WindowManager.LayoutParams and screenBrightness
<p>I have some problem with WindowManager.LayoutParams. I need to poweroff and poweron the screen using the proximity sensors. The proximity sensor is OK, but layoutParams doesn't work</p>

<pre><code>    public void setBright(float value) {
    Window mywindow = getWindow();
    WindowManager.LayoutParams lp = mywindow.getAttributes();
    lp.screenBrightness = value;
    lp.buttonBrightness = value;

    if (value != WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_OFF) {
        lp.flags |= WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
    }

    mywindow.setAttributes(lp);
}
</code></pre>

<p>The screen poweroff correctly. But if I use setBright(WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE) the screen remains black. I also tried using wakeLock</p>

<pre><code>private void powerOnScreen() {
    setBright(WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE);

    onResume();
    if (!wakeLock.isHeld())
        wakeLock.acquire();
}
</code></pre>

<p>where wakeLock is:</p>

<pre><code>PowerManager powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
    wakeLock = powerManager.newWakeLock(
            PowerManager.SCREEN_DIM_WAKE_LOCK
            | PowerManager.ON_AFTER_RELEASE,
            "MY_TAG");
</code></pre>

<p>but it still doesn't work. Any idea? Target platform is Android 2.2</p>
