Merge "Drag and drop to split transition" into sc-v2-dev am: 8653f2eeb5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16224193

Change-Id: Ie294b6d276c9d9862869c54c520f9b898df0919c

14 files changed, 643 insertions, 63 deletions

diff --git a/libs/WindowManager/Shell/res/color/taskbar_background.xml b/libs/WindowManager/Shell/res/color/taskbar_background.xml
new file mode 100644
index 000000000000..329e5b9b31a0
--- /dev/null
+++ b/libs/WindowManager/Shell/res/color/taskbar_background.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2021 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.
+  -->
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:color="@android:color/system_neutral1_500" android:lStar="35" />
+</selector>
\ No newline at end of file
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java
index 6b622044d25d..9500e8aecb57 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java
@@ -56,6 +56,7 @@ import com.android.wm.shell.common.annotations.ShellMainThread;
 import com.android.wm.shell.common.annotations.ShellSplashscreenThread;
 import com.android.wm.shell.displayareahelper.DisplayAreaHelper;
 import com.android.wm.shell.displayareahelper.DisplayAreaHelperController;
+import com.android.wm.shell.draganddrop.DragAndDrop;
 import com.android.wm.shell.draganddrop.DragAndDropController;
 import com.android.wm.shell.freeform.FreeformTaskListener;
 import com.android.wm.shell.fullscreen.FullscreenTaskListener;
@@ -156,8 +157,16 @@ public abstract class WMShellBaseModule {
     @WMSingleton
     @Provides
     static DragAndDropController provideDragAndDropController(Context context,
-            DisplayController displayController, UiEventLogger uiEventLogger) {
-        return new DragAndDropController(context, displayController, uiEventLogger);
+            DisplayController displayController, UiEventLogger uiEventLogger,
+            IconProvider iconProvider, @ShellMainThread ShellExecutor mainExecutor) {
+        return new DragAndDropController(context, displayController, uiEventLogger, iconProvider,
+                mainExecutor);
+    }
+
+    @WMSingleton
+    @Provides
+    static DragAndDrop provideDragAndDrop(DragAndDropController dragAndDropController) {
+        return dragAndDropController.asDragAndDrop();
     }
 
     @WMSingleton
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDrop.java b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDrop.java
new file mode 100644
index 000000000000..edeff6e37182
--- /dev/null
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDrop.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2020 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.wm.shell.draganddrop;
+
+import android.content.res.Configuration;
+
+import com.android.wm.shell.common.annotations.ExternalThread;
+
+/**
+ * Interface for telling DragAndDrop stuff.
+ */
+@ExternalThread
+public interface DragAndDrop {
+
+    /** Called when the theme changes. */
+    void onThemeChanged();
+
+    /** Called when the configuration changes. */
+    void onConfigChanged(Configuration newConfig);
+}
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDropController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDropController.java
index d2b4711d30af..101295d246bc 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDropController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragAndDropController.java
@@ -41,7 +41,6 @@ import android.content.res.Configuration;
 import android.graphics.PixelFormat;
 import android.util.Slog;
 import android.util.SparseArray;
-import android.view.Display;
 import android.view.DragEvent;
 import android.view.LayoutInflater;
 import android.view.SurfaceControl;
@@ -53,8 +52,10 @@ import android.widget.FrameLayout;
 import com.android.internal.logging.InstanceId;
 import com.android.internal.logging.UiEventLogger;
 import com.android.internal.protolog.common.ProtoLog;
+import com.android.launcher3.icons.IconProvider;
 import com.android.wm.shell.R;
 import com.android.wm.shell.common.DisplayController;
+import com.android.wm.shell.common.ShellExecutor;
 import com.android.wm.shell.protolog.ShellProtoLogGroup;
 import com.android.wm.shell.splitscreen.SplitScreenController;
 
@@ -71,16 +72,26 @@ public class DragAndDropController implements DisplayController.OnDisplaysChange
     private final Context mContext;
     private final DisplayController mDisplayController;
     private final DragAndDropEventLogger mLogger;
+    private final IconProvider mIconProvider;
     private SplitScreenController mSplitScreen;
+    private ShellExecutor mMainExecutor;
+    private DragAndDropImpl mImpl;
 
     private final SparseArray<PerDisplay> mDisplayDropTargets = new SparseArray<>();
     private final SurfaceControl.Transaction mTransaction = new SurfaceControl.Transaction();
 
     public DragAndDropController(Context context, DisplayController displayController,
-            UiEventLogger uiEventLogger) {
+            UiEventLogger uiEventLogger, IconProvider iconProvider, ShellExecutor mainExecutor) {
         mContext = context;
         mDisplayController = displayController;
         mLogger = new DragAndDropEventLogger(uiEventLogger);
+        mIconProvider = iconProvider;
+        mMainExecutor = mainExecutor;
+        mImpl = new DragAndDropImpl();
+    }
+
+    public DragAndDrop asDragAndDrop() {
+        return mImpl;
     }
 
     public void initialize(Optional<SplitScreenController> splitscreen) {
@@ -117,7 +128,7 @@ public class DragAndDropController implements DisplayController.OnDisplaysChange
                 R.layout.global_drop_target, null);
         rootView.setOnDragListener(this);
         rootView.setVisibility(View.INVISIBLE);
-        DragLayout dragLayout = new DragLayout(context, mSplitScreen);
+        DragLayout dragLayout = new DragLayout(context, mSplitScreen, mIconProvider);
         rootView.addView(dragLayout,
                 new FrameLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT));
         try {
@@ -267,6 +278,18 @@ public class DragAndDropController implements DisplayController.OnDisplaysChange
         return mimeTypes;
     }
 
