How to adjust device brightness programmatically using SeekBar?
I have two seekbars in my settings application, one for sound and one for brightness. My sound seekbar does change the media volume as I want it to and it stays changed in other activities and applications but the brightness seekbar does not stay changed after I change the activity, it only changes the brightness in settings page. What I wish to accomplish is for both of them to stay as whatever I have set in the application settings page even in other activities and applications.
ApplicationSettings.java
public class ApplicationSettings extends AppCompatActivity {
private SeekBar VolumeSeekbar = null;
private SeekBar BrightnessSeekbar = null;
private AudioManager audioManager = null;
private float BackLightValue;
//Seek bar object
private SeekBar seekBar;
//Variable to store brightness value
private int brightness;
//Content resolver used as a handle to the system's settings
private ContentResolver cResolver;
//Window object, that will store a reference to the current window
private Window window;
TextView txtPerc;
@Override
public void onCreate(Bundle savedInstanceState) {
setVolumeControlStream(AudioManager.STREAM_MUSIC);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_application_settings);
//Instantiate seekbar object
seekBar = (SeekBar) findViewById(R.id.BrightBar);
txtPerc = (TextView) findViewById(R.id.txtPercentage);
//Get the content resolver
cResolver = getContentResolver();
//Get the current window
window = getWindow();
VolumeControl();
BrightnessControl();
}
public void GoToMainScreenButton1 (View view) {
Intent intentStart = new Intent(this, MainScreen.class);
startActivity(intentStart);
}
private void VolumeControl() {
try {
VolumeSeekbar = (SeekBar) findViewById(R.id.SoundBar);
audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
VolumeSeekbar.setMax(audioManager
.getStreamMaxVolume(AudioManager.STREAM_MUSIC));
VolumeSeekbar.setProgress(audioManager
.getStreamVolume(AudioManager.STREAM_MUSIC));
VolumeSeekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar arg0) {
}
@Override
public void onStartTrackingTouch(SeekBar arg0) {
}
@Override
public void onProgressChanged(SeekBar arg0, int progress, boolean arg2) {
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
progress, 0);
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
private void BrightnessControl() {
//Set the seekbar range between 0 and 255
//seek bar settings//
//sets the range between 0 and 255
seekBar = (SeekBar) findViewById(R.id.BrightBar);
seekBar.setMax(255);
//set the seek bar progress to 1
seekBar.setKeyProgressIncrement(1);
try
{
//Get the current system brightness
brightness = Settings.System.getInt(cResolver, Settings.System.SCREEN_BRIGHTNESS);
}
catch (Settings.SettingNotFoundException e)
{
//Throw an error case it couldn't be retrieved
Log.e("Error", "Cannot access system brightness");
e.printStackTrace();
}
//Set the progress of the seek bar based on the system's brightness
seekBar.setProgress(brightness);
//Register OnSeekBarChangeListener, so it can actually change values
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener()
{
public void onStopTrackingTouch(SeekBar seekBar)
{
//Set the system brightness using the brightness variable value
Settings.System.putInt(cResolver, Settings.System.SCREEN_BRIGHTNESS, brightness);
//Get the current window attributes
WindowManager.LayoutParams layoutpars = window.getAttributes();
//Set the brightness of this window
layoutpars.screenBrightness = brightness / (float)255;
//Apply attribute changes to this window
window.setAttributes(layoutpars);
}
public void onStartTrackingTouch(SeekBar seekBar)
{
//Nothing handled here
}
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
{
//Set the minimal brightness level
//if seek bar is 20 or any value below
if(progress<=20)
{
//Set the brightness to 20
brightness=20;
}
else //brightness is greater than 20
{
//Set brightness variable based on the progress bar
brightness = progress;
}
//Calculate the brightness percentage
float perc = (brightness /(float)255)*100;
//Set the brightness percentage
txtPerc.setText((int)perc +" %");
}
});
}
}
activity_application_settings.xml
<!-- android:background="#000000"-->
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text=" Adjust the Sound volume"
android:id="@+id/SOUNDTEXT"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_marginTop="87dp" />
<SeekBar
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/SoundBar"
android:background="#87CEEB"
android:layout_gravity="center_vertical"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_below="@+id/SOUNDTEXT"
android:layout_alignRight="@+id/Mainbutton11"
android:layout_alignEnd="@+id/Mainbutton11" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text=""
android:id="@+id/SoundPercentage"
android:background="#87CEEB"
android:layout_alignBottom="@+id/SoundBar"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_toRightOf="@+id/SoundBar"
android:layout_toEndOf="@+id/SoundBar" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text=" Adjust the Brightness"
android:id="@+id/textView18"
android:layout_above="@+id/BrightBar"
android:layout_toStartOf="@+id/Mainbutton11"
android:layout_toLeftOf="@+id/Mainbutton11"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<SeekBar
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/BrightBar"
android:background="#87CEEB"
android:layout_gravity="left|bottom"
android:layout_centerVertical="true"
android:layout_toLeftOf="@+id/SoundPercentage"
android:layout_toStartOf="@+id/SoundPercentage" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/txtPercentage"
android:layout_alignTop="@+id/BrightBar"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignLeft="@+id/SoundPercentage"
android:layout_alignStart="@+id/SoundPercentage" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Go to chapters"
android:background="#FFE4B5"
android:onClick="GoToMainScreenButton1"
android:id="@+id/Mainbutton11"
android:layout_gravity="center_horizontal|top"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />
Answer
Are you handling the automatic brightness mode?
Settings.System.putInt(cResolver, Settings.System.SCREEN_BRIGHTNESS_MODE, Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
Also do you have the manifest permission?
<uses-permission android:name="android.permission.WRITE_SETTINGS"></uses-permission>
PS: I'd comment these questions but can't comment yet sorry.