android中input的实现

基础理论知识

当我们在分析Android的键盘记录的时候就不得不和input进行打交道，那么input在系统中是怎么进行实现的？ Android手机中默认携带input子系统，并且开在机就会产生默认的mouse和keyboard事件，这样使得用户开机就可以触屏点击和使用按键。 android中键盘实现的系统源码位置\source\frameworks\base\cmds\input\src\com\android\commands\input\Input.java

关键代码实现解析：java层代码

Input类定义

public class Input { //用于定义打印调试信息 private static final String TAG = "Input"; private static final String INVALID_ARGUMENTS = "Error: Invalid arguments for command: "; //用map方式实现关键字和标识对应 private static final Map SOURCES = new HashMap() {{ put("keyboard", InputDevice.SOURCE_KEYBOARD); put("dpad", InputDevice.SOURCE_DPAD); put("gamepad", InputDevice.SOURCE_GAMEPAD); put("touchscreen", InputDevice.SOURCE_TOUCHSCREEN); put("mouse", InputDevice.SOURCE_MOUSE); put("stylus", InputDevice.SOURCE_STYLUS); put("trackball", InputDevice.SOURCE_TRACKBALL); put("touchpad", InputDevice.SOURCE_TOUCHPAD); put("touchnavigation", InputDevice.SOURCE_TOUCH_NAVIGATION); put("joystick", InputDevice.SOURCE_JOYSTICK); }}; 复制代码

sendKeyEvent 函数定义

//函数功能：发送键盘事件 private void sendKeyEvent(int inputSource, int keyCode, boolean longpress) { //获取从开机到现在的毫秒数 long now = SystemClock.uptimeMillis(); //注入键盘事件 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)); } 复制代码

sendSwipe 函数定义

//函数功能：实现滑屏操作 private void sendSwipe(int inputSource, float x1, float y1, float x2, float y2, int duration) { if (duration < 0) { duration = 300; } //获取从开机到现在的毫秒数 long now = SystemClock.uptimeMillis(); //注入触摸事件 injectMotionEvent(inputSource, MotionEvent.ACTION_DOWN, now, x1, y1, 1.0f); //计算开始时间和结束时间 long startTime = now; long endTime = startTime + duration; while (now < endTime) { long elapsedTime = now - startTime; float alpha = (float) elapsedTime / duration; injectMotionEvent(inputSource, MotionEvent.ACTION_MOVE, now, lerp(x1, x2, alpha), lerp(y1, y2, alpha), 1.0f); now = SystemClock.uptimeMillis(); } injectMotionEvent(inputSource, MotionEvent.ACTION_UP, now, x2, y2, 0.0f); } 复制代码

injectKeyEvent 函数定义

//函数功能：注入事件的实现 private void injectKeyEvent(KeyEvent event) { //打印调试信息 Log.i(TAG, "injectKeyEvent: " + event); //获取inputManager的实例事件 InputManager.getInstance().injectInputEvent(event, InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH); } 复制代码

injectMotionEvent 函数定义

函数功能：注入触摸事件 private void injectMotionEvent(int inputSource, int action, long when, float x, float y, float pressure) { final float DEFAULT_SIZE = 1.0f; final int DEFAULT_META_STATE = 0; final float DEFAULT_PRECISION_X = 1.0f; final float DEFAULT_PRECISION_Y = 1.0f; final int DEFAULT_DEVICE_ID = 0; final int DEFAULT_EDGE_FLAGS = 0; MotionEvent event = MotionEvent.obtain(when, when, action, x, y, pressure, DEFAULT_SIZE, DEFAULT_META_STATE, DEFAULT_PRECISION_X, DEFAULT_PRECISION_Y, DEFAULT_DEVICE_ID, DEFAULT_EDGE_FLAGS); event.setSource(inputSource); Log.i(TAG, "injectMotionEvent: " + event); InputManager.getInstance().injectInputEvent(event, InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH); } 复制代码

sendMove 函数定义

//函数功能：发送移动事件 private void sendMove(int inputSource, float dx, float dy) { //获取时间 long now = SystemClock.uptimeMillis(); //调用注入触摸事件 injectMotionEvent(inputSource, MotionEvent.ACTION_MOVE, now, dx, dy, 0.0f); }

Android

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