android -- 小功能 手势操作GestureDetector

package com.sphere.gesturetest;

import android.os.Bundle;
import android.app.Activity;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.Menu;
import android.view.MotionEvent;
import android.widget.Toast;

public class MainActivity extends Activity implements OnGestureListener{

GestureDetector gestureDetector;
private int MIN_DESTANCE = 50;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gestureDetector = new GestureDetector(this,this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onTouchEvent(MotionEvent event) {
//交给手势检测类处理touch事件
return gestureDetector.onTouchEvent(event);
}

//用户按下时触发
@Override
public boolean onDown(MotionEvent arg0) {
// TODO Auto-generated method stub
toast("按下");
return false;
}

//用户在屏幕上拖动时触发
@Override
public boolean onFling(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
if(arg0.getX() - arg1.getX() > MIN_DESTANCE){
toast("向左滑");
}
if(arg0.getX() - arg1.getX() < MIN_DESTANCE){
toast("向右滑");
}
return false;
}

@Override
public void onLongPress(MotionEvent arg0) {
// TODO Auto-generated method stub
toast("长按");
}

@Override
public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
//toast("滚动。。。。");
return false;
}

//当用户在屏幕上按下 而且还未移动和松开时触发
@Override
public void onShowPress(MotionEvent arg0) {
// TODO Auto-generated method stub
toast("onShowPress。。。。");
}

//用户在触摸屏上轻击事件将会触发
@Override
public boolean onSingleTapUp(MotionEvent arg0) {
// TODO Auto-generated method stub
toast("onSingleTapUp。。。。");
return false;
}

public void toast(String text){
Toast.makeText(this, text, Toast.LENGTH_SHORT).show();
}

}