Fix 3237665: Home screen should scroll on tap, not touch down

Change-Id: I61f65beaf982eec54b86668d6da94aa5c52e9355
diff --git a/src/com/android/launcher2/PagedView.java b/src/com/android/launcher2/PagedView.java
index 1965712..4a0f44e 100644
--- a/src/com/android/launcher2/PagedView.java
+++ b/src/com/android/launcher2/PagedView.java
@@ -696,6 +696,20 @@
         super.requestDisallowInterceptTouchEvent(disallowIntercept);
     }
 
+    /**
+     * Return true if a tap at (x, y) should trigger a flip to the previous page.
+     */
+    protected boolean hitsPreviousPage(float x, float y) {
+        return (x < getRelativeChildOffset(mCurrentPage) - mPageSpacing);
+    }
+
+    /**
+     * Return true if a tap at (x, y) should trigger a flip to the next page.
+     */
+    protected boolean hitsNextPage(float x, float y) {
+        return  (x > (getMeasuredWidth() - getRelativeChildOffset(mCurrentPage) + mPageSpacing));
+    }
+
     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         /*
@@ -761,14 +775,11 @@
 
                 // check if this can be the beginning of a tap on the side of the pages
                 // to scroll the current page
-                if ((mTouchState != TOUCH_STATE_PREV_PAGE) && !handlePagingClicks() &&
-                        (mTouchState != TOUCH_STATE_NEXT_PAGE)) {
+                if (mTouchState != TOUCH_STATE_PREV_PAGE && mTouchState != TOUCH_STATE_NEXT_PAGE) {
                     if (getChildCount() > 0) {
-                        int width = getMeasuredWidth();
-                        int offset = getRelativeChildOffset(mCurrentPage);
-                        if (x < offset - mPageSpacing) {
+                        if (hitsPreviousPage(x, y)) {
                             mTouchState = TOUCH_STATE_PREV_PAGE;
-                        } else if (x > (width - offset + mPageSpacing)) {
+                        } else if (hitsNextPage(x, y)) {
                             mTouchState = TOUCH_STATE_NEXT_PAGE;
                         }
                     }
@@ -856,10 +867,6 @@
         }
     }
 
-    protected boolean handlePagingClicks() {
-        return false;
-    }
-
     // This curve determines how the effect of scrolling over the limits of the page dimishes
     // as the user pulls further and further from the bounds
     private float overScrollInfluenceCurve(float f) {
@@ -966,7 +973,7 @@
                 } else {
                     snapToDestination();
                 }
-            } else if (mTouchState == TOUCH_STATE_PREV_PAGE && !handlePagingClicks()) {
+            } else if (mTouchState == TOUCH_STATE_PREV_PAGE) {
                 // at this point we have not moved beyond the touch slop
                 // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                 // we can just page
@@ -976,7 +983,7 @@
                 } else {
                     snapToDestination();
                 }
-            } else if (mTouchState == TOUCH_STATE_NEXT_PAGE && !handlePagingClicks()) {
+            } else if (mTouchState == TOUCH_STATE_NEXT_PAGE) {
                 // at this point we have not moved beyond the touch slop
                 // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                 // we can just page