Waiting until a parameter does not change anymore

General JUCE discussion
1

I have a knob that starts a compute-intensive calculation (in the audio thread).
If I turn the knob, say going from 0 to 100, this calculation is done for most in-between
values, which is too often, I only need to do it for the last value (100).

What is a good way to “wait” until there are no more changes in the knob value?
Use a timer? Or is there a better way to handle this?

2

The Slider class has two (effectively equivalent) ways to do this:

  • If you are using a Slider::Listener, override the sliderDragEnded() method and kick off the computation there.
  • you can pass a lambda to the slider that will be called when the drag operation ends, like:
juce::Slider s;
// config, etc omitted
s.onDragEnd = [this](juce::Slider* s) { startExpensiveCalculation (s->getValue ()); }
3

Understood, but I am using parameter attachments and parameter listeners.

Looks like I need to change the code in my custom control (e.g. mouse-up event),
I still want to see all the in-between values in the editor, but only want to update the valuetree after mouse-up…

4

there is a setChangeNotificationOnlyOnRelease() function in the slider

https://docs.juce.com/master/classSlider.html#ab41e52ab8941619028a8d57103975029

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