Add shadow for minimized dock

Bug: 27972642
Change-Id: Ic4c8145f61694ff2bb0e237da1142093c6a4d965
diff --git a/core/java/android/view/IDockedStackListener.aidl b/core/java/android/view/IDockedStackListener.aidl
index cbc8dbd..88ac271 100644
--- a/core/java/android/view/IDockedStackListener.aidl
+++ b/core/java/android/view/IDockedStackListener.aidl
@@ -42,4 +42,9 @@
      * @param animDuration The duration of the animation for changing the minimized state.
      */
     void onDockedStackMinimizedChanged(boolean minimized, long animDuration);
+
+    /**
+     * Called when window manager repositioned the docked stack after a screen rotation change.
+     */
+    void onDockSideChanged(int newDockSide);
 }
diff --git a/packages/SystemUI/res/layout/docked_stack_divider.xml b/packages/SystemUI/res/layout/docked_stack_divider.xml
index cfaf018..70e5451 100644
--- a/packages/SystemUI/res/layout/docked_stack_divider.xml
+++ b/packages/SystemUI/res/layout/docked_stack_divider.xml
@@ -24,6 +24,11 @@
         android:id="@+id/docked_divider_background"
         android:background="@color/docked_divider_background"/>
 
+    <com.android.systemui.stackdivider.MinimizedDockShadow
+        style="@style/DockedDividerMinimizedShadow"
+        android:id="@+id/minimized_dock_shadow"
+        android:alpha="0"/>">
+
     <com.android.systemui.stackdivider.DividerHandleView
         style="@style/DockedDividerHandle"
         android:id="@+id/docked_divider_handle"
diff --git a/packages/SystemUI/res/values-land/styles.xml b/packages/SystemUI/res/values-land/styles.xml
index b711faa..82cba58 100644
--- a/packages/SystemUI/res/values-land/styles.xml
+++ b/packages/SystemUI/res/values-land/styles.xml
@@ -31,4 +31,8 @@
         <item name="android:layout_height">96dp</item>
     </style>
 
+    <style name="DockedDividerMinimizedShadow">
+        <item name="android:layout_width">8dp</item>
+        <item name="android:layout_height">match_parent</item>
+    </style>
 </resources>
diff --git a/packages/SystemUI/res/values/colors.xml b/packages/SystemUI/res/values/colors.xml
index 18fc419..d26fb06 100644
--- a/packages/SystemUI/res/values/colors.xml
+++ b/packages/SystemUI/res/values/colors.xml
@@ -151,7 +151,9 @@
 
     <color name="docked_divider_background">#ff000000</color>
     <color name="docked_divider_handle">#ffffff</color>
-    <drawable name="forced_resizable_background">#40000000</drawable>
+    <drawable name="forced_resizable_background">#59000000</drawable>
+    <color name="minimize_dock_shadow_start">#60000000</color>
+    <color name="minimize_dock_shadow_end">#00000000</color>
 
     <color name="default_remote_input_background">@*android:color/notification_default_color</color>
     <color name="remote_input_hint">#99ffffff</color>
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index f560a13..0730083 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -308,6 +308,11 @@
         <item name="android:layout_gravity">center_vertical</item>
     </style>
 
+    <style name="DockedDividerMinimizedShadow">
+        <item name="android:layout_width">match_parent</item>
+        <item name="android:layout_height">8dp</item>
+    </style>
+
     <style name="DockedDividerHandle">
         <item name="android:layout_gravity">center_horizontal</item>
         <item name="android:layout_width">96dp</item>
diff --git a/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java b/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
index d294c80..2bf0b40 100644
--- a/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
+++ b/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
@@ -146,5 +146,10 @@
                 throws RemoteException {
             updateMinimizedDockedStack(minimized, animDuration);
         }
+
+        @Override
+        public void onDockSideChanged(final int newDockSide) throws RemoteException {
+            mView.post(() -> mView.notifyDockSideChanged(newDockSide));
+        }
     }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/stackdivider/DividerView.java b/packages/SystemUI/src/com/android/systemui/stackdivider/DividerView.java
index 8461d8e..141f60b 100644
--- a/packages/SystemUI/src/com/android/systemui/stackdivider/DividerView.java
+++ b/packages/SystemUI/src/com/android/systemui/stackdivider/DividerView.java
@@ -88,7 +88,7 @@
     /**
      * How much the background gets scaled when we are in the minimized dock state.
      */
-    private static final float MINIMIZE_DOCK_SCALE = 0.375f;
+    private static final float MINIMIZE_DOCK_SCALE = 0f;
 