+    private void onThemeChange() {
+        for (int i = 0; i < mDisplayDropTargets.size(); i++) {
+            mDisplayDropTargets.get(i).dragLayout.onThemeChange();
+        }
+    }
+
+    private void onConfigChanged(Configuration newConfig) {
+        for (int i = 0; i < mDisplayDropTargets.size(); i++) {
+            mDisplayDropTargets.get(i).dragLayout.onConfigChanged(newConfig);
+        }
+    }
+
     private static class PerDisplay {
         final int displayId;
         final Context context;
@@ -287,4 +310,21 @@ public class DragAndDropController implements DisplayController.OnDisplaysChange
             dragLayout = dl;
         }
     }
+
+    private class DragAndDropImpl implements DragAndDrop {
+
+        @Override
+        public void onThemeChanged() {
+            mMainExecutor.execute(() -> {
+                DragAndDropController.this.onThemeChange();
+            });
+        }
+
+        @Override
+        public void onConfigChanged(Configuration newConfig) {
+            mMainExecutor.execute(() -> {
+                DragAndDropController.this.onConfigChanged(newConfig);
+            });
+        }
+    }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragLayout.java b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragLayout.java
index efc9ed0f75b2..20d8054f6e90 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragLayout.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DragLayout.java
@@ -16,78 +16,138 @@
 
 package com.android.wm.shell.draganddrop;
 
-import static com.android.wm.shell.animation.Interpolators.FAST_OUT_LINEAR_IN;
-import static com.android.wm.shell.animation.Interpolators.FAST_OUT_SLOW_IN;
-import static com.android.wm.shell.animation.Interpolators.LINEAR;
-import static com.android.wm.shell.animation.Interpolators.LINEAR_OUT_SLOW_IN;
+import static android.app.StatusBarManager.DISABLE_NONE;
+
+import static com.android.wm.shell.common.split.SplitLayout.SPLIT_POSITION_TOP_OR_LEFT;
 
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.ObjectAnimator;
+import android.annotation.SuppressLint;
+import android.app.ActivityManager;
+import android.app.ActivityTaskManager;
+import android.app.StatusBarManager;
 import android.content.ClipData;
 import android.content.Context;
-import android.graphics.Canvas;
+import android.content.res.Configuration;
+import android.graphics.Color;
 import android.graphics.Insets;
-import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
+import android.os.RemoteException;
 import android.view.DragEvent;
 import android.view.SurfaceControl;
-import android.view.View;
+import android.view.ViewGroup;
 import android.view.WindowInsets;
 import android.view.WindowInsets.Type;
-
-import androidx.annotation.NonNull;
+import android.widget.LinearLayout;
 
 import com.android.internal.logging.InstanceId;
 import com.android.internal.protolog.common.ProtoLog;
+import com.android.launcher3.icons.IconProvider;
 import com.android.wm.shell.R;
 import com.android.wm.shell.common.DisplayLayout;
 import com.android.wm.shell.protolog.ShellProtoLogGroup;
 import com.android.wm.shell.splitscreen.SplitScreenController;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Coordinates the visible drop targets for the current drag.
  */
-public class DragLayout extends View {
+public class DragLayout extends LinearLayout {
+
+    // While dragging the status bar is hidden.
+    private static final int HIDE_STATUS_BAR_FLAGS = StatusBarManager.DISABLE_NOTIFICATION_ICONS
+            | StatusBarManager.DISABLE_NOTIFICATION_ALERTS
+            | StatusBarManager.DISABLE_CLOCK
+            | StatusBarManager.DISABLE_SYSTEM_INFO;
 
     private final DragAndDropPolicy mPolicy;
+    private final SplitScreenController mSplitScreenController;
+    private final IconProvider mIconProvider;
+    private final StatusBarManager mStatusBarManager;
 
     private DragAndDropPolicy.Target mCurrentTarget = null;
-    private DropOutlineDrawable mDropOutline;
+    private DropZoneView mDropZoneView1;
+    private DropZoneView mDropZoneView2;
+
     private int mDisplayMargin;
     private Insets mInsets = Insets.NONE;
 
     private boolean mIsShowing;
     private boolean mHasDropped;
 
-    public DragLayout(Context context, SplitScreenController splitscreen) {
+    @SuppressLint("WrongConstant")
+    public DragLayout(Context context, SplitScreenController splitScreenController,
+            IconProvider iconProvider) {
         super(context);
-        mPolicy = new DragAndDropPolicy(context, splitscreen);
+        mSplitScreenController = splitScreenController;
+        mIconProvider = iconProvider;
+        mPolicy = new DragAndDropPolicy(context, splitScreenController);
+        mStatusBarManager = context.getSystemService(StatusBarManager.class);
+
         mDisplayMargin = context.getResources().getDimensionPixelSize(
                 R.dimen.drop_layout_display_margin);
-        mDropOutline = new DropOutlineDrawable(context);
-        setBackground(mDropOutline);
-        setWillNotDraw(false);
+
+        mDropZoneView1 = new DropZoneView(context);
+        mDropZoneView2 = new DropZoneView(context);
+        addView(mDropZoneView1, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT));
+        addView(mDropZoneView2, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT));
+        ((LayoutParams) mDropZoneView1.getLayoutParams()).weight = 1;
+        ((LayoutParams) mDropZoneView2.getLayoutParams()).weight = 1;
+        updateContainerMargins();
     }
 
