Make RelativeLayout aware of layout direction

- see bug #5429822 UI should be mirrored for RTL locales (Arabic, Hebrew, farsi)

Change-Id: Ica92841fa0c13c25fcf89c4700b0771eec4fd6d7

Author: Fabrice Di Meglio

api/current.txt

@@ -607,12 +607,16 @@ package android {
     field public static final int layout_above = 16843140; // 0x1010184
     field public static final int layout_alignBaseline = 16843142; // 0x1010186
     field public static final int layout_alignBottom = 16843146; // 0x101018a
+    field public static final int layout_alignEnd = 16843706; // 0x10103ba
     field public static final int layout_alignLeft = 16843143; // 0x1010187
     field public static final int layout_alignParentBottom = 16843150; // 0x101018e
+    field public static final int layout_alignParentEnd = 16843708; // 0x10103bc
     field public static final int layout_alignParentLeft = 16843147; // 0x101018b
     field public static final int layout_alignParentRight = 16843149; // 0x101018d
+    field public static final int layout_alignParentStart = 16843707; // 0x10103bb
     field public static final int layout_alignParentTop = 16843148; // 0x101018c
     field public static final int layout_alignRight = 16843145; // 0x1010189
+    field public static final int layout_alignStart = 16843705; // 0x10103b9
     field public static final int layout_alignTop = 16843144; // 0x1010188
     field public static final int layout_alignWithParentIfMissing = 16843154; // 0x1010192
     field public static final int layout_below = 16843141; // 0x1010185
@@ -634,8 +638,10 @@ package android {
     field public static final int layout_rowSpan = 16843644; // 0x101037c
     field public static final int layout_scale = 16843155; // 0x1010193
     field public static final int layout_span = 16843085; // 0x101014d
+    field public static final int layout_toEndOf = 16843704; // 0x10103b8
     field public static final int layout_toLeftOf = 16843138; // 0x1010182
     field public static final int layout_toRightOf = 16843139; // 0x1010183
+    field public static final int layout_toStartOf = 16843703; // 0x10103b7
     field public static final int layout_weight = 16843137; // 0x1010181
     field public static final int layout_width = 16842996; // 0x10100f4
     field public static final int layout_x = 16843135; // 0x101017f
@@ -24901,9 +24907,12 @@ package android.view {
     ctor public ViewGroup.MarginLayoutParams(int, int);
     ctor public ViewGroup.MarginLayoutParams(android.view.ViewGroup.MarginLayoutParams);
     ctor public ViewGroup.MarginLayoutParams(android.view.ViewGroup.LayoutParams);
+    method public int getLayoutDirection();
     method public int getMarginEnd();
     method public int getMarginStart();
+    method protected boolean isLayoutRtl();
     method public boolean isMarginRelative();
+    method public void setLayoutDirection(int);
     method public void setMargins(int, int, int, int);
     field public int bottomMargin;
     field public int endMargin;
@@ -28198,19 +28207,25 @@ package android.widget {
     field public static final int ABOVE = 2; // 0x2
     field public static final int ALIGN_BASELINE = 4; // 0x4
     field public static final int ALIGN_BOTTOM = 8; // 0x8
+    field public static final int ALIGN_END = 19; // 0x13
     field public static final int ALIGN_LEFT = 5; // 0x5
     field public static final int ALIGN_PARENT_BOTTOM = 12; // 0xc
+    field public static final int ALIGN_PARENT_END = 21; // 0x15
     field public static final int ALIGN_PARENT_LEFT = 9; // 0x9
     field public static final int ALIGN_PARENT_RIGHT = 11; // 0xb
+    field public static final int ALIGN_PARENT_START = 20; // 0x14
     field public static final int ALIGN_PARENT_TOP = 10; // 0xa
     field public static final int ALIGN_RIGHT = 7; // 0x7
+    field public static final int ALIGN_START = 18; // 0x12
     field public static final int ALIGN_TOP = 6; // 0x6
     field public static final int BELOW = 3; // 0x3
     field public static final int CENTER_HORIZONTAL = 14; // 0xe
     field public static final int CENTER_IN_PARENT = 13; // 0xd
     field public static final int CENTER_VERTICAL = 15; // 0xf
+    field public static final int END_OF = 17; // 0x11
     field public static final int LEFT_OF = 0; // 0x0
     field public static final int RIGHT_OF = 1; // 0x1
+    field public static final int START_OF = 16; // 0x10
     field public static final int TRUE = -1; // 0xffffffff
   }
 

