Android的编程学习笔记——手势编程初探（GestureDetector）

2022-07-25 10:40:53

Android sdk给我们提供了GestureDetector类，通过这个类我们可以识别很多的手势，主要是通过他的onTouchEvent(event)方法完成了不同手势的识别。

GestureDetector提供了两个接口：OnGestrueListener、OnDoubleTapListener，从接口的名称来看，前者是手势监听器，后者是双击手势监听器。

OnGestureListener接口含有6个回调方法：

1、onDown(MotionEvent e)

2、onSingleTapUp(MotionEvent e)

3、onShowPress(MotionEvent e)

4、onLongPress(MotionEvent e)

5、onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)

6、onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)

OnDoubleTapListener接口含有3个回调方法：

1、onDoubleTap(MotionEvent e)

2、onDoubleTapEvent(MotionEvent e)

3、onSingleTapConfirmed(MotionEvent e)

为使手势编程更加简洁，Android SDK提供了SimpleOnGestureListener这个内部类，它继承了OnGestureListener、OnDoubleTapListener两个接口，并实现了所有的回调方法，只不过方法体为空，需要程序员在应用程序中重写需要的方法。

以下用一个程序实例来演示SimpleOnGestureListener的用法，以及各回调方法的效果。实例程序界面放置了TextView用来显示屏幕触摸事件的坐标、位移、速度等信息。

界面XML文件代码（activity_gesture_test.xml）

  1 <?xml version="1.0" encoding="utf-8"?>
  2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3     android:id="@+id/container"
  4     android:layout_width="match_parent"
  5     android:layout_height="match_parent"
  6     android:orientation="vertical" >
  7 
  8     <LinearLayout
  9         android:layout_width="fill_parent"
 10         android:layout_height="wrap_content"
 11         android:orientation="horizontal" >
 12 
 13         <LinearLayout
 14             android:layout_width="0dp"
 15             android:layout_height="wrap_content"
 16             android:layout_weight="1"
 17             android:background="#ccc"
 18             android:orientation="vertical" >
 19 
 20             <TextView
 21                 android:id="@+id/showX"
 22                 android:layout_width="fill_parent"
 23                 android:layout_height="wrap_content"
 24                 android:text="X:" />
 25 
 26             <TextView
 27                 android:id="@+id/showY"
 28                 android:layout_width="fill_parent"
 29                 android:layout_height="wrap_content"
 30                 android:text="Y:" />
 31         </LinearLayout>
 32 
 33         <LinearLayout
 34             android:layout_width="0dp"
 35             android:layout_height="wrap_content"
 36             android:layout_weight="1"
 37             android:background="#ddd"
 38             android:orientation="vertical" >
 39 
 40             <TextView
 41                 android:id="@+id/showXV"
 42                 android:layout_width="fill_parent"
 43                 android:layout_height="wrap_content"
 44                 android:text="XV:" />
 45 
 46             <TextView
 47                 android:id="@+id/showYV"
 48                 android:layout_width="fill_parent"
 49                 android:layout_height="wrap_content"
 50                 android:text="YV:" />
 51         </LinearLayout>
 52     </LinearLayout>
 53 
 54     <TextView
 55         android:layout_width="fill_parent"
 56         android:layout_height="wrap_content"
 57         android:text="Scroll Gesture" />
 58 
 59     <LinearLayout
 60         android:layout_width="fill_parent"
 61         android:layout_height="wrap_content"
 62         android:orientation="horizontal" >
 63 
 64         <LinearLayout
 65             android:layout_width="0dp"
 66             android:layout_height="wrap_content"
 67             android:layout_weight="1"
 68             android:background="#ccc"
 69             android:orientation="vertical" >
 70 
 71             <TextView
 72                 android:id="@+id/scrollX1"
 73                 android:layout_width="fill_parent"
 74                 android:layout_height="wrap_content"
 75                 android:text="e1.X:" />
 76 
 77             <TextView
 78                 android:id="@+id/scrollY1"
 79                 android:layout_width="fill_parent"
 80                 android:layout_height="wrap_content"
 81                 android:text="e1.Y:" />
 82 
 83             <TextView
 84                 android:id="@+id/distanceX"
 85                 android:layout_width="fill_parent"
 86                 android:layout_height="wrap_content"
 87                 android:text="distanceX:" />
 88         </LinearLayout>
 89 
 90         <LinearLayout
 91             android:layout_width="0dp"
 92             android:layout_height="wrap_content"
 93             android:layout_weight="1"
 94             android:background="#ddd"
 95             android:orientation="vertical" >
 96 
 97             <TextView
 98                 android:id="@+id/scrollX2"
 99                 android:layout_width="fill_parent"
100                 android:layout_height="wrap_content"
101                 android:text="e2.X:" />
102 
103             <TextView
104                 android:id="@+id/scrollY2"
105                 android:layout_width="fill_parent"
106                 android:layout_height="wrap_content"
107                 android:text="e2.Y:" />
108 
109             <TextView
110                 android:id="@+id/distanceY"
111                 android:layout_width="fill_parent"
112                 android:layout_height="wrap_content"
113                 android:text="distanceY:" />
114         </LinearLayout>
115     </LinearLayout>
116 
117 </LinearLayout>