     @Override
     public WindowInsets onApplyWindowInsets(WindowInsets insets) {
         mInsets = insets.getInsets(Type.systemBars() | Type.displayCutout());
         recomputeDropTargets();
+
+        final int orientation = getResources().getConfiguration().orientation;
+        if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
+            mDropZoneView1.setBottomInset(mInsets.bottom);
+            mDropZoneView2.setBottomInset(mInsets.bottom);
+        } else if (orientation == Configuration.ORIENTATION_PORTRAIT) {
+            mDropZoneView1.setBottomInset(0);
+            mDropZoneView2.setBottomInset(mInsets.bottom);
+        }
         return super.onApplyWindowInsets(insets);
     }
 
-    @Override
-    protected boolean verifyDrawable(@NonNull Drawable who) {
-        return who == mDropOutline || super.verifyDrawable(who);
+    public void onThemeChange() {
+        mDropZoneView1.onThemeChange();
+        mDropZoneView2.onThemeChange();
     }
 
-    @Override
-    protected void onDraw(Canvas canvas) {
-        if (mCurrentTarget != null) {
-            mDropOutline.draw(canvas);
+    public void onConfigChanged(Configuration newConfig) {
+        final int orientation = getResources().getConfiguration().orientation;
+        if (orientation == Configuration.ORIENTATION_LANDSCAPE
+                && getOrientation() != HORIZONTAL) {
+            setOrientation(LinearLayout.HORIZONTAL);
+            updateContainerMargins();
+        } else if (orientation == Configuration.ORIENTATION_PORTRAIT
+                && getOrientation() != VERTICAL) {
+            setOrientation(LinearLayout.VERTICAL);
+            updateContainerMargins();
+        }
+    }
+
+    private void updateContainerMargins() {
+        final int orientation = getResources().getConfiguration().orientation;
+        final float halfMargin = mDisplayMargin / 2f;
+        if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
+            mDropZoneView1.setContainerMargin(
+                    mDisplayMargin, mDisplayMargin, halfMargin, mDisplayMargin);
+            mDropZoneView2.setContainerMargin(
+                    halfMargin, mDisplayMargin, mDisplayMargin, mDisplayMargin);
+        } else if (orientation == Configuration.ORIENTATION_PORTRAIT) {
+            mDropZoneView1.setContainerMargin(
+                    mDisplayMargin, mDisplayMargin, mDisplayMargin, halfMargin);
+            mDropZoneView2.setContainerMargin(
+                    mDisplayMargin, halfMargin, mDisplayMargin, mDisplayMargin);
         }
     }
 
@@ -104,6 +164,43 @@ public class DragLayout extends View {
         mPolicy.start(displayLayout, initialData, loggerSessionId);
         mHasDropped = false;
         mCurrentTarget = null;
+
+        List<ActivityManager.RunningTaskInfo> tasks = null;
+        // Figure out the splashscreen info for the existing task(s).
+        try {
+            tasks = ActivityTaskManager.getService().getTasks(2,
+                            false /* filterOnlyVisibleRecents */,
+                            false /* keepIntentExtra */);
+        } catch (RemoteException e) {
+            // don't show an icon / will just use the defaults
+        }
+        if (tasks != null && !tasks.isEmpty()) {
+            ActivityManager.RunningTaskInfo taskInfo1 = tasks.get(0);
+            Drawable icon1 = mIconProvider.getIcon(taskInfo1.topActivityInfo);
+            int bgColor1 = getResizingBackgroundColor(taskInfo1);
+
+            boolean alreadyInSplit = mSplitScreenController != null
+                    && mSplitScreenController.isSplitScreenVisible();
+            if (alreadyInSplit && tasks.size() > 1) {
+                ActivityManager.RunningTaskInfo taskInfo2 = tasks.get(1);
+                Drawable icon2 = mIconProvider.getIcon(taskInfo2.topActivityInfo);
+                int bgColor2 = getResizingBackgroundColor(taskInfo2);
+
+                // figure out which task is on which side
+                int splitPosition1 = mSplitScreenController.getSplitPosition(taskInfo1.taskId);
+                boolean isTask1TopOrLeft = splitPosition1 == SPLIT_POSITION_TOP_OR_LEFT;
+                if (isTask1TopOrLeft) {
+                    mDropZoneView1.setAppInfo(bgColor1, icon1);
+                    mDropZoneView2.setAppInfo(bgColor2, icon2);
+                } else {
+                    mDropZoneView2.setAppInfo(bgColor1, icon1);
+                    mDropZoneView1.setAppInfo(bgColor2, icon2);
+                }
+            } else {
+                mDropZoneView1.setAppInfo(bgColor1, icon1);
+                mDropZoneView2.setAppInfo(bgColor1, icon1);
+            }
+        }
     }
 
