AnimatorTestRule

Kotlin |Java

class AnimatorTestRule : TestRule

kotlin.Any
↳	androidx.core.animation.AnimatorTestRule

JUnit TestRule that can be used to run Animators without actually waiting for the duration of the animation. This also helps the test to be written in a deterministic manner. Create an instance of AnimatorTestRule and specify it as a org.junit.ClassRule of the test class. Use advanceTimeBy(long) to advance animators that have been started. Note that advanceTimeBy(long) should be called from the same thread you have used to start the animator.

@SmallTest
  @RunWith(AndroidJUnit4.class)
  public class SampleAnimatorTest {
 
      @ClassRule
      public static AnimatorTestRule sAnimatorTestRule = new AnimatorTestRule();
 
      @UiThreadTest
      @Test
      public void sample() {
          final ValueAnimator animator = ValueAnimator.ofInt(0, 1000);
          animator.setDuration(1000L);
          assertThat(animator.getAnimatedValue(), is(0));
          animator.start();
          sAnimatorTestRule.advanceTimeBy(500L);
          assertThat(animator.getAnimatedValue(), is(500));
      }
  }

Summary

Public constructors
`<init>()`

Public methods
Unit	`advanceTimeBy(timeDelta: Long)` Advances the animation clock by the given amount of delta in milliseconds.
Statement	`apply(@NonNull base: Statement, @NonNull description: Description)`
Long	`getCurrentTime()` Returns the current time in milliseconds tracked by AnimationHandler.

Public constructors

<init>

AnimatorTestRule()

Public methods

advanceTimeBy

fun advanceTimeBy(timeDelta: Long): Unit

Advances the animation clock by the given amount of delta in milliseconds. This call will produce an animation frame to all the ongoing animations. This method needs to be called on the same thread as Animator#start().

Parameters
`timeDelta`	Long: the amount of milliseconds to advance

apply

@NonNull fun apply(
    @NonNull base: Statement, 
    @NonNull description: Description
): Statement

getCurrentTime

fun getCurrentTime(): Long

Returns the current time in milliseconds tracked by AnimationHandler. Note that this is a different time than the time tracked by @{link SystemClock} This method needs to be called on the same thread as Animator#start().