activity_gesture_test.xml

java程序代码（GestureTest.java）

  1 package org.kit.test.dataio;
  2 
  3 import android.app.Activity;
  4 import android.os.Bundle;
  5 import android.util.Log;
  6 import android.view.GestureDetector;
  7 import android.view.GestureDetector.SimpleOnGestureListener;
  8 import android.view.MotionEvent;
  9 import android.view.View;
 10 import android.view.View.OnTouchListener;
 11 import android.widget.LinearLayout;
 12 import android.widget.TextView;
 13 import android.widget.Toast;
 14 
 15 public class GestureTest extends Activity implements OnTouchListener {
 16 
 17     GestureDetector detector;
 18 
 19     TextView posX, posY, velX, velY;
 20     TextView scrollX1, scrollY1, scrollX2, scrollY2, _distanceX, _distanceY;
 21 
 22     @Override
 23     protected void onCreate(Bundle savedInstanceState) {
 24         // TODO Auto-generated method stub
 25         super.onCreate(savedInstanceState);
 26         setContentView(R.layout.activity_gesture_test);
 27 
 28         detector = new GestureDetector(this, new MySimpleGestureDetector());
 29 
 30         LinearLayout ll = (LinearLayout) findViewById(R.id.container);
 31         ll.setOnTouchListener(this);
 32         ll.setClickable(true);
 33         ll.setLongClickable(true);
 34 
 35         posX = (TextView) findViewById(R.id.showX);
 36         posY = (TextView) findViewById(R.id.showY);
 37 
 38         velX = (TextView) findViewById(R.id.showXV);
 39         velY = (TextView) findViewById(R.id.showYV);
 40 
 41         scrollX1 = (TextView) findViewById(R.id.scrollX1);
 42         scrollY1 = (TextView) findViewById(R.id.scrollY1);
 43         scrollX2 = (TextView) findViewById(R.id.scrollX2);
 44         scrollY2 = (TextView) findViewById(R.id.scrollY2);
 45         _distanceX = (TextView) findViewById(R.id.distanceX);
 46         _distanceY = (TextView) findViewById(R.id.distanceY);
 47 
 48     }
 49 
 50     @Override
 51     public boolean onTouch(View v, MotionEvent event) {
 52         posX.setText("X:" + event.getX());
 53         posY.setText("Y:" + event.getY());
 54         //
 55         return detector.onTouchEvent(event);
 56     }
 57 
 58     // 内部类inner class
 59     private class MySimpleGestureDetector extends SimpleOnGestureListener {
 60 
 61         @Override
 62         public boolean onDoubleTap(MotionEvent e) {
 63             // TODO Auto-generated method stub
 64 
 65             Toast.makeText(GestureTest.this, "double tap!", Toast.LENGTH_SHORT).show();
 66             return super.onDoubleTap(e);
 67         }
 68 
 69         @Override
 70         public boolean onDown(MotionEvent event) {
 71             // TODO Auto-generated method stub
 72 
 73             posX.setText("X:" + event.getX());
 74             posY.setText("Y:" + event.getY());
 75             return false;
 76         }
 77 
 78         @Override
 79         public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
 80             // TODO Auto-generated method stub
 81             velX.setText("XV:" + velocityX);
 82             velY.setText("YV:" + velocityY);
 83 
 84             Toast.makeText(    getApplicationContext(),
 85                             "Fling!\ne1.X=" + e1.getX() + "  e1.Y=" + e1.getY() + "\ne2.X=" + e2.getX() + "  e2.Y="
 86                                     + e2.getY(),
 87                             Toast.LENGTH_LONG).show();
 88 
 89             return false;
 90         }
 91 
 92         @Override
 93         public void onLongPress(MotionEvent arg0) {
 94             // TODO Auto-generated method stub
 95 
 96             Toast.makeText(getApplicationContext(), "Long Press", Toast.LENGTH_SHORT).show();
 97         }
 98 
 99         @Override
100         public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
101             // TODO Auto-generated method stub
102 
103             scrollX1.setText("e1.X:" + e1.getX());
104             scrollY1.setText("e1.Y:" + e1.getY());
105             scrollX2.setText("e2.X:" + e2.getX());
106             scrollY2.setText("e2.Y:" + e2.getY());
107             _distanceX.setText("distanceX:" + distanceX);
108             _distanceY.setText("distanceY:" + distanceY);
109 
110             return false;
111         }
112 
113         @Override
114         public void onShowPress(MotionEvent arg0) {
115             // TODO Auto-generated method stub
116             Toast.makeText(getApplicationContext(), "Show Press!", Toast.LENGTH_LONG).show();
117 
118         }
119 
120         @Override
121         public boolean onSingleTapUp(MotionEvent e) {
122             // TODO Auto-generated method stub
123 
124             Toast.makeText(getApplicationContext(), "Single Tap", Toast.LENGTH_LONG).show();
125             return false;
126         }
127 
128         @Override
129         public boolean onSingleTapConfirmed(MotionEvent e) {
130             // TODO Auto-generated method stub
131 
132             Toast.makeText(getApplicationContext(), "Single Tap confirmed", Toast.LENGTH_LONG).show();
133 
134             return super.onSingleTapConfirmed(e);
135         }
136 
137         @Override
138         public boolean onDoubleTapEvent(MotionEvent e) {
139             // TODO Auto-generated method stub
140             switch (e.getAction()) {
141                 case MotionEvent.ACTION_DOWN:
142                     Toast.makeText(getApplicationContext(), "double click down", Toast.LENGTH_SHORT).show();
143                     break;
144                 case MotionEvent.ACTION_UP:
145                     Toast.makeText(getApplicationContext(), "double click up", Toast.LENGTH_SHORT).show();
146                     break;
147 
148                 default:
149                     break;
150             }
151             return super.onDoubleTapEvent(e);
152         }
153     }
154 
155 }

GestureTest.java

Android的编程学习笔记——手势编程初探（GestureDetector）,布布扣,bubuko.com

Android的编程学习笔记——手势编程初探（GestureDetector）

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