[a11y] Check for reduced motion frame names (#2451)

Brings parity to the android for the changes in iOS airbnb/lottie-ios/pull/2110

This PR adds support for respecting the system "reduction motion" option.


### Animations Enabled


https://github.com/airbnb/lottie-android/assets/1218420/d29b62f6-db07-49f9-a7de-221949eef646


### Animations Disabled


https://github.com/airbnb/lottie-android/assets/1218420/2f346a78-d637-4c4a-8f60-8aa4e69e140d

Co-authored-by: Gabriel Peal <gpeal@users.noreply.github.com>
Co-authored-by: Steven Bassett <steven.bassett@airbnb.com>

lottie/src/main/java/com/airbnb/lottie/LottieDrawable.java

@@ -51,6 +51,7 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
@@ -91,6 +92,21 @@ private enum OnVisibleAction {
    */
   private static final boolean invalidateSelfOnMainThread = Build.VERSION.SDK_INT <= Build.VERSION_CODES.N_MR1;
 
+  /**
+   * The marker to use if "reduced motion" is enabled.
+   * Supported marker names are case insensitive, and include:
+   *   - reduced motion
+   *   - reducedMotion
+   *   - reduced_motion
+   *   - reduced-motion
+   */
+  private static final List<String> ALLOWED_REDUCED_MOTION_MARKERS = Arrays.asList(
+      "reduced motion",
+      "reduced_motion",
+      "reduced-motion",
+      "reducedmotion"
+  );
+
   private LottieComposition composition;
   private final LottieValueAnimator animator = new LottieValueAnimator();
 
@@ -794,14 +810,38 @@ public void playAnimation() {
       }
     }
     if (!animationsEnabled()) {
-      setFrame((int) (getSpeed() < 0 ? getMinFrame() : getMaxFrame()));
+      Marker markerForAnimationsDisabled = getMarkerForAnimationsDisabled();
+      if (markerForAnimationsDisabled != null) {
+        setFrame((int) markerForAnimationsDisabled.startFrame);
+      } else {
+        setFrame((int) (getSpeed() < 0 ? getMinFrame() : getMaxFrame()));
+      }
       animator.endAnimation();
       if (!isVisible()) {
         onVisibleAction = OnVisibleAction.NONE;
       }
     }
   }
 
+
+  /**
+   * This method is used to get the marker for animations when system animations are disabled.
+   * It iterates over the list of allowed reduced motion markers and returns the first non-null marker it finds.
+   * If no non-null marker is found, it returns null.
+   *
+   * @return The first non-null marker from the list of allowed reduced motion markers, or null if no such marker is found.
+   */
+  private Marker getMarkerForAnimationsDisabled() {
+    Marker marker = null;
+    for (String markerName : ALLOWED_REDUCED_MOTION_MARKERS) {
+      marker = composition.getMarker(markerName);
+      if (marker != null) {
+        break;
+      }
+    }
+    return marker;
+  }
+
   @MainThread
   public void endAnimation() {
     lazyCompositionTasks.clear();
@@ -1185,7 +1225,12 @@ private boolean animationsEnabled() {
   /**
    * Tell Lottie that system animations are disabled. When using {@link LottieAnimationView} or Compose {@code LottieAnimation}, this is done
    * automatically. However, if you are using LottieDrawable on its own, you should set this to false when
-   * {@link com.airbnb.lottie.utils.Utils#getAnimationScale(Context)} is 0.
+   * {@link com.airbnb.lottie.utils.Utils#getAnimationScale(Context)} is 0. If the animation is provided a "reduced motion"
+   * marker name, they will be shown instead of the first or last frame. Supported marker names are case insensitive, and include:
+   * - reduced motion
+   * - reducedMotion
+   * - reduced_motion
+   * - reduced-motion
    */
   public void setSystemAnimationsAreEnabled(Boolean areEnabled) {
     systemAnimationsEnabled = areEnabled;

snapshot-tests/src/androidTest/java/com/airbnb/lottie/snapshots/LottieSnapshotTest.kt

@@ -24,6 +24,7 @@ import com.airbnb.lottie.snapshots.tests.ComposeDynamicPropertiesTestCase
 import com.airbnb.lottie.snapshots.tests.ComposeScaleTypesTestCase
 import com.airbnb.lottie.snapshots.tests.CompositionFrameRate
 import com.airbnb.lottie.snapshots.tests.CustomBoundsTestCase
+import com.airbnb.lottie.snapshots.tests.DisabledAnimationsTestCase
 import com.airbnb.lottie.snapshots.tests.DynamicPropertiesTestCase
 import com.airbnb.lottie.snapshots.tests.FailureTestCase
 import com.airbnb.lottie.snapshots.tests.FrameBoundariesTestCase
@@ -166,6 +167,7 @@ class LottieSnapshotTest {
             PolygonStrokeTestCase(),
             CompositionFrameRate(),
             ClipTextToBoundingBoxTestCase(),
+            DisabledAnimationsTestCase(),
         )
 
         withTimeout(TimeUnit.MINUTES.toMillis(45)) {

snapshot-tests/src/androidTest/java/com/airbnb/lottie/snapshots/SnapshotTestCaseContext.kt

@@ -56,7 +56,7 @@ suspend fun SnapshotTestCaseContext.withDrawable(
     assetName: String,
     snapshotName: String,
     snapshotVariant: String,
-    callback: (LottieDrawable) -> Unit,
+    callback: suspend (LottieDrawable) -> Unit,
 ) {
     val result = LottieCompositionFactory.fromAssetSync(context, assetName)
     val composition = result.value ?: throw IllegalArgumentException("Unable to parse $assetName.", result.exception)
@@ -254,4 +254,4 @@ private suspend fun View.awaitFrame() {
             cont.resume(Unit)
         }
     }
-}
+}

snapshot-tests/src/androidTest/java/com/airbnb/lottie/snapshots/tests/DisabledAnimationsTestCase.kt

@@ -0,0 +1,25 @@
+package com.airbnb.lottie.snapshots.tests
+
+import com.airbnb.lottie.snapshots.SnapshotTestCase
+import com.airbnb.lottie.snapshots.SnapshotTestCaseContext
+import com.airbnb.lottie.snapshots.withDrawable
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+class DisabledAnimationsTestCase : SnapshotTestCase {
+    override suspend fun SnapshotTestCaseContext.run() {
+        withDrawable("Tests/ReducedMotion.json", "System Animations", "Disabled") { drawable ->
+            withContext(Dispatchers.Main) {
+                drawable.setSystemAnimationsAreEnabled(false)
+                drawable.playAnimation()
+            }
+        }
+
+        withDrawable("Tests/ReducedMotion.json", "System Animations", "Enabled") { drawable ->
+            withContext(Dispatchers.Main) {
+                drawable.setSystemAnimationsAreEnabled(false)
+                drawable.playAnimation()
+            }
+        }
+    }
+}