android input命令 模拟按键

我们可以在手机adb shell中，使用input来模拟按键，和之前的sm类似，input也是一个进程，在framework/base/cmds目录下。
一、Input源码

下面我们先看下input的源码：
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private void run(String[] args) {
if (args.length < 1) {
showUsage();
return;
}

   int index = 0;     String command = args[index];     int inputSource = InputDevice.SOURCE_UNKNOWN;     if (SOURCES.containsKey(command)) {         inputSource = SOURCES.get(command);         index++;         command = args[index];     }     final int length = args.length - index;     try {         if (command.equals("text")) {             if (length == 2) {                 inputSource = getSource(inputSource, InputDevice.SOURCE_KEYBOARD);                 sendText(inputSource, args[index+1]);                 return;             }         } else if (command.equals("keyevent")) {             if (length >= 2) {                 final boolean longpress = "--longpress".equals(args[index + 1]);                 final int start = longpress ? index + 2 : index + 1;                 inputSource = getSource(inputSource, InputDevice.SOURCE_KEYBOARD);                 if (length > start) {                     for (int i = start; i < length; i++) {                         int keyCode = KeyEvent.keyCodeFromString(args[i]);                         if (keyCode == KeyEvent.KEYCODE_UNKNOWN) {                             keyCode = KeyEvent.keyCodeFromString("KEYCODE_" + args[i]);                         }                         sendKeyEvent(inputSource, keyCode, longpress);                     }                     return;                 }             }         }.............  

我们再来看看sendKeyEvent函数
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private void sendKeyEvent(int inputSource, int keyCode, boolean longpress) {
long now = SystemClock.uptimeMillis();
injectKeyEvent(new KeyEvent(now, now, KeyEvent.ACTION_DOWN, keyCode, 0, 0,
KeyCharacterMap.VIRTUAL_KEYBOARD, 0, 0, inputSource));
if (longpress) {
injectKeyEvent(new KeyEvent(now, now, KeyEvent.ACTION_DOWN, keyCode, 1, 0,
KeyCharacterMap.VIRTUAL_KEYBOARD, 0, KeyEvent.FLAG_LONG_PRESS,
inputSource));
}
injectKeyEvent(new KeyEvent(now, now, KeyEvent.ACTION_UP, keyCode, 0, 0,
KeyCharacterMap.VIRTUAL_KEYBOARD, 0, 0, inputSource));
}
最后再来看看injectKeyEvent函数，其主要还是调用了，InputManager中的injectInputEvent函数。
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private void injectKeyEvent(KeyEvent event) {
Log.i(TAG, “injectKeyEvent: ” + event);
InputManager.getInstance().injectInputEvent(event,
InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH);
}

二、InputManager相关代码

我们再来看看InputManager的injectInputEvent函数，最后还是调用了InputManagerService的injectInputEvent函数。
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public boolean injectInputEvent(InputEvent event, int mode) {
if (event == null) {
throw new IllegalArgumentException(“event must not be null”);
}
if (mode != INJECT_INPUT_EVENT_MODE_ASYNC
&& mode != INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH
&& mode != INJECT_INPUT_EVENT_MODE_WAIT_FOR_RESULT) {
throw new IllegalArgumentException(“mode is invalid”);
}

try {      return mIm.injectInputEvent(event, mode);//调用了InputManagerService的injectInputEvent函数  } catch (RemoteException ex) {      return false;  }  

}
我们再来看看InputManagerService的injectInputEvent函数
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@Override // Binder call
public boolean injectInputEvent(InputEvent event, int mode) {
return injectInputEventInternal(event, Display.DEFAULT_DISPLAY, mode);
}
我们再来看injectInputEventInternal函数
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private boolean injectInputEventInternal(InputEvent event, int displayId, int mode) {
if (event == null) {
throw new IllegalArgumentException(“event must not be null”);
}
if (mode != InputManager.INJECT_INPUT_EVENT_MODE_ASYNC
&& mode != InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH
&& mode != InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_RESULT) {
throw new IllegalArgumentException(“mode is invalid”);
}

final int pid = Binder.getCallingPid();  final int uid = Binder.getCallingUid();  final long ident = Binder.clearCallingIdentity();  final int result;  try {      result = nativeInjectInputEvent(mPtr, event, displayId, pid, uid, mode,//主要看这个jni函数              INJECTION_TIMEOUT_MILLIS, WindowManagerPolicy.FLAG_DISABLE_KEY_REPEAT);  } finally {      Binder.restoreCallingIdentity(ident);  }  switch (result) {      case INPUT_EVENT_INJECTION_PERMISSION_DENIED:          Slog.w(TAG, "Input event injection from pid " + pid + " permission denied.");          throw new SecurityException(                  "Injecting to another application requires INJECT_EVENTS permission");      case INPUT_EVENT_INJECTION_SUCCEEDED:          return true;      case INPUT_EVENT_INJECTION_TIMED_OUT:          Slog.w(TAG, "Input event injection from pid " + pid + " timed out.");          return false;      case INPUT_EVENT_INJECTION_FAILED:      default:          Slog.w(TAG, "Input event injection from pid " + pid + " failed.");          return false;  }  

}

三、native层代码

上面这个函数主要调用了nativeInjectInputEvent这个native函数。
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static jint nativeInjectInputEvent(JNIEnv* env, jclass /* clazz */,
jlong ptr, jobject inputEventObj, jint displayId, jint injectorPid, jint injectorUid,
jint syncMode, jint timeoutMillis, jint policyFlags) {
NativeInputManager* im = reinterpret_cast