Code checking error in App Designer, it thinks xxxx.BackgroundColor is a scalar
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I'm changing the background color to alert the user about various (async) conditions and button pressed.
if app.STOPTRIALSButton.BackgroundColor == [0.95 0.33 0.10]
app.STOPTRIALSButton.BackgroundColor = [0 1 0];
end
and I get the warning:
Unexpected use of '[' in a scalar context.
but of course colors are RGB three values, so the code runs fine.
Also while the Component browser shows (another) color as 0.65, 0.65, 0.65 that's the wrong syntax (no commas please for easier cut and paste) and in the startup code the values are actually [0.651 0.651 0.651] so my compare failed without significant research as to why.
Finally, App Designer isn't listed as a product below, so I can't flag that. Just saying MATLAB is the product.
0 Comments
Answers (2)
Voss
on 6 Jul 2024
To avoid the warning, use:
if isequal(app.STOPTRIALSButton.BackgroundColor,[0.95 0.33 0.10])
app.STOPTRIALSButton.BackgroundColor = [0 1 0];
end
3 Comments
Walter Roberson
on 7 Jul 2024
Do not compare floating point numbers for exact equality.
if isnumeric(app.STOPTRIALSButton.BackgroundColor) && all(abs(app.STOPTRIALSButton.BackgroundColor - [0.95 0.33 0.10]) <= 0.01)
Voss
on 7 Jul 2024
If App Designer puts a line of code that says
app.STOPTRIALSButton.BackgroundColor = [0.949 0.3294 0.102]
and you want to check that that BackgroundColor is still in effect, use
if isequal(app.STOPTRIALSButton.BackgroundColor,[0.949 0.3294 0.102])
Alessandro Livi
on 10 Jul 2024
1 Comment
Voss
on 10 Jul 2024
Here's the list of named colors in MATLAB
They are the eight colors all of whose RGB components are 0 or 1 (i.e. [0,0,0], [0,0,1], [0,1,0], [0,1,1], [1,0,0], [1,0,1], [1,1,0], [1,1,1]).
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