android 上下左右手势判断 根据别人的改的
GestureUtils.java
package com.gesture;
import android.content.Context;
import android.util.DisplayMetrics;
import android.view.WindowManager;
public class GestureUtils {
//获取屏幕的大小
public static Screen getScreenPix(Context context) {
DisplayMetrics dm = new DisplayMetrics();
WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getMetrics(dm);
return new Screen(dm.widthPixels,dm.heightPixels);
}
public static class Screen{
public int widthPixels;
public int heightPixels;
public Screen(){
}
public Screen(int widthPixels,int heightPixels){
this.widthPixels=widthPixels;
this.heightPixels=heightPixels;
}
@Override
public String toString() {
return "("+widthPixels+","+heightPixels+")";
}
}
}
BuileGestureExt.java
package com.gesture;
import com.gesture.GestureUtils.Screen;
import android.content.Context;
import android.view.GestureDetector;
import android.view.MotionEvent;
public class BuileGestureExt {
public static final int GESTURE_UP=0;
public static final int GESTURE_DOWN=1;
public static final int GESTURE_LEFT=2;
public static final int GESTURE_RIGHT=3;
private OnGestureResult onGestureResult;
private Context mContext;
public BuileGestureExt(Context c,OnGestureResult onGestureResult) {
this.mContext=c;
this.onGestureResult=onGestureResult;
screen = GestureUtils.getScreenPix(c);
}
public GestureDetector Buile()
{
return new GestureDetector(mContext, onGestureListener);
}
private Screen screen;
private GestureDetector.OnGestureListener onGestureListener = new GestureDetector.SimpleOnGestureListener(){
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
float x = e2.getX() - e1.getX();
float y = e2.getY() - e1.getY();
//限制必须得划过屏幕的1/4才能算划过
float x_limit = screen.widthPixels / 4;
float y_limit = screen.heightPixels / 4;
float x_abs = Math.abs(x);
float y_abs = Math.abs(y);
if(x_abs >= y_abs){
//gesture left or right
if(x > x_limit || x < -x_limit){
if(x>0){
//right
doResult(GESTURE_RIGHT);
}else if(x<=0){
//left
doResult(GESTURE_LEFT);
}
}
}else{
//gesture down or up
if(y > y_limit || y < -y_limit){
if(y>0){
//down doResult(GESTURE_DOWN); }else if(y<=0){ //up doResult(GESTURE_UP); } } } return true; } }; public void doResult(int result) { if(onGestureResult!=null) { onGestureResult.onGestureResult(result); } } public interface OnGestureResult { public void onGestureResult(int direction); }}
demo
package
com.gesture;
import
android.app.Activity;
import
android.os.Bundle;
import
android.view.GestureDetector;
import
android.view.MotionEvent;
import
android.widget.Toast;
public
class
GesturetestActivity
extends
Activity {
/** Called when the activity is first created. */
private
GestureDetector gestureDetector;
@Override
public
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.main);
gestureDetector =
new
BuileGestureExt(
this
,
new
BuileGestureExt.OnGestureResult() {
@Override
public
void
onGestureResult(
int
direction) {
show(Integer.toString(direction));
}
}
).Buile();
}
@Override
public
boolean
onTouchEvent(MotionEvent event) {
return
gestureDetector.onTouchEvent(event);
}
private
void
show(String value){
Toast.makeText(
this
, value, Toast.LENGTH_SHORT).show();
}
}