     public void show() {
@@ -139,20 +236,14 @@ public class DragLayout extends View {
             ProtoLog.v(ShellProtoLogGroup.WM_SHELL_DRAG_AND_DROP, "Current target: %s", target);
             if (target == null) {
                 // Animating to no target
-                mDropOutline.startVisibilityAnimation(false, LINEAR);
-                Rect finalBounds = new Rect(mCurrentTarget.drawRegion);
-                finalBounds.inset(mDisplayMargin, mDisplayMargin);
-                mDropOutline.startBoundsAnimation(finalBounds, FAST_OUT_LINEAR_IN);
+                animateSplitContainers(false, null /* animCompleteCallback */);
             } else if (mCurrentTarget == null) {
                 // Animating to first target
-                mDropOutline.startVisibilityAnimation(true, LINEAR);
-                Rect initialBounds = new Rect(target.drawRegion);
-                initialBounds.inset(mDisplayMargin, mDisplayMargin);
-                mDropOutline.setRegionBounds(initialBounds);
-                mDropOutline.startBoundsAnimation(target.drawRegion, LINEAR_OUT_SLOW_IN);
+                animateSplitContainers(true, null /* animCompleteCallback */);
+                animateHighlight(target);
             } else {
-                // Bounds change
-                mDropOutline.startBoundsAnimation(target.drawRegion, FAST_OUT_SLOW_IN);
+                // Switching between targets
+                animateHighlight(target);
             }
             mCurrentTarget = target;
         }
@@ -163,26 +254,7 @@ public class DragLayout extends View {
      */
     public void hide(DragEvent event, Runnable hideCompleteCallback) {
         mIsShowing = false;
-        ObjectAnimator alphaAnimator = mDropOutline.startVisibilityAnimation(false, LINEAR);
-        ObjectAnimator boundsAnimator = null;
-        if (mCurrentTarget != null) {
-            Rect finalBounds = new Rect(mCurrentTarget.drawRegion);
-            finalBounds.inset(mDisplayMargin, mDisplayMargin);
-            boundsAnimator = mDropOutline.startBoundsAnimation(finalBounds, FAST_OUT_LINEAR_IN);
-        }
-
-        if (hideCompleteCallback != null) {
-            ObjectAnimator lastAnim = boundsAnimator != null
-                    ? boundsAnimator
-                    : alphaAnimator;
-            lastAnim.addListener(new AnimatorListenerAdapter() {
-                @Override
-                public void onAnimationEnd(Animator animation) {
-                    hideCompleteCallback.run();
-                }
-            });
-        }
-
+        animateSplitContainers(false, hideCompleteCallback);
         mCurrentTarget = null;
     }
 
