Package icyllis.modernui.core

Interface Choreographer.FrameCallback

Enclosing class:
Choreographer
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public static interface Choreographer.FrameCallback
Implement this interface to receive a callback when a new display frame is being rendered. The callback is invoked on the Looper thread to which the Choreographer is attached.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    doFrame(Choreographer choreographer, long frameTimeNanos)
    Called when a new display frame is being rendered.

  • Method Details

    • doFrame

      void doFrame(@NonNull Choreographer choreographer, long frameTimeNanos)
      Called when a new display frame is being rendered.

      This method provides the time in nanoseconds when the frame started being rendered. The frame time provides a stable time base for synchronizing animations and drawing. It should be used instead of Core.timeMillis() or Core.timeNanos() for animations and drawing in the UI. Using the frame time helps to reduce inter-frame jitter because the frame time is fixed at the time the frame was scheduled to start, regardless of when the animations or drawing callback actually runs. All callbacks that run as part of rendering a frame will observe the same frame time so using the frame time also helps to synchronize effects that are performed by different callbacks.

      Please note that the framework already takes care to process animations and drawing using the frame time as a stable time base. Most applications should not need to use the frame time information directly.

      Parameters:
      choreographer - the choreographer called this method
      frameTimeNanos - The time in nanoseconds when the frame started being rendered, in the Core.timeNanos() timebase. Divide this value by 1000000 to convert it to the Core.timeMillis() time base.