     private static final PathInterpolator SLOWDOWN_INTERPOLATOR =
             new PathInterpolator(0.5f, 1f, 0.5f, 1f);
@@ -97,6 +97,7 @@
 
     private DividerHandleView mHandle;
     private View mBackground;
+    private MinimizedDockShadow mMinimizedShadow;
     private int mStartX;
     private int mStartY;
     private int mStartPosition;
@@ -203,6 +204,7 @@
         super.onFinishInflate();
         mHandle = (DividerHandleView) findViewById(R.id.docked_divider_handle);
         mBackground = findViewById(R.id.docked_divider_background);
+        mMinimizedShadow = (MinimizedDockShadow) findViewById(R.id.minimized_dock_shadow);
         mHandle.setOnTouchListener(this);
         mDividerWindowWidth = getResources().getDimensionPixelSize(
                 com.android.internal.R.dimen.docked_stack_divider_thickness);
@@ -269,6 +271,18 @@
     @Override
     protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
         super.onLayout(changed, left, top, right, bottom);
+        int minimizeLeft = 0;
+        int minimizeTop = 0;
+        if (mDockSide == WindowManager.DOCKED_TOP) {
+            minimizeTop = mBackground.getTop();
+        } else if (mDockSide == WindowManager.DOCKED_LEFT) {
+            minimizeLeft = mBackground.getLeft();
+        } else if (mDockSide == WindowManager.DOCKED_RIGHT) {
+            minimizeLeft = mBackground.getRight() - mMinimizedShadow.getWidth();
+        }
+        mMinimizedShadow.layout(minimizeLeft, minimizeTop,
+                minimizeLeft + mMinimizedShadow.getMeasuredWidth(),
+                minimizeTop + mMinimizedShadow.getMeasuredHeight());
         if (changed) {
             mWindowManagerProxy.setTouchRegion(new Rect(mHandle.getLeft(), mHandle.getTop(),
                     mHandle.getRight(), mHandle.getBottom()));
@@ -327,6 +341,7 @@
 
     private void updateDockSide() {
         mDockSide = mWindowManagerProxy.getDockSide();
+        mMinimizedShadow.setDockSide(mDockSide);
     }
 
     private void initializeSnapAlgorithm() {
@@ -541,6 +556,7 @@
                     : mBackground.getWidth());
             mBackground.setScaleX(MINIMIZE_DOCK_SCALE);
         }
+        mMinimizedShadow.setAlpha(minimized ? 1f : 0f);
         mDockedStackMinimized = minimized;
     }
 
@@ -566,6 +582,11 @@
         if (!minimized) {
             mBackground.animate().withEndAction(mResetBackgroundRunnable);
         }
+        mMinimizedShadow.animate()
+                .alpha(minimized ? 1f : 0f)
+                .setInterpolator(Interpolators.ALPHA_IN)
+                .setDuration(animDuration)
+                .start();
         mBackground.animate()
                 .setInterpolator(Interpolators.FAST_OUT_SLOW_IN)
                 .setDuration(animDuration)
@@ -578,6 +599,7 @@
         mBackground.setPivotY(mBackground.getHeight() / 2);
         mBackground.setScaleX(1f);
         mBackground.setScaleY(1f);
+        mMinimizedShadow.setAlpha(0f);
     }
 