core/java/android/view/ViewGroup.java

@@ -5504,13 +5504,17 @@ public static class MarginLayoutParams extends ViewGroup.LayoutParams {
 
         /**
          * The default start and end margin.
+         * @hide
          */
-        static private final int DEFAULT_RELATIVE = Integer.MIN_VALUE;
+        public static final int DEFAULT_RELATIVE = Integer.MIN_VALUE;
 
         private int initialLeftMargin;
         private int initialRightMargin;
 
-        private int layoutDirection;
+        private static int LAYOUT_DIRECTION_UNDEFINED = -1;
+
+        // Layout direction undefined by default
+        private int layoutDirection = LAYOUT_DIRECTION_UNDEFINED;
 
         /**
          * Creates a new set of layout parameters. The values are extracted from
@@ -5553,9 +5557,6 @@ public MarginLayoutParams(Context c, AttributeSet attrs) {
             initialLeftMargin = leftMargin;
             initialRightMargin = rightMargin;
 
-            // LTR by default
-            layoutDirection = View.LAYOUT_DIRECTION_LTR;
-
             a.recycle();
         }
 
@@ -5585,7 +5586,7 @@ public MarginLayoutParams(MarginLayoutParams source) {
             this.initialLeftMargin = source.leftMargin;
             this.initialRightMargin = source.rightMargin;
 
-            this.layoutDirection = source.layoutDirection;
+            setLayoutDirection(source.layoutDirection);
         }
 
         /**
@@ -5688,19 +5689,41 @@ public int getMarginEnd() {
          * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginStart
          * @attr ref android.R.styleable#ViewGroup_MarginLayout_layout_marginEnd
          *
-         * @return true if either marginStart or marginEnd has been set
+         * @return true if either marginStart or marginEnd has been set.
          */
         public boolean isMarginRelative() {
             return (startMargin != DEFAULT_RELATIVE) || (endMargin != DEFAULT_RELATIVE);
         }
 
+        /**
+         * Set the layout direction
+         * @param layoutDirection the layout direction.
+         *        Should be either {@link View#LAYOUT_DIRECTION_LTR}
+         *                     or {@link View#LAYOUT_DIRECTION_RTL}.
+         */
+        public void setLayoutDirection(int layoutDirection) {
+            if (layoutDirection != View.LAYOUT_DIRECTION_LTR &&
+                    layoutDirection != View.LAYOUT_DIRECTION_RTL) return;
+            this.layoutDirection = layoutDirection;
+        }
+
+        /**
+         * Retuns the layout direction. Can be either {@link View#LAYOUT_DIRECTION_LTR} or
+         * {@link View#LAYOUT_DIRECTION_RTL}.
+         *
+         * @return the layout direction.
+         */
+        public int getLayoutDirection() {
+            return layoutDirection;
+        }
+
         /**
          * This will be called by {@link android.view.View#requestLayout()}. Left and Right margins
          * may be overridden depending on layout direction.
          */
         @Override
         public void onResolveLayoutDirection(int layoutDirection) {
-            this.layoutDirection = layoutDirection;
+            setLayoutDirection(layoutDirection);
 
             if (!isMarginRelative()) return;
 
@@ -5717,6 +5740,10 @@ public void onResolveLayoutDirection(int layoutDirection) {
             }
         }
 
+        protected boolean isLayoutRtl() {
+            return (layoutDirection == View.LAYOUT_DIRECTION_RTL);
+        }
+
         /**
          * @hide
          */