Using cellX and cellY for comparing position when rank is not available

Bug: 22059402
Change-Id: I69ec2b9b68610e171e76cd968de77aaed669672c

src/com/android/launcher3/Folder.java

@@ -61,6 +61,7 @@ import com.android.launcher3.util.Thunk;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Comparator;
 
 /**
  * Represents a set of icons chosen by the user or generated by the system.
@@ -362,7 +363,7 @@ public class Folder extends LinearLayout implements DragSource, View.OnClickList
     void bind(FolderInfo info) {
         mInfo = info;
         ArrayList<ShortcutInfo> children = info.contents;
-        Collections.sort(children, Utilities.RANK_COMPARATOR);
+        Collections.sort(children, ITEM_POS_COMPARATOR);
 
         ArrayList<ShortcutInfo> overflow = mContent.bindItems(children);
 
@@ -1395,4 +1396,19 @@ public class Folder extends LinearLayout implements DragSource, View.OnClickList
             onDragOver(mDragObject, 1);
         }
     }
+
+    // Compares item position based on rank and position giving priority to the rank.
+    private static final Comparator<ItemInfo> ITEM_POS_COMPARATOR = new Comparator<ItemInfo>() {
+
+        @Override
+        public int compare(ItemInfo lhs, ItemInfo rhs) {
+            if (lhs.rank != rhs.rank) {
+                return lhs.rank - rhs.rank;
+            } else if (lhs.cellY != rhs.cellY) {
+                return lhs.cellY - rhs.cellY;
+            } else {
+                return lhs.cellX - rhs.cellX;
+            }
+        }
+    };
 }