@@ -201,4 +273,49 @@ public class DragLayout extends View {
         hide(event, dropCompleteCallback);
         return handledDrop;
     }
+
+    private void animateSplitContainers(boolean visible, Runnable animCompleteCallback) {
+        mStatusBarManager.disable(visible
+                ? HIDE_STATUS_BAR_FLAGS
+                : DISABLE_NONE);
+        mDropZoneView1.setShowingMargin(visible);
+        mDropZoneView2.setShowingMargin(visible);
+        ObjectAnimator animator = mDropZoneView1.getAnimator();
+        if (animCompleteCallback != null) {
+            if (animator != null) {
+                animator.addListener(new AnimatorListenerAdapter() {
+                    @Override
+                    public void onAnimationEnd(Animator animation) {
+                        animCompleteCallback.run();
+                    }
+                });
+            } else {
+                // If there's no animator the animation is done so run immediately
+                animCompleteCallback.run();
+            }
+        }
+    }
+
+    private void animateHighlight(DragAndDropPolicy.Target target) {
+        if (target.type == DragAndDropPolicy.Target.TYPE_SPLIT_LEFT
+                || target.type == DragAndDropPolicy.Target.TYPE_SPLIT_TOP) {
+            mDropZoneView1.setShowingHighlight(true);
+            mDropZoneView1.setShowingSplash(false);
+
+            mDropZoneView2.setShowingHighlight(false);
+            mDropZoneView2.setShowingSplash(true);
+        } else if (target.type == DragAndDropPolicy.Target.TYPE_SPLIT_RIGHT
+                || target.type == DragAndDropPolicy.Target.TYPE_SPLIT_BOTTOM) {
+            mDropZoneView1.setShowingHighlight(false);
+            mDropZoneView1.setShowingSplash(true);
+
+            mDropZoneView2.setShowingHighlight(true);
+            mDropZoneView2.setShowingSplash(false);
+        }
+    }
+
+    private static int getResizingBackgroundColor(ActivityManager.RunningTaskInfo taskInfo) {
+        final int taskBgColor = taskInfo.taskDescription.getBackgroundColor();
+        return Color.valueOf(taskBgColor == -1 ? Color.WHITE : taskBgColor).toArgb();
+    }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DropZoneView.java b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DropZoneView.java
new file mode 100644
index 000000000000..2f47af57d496
--- /dev/null
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/draganddrop/DropZoneView.java
@@ -0,0 +1,313 @@
+/*
+ * Copyright (C) 2021 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.wm.shell.draganddrop;
+
+import static com.android.wm.shell.animation.Interpolators.FAST_OUT_SLOW_IN;
+
+import android.animation.ObjectAnimator;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Path;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import android.util.AttributeSet;
+import android.util.FloatProperty;
+import android.util.IntProperty;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.ImageView;
+
+import androidx.annotation.Nullable;
+
+import com.android.internal.policy.ScreenDecorationsUtils;
+import com.android.wm.shell.R;
+
+/**
+ * Renders a drop zone area for items being dragged.
+ */
+public class DropZoneView extends FrameLayout {
+
+    private static final int SPLASHSCREEN_ALPHA_INT = (int) (255 * 0.90f);
+    private static final int HIGHLIGHT_ALPHA_INT = 255;
+    private static final int MARGIN_ANIMATION_ENTER_DURATION = 400;
+    private static final int MARGIN_ANIMATION_EXIT_DURATION = 250;
+
+    private static final FloatProperty<DropZoneView> INSETS =
+            new FloatProperty<DropZoneView>("insets") {
+                @Override
+                public void setValue(DropZoneView v, float percent) {
+                    v.setMarginPercent(percent);
+                }
+
+                @Override
+                public Float get(DropZoneView v) {
+                    return v.getMarginPercent();
+                }
+            };
+
+    private static final IntProperty<ColorDrawable> SPLASHSCREEN_ALPHA =
+            new IntProperty<ColorDrawable>("splashscreen") {
+                @Override
+                public void setValue(ColorDrawable d, int alpha) {
+                    d.setAlpha(alpha);
+                }
+
+                @Override
+                public Integer get(ColorDrawable d) {
+                    return d.getAlpha();
+                }
+            };
+
+    private static final IntProperty<ColorDrawable> HIGHLIGHT_ALPHA =
+            new IntProperty<ColorDrawable>("highlight") {
+                @Override
+                public void setValue(ColorDrawable d, int alpha) {
+                    d.setAlpha(alpha);
+                }
+
+                @Override
+                public Integer get(ColorDrawable d) {
+                    return d.getAlpha();
+                }
+            };
+
+    private final Path mPath = new Path();
+    private final float[] mContainerMargin = new float[4];
+    private float mCornerRadius;
+    private float mBottomInset;
+    private int mMarginColor; // i.e. color used for negative space like the container insets
+    private int mHighlightColor;
+
+    private boolean mShowingHighlight;
+    private boolean mShowingSplash;
+    private boolean mShowingMargin;
+
+    // TODO: might be more seamless to animate between splash/highlight color instead of 2 separate
+    private ObjectAnimator mSplashAnimator;
+    private ObjectAnimator mHighlightAnimator;
+    private ObjectAnimator mMarginAnimator;
+    private float mMarginPercent;
+
+    // Renders a highlight or neutral transparent color
+    private ColorDrawable mDropZoneDrawable;
+    // Renders the translucent splashscreen with the app icon in the middle
+    private ImageView mSplashScreenView;
+    private ColorDrawable mSplashBackgroundDrawable;
+    // Renders the margin / insets around the dropzone container
+    private MarginView mMarginView;
+
+    public DropZoneView(Context context) {
+        this(context, null);
+    }
+
+    public DropZoneView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public DropZoneView(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public DropZoneView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        setContainerMargin(0, 0, 0, 0); // make sure it's populated
+
+        mCornerRadius = ScreenDecorationsUtils.getWindowCornerRadius(context);
+        mMarginColor = getResources().getColor(R.color.taskbar_background);
+        mHighlightColor = getResources().getColor(android.R.color.system_accent1_500);
+
+        mDropZoneDrawable = new ColorDrawable();
+        mDropZoneDrawable.setColor(mHighlightColor);
+        mDropZoneDrawable.setAlpha(0);
+        setBackgroundDrawable(mDropZoneDrawable);
+
+        mSplashScreenView = new ImageView(context);
+        mSplashScreenView.setScaleType(ImageView.ScaleType.CENTER);
