为了加强鼠标响应事件,Android提供了GestureDetector手势识别类。通过GestureDetector.OnGestureListener来获取当前被触发的操作手势(Single Tap Up、Show Press、Long Press、Scroll、Down、Fling),具体包括以下几种:
boolean onDoubleTap(MotionEvent e) 解释:双击的第二下Touch down时触发 boolean onDoubleTapEvent(MotionEvent e)
解释:双击的第二下Touch down和up都会触发,可用e.getAction()区分。 boolean onDown(MotionEvent e)
解释:Touch down时触发 boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
解释:Touch了滑动一点距离后,up时触发。 void onLongPress(MotionEvent e)
解释:Touch了不移动一直Touch down时触发 boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
解释:Touch了滑动时触发。 void onShowPress(MotionEvent e)
解释:Touch了还没有滑动时触发 (与onDown,onLongPress比较 onDown只要Touch down一定立刻触发。 而Touchdown后过一会没有滑动先触发onShowPress再是onLongPress。 所以Touchdown后一直不滑动,onDown->onShowPress->onLongPress这个顺序触发。
boolean onSingleTapConfirmed(MotionEvent e) boolean onSingleTapUp(MotionEvent e)
解释:上面这两个函数都是在touch down后又没有滑动(onScroll),又没有长按(onLongPress),然后Touchup时触发。
点击一下非常快的(不滑动)Touchup: onDown->onSingleTapUp->onSingleTapConfirmed 点击一下稍微慢点的(不滑动)Touchup: onDown->onShowPress->onSingleTapUp->onSingleTapConfirmed
使用GestureDetector需要在View中重写onTouchEvent事件,例如:
GestureDetector mGesture = null;
@Override public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub return mGesture.onTouchEvent(event);
}
详细的测试例子如下: package com.jiubang.android.gesturetest;
import android.app.Activity;
import android.os.Bundle; import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
public class GestureActivity extends Activity implements OnTouchListener {
private Button mButton = null; GestureDetector mGesture = null;
/** Called when the activity is first created. */
@Override public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.i("TEST", "onCreate");
mButton = (Button)findViewById(R.id.button1);
mButton.setOnTouchListener(this);
mGesture = new GestureDetector(this, new GestureListener());
}
@Override public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub return mGesture.onTouchEvent(event);
} class GestureListener extends SimpleOnGestureListener {
@Override public boolean onDoubleTap(MotionEvent e) {
// TODO Auto-generated method stub Log.i("TEST", "onDoubleTap"); return super.onDoubleTap(e); }
@Override public boolean onDown(MotionEvent e) {
// TODO Auto-generated method stub Log.i("TEST", "onDown"); return super.onDown(e);
}
@Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
// TODO Auto-generated method stub Log.i("TEST", "onFling:velocityX = " + velocityX + " velocityY" + velocityY); return super.onFling(e1, e2, velocityX, velocityY);
}
@Override public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub Log.i("TEST", "onLongPress"); super.onLongPress(e); }
@Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
// TODO Auto-generated method stub Log.i("TEST", "onScroll:distanceX = " + distanceX + " distanceY = " + distanceY); return super.onScroll(e1, e2, distanceX, distanceY);
}
@Override public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub Log.i("TEST", "onSingleTapUp"); return super.onSingleTapUp(e);
}
}
}