NativeActivity.java revision 74323fd1ab8eb11beea286d5c213c63e4b803141 
1package android.app;
2
3import dalvik.system.PathClassLoader;
4
5import android.content.pm.ActivityInfo;
6import android.content.pm.ApplicationInfo;
7import android.content.pm.PackageManager;
8import android.os.Bundle;
9import android.view.SurfaceHolder;
10
11import java.io.File;
12
13/**
14 * Convenience for implementing an activity that will be implemented
15 * purely in native code.  That is, a game (or game-like thing).
16 */
17public class NativeActivity extends Activity implements SurfaceHolder.Callback {
18    public static final String META_DATA_LIB_NAME = "android.app.lib_name";
19
20    private int mNativeHandle;
21
22    private native int loadNativeCode(String path);
23    private native void unloadNativeCode(int handle);
24
25    private native void onStartNative(int handle);
26    private native void onResumeNative(int handle);
27    private native void onSaveInstanceStateNative(int handle);
28    private native void onPauseNative(int handle);
29    private native void onStopNative(int handle);
30    private native void onLowMemoryNative(int handle);
31    private native void onWindowFocusChangedNative(int handle, boolean focused);
32    private native void onSurfaceCreatedNative(int handle, SurfaceHolder holder);
33    private native void onSurfaceChangedNative(int handle, SurfaceHolder holder,
34            int format, int width, int height);
35    private native void onSurfaceDestroyedNative(int handle, SurfaceHolder holder);
36
37    @Override
38    protected void onCreate(Bundle savedInstanceState) {
39        String libname = "main";
40        ActivityInfo ai;
41
42        getWindow().takeSurface(this);
43
44        try {
45            ai = getPackageManager().getActivityInfo(
46                    getIntent().getComponent(), PackageManager.GET_META_DATA);
47            if (ai.metaData != null) {
48                String ln = ai.metaData.getString(META_DATA_LIB_NAME);
49                if (ln != null) libname = ln;
50            }
51        } catch (PackageManager.NameNotFoundException e) {
52            throw new RuntimeException("Error getting activity info", e);
53        }
54
55        String path = null;
56
57        if ((ai.applicationInfo.flags&ApplicationInfo.FLAG_HAS_CODE) == 0) {
58            // If the application does not have (Java) code, then no ClassLoader
59            // has been set up for it.  We will need to do our own search for
60            // the native code.
61            path = ai.applicationInfo.dataDir + "/lib/" + System.mapLibraryName(libname);
62            if (!(new File(path)).exists()) {
63                path = null;
64            }
65        }
66
67        if (path == null) {
68            path = ((PathClassLoader)getClassLoader()).findLibrary(libname);
69        }
70
71        if (path == null) {
72            throw new IllegalArgumentException("Unable to find native library: " + libname);
73        }
74
75        mNativeHandle = loadNativeCode(path);
76        if (mNativeHandle == 0) {
77            throw new IllegalArgumentException("Unable to load native library: " + path);
78        }
79        super.onCreate(savedInstanceState);
80    }
81
82    @Override
83    protected void onDestroy() {
84        unloadNativeCode(mNativeHandle);
85        super.onDestroy();
86    }
87
88    @Override
89    protected void onPause() {
90        super.onPause();
91        onPauseNative(mNativeHandle);
92    }
93
94    @Override
95    protected void onResume() {
96        super.onResume();
97        onResumeNative(mNativeHandle);
98    }
99
100    @Override
101    protected void onSaveInstanceState(Bundle outState) {
102        super.onSaveInstanceState(outState);
103        onSaveInstanceStateNative(mNativeHandle);
104    }
105
106    @Override
107    protected void onStart() {
108        super.onStart();
109        onStartNative(mNativeHandle);
110    }
111
112    @Override
113    protected void onStop() {
114        super.onStop();
115        onStopNative(mNativeHandle);
116    }
117
118    @Override
119    public void onLowMemory() {
120        super.onLowMemory();
121        onLowMemoryNative(mNativeHandle);
122    }
123
124    @Override
125    public void onWindowFocusChanged(boolean hasFocus) {
126        super.onWindowFocusChanged(hasFocus);
127        onWindowFocusChangedNative(mNativeHandle, hasFocus);
128    }
129
130    public void surfaceCreated(SurfaceHolder holder) {
131        onSurfaceCreatedNative(mNativeHandle, holder);
132    }
133
134    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
135        onSurfaceChangedNative(mNativeHandle, holder, format, width, height);
136    }
137
138    public void surfaceDestroyed(SurfaceHolder holder) {
139        onSurfaceDestroyedNative(mNativeHandle, holder);
140    }
141}
142