Screenshots broken for activities with dialog themes

Makes progress towards fixing screenshots and transitions
for non-fullscreen activities.

Partially reverts I48053f551ed1c118764aa30e0b6408db64d4a5f1 and
applies it in a way that does not break screenshots in general.

Note that screenshots of non-fullscreen activities are still somewhat
broken because their insets can currently not be calculated correctly.

Bug: 72757033
Test: Open dialog activity, go to recents, verify it has a reasonable screenshot and smooth transition
Test: Open letterboxed activity, go to recents, verify it has a reasonable screenshot and smooth transition
Change-Id: Ica4d88370df00a91724d59b2cad6b27826beba04

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

@@ -1728,6 +1728,8 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
                 frame.set(win.mContainingFrame);
             }
             surfaceInsets = win.getAttrs().surfaceInsets;
+            // XXX(b/72757033): These are insets relative to the window frame, but we're really
+            // interested in the insets relative to the frame we chose in the if-blocks above.
             insets.set(win.mContentInsets);
             stableInsets.set(win.mStableInsets);
         }
@@ -2120,4 +2122,12 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
         }
         return stringName + ((mIsExiting) ? " mIsExiting=" : "");
     }
+
+    Rect getLetterboxInsets() {
+        if (mLetterbox != null) {
+            return mLetterbox.getInsets();
+        } else {
+            return new Rect();
+        }
+    }
 }

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

@@ -67,6 +67,17 @@ public class Letterbox {
         mRight.setRect(t, inner.right, outer.top, outer.right, inner.bottom);
     }
 
+    /**
+     * Gets the insets between the outer and inner rects.
+     */
+    public Rect getInsets() {
+        return new Rect(
+                mLeft.getWidth(),
+                mTop.getHeight(),
+                mRight.getWidth(),
+                mBottom.getHeight());
+    }
+
     /**
      * Hides the letterbox.
      *
@@ -141,5 +152,13 @@ public class Letterbox {
                 mSurface = null;
             }
         }
+
+        public int getWidth() {
+            return Math.max(0, mLastRight - mLastLeft);
+        }
+
+        public int getHeight() {
+            return Math.max(0, mLastBottom - mLastTop);
+        }
     }
 }

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

@@ -281,17 +281,25 @@ class TaskSnapshotController {
     }
 
     private Rect getInsetsFromTaskBounds(WindowState state, Task task) {
-        final Rect r = new Rect();
-        r.set(state.getContentFrameLw());
-        r.intersectUnchecked(state.getStableFrameLw());
+        // XXX(b/72757033): These are insets relative to the window frame, but we're really
+        // interested in the insets relative to the task bounds.
+        Rect insets = minRect(state.mContentInsets, state.mStableInsets);
+        insets = maxRect(insets, state.mAppToken.getLetterboxInsets());
+        return insets;
+    }
 
-        final Rect taskBounds = task.getBounds();
+    private Rect minRect(Rect rect1, Rect rect2) {
+        return new Rect(Math.min(rect1.left, rect2.left),
+                Math.min(rect1.top, rect2.top),
+                Math.min(rect1.right, rect2.right),
+                Math.min(rect1.bottom, rect2.bottom));
+    }
 
-        r.set(Math.max(0, r.left - taskBounds.left),
-                Math.max(0, r.top - taskBounds.top),
-                Math.max(0, taskBounds.right - r.right),
-                Math.max(0, taskBounds.bottom - r.bottom));
-        return r;
+    private Rect maxRect(Rect rect1, Rect rect2) {
+        return new Rect(Math.max(rect1.left, rect2.left),
+                Math.max(rect1.top, rect2.top),
+                Math.max(rect1.right, rect2.right),
+                Math.max(rect1.bottom, rect2.bottom));
     }
 
     /**