需求场景
?最近应广告机项目需求开发定时开关功能,关机的倒计时需要一个倒计时提示。开始使用的是跳转到一个专门用来计时的Activity,开始测试时都没有问题。后来发现第三方的广告应用会强制跳转,而我们计时的Activity就看不到了,这显然是不行的。所以后来通过查阅资料了解到了全局窗口,也是本文主要讲述的内容。
实现
?先上代码:
private boolean isCountDown;
private final Handler mHandler = new Handler();
private WindowManager wm;
private WindowManager.LayoutParams params;
private View countDownView;
private TextView tv_time;
private static Timer countDown = null;
private int mValue = 60;
......
public void show() {
wm = (WindowManager) getApplicationContext().getSystemService(WINDOW_SERVICE);
......
params = new WindowManager.LayoutParams();
params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT
| WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;
params.gravity = Gravity.CENTER;
params.format = PixelFormat.TRANSPARENT;
int keyFeatures = params.keyFeatures;
keyFeatures |= WindowManager.LayoutParams.KEY_FEATURE_POWER_PASS_TO_USER;
keyFeatures |= WindowManager.LayoutParams.KEY_FEATURE_HOME_PASS_TO_USER;
keyFeatures |= WindowManager.LayoutParams.KEY_FEATURE_VOLUME_PASS_TO_USER;
keyFeatures |= WindowManager.LayoutParams.KEY_FEATURE_APP_LAUNCHER_PASS_TO_USER;
keyFeatures |= WindowManager.LayoutParams.KEY_FEATURE_INPUT_SOURCE_PASS_TO_USER;
if (keyFeatures != params.keyFeatures) {
params.keyFeatures = keyFeatures;
}
countDownView = new View(getApplicationContext());
countDownView = View.inflate(getApplicationContext(),
R.layout.countdown_weight, null);
countDownView.setFocusableInTouchMode(true);
tv_time = (TextView) countDownView.findViewById(R.id.countdown_text);
tv_time.setText(getStyledText(60));
wm.addView(countDownView, params);
countDownView.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View view, int i, KeyEvent keyEvent) {
Log.d(TAG, "onKey: " + keyEvent.getKeyCode());
if (keyEvent.getAction() == KeyEvent.ACTION_UP) {
if (countDownView != null) {
wm.removeView(countDownView);
countDownView = null;
countDown.cancel();
mValue = 60;
}
}
return true;
}
});
countDown = new Timer();
countDown.schedule(new TimerTask() {
@Override
public void run() {
mValue--;
mHandler.post(drawCount);
if (mValue == 0) {
if (countDownView != null) {
wm.removeView(countDownView);
countDownView = null;
countDown.cancel();
goToShutdown();
}
}
}
}, 0, 1000);
}
Runnable drawCount = new Runnable() {
@Override
public void run() {
Log.d(TAG, "Count Down Value: " + mValue);
tv_time.setText(getStyledText(mValue));
}
};
private void goToShutdown() {
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
}
}, 200);
}
在上面代码中,主要有以下几点需要注意: ?①窗口需要设置setFocusableInTouchMode为true,允许触摸获得焦点。因为遥控器响应需要这个属性,同时添加的view不可以设置layoutParams.flags=LayoutParams.FLAG_NOT_FOCUSABLE,否则就完全屏蔽了按键了。满足这两个条件后,为添加的VIew设置的按键监听才可以接收到按键信息,具体怎么处理就是看需求了,我这里的需求就是移除窗口及取消定时任务。 ?②这个倒计时窗口肯定是允许取消的,那我们这里就设置了按下任意键就需要取消这个计时,同时移除窗口。但是在电视上面有些按键是在PhoneWindowManager做过处理的,我们的窗口无法响应,所以才有了上面特殊按键拦截的部分代码。这样即使按下关机键也仅仅只是做为一个取消的按键,而不是真的去关机。
总结
?本文以关机倒计时的窗口举例阐述Android TV上面的全局窗口实现,通过这种方式启动的窗口,在所有的应用页面都能看的到,不会因为Activity的生命周期而受到影响。这里需要注意,高版本下Android对服务管理还是很严格的,跳转应用后有可能服务无法正常工作,而我们的窗口也会受到影响,这里需要参考自家项目如何添加白名单去实现这种全局保活窗口的效果。
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