Fixes flickering when the same URL is set to the LottieAnimationView

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

@@ -40,6 +40,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 /**
@@ -90,7 +91,7 @@ public WeakSuccessListener(LottieAnimationView target) {
       if (targetView == null) {
         return;
       }
-      targetView.setComposition(result);
+      targetView.setCompositionInternal(result);
     }
   }
 
@@ -123,6 +124,7 @@ public WeakFailureListener(LottieAnimationView target) {
 
   private final LottieDrawable lottieDrawable = new LottieDrawable();
   private String animationName;
+  private String animationUrl;
   private @RawRes int animationResId;
 
   /**
@@ -457,6 +459,7 @@ public void setOutlineMasksAndMattes(boolean outline) {
   public void setAnimation(@RawRes final int rawRes) {
     this.animationResId = rawRes;
     animationName = null;
+    animationUrl = null;
     setCompositionTask(fromRawRes(rawRes));
   }
 
@@ -474,6 +477,7 @@ private LottieTask<LottieComposition> fromRawRes(@RawRes final int rawRes) {
   public void setAnimation(final String assetName) {
     this.animationName = assetName;
     animationResId = 0;
+    animationUrl = null;
     setCompositionTask(fromAssets(assetName));
   }
 
@@ -514,6 +518,7 @@ public void setAnimationFromJson(String jsonString, @Nullable String cacheKey) {
    * Auto-closes the stream.
    */
   public void setAnimation(InputStream stream, @Nullable String cacheKey) {
+    animationUrl = null;
     setCompositionTask(LottieCompositionFactory.fromJsonInputStream(stream, cacheKey));
   }
 
@@ -532,6 +537,10 @@ public void setAnimation(InputStream stream, @Nullable String cacheKey) {
    * @see Lottie#initialize(LottieConfig)
    */
   public void setAnimationFromUrl(String url) {
+    if (Objects.equals(animationUrl, url)) {
+      return;
+    }
+    animationUrl = url;
     LottieTask<LottieComposition> task = cacheComposition ?
         LottieCompositionFactory.fromUrl(getContext(), url) : LottieCompositionFactory.fromUrl(getContext(), url, null);
     setCompositionTask(task);
@@ -552,6 +561,10 @@ public void setAnimationFromUrl(String url) {
    * @see Lottie#initialize(LottieConfig)
    */
   public void setAnimationFromUrl(String url, @Nullable String cacheKey) {
+    if (Objects.equals(animationUrl, url)) {
+      return;
+    }
+    animationUrl = url;
     LottieTask<LottieComposition> task = LottieCompositionFactory.fromUrl(getContext(), url, cacheKey);
     setCompositionTask(task);
   }
@@ -608,6 +621,11 @@ private void cancelLoaderTask() {
    * using {@link R.attr#lottie_cacheComposition}.
    */
   public void setComposition(@NonNull LottieComposition composition) {
+    animationUrl = null;
+    setCompositionInternal(composition);
+  }
+
+  private void setCompositionInternal(@NonNull LottieComposition composition) {
     if (L.DBG) {
       Log.v(TAG, "Set Composition \n" + composition);
     }

sample/src/androidTest/java/com/airbnb/lottie/samples/LottieAnimationViewTest.kt

@@ -5,7 +5,9 @@ import android.graphics.drawable.ColorDrawable
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.testing.launchFragmentInContainer
 import androidx.lifecycle.Lifecycle
+import androidx.test.espresso.Espresso.onIdle
 import androidx.test.espresso.Espresso.onView
+import androidx.test.espresso.IdlingRegistry
 import androidx.test.espresso.assertion.ViewAssertions.matches
 import androidx.test.espresso.matcher.ViewMatchers.isDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.withId
@@ -14,7 +16,10 @@ import androidx.test.filters.LargeTest
 import com.airbnb.lottie.LottieAnimationView
 import com.airbnb.lottie.LottieCompositionFactory
 import com.airbnb.lottie.LottieDrawable
+import com.airbnb.lottie.model.LottieCompositionCache
 import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
 import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -62,4 +67,38 @@ class LottieAnimationViewTest {
             assertFalse(view.isAnimating)
         }
     }
+
+    @Test
+    fun testDoesNotLoadSameUrlTwice() {
+        val url = "https://raw.githubusercontent.com/airbnb/lottie-android/master/sample/src/main/res/raw/heart.json"
+        val cacheKey = "url_${url}"
+
+        val idlingResource = LottieIdlingResource()
+        IdlingRegistry.getInstance().register(idlingResource)
+
+        class TestFragment : Fragment(R.layout.lottie_activity_main)
+
+        val scenario = launchFragmentInContainer<TestFragment>()
+        scenario.moveToState(Lifecycle.State.RESUMED)
+        scenario.onFragment { fragment ->
+            val view = fragment.requireView().findViewById<LottieAnimationView>(R.id.animation_view)
+            view.setAnimationFromUrl(url)
+        }
+
+        onIdle()
+        assertNotNull(LottieCompositionCache.getInstance()[cacheKey])
+        LottieCompositionCache.getInstance().clear()
+
+        scenario.onFragment { fragment ->
+            val view = fragment.requireView().findViewById<LottieAnimationView>(R.id.animation_view)
+            view.setAnimationFromUrl(url)
+        }
+
+        // The second call to setAnimationFromUrl() using the same url should avoid reloading the composition
+        // and thus the underlying cache would not have been re-populated.
+        onIdle()
+        assertNull(LottieCompositionCache.getInstance()[cacheKey])
+
+        IdlingRegistry.getInstance().unregister(idlingResource)
+    }
 }