Properly restore RTL state in HorizontalScrollView

Fix an incorrect unparceling of the previous saved state in
HorizontalScrollView. Remove an unneeded field in the saved state by
storing scroll offset from start instead of scrollX + isRtl.

Bug 20666194

Change-Id: I1ec45b3e3bd0846b5f659356df7ff94f42e61055

1 files changed, 9 insertions, 15 deletions

diff --git a/core/java/android/widget/HorizontalScrollView.java b/core/java/android/widget/HorizontalScrollView.java
index cf67905af3d6..ebc7eb3e3646 100644
--- a/core/java/android/widget/HorizontalScrollView.java
+++ b/core/java/android/widget/HorizontalScrollView.java
@@ -1505,11 +1505,9 @@ public class HorizontalScrollView extends FrameLayout {
             final int scrollRange = Math.max(0,
                     childWidth - (r - l - mPaddingLeft - mPaddingRight));
             if (mSavedState != null) {
-                if (isLayoutRtl() == mSavedState.isLayoutRtl) {
-                    mScrollX = mSavedState.scrollPosition;
-                } else {
-                    mScrollX = scrollRange - mSavedState.scrollPosition;
-                }
+                mScrollX = isLayoutRtl()
+                        ? scrollRange - mSavedState.scrollOffsetFromStart
+                        : mSavedState.scrollOffsetFromStart;
                 mSavedState = null;
             } else {
                 if (isLayoutRtl()) {
@@ -1692,8 +1690,7 @@ public class HorizontalScrollView extends FrameLayout {
         }
         Parcelable superState = super.onSaveInstanceState();
         SavedState ss = new SavedState(superState);
-        ss.scrollPosition = mScrollX;
-        ss.isLayoutRtl = isLayoutRtl();
+        ss.scrollOffsetFromStart = isLayoutRtl() ? -mScrollX : mScrollX;
         return ss;
     }
 
@@ -1705,8 +1702,7 @@ public class HorizontalScrollView extends FrameLayout {
     }
 
     static class SavedState extends BaseSavedState {
-        public int scrollPosition;
-        public boolean isLayoutRtl;
+        public int scrollOffsetFromStart;
 
         SavedState(Parcelable superState) {
             super(superState);
@@ -1714,23 +1710,21 @@ public class HorizontalScrollView extends FrameLayout {
 
         public SavedState(Parcel source) {
             super(source);
-            scrollPosition = source.readInt();
-            isLayoutRtl = (source.readInt() == 0) ? true : false;
+            scrollOffsetFromStart = source.readInt();
         }
 
         @Override
         public void writeToParcel(Parcel dest, int flags) {
             super.writeToParcel(dest, flags);
-            dest.writeInt(scrollPosition);
-            dest.writeInt(isLayoutRtl ? 1 : 0);
+            dest.writeInt(scrollOffsetFromStart);
         }
 
         @Override
         public String toString() {
             return "HorizontalScrollView.SavedState{"
                     + Integer.toHexString(System.identityHashCode(this))
-                    + " scrollPosition=" + scrollPosition
-                    + " isLayoutRtl=" + isLayoutRtl + "}";
+                    + " scrollPosition=" + scrollOffsetFromStart
+                    + "}";
         }
 
         public static final Parcelable.Creator<SavedState> CREATOR