[key event focus handling] (1)hotseat <-> icon now symmetric, (2)support DEL keycode

TL;DR; (1) Key event navigation from and to the hotseat and icons in the workspace
is now symmetric. Since there is one more icon in the hotseat, only left
N-1 icon navigation was symmetric.

(2) KeyEvent.KEYCODE_DEL and KeyEvent.KEYCODE_FORWARD_DEL can now delete icons
from the workspace. The focus move to the previous icon where the focus
traveled from.

Also contains minor styling and indexing issues.

Bug: 15408321
Bug: 19381790

Change-Id: I16cbcb2693e92eebb830997d01c0bf674073dd51
diff --git a/src/com/android/launcher3/Hotseat.java b/src/com/android/launcher3/Hotseat.java
index 289b08b..bd6c21a 100644
--- a/src/com/android/launcher3/Hotseat.java
+++ b/src/com/android/launcher3/Hotseat.java
@@ -83,13 +83,24 @@
     int getOrderInHotseat(int x, int y) {
         return hasVerticalHotseat() ? (mContent.getCountY() - y - 1) : x;
     }
+
     /* Get the orientation specific coordinates given an invariant order in the hotseat. */
     int getCellXFromOrder(int rank) {
         return hasVerticalHotseat() ? 0 : rank;
     }
+
     int getCellYFromOrder(int rank) {
         return hasVerticalHotseat() ? (mContent.getCountY() - (rank + 1)) : 0;
     }
+
+    public int getAllAppsButtonRank() {
+        if (LauncherAppState.isDisableAllApps()) {
+            return -1;
+        } else {
+            return mAllAppsButtonRank;
+        }
+    }
+
     public boolean isAllAppsButtonRank(int rank) {
         if (LauncherAppState.isDisableAllApps()) {
             return false;