Fix alpha when swiping recents on tablets

When you swipe to dismiss a recent item on a
tablet, fade the item to 0 alpha

Also, create common interface for Recents-specific
methods for Recents[Horizontal/Vertical]ScrollView

Bug: 5953654

Change-Id: I0a72b49b3cfae0607b42dbf8f6d4da9898d7e491

3 files changed, 35 insertions, 23 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java b/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
index 76e6ee8..97c9553 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
@@ -44,7 +44,7 @@ import com.android.systemui.recent.RecentsPanelView.TaskDescriptionAdapter;
 import java.util.ArrayList;
 
 public class RecentsHorizontalScrollView extends HorizontalScrollView
-    implements SwipeHelper.Callback {
+        implements SwipeHelper.Callback, RecentsPanelView.RecentsScrollView {
     private static final String TAG = RecentsPanelView.TAG;
     private static final boolean DEBUG = RecentsPanelView.DEBUG;
     private LinearLayout mLinearLayout;
@@ -65,6 +65,10 @@ public class RecentsHorizontalScrollView extends HorizontalScrollView
         mRecycledViews = new ArrayList<View>();
     }
 
+    public void setMinSwipeAlpha(float minAlpha) {
+        mSwipeHelper.setMinAlpha(minAlpha);
+    }
+
     private int scrollPositionOfMostRecent() {
         return mLinearLayout.getWidth() - getWidth();
     }
diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java b/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
index 18132ff..61aaa43 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
@@ -92,6 +92,13 @@ public class RecentsPanelView extends FrameLayout implements OnItemClickListener
         public void onRecentsPanelVisibilityChanged(boolean visible);
     }
 
+    public static interface RecentsScrollView {
+        public int numItemsInOneScreenful();
+        public void setAdapter(TaskDescriptionAdapter adapter);
+        public void setCallback(RecentsCallback callback);
+        public void setMinSwipeAlpha(float minAlpha);
+    }
+
     private final class OnLongClickDelegate implements View.OnLongClickListener {
         View mOtherView;
         OnLongClickDelegate(View other) {
@@ -196,16 +203,11 @@ public class RecentsPanelView extends FrameLayout implements OnItemClickListener
     }
 
     public int numItemsInOneScreenful() {
-        if (mRecentsContainer instanceof RecentsHorizontalScrollView){
-            RecentsHorizontalScrollView scrollView
-                    = (RecentsHorizontalScrollView) mRecentsContainer;
-            return scrollView.numItemsInOneScreenful();
-        } else if (mRecentsContainer instanceof RecentsVerticalScrollView){
-            RecentsVerticalScrollView scrollView
-                    = (RecentsVerticalScrollView) mRecentsContainer;
+        if (mRecentsContainer instanceof RecentsScrollView){
+            RecentsScrollView scrollView
+                    = (RecentsScrollView) mRecentsContainer;
             return scrollView.numItemsInOneScreenful();
-        }
-        else {
+        }  else {
             throw new IllegalArgumentException("missing Recents[Horizontal]ScrollView");
         }
     }
@@ -427,18 +429,12 @@ public class RecentsPanelView extends FrameLayout implements OnItemClickListener
         mRecentsContainer = (ViewGroup) findViewById(R.id.recents_container);
         mStatusBarTouchProxy = (StatusBarTouchProxy) findViewById(R.id.status_bar_touch_proxy);
         mListAdapter = new TaskDescriptionAdapter(mContext);
-        if (mRecentsContainer instanceof RecentsHorizontalScrollView){
-            RecentsHorizontalScrollView scrollView
-                    = (RecentsHorizontalScrollView) mRecentsContainer;
-            scrollView.setAdapter(mListAdapter);
-            scrollView.setCallback(this);
-        } else if (mRecentsContainer instanceof RecentsVerticalScrollView){
-            RecentsVerticalScrollView scrollView
-                    = (RecentsVerticalScrollView) mRecentsContainer;
+        if (mRecentsContainer instanceof RecentsScrollView){
+            RecentsScrollView scrollView
+                    = (RecentsScrollView) mRecentsContainer;
             scrollView.setAdapter(mListAdapter);
             scrollView.setCallback(this);
-        }
-        else {
+        } else {
             throw new IllegalArgumentException("missing Recents[Horizontal]ScrollView");
         }
 
@@ -467,6 +463,14 @@ public class RecentsPanelView extends FrameLayout implements OnItemClickListener
         };
     }
 
+    public void setMinSwipeAlpha(float minAlpha) {
+        if (mRecentsContainer instanceof RecentsScrollView){
+            RecentsScrollView scrollView
+                = (RecentsScrollView) mRecentsContainer;
+            scrollView.setMinSwipeAlpha(minAlpha);
+        }
+    }
+
     private void createCustomAnimations(LayoutTransition transitioner) {
         transitioner.setDuration(200);
         transitioner.setStartDelay(LayoutTransition.CHANGE_DISAPPEARING, 0);
@@ -523,8 +527,7 @@ public class RecentsPanelView extends FrameLayout implements OnItemClickListener
         synchronized (td) {
             if (mRecentsContainer != null) {
                 ViewGroup container = mRecentsContainer;
-                if (container instanceof HorizontalScrollView
-                        || container instanceof ScrollView) {
+                if (container instanceof RecentsScrollView) {
                     container = (ViewGroup) container.findViewById(
                             R.id.recents_linear_layout);
                 }
diff --git a/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java b/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java
index 1bfd000..f4e516c 100644
--- a/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java
+++ b/packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java
@@ -43,7 +43,8 @@ import com.android.systemui.recent.RecentsPanelView.TaskDescriptionAdapter;
 
 import java.util.ArrayList;
 
-public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper.Callback {
+public class RecentsVerticalScrollView extends ScrollView
+        implements SwipeHelper.Callback, RecentsPanelView.RecentsScrollView {
     private static final String TAG = RecentsPanelView.TAG;
     private static final boolean DEBUG = RecentsPanelView.DEBUG;
     private LinearLayout mLinearLayout;
@@ -65,6 +66,10 @@ public class RecentsVerticalScrollView extends ScrollView implements SwipeHelper
         mRecycledViews = new ArrayList<View>();
     }
 
+    public void setMinSwipeAlpha(float minAlpha) {
+        mSwipeHelper.setMinAlpha(minAlpha);
+    }
+
     private int scrollPositionOfMostRecent() {
         return mLinearLayout.getHeight() - getHeight();
     }