Simplify on fade listener

Reviewed By: oprisnik Differential Revision: D24799754 fbshipit-source-id: b5a094c3fce11ab13c04e1bdc8868341b47e51e3
facebook · Dec 16, 2020 · 9aa485d · 9aa485d
1 parent 29c0ff1
commit 9aa485d
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Showing 4 changed files with 252 additions and 37 deletions.
diff --git a/drawee/src/main/java/com/facebook/drawee/drawable/FadeDrawable.java b/drawee/src/main/java/com/facebook/drawee/drawable/FadeDrawable.java
@@ -65,8 +65,7 @@ public class FadeDrawable extends ArrayDrawable {
   @VisibleForTesting int mPreventInvalidateCount;
 
   private @Nullable OnFadeListener mOnFadeListener;
-  private boolean mCallOnFadeStartedListener;
-  private boolean mCallOnFadeFinishedListener;
+  private boolean mIsFadingActualImage;
 
   /**
    * Creates a new fade drawable. The first layer is displayed with full opacity whereas all other
@@ -98,7 +97,6 @@ public FadeDrawable(Drawable[] layers, boolean allLayersVisible, int actualImage
     mPreventInvalidateCount = 0;
     mDefaultLayerIsOn = allLayersVisible;
     mDefaultLayerAlpha = mDefaultLayerIsOn ? 255 : 0;
-    mCallOnFadeStartedListener = true;
     mActualImageLayer = actualImageLayer;
     resetInternal();
   }
@@ -162,9 +160,6 @@ public void reset() {
    * @param index the index of the layer to fade in.
    */
   public void fadeInLayer(int index) {
-    mCallOnFadeFinishedListener = index == mActualImageLayer;
-    maybeNotifyOnFadeStarted(index);
-
     mTransitionState = TRANSITION_STARTING;
     mIsLayerOn[index] = true;
     invalidateSelf();
@@ -176,10 +171,6 @@ public void fadeInLayer(int index) {
    * @param index the index of the layer to fade out.
    */
   public void fadeOutLayer(int index) {
-    if (index == mActualImageLayer) {
-      mCallOnFadeStartedListener = true;
-      mCallOnFadeFinishedListener = true;
-    }
     mTransitionState = TRANSITION_STARTING;
     mIsLayerOn[index] = false;
     invalidateSelf();
@@ -299,11 +290,8 @@ public void draw(Canvas canvas) {
         ratio = (mDurationMs == 0) ? 1.0f : 0.0f;
         // if all the layers have reached their target opacity, transition is done
         done = updateAlphas(ratio);
+        onFadeStarted();
         mTransitionState = done ? TRANSITION_NONE : TRANSITION_RUNNING;
-
-        if (done) {
-          maybeNotifyOnFadeFinished();
-        }
         break;
 
       case TRANSITION_RUNNING:
@@ -313,43 +301,25 @@ public void draw(Canvas canvas) {
         // if all the layers have reached their target opacity, transition is done
         done = updateAlphas(ratio);
         mTransitionState = done ? TRANSITION_NONE : TRANSITION_RUNNING;
-
-        if (done) {
-          maybeNotifyOnFadeFinished();
-        }
         break;
 
       case TRANSITION_NONE:
         // there is no transition in progress and mAlphas should be left as is.
         done = true;
-
-        maybeNotifyOnFadeFinished();
         break;
     }
 
     for (int i = 0; i < mLayers.length; i++) {
       drawDrawableWithAlpha(canvas, mLayers[i], (int) Math.ceil(mAlphas[i] * mAlpha / 255.0));
     }
 
-    if (!done) {
+    if (done) {
+      onFadeFinished();
+    } else {
       invalidateSelf();
     }
   }
 
-  private void maybeNotifyOnFadeStarted(int index) {
-    if (mOnFadeListener != null && index == mActualImageLayer && mCallOnFadeStartedListener) {
-      mOnFadeListener.onFadeStarted();
-      mCallOnFadeStartedListener = false;
-    }
-  }
-
-  private void maybeNotifyOnFadeFinished() {
-    if (mOnFadeListener != null && mCallOnFadeFinishedListener) {
-      mOnFadeListener.onFadeFinished();
-      mCallOnFadeFinishedListener = false;
-    }
-  }
-
   private void drawDrawableWithAlpha(Canvas canvas, Drawable drawable, int alpha) {
     if (drawable != null && alpha > 0) {
       mPreventInvalidateCount++;
@@ -403,6 +373,33 @@ public void setOnFadeListener(OnFadeListener onFadeListener) {
     mOnFadeListener = onFadeListener;
   }
 