     @Override
@@ -586,6 +608,13 @@
         updateDisplayInfo();
     }
 
+
+    public void notifyDockSideChanged(int newDockSide) {
+        mDockSide = newDockSide;
+        mMinimizedShadow.setDockSide(mDockSide);
+        requestLayout();
+    }
+
     private void updateDisplayInfo() {
         final DisplayManager displayManager =
                 (DisplayManager) mContext.getSystemService(Context.DISPLAY_SERVICE);
diff --git a/packages/SystemUI/src/com/android/systemui/stackdivider/MinimizedDockShadow.java b/packages/SystemUI/src/com/android/systemui/stackdivider/MinimizedDockShadow.java
new file mode 100644
index 0000000..ecff54f
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/stackdivider/MinimizedDockShadow.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.systemui.stackdivider;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.LinearGradient;
+import android.graphics.Paint;
+import android.graphics.Shader;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.WindowManager;
+
+import com.android.systemui.R;
+
+/**
+ * Shadow for the minimized dock state on homescreen.
+ */
+public class MinimizedDockShadow extends View {
+
+    private final Paint mShadowPaint = new Paint();
+
+    private int mDockSide = WindowManager.DOCKED_INVALID;
+
+    public MinimizedDockShadow(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public void setDockSide(int dockSide) {
+        if (dockSide != mDockSide) {
+            mDockSide = dockSide;
+            updatePaint(getLeft(), getTop(), getRight(), getBottom());
+            invalidate();
+        }
+    }
+
+    private void updatePaint(int left, int top, int right, int bottom) {
+        int startColor = mContext.getResources().getColor(
+                R.color.minimize_dock_shadow_start, null);
+        int endColor = mContext.getResources().getColor(
+                R.color.minimize_dock_shadow_end, null);
+        final int middleColor = Color.argb(
+                (Color.alpha(startColor) + Color.alpha(endColor)) / 2, 0, 0, 0);
+        final int quarter = Color.argb(
+                (int) (Color.alpha(startColor) * 0.25f + Color.alpha(endColor) * 0.75f),
+                0, 0, 0);
+        if (mDockSide == WindowManager.DOCKED_TOP) {
+            mShadowPaint.setShader(new LinearGradient(
+                    0, 0, 0, bottom - top,
+                    new int[] { startColor, middleColor, quarter, endColor },
+                    new float[] { 0f, 0.35f, 0.6f, 1f }, Shader.TileMode.CLAMP));
+        } else if (mDockSide == WindowManager.DOCKED_LEFT) {
+            mShadowPaint.setShader(new LinearGradient(
+                    0, 0, right - left, 0,
+                    new int[] { startColor, middleColor, quarter, endColor },
+                    new float[] { 0f, 0.35f, 0.6f, 1f }, Shader.TileMode.CLAMP));
+        } else if (mDockSide == WindowManager.DOCKED_RIGHT) {
+            mShadowPaint.setShader(new LinearGradient(
+                    right - left, 0, 0, 0,
+                    new int[] { startColor, middleColor, quarter, endColor },
+                    new float[] { 0f, 0.35f, 0.6f, 1f }, Shader.TileMode.CLAMP));
+        }
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        super.onLayout(changed, left, top, right, bottom);
+        if (changed) {
+            updatePaint(left, top, right, bottom);
+            invalidate();
+        }
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        canvas.drawRect(0, 0, getWidth(), getHeight(), mShadowPaint);
+    }
+
+    @Override
+    public boolean hasOverlappingRendering() {
+        return false;
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java
index 6859348..581b611 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java
@@ -526,6 +526,10 @@
                 public void onDockedStackMinimizedChanged(boolean minimized, long animDuration)
                         throws RemoteException {
                 }
+
+                @Override
+                public void onDockSideChanged(int newDockSide) throws RemoteException {
+                }
             });
         } catch (RemoteException e) {
             Log.e(TAG, "Failed registering docked stack exists listener", e);
diff --git a/services/core/java/com/android/server/wm/DockedStackDividerController.java b/services/core/java/com/android/server/wm/DockedStackDividerController.java
index 6ac71c7..ff537be 100644
--- a/services/core/java/com/android/server/wm/DockedStackDividerController.java
+++ b/services/core/java/com/android/server/wm/DockedStackDividerController.java
@@ -270,6 +270,19 @@
         mDockedStackListeners.finishBroadcast();
     }
 
