Add window to child window list with correct order

The original logic of comparing with mBaseLayer of two child windows
of the same parent was wrong, because the mBaseLayer is always the
same.

After adding two child windows with the same positive sublayer, the
one added later should have greater z-order. The order should be
consistent with WindowManagerService.addAttachedWindowToListLocked()

Change-Id: I789179aee61d141fad86bd24262fabfb1e517e66

1 files changed, 16 insertions, 18 deletions

diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index b4a7f04..04dab3e 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -386,28 +386,26 @@ final class WindowState implements WindowManagerPolicy.WindowState {
             mAttachedWindow = attachedWindow;
             if (WindowManagerService.DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + this + " to " + mAttachedWindow);
 
-            int children_size = mAttachedWindow.mChildWindows.size();
-            if (children_size == 0) {
-                mAttachedWindow.mChildWindows.add(this);
+            final WindowList childWindows = mAttachedWindow.mChildWindows;
+            final int numChildWindows = childWindows.size();
+            if (numChildWindows == 0) {
+                childWindows.add(this);
             } else {
-                for (int i = 0; i < children_size; i++) {
-                    WindowState child = (WindowState)mAttachedWindow.mChildWindows.get(i);
-                    if (this.mSubLayer < child.mSubLayer) {
-                        mAttachedWindow.mChildWindows.add(i, this);
+                boolean added = false;
+                for (int i = 0; i < numChildWindows; i++) {
+                    final int childSubLayer = childWindows.get(i).mSubLayer;
+                    if (mSubLayer < childSubLayer
+                            || (mSubLayer == childSubLayer && childSubLayer < 0)) {
+                        // We insert the child window into the list ordered by the sub-layer. For
+                        // same sub-layers, the negative one should go below others; the positive
+                        // one should go above others.
+                        childWindows.add(i, this);
+                        added = true;
                         break;
-                    } else if (this.mSubLayer > child.mSubLayer) {
-                        continue;
-                    }
-
-                    if (this.mBaseLayer <= child.mBaseLayer) {
-                        mAttachedWindow.mChildWindows.add(i, this);
-                        break;
-                    } else {
-                        continue;
                     }
                 }
-                if (children_size == mAttachedWindow.mChildWindows.size()) {
-                    mAttachedWindow.mChildWindows.add(this);
+                if (!added) {
+                    childWindows.add(this);
                 }
             }