+        mSplashBackgroundDrawable = new ColorDrawable();
+        mSplashBackgroundDrawable.setColor(Color.WHITE);
+        mSplashBackgroundDrawable.setAlpha(SPLASHSCREEN_ALPHA_INT);
+        mSplashScreenView.setBackgroundDrawable(mSplashBackgroundDrawable);
+        addView(mSplashScreenView, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT));
+        mSplashScreenView.setAlpha(0f);
+
+        mMarginView = new MarginView(context);
+        addView(mMarginView, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT));
+    }
+
+    public void onThemeChange() {
+        mCornerRadius = ScreenDecorationsUtils.getWindowCornerRadius(getContext());
+        mMarginColor = getResources().getColor(R.color.taskbar_background);
+        mHighlightColor = getResources().getColor(android.R.color.system_accent1_500);
+
+        final int alpha = mDropZoneDrawable.getAlpha();
+        mDropZoneDrawable.setColor(mHighlightColor);
+        mDropZoneDrawable.setAlpha(alpha);
+
+        if (mMarginPercent > 0) {
+            mMarginView.invalidate();
+        }
+    }
+
+    /** Sets the desired margins around the drop zone container when fully showing. */
+    public void setContainerMargin(float left, float top, float right, float bottom) {
+        mContainerMargin[0] = left;
+        mContainerMargin[1] = top;
+        mContainerMargin[2] = right;
+        mContainerMargin[3] = bottom;
+        if (mMarginPercent > 0) {
+            mMarginView.invalidate();
+        }
+    }
+
+    /** Sets the bottom inset so the drop zones are above bottom navigation. */
+    public void setBottomInset(float bottom) {
+        mBottomInset = bottom;
+        ((LayoutParams) mSplashScreenView.getLayoutParams()).bottomMargin = (int) bottom;
+        if (mMarginPercent > 0) {
+            mMarginView.invalidate();
+        }
+    }
+
+    /** Sets the color and icon to use for the splashscreen when shown. */
+    public void setAppInfo(int splashScreenColor, Drawable appIcon) {
+        mSplashBackgroundDrawable.setColor(splashScreenColor);
+        mSplashScreenView.setImageDrawable(appIcon);
+    }
+
+    /** @return an active animator for this view if one exists. */
+    @Nullable
+    public ObjectAnimator getAnimator() {
+        if (mMarginAnimator != null && mMarginAnimator.isRunning()) {
+            return mMarginAnimator;
+        } else if (mHighlightAnimator != null && mHighlightAnimator.isRunning()) {
+            return mHighlightAnimator;
+        } else if (mSplashAnimator != null && mSplashAnimator.isRunning()) {
+            return mSplashAnimator;
+        }
+        return null;
+    }
+
+    /** Animates the splashscreen to show or hide. */
+    public void setShowingSplash(boolean showingSplash) {
+        if (mShowingSplash != showingSplash) {
+            mShowingSplash = showingSplash;
+            animateSplashToState();
+        }
+    }
+
+    /** Animates the highlight indicating the zone is hovered on or not. */
+    public void setShowingHighlight(boolean showingHighlight) {
+        if (mShowingHighlight != showingHighlight) {
+            mShowingHighlight = showingHighlight;
+            animateHighlightToState();
+        }
+    }
+
+    /** Animates the margins around the drop zone to show or hide. */
+    public void setShowingMargin(boolean visible) {
+        if (mShowingMargin != visible) {
+            mShowingMargin = visible;
+            animateMarginToState();
+        }
+        if (!mShowingMargin) {
+            setShowingHighlight(false);
+            setShowingSplash(false);
+        }
+    }
+
+    private void animateSplashToState() {
+        if (mSplashAnimator != null) {
+            mSplashAnimator.cancel();
+        }
+        mSplashAnimator = ObjectAnimator.ofInt(mSplashBackgroundDrawable,
+                SPLASHSCREEN_ALPHA,
+                mSplashBackgroundDrawable.getAlpha(),
+                mShowingSplash ? SPLASHSCREEN_ALPHA_INT : 0);
+        if (!mShowingSplash) {
+            mSplashAnimator.setInterpolator(FAST_OUT_SLOW_IN);
+        }
+        mSplashAnimator.start();
+        mSplashScreenView.animate().alpha(mShowingSplash ? 1f : 0f).start();
+    }
+
+    private void animateHighlightToState() {
+        if (mHighlightAnimator != null) {
+            mHighlightAnimator.cancel();
+        }
+        mHighlightAnimator = ObjectAnimator.ofInt(mDropZoneDrawable,
+                HIGHLIGHT_ALPHA,
+                mDropZoneDrawable.getAlpha(),
+                mShowingHighlight ? HIGHLIGHT_ALPHA_INT : 0);
+        if (!mShowingHighlight) {
+            mHighlightAnimator.setInterpolator(FAST_OUT_SLOW_IN);
+        }
+        mHighlightAnimator.start();
+    }
+
+    private void animateMarginToState() {
+        if (mMarginAnimator != null) {
+            mMarginAnimator.cancel();
+        }
+        mMarginAnimator = ObjectAnimator.ofFloat(this, INSETS,
+                mMarginPercent,
+                mShowingMargin ? 1f : 0f);
+        mMarginAnimator.setInterpolator(FAST_OUT_SLOW_IN);
+        mMarginAnimator.setDuration(mShowingMargin
+                ? MARGIN_ANIMATION_ENTER_DURATION
+                : MARGIN_ANIMATION_EXIT_DURATION);
+        mMarginAnimator.start();
+    }
+
+    private void setMarginPercent(float percent) {
+        if (percent != mMarginPercent) {
+            mMarginPercent = percent;
+            mMarginView.invalidate();
+        }
+    }
+
+    private float getMarginPercent() {
+        return mMarginPercent;
+    }
+
+    /** Simple view that draws a rounded rect margin around its contents. **/
+    private class MarginView extends View {
+
+        MarginView(Context context) {
+            super(context);
+        }
+
+        @Override
+        protected void onDraw(Canvas canvas) {
+            super.onDraw(canvas);
+            mPath.reset();
+            mPath.addRoundRect(mContainerMargin[0] * mMarginPercent,
+                    mContainerMargin[1] * mMarginPercent,
+                    getWidth() - (mContainerMargin[2] * mMarginPercent),
+                    getHeight() - (mContainerMargin[3] * mMarginPercent) - mBottomInset,
+                    mCornerRadius * mMarginPercent,
+                    mCornerRadius * mMarginPercent,
+                    Path.Direction.CW);
+            mPath.setFillType(Path.FillType.INVERSE_EVEN_ODD);
+            canvas.clipPath(mPath);
+            canvas.drawColor(mMarginColor);
+        }
+    }
+}
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java
index 262a9a1ba2be..d2e341d3c38c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/SplitScreenController.java
@@ -188,6 +188,10 @@ public class SplitScreenController implements DragAndDropPolicy.Starter,
                 && mStageCoordinator.getStageOfTask(taskId) != STAGE_TYPE_UNDEFINED;
     }
 
