onIncrease property
final
The handler for SemanticsAction.increase.
This is a request to increase the value represented by the widget. For example, this action might be recognized by a slider control.
If a value is set, increasedValue must also be provided and onIncrease must ensure that value will be set to increasedValue.
VoiceOver users on iOS can trigger this action by swiping up with one finger. TalkBack users on Android can trigger this action by pressing the volume up button.
Implementation
final VoidCallback onIncrease