From 11298830114a195a149ef23633c96fb3cef5399b Mon Sep 17 00:00:00 2001
From: Jorim Jaggi <jjaggi@google.com>
Date: Sat, 24 May 2014 16:18:38 +0200
Subject: [PATCH] Fade notification contents when expanding/contracting

Bug: 15284460
Change-Id: If0f18e0b8fc9e7410cc6ef2a7976bcec49a6eb6e
---
 .../statusbar/ExpandableNotificationRow.java  |  7 --
 .../statusbar/NotificationContentView.java    | 87 ++++++++++++++-----
 2 files changed, 67 insertions(+), 27 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
index 5bad60205dc68..59818981188e2 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
@@ -212,13 +212,6 @@ public class ExpandableNotificationRow extends ActivatableNotificationView {
         return mShowingPublic ? mRowMinHeight : mMaxExpandHeight;
     }
 
-    /**
-     * @return the potential height this view could expand in addition.
-     */
-    public int getExpandPotential() {
-        return getIntrinsicHeight() - getActualHeight();
-    }
-
     @Override
     public boolean isContentExpandable() {
         NotificationContentView showingLayout = getShowingLayout();
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java
index 5cde9792aa00c..f91950166bd2a 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java
@@ -17,12 +17,16 @@
 package com.android.systemui.statusbar;
 
 import android.content.Context;
+import android.graphics.Paint;
+import android.graphics.PorterDuff;
+import android.graphics.PorterDuffXfermode;
 import android.graphics.Rect;
 import android.util.AttributeSet;
-import android.view.Gravity;
 import android.view.View;
-
+import android.view.animation.Interpolator;
+import android.view.animation.LinearInterpolator;
 import android.widget.FrameLayout;
+
 import com.android.systemui.R;
 
 /**
@@ -32,6 +36,8 @@ import com.android.systemui.R;
  */
 public class NotificationContentView extends FrameLayout {
 
+    private static final long ANIMATION_DURATION_LENGTH = 170;
+
     private final Rect mClipBounds = new Rect();
 
     private View mContractedChild;
@@ -41,10 +47,17 @@ public class NotificationContentView extends FrameLayout {
     private int mClipTopAmount;
     private int mActualHeight;
 
+    private final Interpolator mLinearInterpolator = new LinearInterpolator();
+
+    private boolean mContractedVisible = true;
+
+    private Paint mFadePaint = new Paint();
+
     public NotificationContentView(Context context, AttributeSet attrs) {
         super(context, attrs);
         mSmallHeight = getResources().getDimensionPixelSize(R.dimen.notification_min_height);
         mActualHeight = mSmallHeight;
+        mFadePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.ADD));
     }
 
     @Override
@@ -60,7 +73,7 @@ public class NotificationContentView extends FrameLayout {
         sanitizeContractedLayoutParams(child);
         addView(child);
         mContractedChild = child;
-        selectLayout();
+        selectLayout(false /* animate */, true /* force */);
     }
 
     public void setExpandedChild(View child) {
@@ -69,12 +82,12 @@ public class NotificationContentView extends FrameLayout {
         }
         addView(child);
         mExpandedChild = child;
-        selectLayout();
+        selectLayout(false /* animate */, true /* force */);
     }
 
     public void setActualHeight(int actualHeight) {
         mActualHeight = actualHeight;
-        selectLayout();
+        selectLayout(true /* animate */, false /* force */);
         updateClipping();
     }
 
@@ -104,26 +117,60 @@ public class NotificationContentView extends FrameLayout {
         contractedChild.setLayoutParams(lp);
     }
 
-    private void selectLayout() {
-        if (mActualHeight <= mSmallHeight || mExpandedChild == null) {
-            if (mContractedChild != null && mContractedChild.getVisibility() != View.VISIBLE) {
-                mContractedChild.setVisibility(View.VISIBLE);
-            }
-            if (mExpandedChild != null && mExpandedChild.getVisibility() != View.INVISIBLE) {
-                mExpandedChild.setVisibility(View.INVISIBLE);
-            }
-        } else {
-            if (mExpandedChild.getVisibility() != View.VISIBLE) {
-                mExpandedChild.setVisibility(View.VISIBLE);
-            }
-            if (mContractedChild != null && mContractedChild.getVisibility() != View.INVISIBLE) {
-                mContractedChild.setVisibility(View.INVISIBLE);
+    private void selectLayout(boolean animate, boolean force) {
+        if (mContractedChild == null) {
+            return;
+        }
+        boolean showContractedChild = showContractedChild();
+        if (showContractedChild != mContractedVisible || force) {
+            if (animate && mExpandedChild != null) {
+                runSwitchAnimation(showContractedChild);
+            } else if (mExpandedChild != null) {
+                mContractedChild.setVisibility(showContractedChild ? View.VISIBLE : View.INVISIBLE);
+                mContractedChild.setAlpha(showContractedChild ? 1f : 0f);
+                mExpandedChild.setVisibility(showContractedChild ? View.INVISIBLE : View.VISIBLE);
+                mExpandedChild.setAlpha(showContractedChild ? 0f : 1f);
             }
         }
+        mContractedVisible = showContractedChild;
+    }
+
+    private void runSwitchAnimation(final boolean showContractedChild) {
+        mContractedChild.setVisibility(View.VISIBLE);
+        mExpandedChild.setVisibility(View.VISIBLE);
+        mContractedChild.setLayerType(LAYER_TYPE_HARDWARE, mFadePaint);
+        mExpandedChild.setLayerType(LAYER_TYPE_HARDWARE, mFadePaint);
+        setLayerType(LAYER_TYPE_HARDWARE, null);
+        mContractedChild.animate()
+                .alpha(showContractedChild ? 1f : 0f)
+                .setDuration(ANIMATION_DURATION_LENGTH)
+                .setInterpolator(mLinearInterpolator);
+        mExpandedChild.animate()
+                .alpha(showContractedChild ? 0f : 1f)
+                .setDuration(ANIMATION_DURATION_LENGTH)
+                .setInterpolator(mLinearInterpolator)
+                .withEndAction(new Runnable() {
+                    @Override
+                    public void run() {
+                        mContractedChild.setLayerType(LAYER_TYPE_NONE, null);
+                        mExpandedChild.setLayerType(LAYER_TYPE_NONE, null);
+                        setLayerType(LAYER_TYPE_NONE, null);
+                        mContractedChild.setVisibility(showContractedChild
+                                ? View.VISIBLE
+                                : View.INVISIBLE);
+                        mExpandedChild.setVisibility(showContractedChild
+                                ? View.INVISIBLE
+                                : View.VISIBLE);
+                    }
+                });
+    }
+
+    private boolean showContractedChild() {
+        return mActualHeight <= mSmallHeight || mExpandedChild == null;
     }
 
     public void notifyContentUpdated() {
-        selectLayout();
+        selectLayout(false /* animate */, true /* force */);
     }
 
     public boolean isContentExpandable() {