1.GestureDetector.OnGestureListener

onDown：表示用戶的按下動作，只要用戶觸摸屏幕，不管是點擊、長按、拖動、滑動都會先觸發。

onShowPress：表示用戶按下后，并沒有立刻松開，而是停留了極短的時間后就會觸發。

onSingleTapUp：表示用戶單純的一次點擊事件，并沒有其他事件，就會觸發。

onScroll：表示用戶的滑動，滑動時會連續觸發。

onLongPress：表示用戶的長按事件，按下后超過一定的時間會觸發。

onFling：表示用戶滑動后，剩下的慣性會繼續滑動，就會觸發。

------GestureDetector.OnGestureListener事件執行順序------

快速點擊屏幕：onDown→onSingleTapUp

稍微慢速的點擊屏幕：onDown→onShowPress→onSingleTapUp

長按屏幕：onDown→onShowPress→onLongPress

快速點擊屏幕后滑動無慣性：onDown→onScroll→onScroll→onScroll...........

慢速點擊屏幕后滑動無慣性：onDown→onShowPress→onScroll→onScroll→onScroll...........

快速點擊屏幕后滑動有慣性：onDown→onScroll→onScroll→onScroll...........→onFling

慢速點擊屏幕后滑動有慣性：onDown→onShowPress→onScroll→onScroll→onScroll...........→onFling

2.GestureDetector.OnDoubleTapListener

onSingleTapConfirmed：單擊事件，用來判定該次點擊是單純的SingleTap而不是DoubleTap。

onDoubleTap：雙擊事件

onDoubleTapEvent：

------GestureDetector.OnGestureListener加上GestureDetector.OnDoubleTapListener事件執行順序------

快速點擊屏幕：onDown→onSingleTapUp→onSingleTapConfirmed

稍微慢速的點擊屏幕：onDown→onShowPress→onSingleTapUp→onSingleTapConfirmed

雙擊屏幕：onDown→onSingleTapUp→onDoubleTap→onDoubleTapEvent→onDown→onDoubleTapEvent

3.用法

public class GestureActivity extends AppCompatActivity {

    private GestureDetector gestureDetector;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gesture);

        gestureDetector = new GestureDetector(this, new MyGestureListener());
        gestureDetector.setOnDoubleTapListener(new MyDoubleTapListener());

        ImageView imageView = findViewById(R.id.image);
        imageView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                return gestureDetector.onTouchEvent(motionEvent);
            }
        });
    }

    class MyGestureListener implements GestureDetector.OnGestureListener {

        @Override
        public boolean onDown(MotionEvent motionEvent) {
            System.out.println("OnGestureListener:" + "onDown");
            return true;
        }

        @Override
        public void onShowPress(MotionEvent motionEvent) {
            System.out.println("OnGestureListener:" + "onShowPress");
        }

        @Override
        public boolean onSingleTapUp(MotionEvent motionEvent) {
            System.out.println("OnGestureListener:" + "onSingleTapUp");
            return true;
        }

        @Override
        public boolean onScroll(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {
            System.out.println("OnGestureListener:" + "onScroll");
            return true;
        }

        @Override
        public void onLongPress(MotionEvent motionEvent) {
            System.out.println("OnGestureListener:" + "onLongPress");
        }

        @Override
        public boolean onFling(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {
            System.out.println("OnGestureListener:" + "onFling");
            return true;
        }
    }

    class MyDoubleTapListener implements GestureDetector.OnDoubleTapListener{

        @Override
        public boolean onSingleTapConfirmed(MotionEvent motionEvent) {
            System.out.println("OnDoubleTapListener:" + "onSingleTapConfirmed");
            return true;
        }

        @Override
        public boolean onDoubleTap(MotionEvent motionEvent) {
            System.out.println("OnDoubleTapListener:" + "onDoubleTap");
            return true;
        }

        @Override
        public boolean onDoubleTapEvent(MotionEvent motionEvent) {
            System.out.println("OnDoubleTapListener:" + "onDoubleTapEvent");
            return true;
        }
    }

    @RequiresApi(api = Build.VERSION_CODES.M)
    class MyContextClickListener implements GestureDetector.OnContextClickListener {

        @Override
        public boolean onContextClick(MotionEvent motionEvent) {
            System.out.println("OnContextClickListener:" + "onContextClick");
            return true;
        }
    }
}