BrightnessHelper.java

package tv.danmaku.android.util;

import android.app.Activity;
import android.content.ContentResolver;
import android.net.Uri;
import android.provider.Settings;
import android.provider.Settings.SettingNotFoundException;
import android.view.WindowManager;

public class BrightnessHelper {
    public static boolean isAutoBrightness(ContentResolver aContentResolver) {
        boolean automicBrightness = false;
        try {
            automicBrightness = Settings.System.getInt(aContentResolver,
                    Settings.System.SCREEN_BRIGHTNESS_MODE) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
        } catch (SettingNotFoundException e) {
            e.printStackTrace();
        }
        return automicBrightness;
    }

    public static float getScreenBrightness(Activity activity) {
        float nowBrightnessValue = -1;
        ContentResolver resolver = activity.getContentResolver();
        try {
            nowBrightnessValue = android.provider.Settings.System.getInt(
                    resolver, Settings.System.SCREEN_BRIGHTNESS, -1);

            nowBrightnessValue /= 255;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return nowBrightnessValue;
    }

    public static void setBrightness(Activity activity, float brightness) {
        // Settings.System.putInt(activity.getContentResolver(),
        // Settings.System.SCREEN_BRIGHTNESS_MODE,
        // Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
        WindowManager.LayoutParams lp = activity.getWindow().getAttributes();
        // some ROM may ANF if set brightness to 0
        lp.screenBrightness = Math.max(brightness, 0.01f);
        activity.getWindow().setAttributes(lp);

    }

    public static void stopAutoBrightness(Activity activity) {
        Settings.System.putInt(activity.getContentResolver(),
                Settings.System.SCREEN_BRIGHTNESS_MODE,
                Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
    }

    public static void startAutoBrightness(Activity activity) {
        Settings.System.putInt(activity.getContentResolver(),
                Settings.System.SCREEN_BRIGHTNESS_MODE,
                Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
    }

    public static void saveBrightness(ContentResolver resolver, int brightness) {
        Uri uri = Settings.System.getUriFor("screen_brightness");
        Settings.System.putInt(resolver, "screen_brightness", brightness);
        // resolver.registerContentObserver(uri, true, myContentObserver);
        resolver.notifyChange(uri, null);
    }
}