+    public @SplitPosition int getSplitPosition(int taskId) {
+        return mStageCoordinator.getSplitPosition(taskId);
+    }
+
     public boolean moveToSideStage(int taskId, @SplitPosition int sideStagePosition) {
         return moveToStage(taskId, STAGE_TYPE_SIDE, sideStagePosition,
                 new WindowContainerTransaction());
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java
index a5579ae7dc25..8ad0f200d448 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageCoordinator.java
@@ -678,6 +678,16 @@ class StageCoordinator implements SplitLayout.SplitLayoutHandler,
         outBottomOrRightBounds.set(mSplitLayout.getBounds2());
     }
 
+    @SplitPosition
+    int getSplitPosition(int taskId) {
+        if (mSideStage.getTopVisibleChildTaskId() == taskId) {
+            return getSideStagePosition();
+        } else if (mMainStage.getTopVisibleChildTaskId() == taskId) {
+            return getMainStagePosition();
+        }
+        return SPLIT_POSITION_UNDEFINED;
+    }
+
     private void addActivityOptions(Bundle opts, StageTaskListener stage) {
         opts.putParcelable(KEY_LAUNCH_ROOT_TASK_TOKEN, stage.mRootTaskInfo.token);
     }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/draganddrop/DragAndDropControllerTest.java b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/draganddrop/DragAndDropControllerTest.java
index bfa2c92f6679..9f745208d3ed 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/draganddrop/DragAndDropControllerTest.java
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/draganddrop/DragAndDropControllerTest.java
@@ -30,7 +30,9 @@ import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.filters.SmallTest;
 
 import com.android.internal.logging.UiEventLogger;
+import com.android.launcher3.icons.IconProvider;
 import com.android.wm.shell.common.DisplayController;
+import com.android.wm.shell.common.ShellExecutor;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -59,8 +61,8 @@ public class DragAndDropControllerTest {
     @Before
     public void setUp() throws RemoteException {
         MockitoAnnotations.initMocks(this);
-
-        mController = new DragAndDropController(mContext, mDisplayController, mUiEventLogger);
+        mController = new DragAndDropController(mContext, mDisplayController, mUiEventLogger,
+                mock(IconProvider.class), mock(ShellExecutor.class));
     }
 
     @Test
diff --git a/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java b/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java
index d37dcafde92a..bb0e79fe23a8 100644
--- a/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java
+++ b/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java
@@ -121,7 +121,8 @@ public class SystemUIFactory {
                     .setDisplayAreaHelper(mWMComponent.getDisplayAreaHelper())
                     .setTaskSurfaceHelper(mWMComponent.getTaskSurfaceHelper())
                     .setRecentTasks(mWMComponent.getRecentTasks())
-                    .setSizeCompatUI(Optional.of(mWMComponent.getSizeCompatUI()));
+                    .setSizeCompatUI(Optional.of(mWMComponent.getSizeCompatUI()))
+                    .setDragAndDrop(Optional.of(mWMComponent.getDragAndDrop()));
         } else {
             // TODO: Call on prepareSysUIComponentBuilder but not with real components. Other option
             // is separating this logic into newly creating SystemUITestsFactory.
@@ -140,7 +141,8 @@ public class SystemUIFactory {
                     .setStartingSurface(Optional.ofNullable(null))
                     .setTaskSurfaceHelper(Optional.ofNullable(null))
                     .setRecentTasks(Optional.ofNullable(null))
-                    .setSizeCompatUI(Optional.ofNullable(null));
+                    .setSizeCompatUI(Optional.ofNullable(null))
+                    .setDragAndDrop(Optional.ofNullable(null));
         }
         mSysUIComponent = builder.build();
         if (mInitializeComponents) {
diff --git a/packages/SystemUI/src/com/android/systemui/dagger/SysUIComponent.java b/packages/SystemUI/src/com/android/systemui/dagger/SysUIComponent.java
index 5fdf026b86f3..c5d3a70676d0 100644
--- a/packages/SystemUI/src/com/android/systemui/dagger/SysUIComponent.java
+++ b/packages/SystemUI/src/com/android/systemui/dagger/SysUIComponent.java
@@ -32,6 +32,7 @@ import com.android.wm.shell.TaskViewFactory;
 import com.android.wm.shell.apppairs.AppPairs;
 import com.android.wm.shell.bubbles.Bubbles;
 import com.android.wm.shell.displayareahelper.DisplayAreaHelper;
+import com.android.wm.shell.draganddrop.DragAndDrop;
 import com.android.wm.shell.hidedisplaycutout.HideDisplayCutout;
 import com.android.wm.shell.legacysplitscreen.LegacySplitScreen;
 import com.android.wm.shell.onehanded.OneHanded;
@@ -111,6 +112,9 @@ public interface SysUIComponent {
         @BindsInstance
         Builder setSizeCompatUI(Optional<SizeCompatUI> s);
 
+        @BindsInstance
+        Builder setDragAndDrop(Optional<DragAndDrop> d);
+
         SysUIComponent build();
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/dagger/WMComponent.java b/packages/SystemUI/src/com/android/systemui/dagger/WMComponent.java
index 543ba8f9b854..90a3ad225f51 100644
--- a/packages/SystemUI/src/com/android/systemui/dagger/WMComponent.java
+++ b/packages/SystemUI/src/com/android/systemui/dagger/WMComponent.java
@@ -29,6 +29,7 @@ import com.android.wm.shell.dagger.TvWMShellModule;
 import com.android.wm.shell.dagger.WMShellModule;
 import com.android.wm.shell.dagger.WMSingleton;
 import com.android.wm.shell.displayareahelper.DisplayAreaHelper;
+import com.android.wm.shell.draganddrop.DragAndDrop;
 import com.android.wm.shell.hidedisplaycutout.HideDisplayCutout;
 import com.android.wm.shell.legacysplitscreen.LegacySplitScreen;
 import com.android.wm.shell.onehanded.OneHanded;
@@ -119,4 +120,7 @@ public interface WMComponent {
 
