[App Designer] Get the object indentifier that triggered the callback

I have several objects such spinners that execute a callback. I could create a callback for each one of them, but I want to write less lines in the app to make it clean. My question is if there is any way to identify which object triggered the callback.

% Value changed function: ASpinner, BSpinner, CSpinner
         function VChanged(app, event)
   % I want here somthing like if event.Source.Name==ASpinner
  do that
  end 
          end

event.EventName is always 'ValueChanged', i tried with the event.Source, but those are the properties I am able to see and none refrer to the name of the spinner.

Spinner (1.75) with properties:

                    Value: 1.7500
       ValueDisplayFormat: '%11.4g'
    RoundFractionalValues: 'off'
                     Step: 0.2500
                   Limits: [0 5]
      LowerLimitInclusive: 'on'
      UpperLimitInclusive: 'on'
          ValueChangedFcn: [function_handle]
         ValueChangingFcn: ''
                 Position: [114 12 80.8954 22]

Use get to show all properties

                     Step: 0.2500
         ValueChangingFcn: ''
                    Value: 1.5000
                   Limits: [0 5]
      LowerLimitInclusive: 'on'
      UpperLimitInclusive: 'on'
    RoundFractionalValues: 'off'
       ValueDisplayFormat: '%11.4g'
          ValueChangedFcn: [function_handle]
                   Parent: [1×1 Panel]
         HandleVisibility: 'on'
               BusyAction: 'queue'
             BeingDeleted: 'off'
            Interruptible: 'on'
                CreateFcn: ''
                DeleteFcn: ''
                     Type: 'uispinner'
                      Tag: ''
                 UserData: []
                 Editable: 'on'
      HorizontalAlignment: 'right'
                 FontName: 'Helvetica'
                 FontSize: 14
               FontWeight: 'normal'
                FontAngle: 'normal'
                FontColor: [0 0 0]
          BackgroundColor: [0.9373 0.9373 0.9373]
            InnerPosition: [114 12 80.8954 22]
                 Position: [114 12 80.8954 22]
            OuterPosition: [114 12 80.8954 22]
                   Enable: 'on'
                  Visible: 'on'

PS: while I could use event.Source.Position, if the user resize the app is not gonna work. Thanks in advance

[Adam]

event.Source should be the handle of the component that triggered the callback. If you need to know which of your properties it is you can just test equality of e.g.

event.Source == app.ASpinner

as far as I am aware, though I rarely use AppDesigner.

Answer 1

[Miguel Garcia]

So obvious and I didnt saw it ! Thank you very much!

Answer 2

[J. Alex Lee]

I think a cleaner way is to pass an identifier with the callback definition:

ASpinner.ValueChangedFcn = @(evnt)app.VChanged(evnt,'ASpinner')
BSpinner.ValueChangedFcn = @(evnt)app.VChanged(evnt,'BSpinner')
CSpinner.ValueChangedFcn = @(evnt)app.VChanged(evnt,'CSpinner')

function VChanged(app, evnt,SpinnerName)
    source = app.(SpinnerName)
    if SpinnerName=='ASpinner'
        
    end
    switch SpinnerName
        case 'ASpinner'
    end
end

Alternatively, make use of the "Tag" or "UserData" properties of the spinner to store the name in.

Answer 3

[Niraj Desai]

You can also specify the object's "Tag" and then access the tag like this: event.Source.Tag.

[J. Alex Lee]

yes, i agree. the usefulness would probably depend on whether you need to query the spinner's user-facing identity in any other context than the ValueChanged callback.

[Dominik Müller]

Is there a way to have two identifiers? Let's say Tag and Name for example? I'm asking because I have a structure containing names different than the Spinner names. It would be nice to get two identifiers to easily access both of them.