+  private void onFadeStarted() {
+    if (mIsFadingActualImage) {
+      return;
+    }
+
+    if (!mIsLayerOn[mActualImageLayer]) {
+      return;
+    }
+
+    mIsFadingActualImage = true;
+
+    if (mOnFadeListener != null) {
+      mOnFadeListener.onFadeStarted();
+    }
+  }
+
+  private void onFadeFinished() {
+    if (!mIsFadingActualImage) {
+      return;
+    }
+    mIsFadingActualImage = false;
+
+    if (mOnFadeListener != null) {
+      mOnFadeListener.onFadeFinished();
+    }
+  }
+
   public interface OnFadeListener {
     void onFadeStarted();
 

diff --git a/drawee/src/test/java/com/facebook/drawee/drawable/FadeDrawableAllOnTest.java b/drawee/src/test/java/com/facebook/drawee/drawable/FadeDrawableAllOnTest.java
@@ -414,7 +414,7 @@ private static class FakeFadeDrawable extends FadeDrawable {
     private long mCurrentTimeMs;
 
     public FakeFadeDrawable(Drawable[] layers) {
-      super(layers, true, -1);
+      super(layers, true, 0);
       mCurrentTimeMs = 0;
     }
 

diff --git a/drawee/src/test/java/com/facebook/drawee/drawable/FadeDrawableOnFadeListenerTest.java b/drawee/src/test/java/com/facebook/drawee/drawable/FadeDrawableOnFadeListenerTest.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.drawee.drawable;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.os.SystemClock;
+import com.facebook.testing.robolectric.v4.WithTestDefaultsRunner;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+
+/** Tests {@link FadeDrawable.OnFadeListener} */
+@RunWith(WithTestDefaultsRunner.class)
+@PrepareForTest({
+  //  SystemClock.class,
+  Rect.class,
+})
+public class FadeDrawableOnFadeListenerTest {
+
+  public static final int DURATION = 1000;
+  public static final int ACTUAL_LAYER_INDEX = 1;
+  public static final int OTHER_LAYER_INDEX = 2;
+
+  private Drawable[] mLayers =
+      new Drawable[] {
+        DrawableTestUtils.mockDrawable(),
+        DrawableTestUtils.mockDrawable(),
+        DrawableTestUtils.mockDrawable(),
+      };
+
+  private FadeDrawable mFadeDrawable;
+  private FadeDrawable.OnFadeListener mOnFadeListener = mock(FadeDrawable.OnFadeListener.class);
+
+  private Canvas mCanvas = mock(Canvas.class);
+
+  @Before
+  public void setUp() {
+    //    PowerMockito.mockStatic(SystemClock.class);
+    mFadeDrawable = new FadeDrawable(mLayers, false, 1);
+    mFadeDrawable.setTransitionDuration(DURATION);
+    mFadeDrawable.setOnFadeListener(mOnFadeListener);
+  }
+
+  @Test
+  public void testSimple() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeStarted();
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.5));
+    mFadeDrawable.draw(mCanvas);
+    mFadeDrawable.draw(mCanvas);
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, never()).onFadeFinished();
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.5));
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testComplex() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.fadeOutLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeStarted();
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.5));
+    mFadeDrawable.draw(mCanvas);
+    mFadeDrawable.draw(mCanvas);
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, never()).onFadeFinished();
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.1));
+    //    mFadeDrawable.fadeInAllLayers();
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testFinishImmediately() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeStarted();
+
+    mFadeDrawable.finishTransitionImmediately();
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testFadeInAll() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    mFadeDrawable.fadeInAllLayers();
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeStarted();
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.1));
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testFadeTheOtherLayer() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    mFadeDrawable.fadeInLayer(OTHER_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.1));
+    mFadeDrawable.draw(mCanvas);
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testFadeOut() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+    mFadeDrawable.fadeInAllLayers();
+    // Notice we finish immediately before the draw call:
+    mFadeDrawable.finishTransitionImmediately();
+    mFadeDrawable.draw(mCanvas);
+
+    mFadeDrawable.fadeOutLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.1));
+    mFadeDrawable.draw(mCanvas);
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testFadeOut2() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+    mFadeDrawable.fadeInAllLayers();
+    // Notice we call draw before finishing immediately
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeStarted();
+    mFadeDrawable.finishTransitionImmediately();
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+
+  @Test
+  public void testMultipleFades() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeStarted();
+
+    mFadeDrawable.fadeInLayer(OTHER_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+    verifyNoMoreInteractions(mOnFadeListener);
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.2));
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+  }
+
+  @Test
+  public void testLateListener() {
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.1));
+
+    // No listener set:
+    mFadeDrawable.setOnFadeListener(null);
+
+    mFadeDrawable.fadeInLayer(ACTUAL_LAYER_INDEX);
+    mFadeDrawable.draw(mCanvas);
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 0.5));
+    mFadeDrawable.draw(mCanvas);
+    mFadeDrawable.draw(mCanvas);
+    mFadeDrawable.draw(mCanvas);
+
+    // Set the listener back
+    mFadeDrawable.setOnFadeListener(mOnFadeListener);
+
+    SystemClock.setCurrentTimeMillis((long) (DURATION * 1.5));
+    mFadeDrawable.draw(mCanvas);
+    verify(mOnFadeListener, times(1)).onFadeFinished();
+
+    verifyNoMoreInteractions(mOnFadeListener);
+  }
+}
diff --git a/drawee/src/test/java/com/facebook/drawee/drawable/FadeDrawableTest.java b/drawee/src/test/java/com/facebook/drawee/drawable/FadeDrawableTest.java
@@ -402,7 +402,7 @@ private static class FakeFadeDrawable extends FadeDrawable {
     private long mCurrentTimeMs;
 
     public FakeFadeDrawable(Drawable[] layers) {
-      super(layers);
+      super(layers, false, 0);
       mCurrentTimeMs = 0;
     }