARGIN)
% Choose default command line output for Table
handles.output = hObject;
data = {'1', false; '2', false; '3', false; '4', false};
setappdata(handles.uitable1, 'data', data);
set(handles.uitable1, 'data', data);
% Update handles structure
guidata(hObject, handles);
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)
if isempty(eventdata.Indices)
return
end
row = eventdata.Indices(1)
column = eventdata.Indices(2)
setappdata(handles.uitable1, 'row', row);
setappdata(handles.uitable1, 'column', column);
if column == 1
colergen = @(color, text) ['<html><table border=0 width=400 bgcolor=',color,'><TR><TD>',text,'</TD></TR></table></html>'];
data = getappdata(handles.uitable1, 'data')
data{1,1} = colergen('#33ffff',(data{1,1}))
set(handles.uitable1, 'data', data);
end
My version of Matlab is R2018b.
Adam Danz
on 30 Jul 2019
I don't know what Table_OpeningFcn() is or what how it plays a role in your GUI.
When I created a quick, fake GUI with a UI table and ran your uitable1_CellSelectionCallback() function, I also could not edit the cells. However, when I set the ColumnEditable values to true, I could edit them.
handles.uitable1.ColumnEditable = [true,true]; %one for each column
Reeny
on 31 Jul 2019
Adam Danz
on 31 Jul 2019
Could you attach the GUI with instructions how to recreat the problem? The m file and figure are needed.
Reeny
on 31 Jul 2019
Adam Danz
on 31 Jul 2019
You m file contains the following Cell Selection function
function uitable1_CellSelectionCallback(hObject, eventdata, handles)
However, when I open you GUI in GUIDE and look at the table properties, I see that you've assigned a different Cell Selection function
@(hObject,eventdata)Test('uitable1_CellSelectionCallback',hObject,eventdata,guidata(hObject))
And you've also assigned at Cell Edit function that doesn't appear in the m file
@(hObject,eventdata)Test('uitable1_CellEditCallback',hObject,eventdata,guidata(hObject))
If "Test()" is the correct function, then those should be included in the m file.
Adam Danz
on 1 Aug 2019
Ok, this version of your code makes more sense.
Good news. I have a final answer on the issue.
Bad news. You can't have your cake and eat it too. The HTML code interferes with the ColumnEditable property within the CellSelection callback function. The explanation is a bit long so I'll break it down into parts.
- Just a side-note. When you replace the simple string with HTML code, the entire code becomes the text for that UITable cell (see code [1] below). If another section in your GUI reads the UITable, it will not read "2" in cell (2,1). It will read the long html string instead. This is a common problem.
- The CellSelection callback function is invoked every time you select a cell before you have a chance to change anything. If you move your code from the CellSelection callback function into a CellEditCallback function (first you'll need to add one from GUIDE), then you'll have the chance to edit the cell before the html comes into effect. Pro: Now you can edit the cell. Con1: the cell won't be highlighted until after you're done editing. Con2: When you select the cell to make a change, the simple string you see (ie, "2") will become the full html string shown in code [1] below. Con3: See point #1 above.
- If you decide to try out point #2 above, you'll need to change a line of your code. Currently you're not reading the current UI table. You're reading whatever was stored in "setappdata" previously. I'm not sure why you're using this approach when the first input to any callback function is the handle to the object you're manipulating. To fix that, make the change shown in code [2] below.
% [1] After selecting cell (2,1)
data =
4×2 cell array
{'1' } {[0]}
{'<html><table border=0 width=400 bgcolor=#33ffff><TR><TD>2<…'} {[0]}
{'3' } {[0]}
{'4' } {[0]}
% [2] correctly grab the current table data
data = getappdata(handles.uitable1, 'data') % INCORRECT
data = hObject.Data; % CORRECT
Recommendations
I recommend you abandon this approach alltogether. Mixing HTML with important text might look pretty but it's a nightmare to work with. If you need to highlight the most recently edited row, you could a 3rd column to your UItable that is not editable and contains no text. The purpose of this column would only be to implement the HTML colors on the row most recently edited (or whatever other rule you'd like to use).
Reeny
on 1 Aug 2019
Adam Danz
on 1 Aug 2019
Nice work! In your HTML version, you were changing the color of single cells. BackgroundColor property changes the color of the entire row. If this is what you want to do it's definitly a better choice than HTML. Thanks for providng the additional answer!
Reeny
on 1 Aug 2019
More Answers (1)
Reeny
on 1 Aug 2019
Edited: madhan ravi
on 1 Aug 2019
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