     @WMSingleton
     SizeCompatUI getSizeCompatUI();
+
+    @WMSingleton
+    DragAndDrop getDragAndDrop();
 }
diff --git a/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java b/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java
index a56c177ef9ae..b546edf428b8 100644
--- a/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java
+++ b/packages/SystemUI/src/com/android/systemui/wmshell/WMShell.java
@@ -56,6 +56,7 @@ import com.android.systemui.statusbar.policy.UserInfoController;
 import com.android.systemui.tracing.ProtoTracer;
 import com.android.systemui.tracing.nano.SystemUiTraceProto;
 import com.android.wm.shell.ShellCommandHandler;
+import com.android.wm.shell.draganddrop.DragAndDrop;
 import com.android.wm.shell.hidedisplaycutout.HideDisplayCutout;
 import com.android.wm.shell.legacysplitscreen.LegacySplitScreen;
 import com.android.wm.shell.nano.WmShellTraceProto;
@@ -114,6 +115,7 @@ public final class WMShell extends SystemUI
     private final Optional<HideDisplayCutout> mHideDisplayCutoutOptional;
     private final Optional<ShellCommandHandler> mShellCommandHandler;
     private final Optional<SizeCompatUI> mSizeCompatUIOptional;
+    private final Optional<DragAndDrop> mDragAndDropOptional;
 
     private final CommandQueue mCommandQueue;
     private final ConfigurationController mConfigurationController;
@@ -142,6 +144,7 @@ public final class WMShell extends SystemUI
             Optional<HideDisplayCutout> hideDisplayCutoutOptional,
             Optional<ShellCommandHandler> shellCommandHandler,
             Optional<SizeCompatUI> sizeCompatUIOptional,
+            Optional<DragAndDrop> dragAndDropOptional,
             CommandQueue commandQueue,
             ConfigurationController configurationController,
             KeyguardUpdateMonitor keyguardUpdateMonitor,
@@ -167,6 +170,7 @@ public final class WMShell extends SystemUI
         mProtoTracer = protoTracer;
         mShellCommandHandler = shellCommandHandler;
         mSizeCompatUIOptional = sizeCompatUIOptional;
+        mDragAndDropOptional = dragAndDropOptional;
         mSysUiMainExecutor = sysUiMainExecutor;
     }
 
@@ -182,6 +186,7 @@ public final class WMShell extends SystemUI
         mOneHandedOptional.ifPresent(this::initOneHanded);
         mHideDisplayCutoutOptional.ifPresent(this::initHideDisplayCutout);
         mSizeCompatUIOptional.ifPresent(this::initSizeCompatUi);
+        mDragAndDropOptional.ifPresent(this::initDragAndDrop);
     }
 
     @VisibleForTesting
@@ -396,6 +401,20 @@ public final class WMShell extends SystemUI
         mKeyguardUpdateMonitor.registerCallback(mSizeCompatUIKeyguardCallback);
     }
 
+    void initDragAndDrop(DragAndDrop dragAndDrop) {
+        mConfigurationController.addCallback(new ConfigurationController.ConfigurationListener() {
+            @Override
+            public void onConfigChanged(Configuration newConfig) {
+                dragAndDrop.onConfigChanged(newConfig);
+            }
+
+            @Override
+            public void onThemeChanged() {
+                dragAndDrop.onThemeChanged();
+            }
+        });
+    }
+
     @Override
     public void writeToProto(SystemUiTraceProto proto) {
         if (proto.wmShell == null) {
diff --git a/packages/SystemUI/tests/src/com/android/systemui/wmshell/WMShellTest.java b/packages/SystemUI/tests/src/com/android/systemui/wmshell/WMShellTest.java
index ae7afcef57a6..1e15d2ae0bdb 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/wmshell/WMShellTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/wmshell/WMShellTest.java
@@ -35,6 +35,7 @@ import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.tracing.ProtoTracer;
 import com.android.wm.shell.ShellCommandHandler;
 import com.android.wm.shell.common.ShellExecutor;
+import com.android.wm.shell.draganddrop.DragAndDrop;
 import com.android.wm.shell.hidedisplaycutout.HideDisplayCutout;
 import com.android.wm.shell.legacysplitscreen.LegacySplitScreen;
 import com.android.wm.shell.onehanded.OneHanded;
@@ -79,6 +80,7 @@ public class WMShellTest extends SysuiTestCase {
     @Mock ShellCommandHandler mShellCommandHandler;
     @Mock SizeCompatUI mSizeCompatUI;
     @Mock ShellExecutor mSysUiMainExecutor;
+    @Mock DragAndDrop mDragAndDrop;
 
     @Before
     public void setUp() {
@@ -87,6 +89,7 @@ public class WMShellTest extends SysuiTestCase {
         mWMShell = new WMShell(mContext, Optional.of(mPip), Optional.of(mLegacySplitScreen),
                 Optional.of(mSplitScreen), Optional.of(mOneHanded), Optional.of(mHideDisplayCutout),
                 Optional.of(mShellCommandHandler), Optional.of(mSizeCompatUI),
+                Optional.of(mDragAndDrop),
                 mCommandQueue, mConfigurationController, mKeyguardUpdateMonitor,
                 mNavigationModeController, mScreenLifecycle, mSysUiState, mProtoTracer,
                 mWakefulnessLifecycle, mSysUiMainExecutor);