Fix shadow problems with Folder animation.

The shadow from the top of the Folder is visible through
the transparent part of the 'preview' background. When we
remove the elevation as part of the animation, the shadow
jumps into visibility when the animation is done.

To solve this, we remove the elevation during the Folder animation and
 * Animate the elevation at the end of the Folder opening animation.
 * Animate the shadow of the FolderIcon bg in once the Folder is closed.

Bug: 62787582
Bug: 35064148
Change-Id: Id5d8fcbfa4f74882531334f12488560da2496faf

4 files changed, 45 insertions, 3 deletions

diff --git a/src/com/android/launcher3/anim/RoundedRectRevealOutlineProvider.java b/src/com/android/launcher3/anim/RoundedRectRevealOutlineProvider.java
index d01b26c8f..7c5fa1ced 100644
--- a/src/com/android/launcher3/anim/RoundedRectRevealOutlineProvider.java
+++ b/src/com/android/launcher3/anim/RoundedRectRevealOutlineProvider.java
@@ -56,7 +56,7 @@ public class RoundedRectRevealOutlineProvider extends RevealOutlineAnimation {
 
     @Override
     public boolean shouldRemoveElevationDuringAnimation() {
-        return false;
+        return true;
     }
 
     @Override
diff --git a/src/com/android/launcher3/folder/Folder.java b/src/com/android/launcher3/folder/Folder.java
index fc25c9ab2..283835153 100644
--- a/src/com/android/launcher3/folder/Folder.java
+++ b/src/com/android/launcher3/folder/Folder.java
@@ -791,8 +791,11 @@ public class Folder extends AbstractFloatingView implements DragSource, View.OnC
         mDragController.removeDropTarget(this);
         clearFocus();
         if (mFolderIcon != null) {
-            mFolderIcon.setBackgroundVisible(true);
             mFolderIcon.setVisibility(View.VISIBLE);
+            if (FeatureFlags.LAUNCHER3_NEW_FOLDER_ANIMATION) {
+                mFolderIcon.setBackgroundVisible(true);
+                mFolderIcon.mBackground.fadeInBackgroundShadow();
+            }
             if (wasAnimated) {
                 mFolderIcon.mBackground.animateBackgroundStroke();
                 if (mFolderIcon.hasBadge()) {
diff --git a/src/com/android/launcher3/folder/FolderAnimationManager.java b/src/com/android/launcher3/folder/FolderAnimationManager.java
index bb2d1a2f5..74e8d3b29 100644
--- a/src/com/android/launcher3/folder/FolderAnimationManager.java
+++ b/src/com/android/launcher3/folder/FolderAnimationManager.java
@@ -221,6 +221,12 @@ public class FolderAnimationManager {
                 mFolder.setTranslationY(0.0f);
                 mFolder.setScaleX(1f);
                 mFolder.setScaleY(1f);
+
+                if (mIsOpening) {
+                    getAnimator(mFolder, View.TRANSLATION_Z, -mFolder.getElevation(), 0)
+                            .setDuration(150)
+                            .start();
+                }
             }
         });
 
diff --git a/src/com/android/launcher3/folder/FolderIcon.java b/src/com/android/launcher3/folder/FolderIcon.java
index aaa19afa5..ca5d308f0 100644
--- a/src/com/android/launcher3/folder/FolderIcon.java
+++ b/src/com/android/launcher3/folder/FolderIcon.java
@@ -555,6 +555,7 @@ public class FolderIcon extends FrameLayout implements FolderListener {
         private int mBgColor;
         private float mStrokeWidth;
         private int mStrokeAlpha = MAX_BG_OPACITY;
+        private int mShadowAlpha = 255;
         private View mInvalidateDelegate;
 
         public int previewSize;
@@ -580,6 +581,7 @@ public class FolderIcon extends FrameLayout implements FolderListener {
 
         ValueAnimator mScaleAnimator;
         ObjectAnimator mStrokeAlphaAnimator;
+        ObjectAnimator mShadowAnimator;
 
         private static final Property<PreviewBackground, Integer> STROKE_ALPHA =
                 new Property<PreviewBackground, Integer>(Integer.class, "strokeAlpha") {
@@ -595,6 +597,20 @@ public class FolderIcon extends FrameLayout implements FolderListener {
                     }
                 };
 
+        private static final Property<PreviewBackground, Integer> SHADOW_ALPHA =
+                new Property<PreviewBackground, Integer>(Integer.class, "shadowAlpha") {
+                    @Override
+                    public Integer get(PreviewBackground previewBackground) {
+                        return previewBackground.mShadowAlpha;
+                    }
+
+                    @Override
+                    public void set(PreviewBackground previewBackground, Integer alpha) {
+                        previewBackground.mShadowAlpha = alpha;
+                        previewBackground.invalidate();
+                    }
+                };
+
         public void setup(Launcher launcher, View invalidateDelegate,
                    int availableSpace, int topPadding) {
             mInvalidateDelegate = invalidateDelegate;
@@ -692,10 +708,11 @@ public class FolderIcon extends FrameLayout implements FolderListener {
             mShaderMatrix.setScale(shadowRadius, shadowRadius);
             mShaderMatrix.postTranslate(radius + offsetX, shadowRadius + offsetY);
             mShadowShader.setLocalMatrix(mShaderMatrix);
+            mPaint.setAlpha(mShadowAlpha);
             mPaint.setShader(mShadowShader);
             canvas.drawPaint(mPaint);
+            mPaint.setAlpha(255);
             mPaint.setShader(null);
-
             if (canvas.isHardwareAccelerated()) {
                 mPaint.setXfermode(mShadowPorterDuffXfermode);
                 canvas.drawCircle(radius + offsetX, radius + offsetY, radius, mPaint);
@@ -705,6 +722,22 @@ public class FolderIcon extends FrameLayout implements FolderListener {
             canvas.restoreToCount(saveCount);
         }
 
+        public void fadeInBackgroundShadow() {
+            if (mShadowAnimator != null) {
+                mShadowAnimator.cancel();
+            }
+            mShadowAnimator = ObjectAnimator
+                    .ofInt(this, SHADOW_ALPHA, 0, 255)
+                    .setDuration(100);
+            mShadowAnimator.addListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mShadowAnimator = null;
+                }
+            });
+            mShadowAnimator.start();
+        }
+
         public void animateBackgroundStroke() {
             if (mStrokeAlphaAnimator != null) {
                 mStrokeAlphaAnimator.cancel();