From a0786f3fc756589897b4b660e72461e5a51f88df Mon Sep 17 00:00:00 2001
From: mattsziklay <mattsziklay@google.com>
Date: Fri, 28 Jul 2023 16:00:49 -0700
Subject: [PATCH] Allow entering split screen on an app currently open in
 desktop mode.

Registers a SplitScreenListener to perform necessary windowing changes
when split is requested for an app currently open in desktop mode.

Test: Manual; open a task in desktop, go to overview, perform a split
transition where the second app is the one open in desktop.
Bug: 279586624

Change-Id: Ib00e0fe5d0dd0dfa49b025d78de994fd68af2145
---
 .../common/split/SplitScreenConstants.java    |  4 +++-
 .../desktopmode/DesktopTasksController.kt     | 19 +++++++++++++++++++
 .../DesktopModeWindowDecorViewModel.java      | 14 ++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitScreenConstants.java b/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitScreenConstants.java
index ef93a336305fb..be1b9b1227de2 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitScreenConstants.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/common/split/SplitScreenConstants.java
@@ -16,6 +16,7 @@
 package com.android.wm.shell.common.split;
 
 import static android.app.WindowConfiguration.ACTIVITY_TYPE_STANDARD;
+import static android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM;
 import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
 import static android.app.WindowConfiguration.WINDOWING_MODE_MULTI_WINDOW;
 import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
@@ -60,7 +61,8 @@ public class SplitScreenConstants {
     public static final int[] CONTROLLED_WINDOWING_MODES =
             {WINDOWING_MODE_FULLSCREEN, WINDOWING_MODE_UNDEFINED};
     public static final int[] CONTROLLED_WINDOWING_MODES_WHEN_ACTIVE =
-            {WINDOWING_MODE_FULLSCREEN, WINDOWING_MODE_UNDEFINED, WINDOWING_MODE_MULTI_WINDOW};
+            {WINDOWING_MODE_FULLSCREEN, WINDOWING_MODE_UNDEFINED, WINDOWING_MODE_MULTI_WINDOW,
+            WINDOWING_MODE_FREEFORM};
 
     /** Flag applied to a transition change to identify it as a divider bar for animation. */
     public static final int FLAG_IS_DIVIDER_BAR = FLAG_FIRST_CUSTOM;
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
index 1d46e755ec9d6..633f627e8e71a 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
@@ -18,6 +18,7 @@ package com.android.wm.shell.desktopmode
 
 import android.R
 import android.app.ActivityManager.RunningTaskInfo
+import android.app.WindowConfiguration
 import android.app.WindowConfiguration.ACTIVITY_TYPE_HOME
 import android.app.WindowConfiguration.ACTIVITY_TYPE_STANDARD
 import android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM
@@ -301,6 +302,24 @@ class DesktopTasksController(
         }
     }
 
+    /** Move a desktop app to split screen. */
+    fun moveToSplit(task: RunningTaskInfo) {
+        KtProtoLog.v(
+            WM_SHELL_DESKTOP_MODE,
+            "DesktopTasksController: moveToSplit taskId=%d",
+            task.taskId
+        )
+        val wct = WindowContainerTransaction()
+        wct.setWindowingMode(task.token, WindowConfiguration.WINDOWING_MODE_MULTI_WINDOW)
+        wct.setBounds(task.token, null)
+        wct.setDensityDpi(task.token, getDefaultDensityDpi())
+        if (Transitions.ENABLE_SHELL_TRANSITIONS) {
+            transitions.startTransition(TRANSIT_CHANGE, wct, null /* handler */)
+        } else {
+            shellTaskOrganizer.applyTransaction(wct)
+        }
+    }
+
     /**
      * The second part of the animated move to desktop transition, called after
      * {@link startMoveToDesktop}. Move a task to fullscreen after being dragged from fullscreen
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
index 2be7a491fdf20..29fff03500a58 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
@@ -71,6 +71,7 @@ import com.android.wm.shell.desktopmode.DesktopModeController;
 import com.android.wm.shell.desktopmode.DesktopModeStatus;
 import com.android.wm.shell.desktopmode.DesktopTasksController;
 import com.android.wm.shell.freeform.FreeformTaskTransitionStarter;
+import com.android.wm.shell.splitscreen.SplitScreen;
 import com.android.wm.shell.splitscreen.SplitScreenController;
 import com.android.wm.shell.sysui.KeyguardChangeListener;
 import com.android.wm.shell.sysui.ShellController;
@@ -200,6 +201,19 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
     @Override
     public void setSplitScreenController(SplitScreenController splitScreenController) {
         mSplitScreenController = splitScreenController;
+        mSplitScreenController.registerSplitScreenListener(new SplitScreen.SplitScreenListener() {
+            @Override
+            public void onTaskStageChanged(int taskId, int stage, boolean visible) {
+                if (visible) {
+                    DesktopModeWindowDecoration decor = mWindowDecorByTaskId.get(taskId);
+                    if (decor != null && DesktopModeStatus.isActive(mContext)
+                            && decor.mTaskInfo.getWindowingMode() == WINDOWING_MODE_FREEFORM) {
+                        mDesktopModeController.ifPresent(c -> c.setDesktopModeActive(false));
+                        mDesktopTasksController.ifPresent(c -> c.moveToSplit(decor.mTaskInfo));
+                    }
+                }
+            }
+        });
     }
 
     @Override