Merge "Adjust drag regions to accomodate split-minimized home" into rvc-dev

services/core/java/com/android/server/wm/Task.java

@@ -2924,7 +2924,12 @@ class Task extends WindowContainer<WindowContainer> {
     }
 
     boolean cropWindowsToStackBounds() {
-        return isResizeable();
+        // Don't crop HOME/RECENTS windows to stack bounds. This is because in split-screen
+        // they extend past their stack and sysui uses the stack surface to control cropping.
+        // TODO(b/158242495): get rid of this when drag/drop can use surface bounds.
+        final boolean isTopHomeOrRecents = (isActivityTypeHome() || isActivityTypeRecents())
+                && getRootTask().getTopMostTask() == this;
+        return isResizeable() && !isTopHomeOrRecents;
     }
 
     /**

services/core/java/com/android/server/wm/TaskDisplayArea.java

@@ -207,6 +207,15 @@ final class TaskDisplayArea extends DisplayArea<ActivityStack> {
         return mRootSplitScreenPrimaryTask;
     }
 
+    ActivityStack getRootSplitScreenSecondaryTask() {
+        for (int i = mChildren.size() - 1; i >= 0; --i) {
+            if (mChildren.get(i).inSplitScreenSecondaryWindowingMode()) {
+                return mChildren.get(i);
+            }
+        }
+        return null;
+    }
+
     ArrayList<Task> getVisibleTasks() {
         final ArrayList<Task> visibleTasks = new ArrayList<>();
         forAllTasks(task -> {

services/core/java/com/android/server/wm/WindowState.java

@@ -1528,6 +1528,29 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
                 && dc != null ? dc.getDefaultTaskDisplayArea().getRootHomeTask() : null;
     }
 
+    /**
+     * This is a form of rectangle "difference". It cut off each dimension of rect by the amount
+     * that toRemove is "pushing into" it from the outside. Any dimension that fully contains
+     * toRemove won't change.
+     */
+    private void cutRect(Rect rect, Rect toRemove) {
+        if (toRemove.isEmpty()) return;
+        if (toRemove.top < rect.bottom && toRemove.bottom > rect.top) {
+            if (toRemove.right >= rect.right && toRemove.left >= rect.left) {
+                rect.right = toRemove.left;
+            } else if (toRemove.left <= rect.left && toRemove.right <= rect.right) {
+                rect.left = toRemove.right;
+            }
+        }
+        if (toRemove.left < rect.right && toRemove.right > rect.left) {
+            if (toRemove.bottom >= rect.bottom && toRemove.top >= rect.top) {
+                rect.bottom = toRemove.top;
+            } else if (toRemove.top <= rect.top && toRemove.bottom <= rect.bottom) {
+                rect.top = toRemove.bottom;
+            }
+        }
+    }
+
     /**
      * Retrieves the visible bounds of the window.
      * @param bounds The rect which gets the bounds.
@@ -1544,6 +1567,20 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
             } else {
                 intersectWithStackBounds = false;
             }
+            if (inSplitScreenPrimaryWindowingMode()) {
+                // If this is in the primary split and the home stack is the top visible task in
+                // the secondary split, it means this is "minimized" and thus must prevent
+                // overlapping with home.
+                // TODO(b/158242495): get rid of this when drag/drop can use surface bounds.
+                final ActivityStack rootSecondary =
+                        task.getDisplayArea().getRootSplitScreenSecondaryTask();
+                if (rootSecondary.isActivityTypeHome() || rootSecondary.isActivityTypeRecents()) {
+                    final WindowContainer topTask = rootSecondary.getTopChild();
+                    if (topTask.isVisible()) {
+                        cutRect(mTmpRect, topTask.getBounds());
+                    }
+                }
+            }
         }
 
         bounds.set(mWindowFrames.mVisibleFrame);