Android : call back function for native code

就是 C code call java code.

從 InputManager.java 看到
/* * Callbacks from native. */ private class Callbacks { static final String TAG = "InputManager-Callbacks"; private static final boolean DEBUG_VIRTUAL_KEYS = false; private static final String EXCLUDED_DEVICES_PATH = "etc/excluded-input-devices.xml"; private static final String CALIBRATION_DIR_PATH = "usr/idc/"; @SuppressWarnings("unused") public void notifyConfigurationChanged(long whenNanos) { mWindowManagerService.sendNewConfiguration(); } .... @SuppressWarnings("unused") public int interceptKeyBeforeQueueing(long whenNanos, int action, int flags, int keyCode, int scanCode, int policyFlags, boolean isScreenOn) { return mWindowManagerService.mInputMonitor.interceptKeyBeforeQueueing( whenNanos, action, flags, keyCode, scanCode, policyFlags, isScreenOn); } 然後 class InputManager 就有
private final Callbacks mCallbacks; 和 class Init 時..
nativeInit(mCallbacks); nativeInit 實際上是 implement 在 C code :
./base/services/jni/com_android_server_InputManager.cpp:1300: { "nativeInit", "(Lcom/android/server/InputManager$Callbacks;)V", ..... static void android_server_InputManager_nativeInit(JNIEnv* env, jclass clazz, jobject callbacks) { if (gNativeInputManager == NULL) { gNativeInputManager = new NativeInputManager(callbacks); } else { LOGE("Input manager already initialized."); jniThrowRuntimeException(env, "Input manager already initialized."); } }
這樣切開，看 com_android_server_InputManager.cpp 的 code .. 裡面都是 call InputManager.java 的 callback function。
--- 為什麼不都用 java 作算了呢？

com_android_server_InputManager.cpp 的 register_android_server_InputManager(JNIEnv*) 是由 onload.cpp 的 JNI_OnLoad( ) 呼叫的。
這個 (/frameworks/base/services/jni) Android.mk 的 target module name 是 libandroid_servers。

是由 ./frameworks/base/services/java/com/android/server/SystemServer.java:634: System.loadLibrary("android_servers"); load 進來的。
也就是 service.


亂入一下，設定系統時間是...
SystemClock.setCurrentTimeMillis(EARLIEST_SUPPORTED_TIME);