GltfAnimation

public final void addAnimationStateListener(
    @NonNull Consumer<@NonNull GltfAnimation.AnimationState> listener
)

Registers a listener to be invoked on the main thread when the animation state of the GltfAnimation changes.

public final void addAnimationStateListener(
    @NonNull Executor executor,
    @NonNull Consumer<@NonNull GltfAnimation.AnimationState> listener
)

Registers a listener to be invoked when the animation state of this GltfAnimation changes.

@MainThread
public final @NonNull GltfAnimation.AnimationState getAnimationState()

The current state of this animation.

public final @NonNull Duration getDuration()

The duration of this animation.

public final int getIndex()

The index of this animation in the source glTF model.

public final String getName()

The name of this animation, or null if the animation is unnamed.

@MainThread
public final void pause()

Pauses this animation.

This freezes the animation at the current frame and transitions the animation state to AnimationState.PAUSED. Use resume to continue playback.

Note: Calling start while in the AnimationState.PAUSED state will reset the playback time to animationOptions.seekStartTime and transition the state to AnimationState.PLAYING.

public final void removeAnimationStateListener(
    @NonNull Consumer<@NonNull GltfAnimation.AnimationState> listener
)

Unregisters a previously registered animation state update listener.

@MainThread
public final void resume()

Resumes this animation.

This continues the animation from the point where it was paused and transitions the animation state to AnimationState.PLAYING.

Note: Calling resume while in the AnimationState.PLAYING and AnimationState.STOPPED state will have no effect.

@MainThread
public final void seekTo(@NonNull Duration time)

Seeks the animation to a specific time position.

Note: This call is only valid during the AnimationState.PLAYING and AnimationState.PAUSED states. Calling this method while in the AnimationState.STOPPED state has no effect.

The behavior depends on whether the animation is looping:

• Looping Enabled: The time is treated as cyclical. Values exceeding the duration will wrap around (modulo arithmetic).

• Looping Disabled: The time is clamped to the valid playback range. Values less than GltfAnimationStartOptions.seekStartTime clamp to the start. Values exceeding the duration (or end time) clamp to the end.

Interaction with GltfAnimationStartOptions.seekStartTime:

• Positive Speed: If the seek time is less than GltfAnimationStartOptions.seekStartTime, the animation clamps to GltfAnimationStartOptions.seekStartTime (the start of the valid window).

• Negative Speed: If the seek time is less than GltfAnimationStartOptions.seekStartTime, the animation clamps to GltfAnimationStartOptions.seekStartTime. Since the animation plays in reverse, it effectively stops there if looping is disabled.

@MainThread
public final void setSpeed(float speed)

Sets the playback speed for this animation.

The speed multiplier determines the playback rate:

• 1.0: Normal speed.

• > 1.0: Faster playback.

• > 0.0 and < 1.0: Slower playback (e.g., 0.5 is half speed).

• 0.0: Freezes the animation at the current frame while keeping it active (unlike pausing).

• < 0.0: Plays the animation in reverse.

Note: This call is only valid during the AnimationState.PLAYING and AnimationState.PAUSED states. Calling this method while in the AnimationState.STOPPED state will have no effect.

@MainThread
public final void start(@NonNull GltfAnimationStartOptions options)

Starts playing this animation.

This transitions the animation state to AnimationState.PLAYING.

@MainThread
public final void stop()

Stops this animation.

This resets the playback time to 0 and transitions the animation state to AnimationState.STOPPED. If this animation is not currently playing or pausing, this method has no effect.