+    void notifyDockSideChanged(int newDockSide) {
+        final int size = mDockedStackListeners.beginBroadcast();
+        for (int i = 0; i < size; ++i) {
+            final IDockedStackListener listener = mDockedStackListeners.getBroadcastItem(i);
+            try {
+                listener.onDockSideChanged(newDockSide);
+            } catch (RemoteException e) {
+                Slog.e(TAG_WM, "Error delivering dock side changed event.", e);
+            }
+        }
+        mDockedStackListeners.finishBroadcast();
+    }
+
     void registerDockedStackListener(IDockedStackListener listener) {
         mDockedStackListeners.register(listener);
         notifyDockedDividerVisibilityChanged(wasVisible());
diff --git a/services/core/java/com/android/server/wm/TaskStack.java b/services/core/java/com/android/server/wm/TaskStack.java
index 1475686..7074a83 100644
--- a/services/core/java/com/android/server/wm/TaskStack.java
+++ b/services/core/java/com/android/server/wm/TaskStack.java
@@ -16,6 +16,20 @@
 
 package com.android.server.wm;
 
+import static android.app.ActivityManager.DOCKED_STACK_CREATE_MODE_TOP_OR_LEFT;
+import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
+import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
+import static android.content.res.Configuration.DENSITY_DPI_UNDEFINED;
+import static android.content.res.Configuration.ORIENTATION_PORTRAIT;
+import static android.view.WindowManager.DOCKED_BOTTOM;
+import static android.view.WindowManager.DOCKED_INVALID;
+import static android.view.WindowManager.DOCKED_LEFT;
+import static android.view.WindowManager.DOCKED_RIGHT;
+import static android.view.WindowManager.DOCKED_TOP;
+import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_TASK_MOVEMENT;
+import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
+import static com.android.server.wm.WindowManagerService.H.RESIZE_STACK;
+
 import android.app.ActivityManager.StackId;
 import android.content.res.Configuration;
 import android.graphics.Rect;
@@ -35,20 +49,6 @@
 import java.io.PrintWriter;
 import java.util.ArrayList;
 
-import static android.app.ActivityManager.DOCKED_STACK_CREATE_MODE_TOP_OR_LEFT;
-import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;
-import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
-import static android.content.res.Configuration.DENSITY_DPI_UNDEFINED;
-import static android.content.res.Configuration.ORIENTATION_PORTRAIT;
-import static android.view.WindowManager.DOCKED_BOTTOM;
-import static android.view.WindowManager.DOCKED_INVALID;
-import static android.view.WindowManager.DOCKED_LEFT;
-import static android.view.WindowManager.DOCKED_RIGHT;
-import static android.view.WindowManager.DOCKED_TOP;
-import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_TASK_MOVEMENT;
-import static com.android.server.wm.WindowManagerService.H.RESIZE_STACK;
-import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
-
 public class TaskStack implements DimLayer.DimLayerUser,
         BoundsAnimationController.AnimateBoundsUser {
 
@@ -379,10 +379,15 @@
             return false;
         }
 
+        final int oldDockSide = mStackId == DOCKED_STACK_ID ? getDockSide() : DOCKED_INVALID;
         mDisplayContent.rotateBounds(mRotation, newRotation, mTmpRect2);
         if (mStackId == DOCKED_STACK_ID) {
             repositionDockedStackAfterRotation(mTmpRect2);
             snapDockedStackAfterRotation(mTmpRect2);
+            final int newDockSide = getDockSide(mTmpRect2);
+            if (oldDockSide != newDockSide) {
+                mDisplayContent.getDockedDividerController().notifyDockSideChanged(newDockSide);
+            }
         }
 
         if (scheduleResize) {