Support for Adaptive Handle Orientation

content/public/android/java/src/org/chromium/content/browser/input/PopupTouchHandleDrawable.java

Index: content/public/android/java/src/org/chromium/content/browser/input/PopupTouchHandleDrawable.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/input/PopupTouchHandleDrawable.java b/content/public/android/java/src/org/chromium/content/browser/input/PopupTouchHandleDrawable.java
index 04722877ecabdcc8cc37b88a047c3a51740021a5..f6223f38a4c504924ecec91b962bfe26aa1773b7 100644
--- a/content/public/android/java/src/org/chromium/content/browser/input/PopupTouchHandleDrawable.java
+++ b/content/public/android/java/src/org/chromium/content/browser/input/PopupTouchHandleDrawable.java
@@ -50,9 +50,9 @@ public class PopupTouchHandleDrawable extends View {
     private int mParentPositionX;
     private int mParentPositionY;
 
-    // The offset from this handles position to the "tip" of the handle.
-    private float mHotspotX;
-    private float mHotspotY;
+    // The mirror values based on which the handles are inverted about X and Y axes.
+    private boolean mMirrorHorizontal;
+    private boolean mMirrorVertical;
 
     private float mAlpha;
 
@@ -145,46 +145,42 @@ public class PopupTouchHandleDrawable extends View {
     }
 
     @CalledByNative
-    private void setOrientation(int orientation) {
+    private void setOrientation(int orientation, boolean mirrorVertical, boolean mirrorHorizontal) {
         assert (orientation >= TouchHandleOrientation.LEFT
                 && orientation <= TouchHandleOrientation.UNDEFINED);
-        if (mOrientation == orientation) return;
 
         final boolean hadValidOrientation = mOrientation != TouchHandleOrientation.UNDEFINED;
+        final boolean orientationChanged = mOrientation != orientation;
         mOrientation = orientation;
+        mMirrorHorizontal = mirrorHorizontal;
+        mMirrorVertical = mirrorVertical;
 
-        final int oldAdjustedPositionX = getAdjustedPositionX();
-        final int oldAdjustedPositionY = getAdjustedPositionY();
+        // Create new InvertedDrawable only if orientation has changed.
+        // Otherwise, change the mirror values to scale canvas on draw() calls.
+        if (orientationChanged) mDrawable = getHandleDrawable();
 
-        switch (orientation) {
+        mDrawable.setAlpha((int) (255 * mAlpha));
+    }
+
+    private Drawable getHandleDrawable() {
+        switch (mOrientation) {
             case TouchHandleOrientation.LEFT: {
-                mDrawable = HandleViewResources.getLeftHandleDrawable(mContext);
-                mHotspotX = (mDrawable.getIntrinsicWidth() * 3) / 4f;
-                break;
+                return HandleViewResources.getLeftHandleDrawable(mContext);
             }
 
             case TouchHandleOrientation.RIGHT: {
-                mDrawable = HandleViewResources.getRightHandleDrawable(mContext);
-                mHotspotX = mDrawable.getIntrinsicWidth() / 4f;
-                break;
+                return HandleViewResources.getRightHandleDrawable(mContext);
             }
 
             case TouchHandleOrientation.CENTER: {
-                mDrawable = HandleViewResources.getCenterHandleDrawable(mContext);
-                mHotspotX = mDrawable.getIntrinsicWidth() / 2f;
-                break;
+                return HandleViewResources.getCenterHandleDrawable(mContext);
             }
 
             case TouchHandleOrientation.UNDEFINED:
             default:
-                break;
+                assert false;
+                return HandleViewResources.getCenterHandleDrawable(mContext);
         }
-        mHotspotY = 0;
-
-        // Force handle repositioning to accommodate the new orientation's hotspot.
-        if (hadValidOrientation) setFocus(oldAdjustedPositionX, oldAdjustedPositionY);
-        mDrawable.setAlpha((int) (255 * mAlpha));
-        scheduleInvalidate();
     }
 
     private void updateParentPosition(int parentPositionX, int parentPositionY) {
@@ -299,9 +295,17 @@ public class PopupTouchHandleDrawable extends View {
     @Override
     protected void onDraw(Canvas c) {
         if (mDrawable == null) return;
+        final boolean needsMirror = mMirrorHorizontal || mMirrorVertical;
+        if (needsMirror) {
+            c.save();
+            float scaleX = mMirrorHorizontal ? -1.f : 1.f;
+            float scaleY = mMirrorVertical ? -1.f : 1.f;
+            c.scale(scaleX, scaleY, getWidth() / 2.0f, getHeight() / 2.0f);
+        }
         updateAlpha();
         mDrawable.setBounds(0, 0, getRight() - getLeft(), getBottom() - getTop());
         mDrawable.draw(c);
+        if (needsMirror) c.restore();
     }
 
     @Override
@@ -310,18 +314,6 @@ public class PopupTouchHandleDrawable extends View {
         hide();
     }
 
-    // Returns the x coordinate of the position that the handle appears to be pointing to relative
-    // to the handles "parent" view.
-    private int getAdjustedPositionX() {
-        return mPositionX + Math.round(mHotspotX);
-    }
-
-    // Returns the y coordinate of the position that the handle appears to be pointing to relative
-    // to the handles "parent" view.
-    private int getAdjustedPositionY() {
-        return mPositionY + Math.round(mHotspotY);
-    }
-
     private PopupTouchHandleDrawableDelegate getDelegateAndHideIfNull() {
         final PopupTouchHandleDrawableDelegate delegate = mDelegate.get();
         // If the delegate is gone, we should immediately dispose of the popup.
@@ -369,12 +361,10 @@ public class PopupTouchHandleDrawable extends View {
     }
 
     @CalledByNative
-    private void setFocus(float focusX, float focusY) {
-        int x = (int) focusX - Math.round(mHotspotX);
-        int y = (int) focusY - Math.round(mHotspotY);
-        if (mPositionX == x && mPositionY == y) return;
-        mPositionX = x;
-        mPositionY = y;
+    private void setOrigin(float originX, float originY) {
+        if (mPositionX == originX && mPositionY == originY) return;
+        mPositionX = (int) originX;
+        mPositionY = (int) originY;
         if (isScrollInProgress()) {
             temporarilyHide();
         } else {
@@ -396,6 +386,11 @@ public class PopupTouchHandleDrawable extends View {
     }
 
     @CalledByNative
+    private float getHandleHorizontalPadding() {
+        return HandleViewResources.getHandleHorizontalPadding();
+    }
+
+    @CalledByNative
     private int getPositionY() {
         return mPositionY;
     }