androidジェスチャー:GestureDetector

android.view.GestureDetector
Detects various gestures and events using the supplied MotionEvent s. The OnGestureListener callback will notify users when a particular motion event has occurred. This class should only be used with MotionEvent s reported via touch (don't use for trackball events). To use this class:

Create an instance of the GestureDetector for your View

In the View.onTouchEvent(MotionEvent) method ensure you call onTouchEvent(MotionEvent) . The methods defined in your callback will be executed when the events occur.

boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
@
Override
Notified of a fling event when it occurs with the initial on down MotionEvent and the matching up MotionEvent . The calculated velocity is supplied along the x and y axis in pixels per second.
Specified by:
onFling(...)
in
OnGestureListener
Parameters
:
e1
The first down motion event that started the fling.
e2
The move motion event that triggered the current onFling.
velocityX
The velocity of this fling measured in pixels per second along the x axis.
velocityY
The velocity of this fling measured in pixels per second along the y axis.
Returns
:
true if the event is consumed, else false
GestureDetectorを作成すると、OnGestureListenerインタフェースのコールバックメソッドが実装されます.

GestureDetector gestureDetector = new GestureDetector(getActivity(),
        new GestureDetector.OnGestureListener() {
                                                                                                                                   
    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        return false;
    }
                                                                                                                                   
    @Override
    public void onShowPress(MotionEvent e) {
                                                                                                                                       
    }
                                                                                                                                   
    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        return false;
    }
                                                                                                                                   
    @Override
    public void onLongPress(MotionEvent e) {
                                                                                                                                       
    }
                                                                                                                                   
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        Logger.i(TAG, "++onFling++");
        Logger.i(TAG, "e1.getAction():"+e1.getAction()+", e1.getX():"+e1.getX()+", e1.getY():"+e1.getY());
        Logger.i(TAG, "e2.getAction():"+e2.getAction()+", e2.getX():"+e2.getX()+", e2.getY():"+e2.getY());
        Logger.i(TAG, "velocityX:"+velocityX+", velocityY:"+velocityY);
        return true; //     true
    }
                                                                                                                                   
    @Override
    public boolean onDown(MotionEvent e) {
        return false;
    }
});

onTouchEventメソッドでGestureDetectorを呼び出す.onTouchEventメソッド.

class OnProgramTouchListener implements View.OnTouchListener {
                                             
    float xDown;
    float xLast;
    float xCurrent;
    float xUp;
    float xDistance;
    int newLeftMargin;
    FrameLayout.LayoutParams params = null;
                                             
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        Logger.i(TAG, "++programTouchListener.onTouch++");
        gestureDetector.onTouchEvent(event);

OnProgramTouchListenerのインスタンスオブジェクトを作成し、onActivity Createdメソッドで使用します.

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    programListFragment.getView().setOnTouchListener(programTouchListener);
}
View.OnTouchListener programTouchListener = new OnProgramTouchListener();

onFlingメソッドで印刷するログでは、onFlingメソッドのgetAction()の値がMotionEventに等しいことがわかります.ACTION_UP時に呼び出されます.

11-01 14:02:25.057: D/WatchTvFragment(20176): ++programTouchListener.onTouch++
11-01 14:02:25.057: D/WatchTvFragment(20176): event.getAction():2
11-01 14:02:25.057: D/WatchTvFragment(20176): leftMargin:337
11-01 14:02:25.057: D/WatchTvFragment(20176): ++programTouchListener.onTouch++
11-01 14:02:25.057: D/WatchTvFragment(20176): ++onFling++
11-01 14:02:25.057: D/WatchTvFragment(20176): e1.getAction():0, e1.getX():155.7273, e1.getY():503.875
11-01 14:02:25.057: D/WatchTvFragment(20176): e2.getAction():1, e2.getX():206.13757, e2.getY():487.01965
11-01 14:02:25.067: D/WatchTvFragment(20176): velocityX:604.2696, velocityY:-86.63345
11-01 14:02:25.067: D/WatchTvFragment(20176): event.getAction():1

ログ内getAction()のオプション値は、ACTION_UP(1), ACTION_MOVE(2), ACTION_DOWN(0).