MATLAB Answers

Matlab App - Value of numeric field to reset to default starting value if condition not met

4 views (last 30 days)
Hi folks,
I am creating an app in which I need to specify some numeric values, among which:
  • a start distance
  • an end distance
  • a step
This in turn creates a distance vector.
I then have 3 numeric fields that the user can edit with the desired distance.
I set a "default" starting value, which shows up in the boxes when the app starts.
I want to implement condition tests whenever the user tries to edit those fields. If the input start distance is higher than the end distance, it should display a warning message box and I would like the start distance to reset automatically to the value it was at. The problem is that the default starting value is stored as not stored as app.numericfield.DefaultValue but as app.numericfield.Value. So the default value is erased each time.
Has anyone got a solution for that?
Thanks in advance

Accepted Answer

Mario Malic
Mario Malic on 29 Apr 2021
Hi Antoine,
Assuming you have a simpler app, you can create a property that will hold your default values, for one or more components.
properties (Access = Public)
defValues = struct();
end
Then create a startupFcn callback (read about it), you can define initial values for some components from which you'll read default values
function startupFcn(app)
defValues.Component1 = 5;
defValues.Component2 = 2;
end
Then, in callback which changes the component value, you can set the default one in case condition is not fulfilled
function EditFieldValueChangedFcn(app, event)
if %condition
% do something
else
app.EditField.Value = app.defValues.Component1;
% uialert('title', 'text'); use uialert to display alerts/warnings
end
end
  1 Comment
Antoine Purier
Antoine Purier on 3 May 2021
Hi Mario,
Thaks for taking the time to provide such a complete answer.
It works perfectly after implementation.
I actually implemented something slightly different as I stored the previous value and not the default starting value. So the value that is in the text field just before entering a new "wrong" one.
But the logic is here!
Many thanks
Antoine

Sign in to comment.

More Answers (0)

Products


Release

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by