From c8fcf08dfd2475dd76c72cbda7bbbd0cd946b261 Mon Sep 17 00:00:00 2001
From: Suhua Lei <lsuhua@google.com>
Date: Tue, 11 Mar 2025 00:50:28 +0000
Subject: [PATCH] Handle visibility of AddDesktopButton for
 overview/quickswitch

This change introduces mDisallowScrollToAddDesk to handle the visibility
of AddDesktopButton in overview/quickswitch. In overview, set its scroll
as the first task; in quick switch, set its scroll out range of
[minScroll, maxScroll].

Bug: 398036110
Flag: com.android.window.flags.enable_multiple_desktops_frontend
Flag: com.android.window.flags.enable_multiple_desktops_backend
Test: manual quick switch
Change-Id: I5fada0c4c5bccc5572b458da9970e3524087508d
---
 .../fallback/FallbackRecentsView.java         |  1 +
 .../quickstep/views/LauncherRecentsView.java  |  4 +++
 .../android/quickstep/views/RecentsView.java  | 28 ++++++++++++++++++-
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
index f426bf5124..12c043ef82 100644
--- a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
+++ b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
@@ -302,6 +302,7 @@ public class FallbackRecentsView<CONTAINER_TYPE extends Context & RecentsViewCon
         if (enabled) {
             RecentsState state = mContainer.getStateManager().getState();
             setDisallowScrollToClearAll(!state.hasClearAllButton());
+            setDisallowScrollToAddDesk(!state.hasAddDeskButton());
         }
     }
 
diff --git a/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java b/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java
index 0f1c2941b3..b65bdc1efb 100644
--- a/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/LauncherRecentsView.java
@@ -19,6 +19,7 @@ import static android.app.ActivityTaskManager.INVALID_TASK_ID;
 import static android.window.DesktopModeFlags.ENABLE_DESKTOP_WINDOWING_WALLPAPER_ACTIVITY;
 
 import static com.android.launcher3.LauncherState.CLEAR_ALL_BUTTON;
+import static com.android.launcher3.LauncherState.ADD_DESK_BUTTON;
 import static com.android.launcher3.LauncherState.NORMAL;
 import static com.android.launcher3.LauncherState.OVERVIEW;
 import static com.android.launcher3.LauncherState.OVERVIEW_MODAL_TASK;
@@ -198,7 +199,10 @@ public class LauncherRecentsView extends RecentsView<QuickstepLauncher, Launcher
             LauncherState state = getStateManager().getState();
             boolean hasClearAllButton = (state.getVisibleElements(mContainer)
                     & CLEAR_ALL_BUTTON) != 0;
+            boolean hasAddDeskButton = (state.getVisibleElements(mContainer)
+                    & ADD_DESK_BUTTON) != 0;
             setDisallowScrollToClearAll(!hasClearAllButton);
+            setDisallowScrollToAddDesk(!hasAddDeskButton);
         }
     }
 
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index b5483e2385..e698c018fc 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -586,6 +586,8 @@ public abstract class RecentsView<
     private final TaskOverlayFactory mTaskOverlayFactory;
 
     protected boolean mDisallowScrollToClearAll;
+    // True if it is not allowed to scroll to [AddDesktopButton].
+    protected boolean mDisallowScrollToAddDesk;
     private boolean mOverlayEnabled;
     protected boolean mFreezeViewVisibility;
     private boolean mOverviewGridEnabled;
@@ -6164,6 +6166,17 @@ public abstract class RecentsView<
             updateMinAndMaxScrollX();
         }
     }
+    /**
+     * Update the value of [mDisallowScrollToAddDesk]
+     */
+    public void setDisallowScrollToAddDesk(boolean disallowScrollToAddDesk) {
+        if (mDisallowScrollToAddDesk != disallowScrollToAddDesk) {
+            mDisallowScrollToAddDesk = disallowScrollToAddDesk;
+            updateMinAndMaxScrollX();
+        }
+    }
+
+
 
     /**
      * Updates page scroll synchronously after measure and layout child views.
@@ -6309,7 +6322,20 @@ public abstract class RecentsView<
         if (addDesktopButtonIndex >= 0 && addDesktopButtonIndex < outPageScrolls.length) {
             int firstViewIndex = getFirstViewIndex();
             if (firstViewIndex >= 0 && firstViewIndex < outPageScrolls.length) {
-                outPageScrolls[addDesktopButtonIndex] = outPageScrolls[firstViewIndex];
+                // If we can scroll to [AddDesktopButton], make its page scroll equal to
+                // the first [TaskView]. Otherwise, make its page scroll out of range of
+                // [minScroll, maxScroll].
+                if (!mDisallowScrollToAddDesk) {
+                    outPageScrolls[addDesktopButtonIndex] = outPageScrolls[firstViewIndex];
+                } else {
+                    outPageScrolls[addDesktopButtonIndex] =
+                            outPageScrolls[firstViewIndex] + (mIsRtl ? 1 : -1);
+                }
+            }
+
+            if (DEBUG) {
+                Log.d(TAG, "getPageScrolls - addDesktopButtonScroll: "
+                        + outPageScrolls[addDesktopButtonIndex]);
             }
         }
         if (DEBUG) {