Hover and stylus API cleanup.

Added missing setOnHoverListener method.
Removed BUTTON_STATE_ERASER.

Change-Id: I5d820d0a8e47fe5fd2d88e9fd9fc3fc6ce0dea0d
diff --git a/api/current.txt b/api/current.txt
index e2f7f8b..8b63be8 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -21425,7 +21425,6 @@
     field public static final int AXIS_Y = 1; // 0x1
     field public static final int AXIS_Z = 11; // 0xb
     field public static final int BUTTON_BACK = 8; // 0x8
-    field public static final int BUTTON_ERASER = 32; // 0x20
     field public static final int BUTTON_FORWARD = 16; // 0x10
     field public static final int BUTTON_PRIMARY = 1; // 0x1
     field public static final int BUTTON_SECONDARY = 2; // 0x2
@@ -22010,6 +22009,7 @@
     method public void setOnDragListener(android.view.View.OnDragListener);
     method public void setOnFocusChangeListener(android.view.View.OnFocusChangeListener);
     method public void setOnGenericMotionListener(android.view.View.OnGenericMotionListener);
+    method public void setOnHoverListener(android.view.View.OnHoverListener);
     method public void setOnKeyListener(android.view.View.OnKeyListener);
     method public void setOnLongClickListener(android.view.View.OnLongClickListener);
     method public void setOnSystemUiVisibilityChangeListener(android.view.View.OnSystemUiVisibilityChangeListener);
diff --git a/core/java/android/view/MotionEvent.java b/core/java/android/view/MotionEvent.java
index 3436cd1..f45e78b 100644
--- a/core/java/android/view/MotionEvent.java
+++ b/core/java/android/view/MotionEvent.java
@@ -1130,14 +1130,14 @@
     public static final int BUTTON_PRIMARY = 1 << 0;
 
     /**
-     * Button constant: Secondary button (right mouse button, stylus barrel).
+     * Button constant: Secondary button (right mouse button, stylus first button).
      *
      * @see #getButtonState
      */
     public static final int BUTTON_SECONDARY = 1 << 1;
 
     /**
-     * Button constant: Tertiary button (middle mouse button).
+     * Button constant: Tertiary button (middle mouse button, stylus second button).
      *
      * @see #getButtonState
      */
@@ -1165,13 +1165,6 @@
      */
     public static final int BUTTON_FORWARD = 1 << 4;
 
-    /**
-     * Button constant: Eraser button pressed (stylus end).
-     *
-     * @see #getButtonState
-     */
-    public static final int BUTTON_ERASER = 1 << 5;
-
     // NOTE: If you add a new axis here you must also add it to:
     //  native/include/android/input.h
 
@@ -1183,7 +1176,7 @@
         "BUTTON_TERTIARY",
         "BUTTON_BACK",
         "BUTTON_FORWARD",
-        "BUTTON_ERASER",
+        "0x00000020",
         "0x00000040",
         "0x00000080",
         "0x00000100",
@@ -2176,7 +2169,6 @@
      * @see #BUTTON_TERTIARY
      * @see #BUTTON_FORWARD
      * @see #BUTTON_BACK
-     * @see #BUTTON_ERASER
      */
     public final int getButtonState() {
         return nativeGetButtonState(mNativePtr);
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 5743134..411b714 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -3390,6 +3390,14 @@
     }
 
     /**
+     * Register a callback to be invoked when a hover event is sent to this view.
+     * @param l the hover listener to attach to this view
+     */
+    public void setOnHoverListener(OnHoverListener l) {
+        mOnHoverListener = l;
+    }
+
+    /**
      * Register a drag event listener callback object for this View. The parameter is
      * an implementation of {@link android.view.View.OnDragListener}. To send a drag event to a
      * View, the system calls the
diff --git a/native/include/android/input.h b/native/include/android/input.h
index 26cac50..0d8ea28 100644
--- a/native/include/android/input.h
+++ b/native/include/android/input.h
@@ -404,7 +404,6 @@
     AMOTION_EVENT_BUTTON_TERTIARY = 1 << 2,
     AMOTION_EVENT_BUTTON_BACK = 1 << 3,
     AMOTION_EVENT_BUTTON_FORWARD = 1 << 4,
-    AMOTION_EVENT_BUTTON_ERASER = 1 << 5,
 };
 
 /*
diff --git a/services/input/InputReader.cpp b/services/input/InputReader.cpp
index 3e4c666..5a25f8c 100644
--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -154,14 +154,15 @@
     case BTN_LEFT:
         return AMOTION_EVENT_BUTTON_PRIMARY;
     case BTN_RIGHT:
+    case BTN_STYLUS:
         return AMOTION_EVENT_BUTTON_SECONDARY;
     case BTN_MIDDLE:
+    case BTN_STYLUS2:
         return AMOTION_EVENT_BUTTON_TERTIARY;
     case BTN_SIDE:
         return AMOTION_EVENT_BUTTON_BACK;
-    case BTN_EXTRA:
-        return AMOTION_EVENT_BUTTON_FORWARD;
     case BTN_FORWARD:
+    case BTN_EXTRA:
         return AMOTION_EVENT_BUTTON_FORWARD;
     case BTN_BACK:
         return AMOTION_EVENT_BUTTON_BACK;
@@ -176,8 +177,7 @@
 static bool isPointerDown(int32_t buttonState) {
     return buttonState &
             (AMOTION_EVENT_BUTTON_PRIMARY | AMOTION_EVENT_BUTTON_SECONDARY
-                    | AMOTION_EVENT_BUTTON_TERTIARY
-                    | AMOTION_EVENT_BUTTON_ERASER);
+                    | AMOTION_EVENT_BUTTON_TERTIARY);
 }
 
 static int32_t calculateEdgeFlagsUsingPointerBounds(