Android2.2.3 實現多點縮放功能

Android2.2.3 實現多點縮放功能：

1. // 觸摸事件   
2.     @Override  
3.     public boolean onTouchEvent(MotionEvent event) {  
4.         if (false == this.is_initialized()) {  
5.             return false;  
6.         }  
7.   
8.         try {  
9.             PointF point_s = new PointF();  
10.             point_s.x = event.getX();  
11.             point_s.y = event.getY();  
12.             int x = (int) point_s.x;// Float.to( event.getX() );   
13.             int y = (int) point_s.y;// Float.floatToIntBits( event.getY() );   
14.   
15.             switch (event.getAction() & MotionEvent.ACTION_MASK) {  
16.             case MotionEvent.ACTION_DOWN:  
17.                 m_pressPt.set(x, y);  
18.                 mode = DRAG;  
19.                 break;  
20.             case MotionEvent.ACTION_UP:  
21.   
22.                 if (mode == DRAG) {  
23.                     int px = x - m_pressPt.x;  
24.                     int py = y - m_pressPt.y;  
25.   
26.                     if (px != 0 && py != 0) {  
27.                         m_naviEngine.SetCenter(480 - px, 270 - py);  
28.                     }  
29.                 }  
30.   
31.   
32.                 mode = NONE;  
33.   
34.                 break;  
35.                   
36.             case MotionEvent.ACTION_POINTER_UP:  
37.                 if (mode == ZOOM) {  
38.                     float newDist = spacing(event);  
39.                     if (newDist > 10f) {  
40.                         float scale = newDist - oldDist;  
41.                         if (scale > 0) {  
42.                             m_levelIndex = getLevelIndex();  
43.                             // 設置當前比例尺   
44.                             if (m_levelIndex < m_level.length - 1) {  
45.                                 m_levelIndex++;  
46.                                 m_naviEngine.SetLevel(m_level[m_levelIndex]);  
47.                                 m_btnZoomOut.setEnabled(true);  
48.                                 if (m_levelIndex == m_level.length - 1) {  
49.                                     m_btnZoomIn.setEnabled(false);  
50.                                 }  
51.   
52.                                 // 更新信息彈出框   
53.                                 // showPopSign();   
54.                           
55.                             }  
56.                         } else {  
57.                             m_levelIndex = getLevelIndex();  
58.                             // 設置當前比例尺以及按鈕狀態   
59.                             if (m_levelIndex > 0) {  
60.                                 m_levelIndex--;  
61.                                 m_naviEngine.SetLevel(m_level[m_levelIndex]);  
62.                                 m_btnZoomIn.setEnabled(true);  
63.                                 if (m_levelIndex == 0) {  
64.                                     m_btnZoomOut.setEnabled(false);  
65.                                 }  
66.   
67.                                 // 更新信息彈出框   
68.                                 // showPopSign();   
69.                             }  
70.                         }  
71.                     }  
72.                 }  
73.                 break;  
74.             case MotionEvent.ACTION_POINTER_DOWN:  
75.                 oldDist = spacing(event);  
76.                 if (oldDist > 10f) {  
77.   
78.                     mode = ZOOM;  
79.   
80.                 }  
81.                 break;  
82.             }  
83.         } catch (UnsatisfiedLinkError e) {  
84.             return false;  
85.         }  
86.   
87.         return m_gestureScanner.onTouchEvent(event);  
88.     }