Android SystemUI 修复：先调节通知栏上的亮度条，再使用键盘增加亮度时会先减小亮度再增加

由于Android源码（AOSP）亮度算法只针对触摸设备进行计算，使用键盘的设备均会有不同的BUG，所以我打算如果用户下拉了状态栏，他只能滑动亮度条调节亮度，要想用按键调节亮度则需要把状态栏隐藏，避免出现亮度条动画异常问题。

frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBarView.java

expanded 表示当前用户是否打开状态栏

    @Override
    public void panelExpansionChanged(float frac, boolean expanded) {
        super.panelExpansionChanged(frac, expanded);
        //wangrui Get status bar open state
        Intent intent = new Intent("com.xxx.statusBarFlag");
        intent.putExtra("statusBarFlag",expanded);
        mContext.sendBroadcast(intent);
        updateScrimFraction();
        if ((frac == 0 || frac == 1) && mBar.getNavigationBarView() != null) {
            mBar.getNavigationBarView().onStatusBarPanelStateChanged();
        }
    }

frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java

    //wangrui status bar status
    private boolean statusBarFlag = false;

      //wangrui Register the broadcast to get the status bar open state
        context.registerReceiver(mstatusBarReceiver, new IntentFilter("com.xxx.statusBarFlag"));

若用户打开了状态栏，禁止按键调节亮度

    @Override
    public long interceptKeyBeforeDispatching(IBinder focusedToken, KeyEvent event,
                                              int policyFlags) {
else if (keyCode == KeyEvent.KEYCODE_BRIGHTNESS_UP || keyCode == KeyEvent.KEYCODE_BRIGHTNESS_DOWN) {
            //wangrui When the status bar is open, buttons are not allowed to adjust the brightness
++            if (statusBarFlag){
++                return 0;
++            }
}

    //wangrui Broadcast receiver Get status bar status
    BroadcastReceiver mstatusBarReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            statusBarFlag = intent.getBooleanExtra("statusBarFlag",false);
        }
    };