Fixing drag-n-drop for folders in hotseat.

The current drag-n-drop model assums that when a folder is open
it completely covers the folderIcon and its not possible to drop
anything on the icon. But its not true when a folder is in the
hotseat.

> When DnD finishes revert folder to the normal state
> Ensure that only one folder is open at a time
> Prevent folder icon from moving when the folder is open

Bug: 13646281,14680549
Change-Id: I016a4c3f0d9b57c388eaa28f40df9e7b7bbab5fc
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 42e145b..9ad87c3 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -3112,10 +3112,19 @@
      */
     public void openFolder(FolderIcon folderIcon) {
         Folder folder = folderIcon.getFolder();
+        Folder openFolder = mWorkspace != null ? mWorkspace.getOpenFolder() : null;
+        if (openFolder != null && openFolder != folder) {
+            // Close any open folder before opening a folder.
+            closeFolder();
+        }
+
         FolderInfo info = folder.mInfo;
 
         info.opened = true;
 
+        // While the folder is open, the position of the icon cannot change.
+        ((CellLayout.LayoutParams) folderIcon.getLayoutParams()).canReorder = false;
+
         // Just verify that the folder hasn't already been added to the DragLayer.
         // There was a one-off crash where the folder had a parent already.
         if (folder.getParent() == null) {
@@ -3151,6 +3160,9 @@
         if (parent != null) {
             FolderIcon fi = (FolderIcon) mWorkspace.getViewForTag(folder.mInfo);
             shrinkAndFadeInFolderIcon(fi);
+            if (fi != null) {
+                ((CellLayout.LayoutParams) fi.getLayoutParams()).canReorder = true;
+            }
         }
         folder.animateClosed();