From 4b26997eeb6bbb526738bcbfaaa9b7147ba0f4a2 Mon Sep 17 00:00:00 2001
From: Yohei Yukawa <yukawa@google.com>
Date: Wed, 15 Jul 2015 19:01:32 -0700
Subject: [PATCH] PopupWindow position must be specified in window coordinates.

This CL addresses TODOs in Ib641dda49f7ab1c7d60207c36a47767bb408.

With this CL the position of PopupWindow is always specified in
window-local coordinates even if FloatingToolbar#mParent is not a
decor view.

Bug: 22335001
Change-Id: I0cdd63a00051fa30981e517c07682075467ac598
---
 .../internal/widget/FloatingToolbar.java      | 43 ++++++++++---------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/core/java/com/android/internal/widget/FloatingToolbar.java b/core/java/com/android/internal/widget/FloatingToolbar.java
index 3482d3ce2ba39..ca6fe619f528d 100644
--- a/core/java/com/android/internal/widget/FloatingToolbar.java
+++ b/core/java/com/android/internal/widget/FloatingToolbar.java
@@ -285,7 +285,6 @@ public final class FloatingToolbar {
 
         private final Context mContext;
         private final View mParent;
-        private final int[] mParentPositionOnScreen = new int[2];
         private final PopupWindow mPopupWindow;
         private final ViewGroup mContentContainer;
         private final int mMarginHorizontal;
@@ -339,7 +338,8 @@ public final class FloatingToolbar {
         };
 
         private final Rect mViewPortOnScreen = new Rect();
-        private final Point mCoordsOnScreen = new Point();
+        private final Point mCoordsOnWindow = new Point();
+        private final int[] mTmpCoords = new int[2];
         private final Rect mTmpRect = new Rect();
 
         private final Region mTouchableRegion = new Region();
@@ -450,16 +450,11 @@ public final class FloatingToolbar {
             }
             refreshCoordinatesAndOverflowDirection(contentRectOnScreen);
             preparePopupContent();
-            // PopupWindow#showAtLocation() receives the location relative to the attached window
-            // hence the following code is correct when and only when mParent is aligned to the
-            // top-left of the attached window.
-            // TODO: Fix the following logic so that mParent can be placed at anywhere.
+            // We need to specify the position in window coordinates.
             // TODO: Consider to use PopupWindow.setLayoutInScreenEnabled(true) so that we can
             // specify the popup poision in screen coordinates.
-            mParent.getLocationOnScreen(mParentPositionOnScreen);
-            final int relativeX = mCoordsOnScreen.x - mParentPositionOnScreen[0];
-            final int relativeY = mCoordsOnScreen.y - mParentPositionOnScreen[1];
-            mPopupWindow.showAtLocation(mParent, Gravity.NO_GRAVITY, relativeX, relativeY);
+            mPopupWindow.showAtLocation(mParent, Gravity.NO_GRAVITY, mCoordsOnWindow.x,
+                    mCoordsOnWindow.y);
             setTouchableSurfaceInsetsComputer();
             runShowAnimation();
         }
@@ -522,17 +517,10 @@ public final class FloatingToolbar {
             cancelOverflowAnimations();
             refreshCoordinatesAndOverflowDirection(contentRectOnScreen);
             preparePopupContent();
-            // PopupWindow#update() receives the location relative to the attached window hence
-            // the following code is correct when and only when mParent is aligned to the top-left
-            // of the attached window.
-            // TODO: Fix the following logic so that mParent can be placed at anywhere.
-            // We need to specify the offset relative to mParent.
+            // We need to specify the position in window coordinates.
             // TODO: Consider to use PopupWindow.setLayoutInScreenEnabled(true) so that we can
             // specify the popup poision in screen coordinates.
-            mParent.getLocationOnScreen(mParentPositionOnScreen);
-            final int relativeX = mCoordsOnScreen.x - mParentPositionOnScreen[0];
-            final int relativeY = mCoordsOnScreen.y - mParentPositionOnScreen[1];
-            mPopupWindow.update(relativeX, relativeY, getWidth(), getHeight());
+            mPopupWindow.update(mCoordsOnWindow.x, mCoordsOnWindow.y, getWidth(), getHeight());
         }
 
         /**
@@ -631,7 +619,22 @@ public final class FloatingToolbar {
                 mOverflowPanel.setOverflowDirection(mOverflowDirection);
             }
 
-            mCoordsOnScreen.set(x, y);
+            // We later specify the location of PopupWindow relative to the attached window.
+            // The idea here is that 1) we can get the location of a View in both window coordinates
+            // and screen coordiantes, where the offset between them should be equal to the window
+            // origin, and 2) we can use an arbitrary for this calculation while calculating the
+            // location of the rootview is supposed to be least expensive.
+            // TODO: Consider to use PopupWindow.setLayoutInScreenEnabled(true) so that we can avoid
+            // the following calculation.
+            mParent.getRootView().getLocationOnScreen(mTmpCoords);
+            int rootViewLeftOnScreen = mTmpCoords[0];
+            int rootViewTopOnScreen = mTmpCoords[1];
+            mParent.getRootView().getLocationInWindow(mTmpCoords);
+            int rootViewLeftOnWindow = mTmpCoords[0];
+            int rootViewTopOnWindow = mTmpCoords[1];
+            int windowLeftOnScreen = rootViewLeftOnScreen - rootViewLeftOnWindow;
+            int windowTopOnScreen = rootViewTopOnScreen - rootViewTopOnWindow;
+            mCoordsOnWindow.set(x - windowLeftOnScreen, y - windowTopOnScreen);
         }
 
         private int getToolbarHeightWithVerticalMargin() {