Add support for mouse hover and scroll wheel.

Dispatch ACTION_HOVER_MOVE and ACTION_SCROLL through the View
hierarchy as onGenericTouchEvent.  Pointer events dispatched
this way are delivered to the view under the pointer.  Non-pointer
events continue to be delivered to the focused view.

Added scroll wheel support to AbsListView, ScrollView,
HorizontalScrollView and WebView.  Shift+VSCROLL is translated
to HSCROLL as appropriate.

Added logging of new pointer events in PointerLocationView.

Fixed a problem in EventHub when a USB device is removed that
resulted in a long stream of ENODEV errors being logged until INotify
noticed the device was gone.

Note that the new events are not supported by wallpapers at this time
because the wallpaper engine only delivers touch events.

Make all mouse buttons behave identically.  (Effectively we only
support one button.)

Change-Id: I9ab445ffb63c813fcb07db6693987b02475f3756

1 files changed, 59 insertions, 1 deletions

diff --git a/core/java/android/view/MotionEvent.java b/core/java/android/view/MotionEvent.java
index cc37a28f62cd..a26dd0425b69 100644
--- a/core/java/android/view/MotionEvent.java
+++ b/core/java/android/view/MotionEvent.java
@@ -40,6 +40,12 @@ import android.util.SparseArray;
  * by a motion event with {@link #ACTION_UP} or when gesture is canceled
  * with {@link #ACTION_CANCEL}.
  * </p><p>
+ * Some pointing devices such as mice may support vertical and/or horizontal scrolling.
+ * A scroll event is reported as a generic motion event with {@link #ACTION_SCROLL} that
+ * includes the relative scroll offset in the {@link #AXIS_VSCROLL} and
+ * {@link #AXIS_HSCROLL} axes.  See {@link #getAxisValue(int)} for information
+ * about retrieving these additional axes.
+ * </p><p>
  * On trackball devices with source class {@link InputDevice#SOURCE_CLASS_TRACKBALL},
  * the pointer coordinates specify relative movements as X/Y deltas.
  * A trackball gesture consists of a sequence of movements described by motion
@@ -51,6 +57,8 @@ import android.util.SparseArray;
  * The joystick axis values are normalized to a range of -1.0 to 1.0 where 0.0 corresponds
  * to the center position.  More information about the set of available axes and the
  * range of motion can be obtained using {@link InputDevice#getMotionRange}.
+ * Some common joystick axes are {@link #AXIS_X}, {@link #AXIS_Y},
+ * {@link #AXIS_HAT_X}, {@link #AXIS_HAT_Y}, {@link #AXIS_Z} and {@link #AXIS_RZ}.
  * </p><p>
  * Motion events always report movements for all pointers at once.  The number
  * of pointers only ever changes by one as individual pointers go up and down,
@@ -163,10 +171,30 @@ public final class MotionEvent extends InputEvent implements Parcelable {
      * is not down (unlike {@link #ACTION_MOVE}).  The motion contains the most
      * recent point, as well as any intermediate points since the last
      * hover move event.
+     * <p>
+     * This action is not a touch event so it is delivered to
+     * {@link View#onGenericMotionEvent(MotionEvent)} rather than
+     * {@link View#onTouchEvent(MotionEvent)}.
+     * </p>
      */
     public static final int ACTION_HOVER_MOVE       = 7;
 
     /**
+     * Constant for {@link #getAction}: The motion event contains relative
+     * vertical and/or horizontal scroll offsets.  Use {@link #getAxisValue(int)}
+     * to retrieve the information from {@link #AXIS_VSCROLL} and {@link #AXIS_HSCROLL}.
+     * The pointer may or may not be down when this event is dispatched.
+     * This action is always delivered to the winder under the pointer, which
+     * may not be the window currently touched.
+     * <p>
+     * This action is not a touch event so it is delivered to
+     * {@link View#onGenericMotionEvent(MotionEvent)} rather than
+     * {@link View#onTouchEvent(MotionEvent)}.
+     * </p>
+     */
+    public static final int ACTION_SCROLL           = 8;
+
+    /**
      * Bits in the action code that represent a pointer index, used with
      * {@link #ACTION_POINTER_DOWN} and {@link #ACTION_POINTER_UP}.  Shifting
      * down by {@link #ACTION_POINTER_INDEX_SHIFT} provides the actual pointer
@@ -483,7 +511,7 @@ public final class MotionEvent extends InputEvent implements Parcelable {
      * <p>
      * <ul>
      * <li>For a mouse, reports the relative movement of the vertical scroll wheel.
-     * The value is normalized to a range from -1.0 (up) to 1.0 (down).
+     * The value is normalized to a range from -1.0 (down) to 1.0 (up).
      * </ul>
      * </p><p>
      * This axis should be used to scroll views vertically.
@@ -1237,6 +1265,32 @@ public final class MotionEvent extends InputEvent implements Parcelable {
     }
 
     /**
+     * Returns true if this motion event is a touch event.
+     * <p>
+     * Specifically excludes pointer events with action {@link #ACTION_HOVER_MOVE}
+     * or {@link #ACTION_SCROLL} because they are not actually touch events
+     * (the pointer is not down).
+     * </p>
+     * @return True if this motion event is a touch event.
+     * @hide
+     */
+    public final boolean isTouchEvent() {
+        if ((getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
+            switch (getActionMasked()) {
+                case MotionEvent.ACTION_DOWN:
+                case MotionEvent.ACTION_MOVE:
+                case MotionEvent.ACTION_UP:
+                case MotionEvent.ACTION_POINTER_DOWN:
+                case MotionEvent.ACTION_POINTER_UP:
+                case MotionEvent.ACTION_CANCEL:
+                case MotionEvent.ACTION_OUTSIDE:
+                    return true;
+            }
+        }
+        return false;
+    }
+
+    /**
      * Gets the motion event flags.
      *
      * @see #FLAG_WINDOW_IS_OBSCURED
@@ -2174,10 +2228,14 @@ public final class MotionEvent extends InputEvent implements Parcelable {
                 return "ACTION_UP";
             case ACTION_CANCEL:
                 return "ACTION_CANCEL";
+            case ACTION_OUTSIDE:
+                return "ACTION_OUTSIDE";
             case ACTION_MOVE:
                 return "ACTION_MOVE";
             case ACTION_HOVER_MOVE:
                 return "ACTION_HOVER_MOVE";
+            case ACTION_SCROLL:
+                return "ACTION_SCROLL";
         }
         int index = (action & ACTION_POINTER_INDEX_MASK) >> ACTION_POINTER_INDEX_SHIFT;
         switch (action & ACTION_MASK) {