The old approach
Window window = getWindow();
LayoutParams layoutParams = window.getAttributes();
layoutParams.screenBrightness = newFloatValue;
window.setAttributes(layoutParams);
doesn't work on HTC Desire with Automatic brightness checked in Settings > Display > Brightness.
Is there a HTC-specific workaround for that?
Of course you don't see any changes since the settings are set to Automatic Brightness. That means, any manual changes are disregarded. Or am I missing something?
I've just tested it on a HTC Desire HD (2.3.5) and the screen brightness DOES change for about a second, but then it's immediately re-adjusted/overwritten by the automatic brightness. However, if you uncheck Auto Brightness option in the settings, you can see that the value has changed correctly.
So, imo everything is working as expected. If you want your changes to take effect you might have to disable Auto Brightness first:
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS_MODE, Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
Related
I'm trying to set System Screen Brightness instantaneously. I'm using a service to do that. Here it the code that I'm using.
Settings.System.putInt(cResolver,
Settings.System.SCREEN_BRIGHTNESS, 255);
This code works fine. But it is not instantaneous. The screen brightness value changes but the screen still looks dull. I can confirm this by reading back the screen brightness value and it is 255. If I lock the screen and come back, the screen is fully bright. How can I achieve this that the moment I set the system brightness to the maximum, I see fully bright screen?
BTW, I want to do this using a service and not an activity!
I would take a look at this link, specifically the first answer. It's a bit hackish though.
Changing screen brightness programmatically (as with the power widget)
Essentially you need to force the screen to refresh through starting a dummy activity and then finish() said dummy activity. I would have commented but I don't have enough points.
here's my code to change the brightness settings of my phone.
After running the app, if I go to the settings>display>brightness of my phone, I see the value changed however not 'updated'. So when I click on the dialog box's ok/cancel button, that's when it gets updated. So am I missing a call that finally after changing the values will update the screen brightness? Thanks.
The code is in C# though, I am using Xamarin and monodroid to develop my App. Thanks people!
Android.Provider.Settings.System.PutInt(ContentResolver, Android.Provider.Settings.System.ScreenBrightnessMode, 0);
int brightnessInt = (int)(1.0 * 255); //To set max brightness
Android.Provider.Settings.System.PutInt(ContentResolver, Android.Provider.Settings.System.ScreenBrightness, brightnessInt);
View v = Window.DecorView.FindViewById(Android.Resource.Id.Content);
v.Invalidate();
Make sure it's not on auto adjust
Android 2.2: Adjusting screen brightness
The last few lines solve your problem.
Also make sure android:minSdkVersion is at least v 2.3.3
I need to change the screen brightness programmatically. I read multiple solutions like this Can't apply system screen brightness programmatically in Android.
My problem is that those solutions implies changing the activity to be effective (having something like a dummy activity finishing immediately) and I would like to avoid the overhead of an activity switch.
Is there any other solution... maybe using native code so that the screen brightness will change immediately ?
The following affects immediately the single activity, no need to restart it. The activity also remembers the screenBrightness attribute over pause/resume.
WindowManager.LayoutParams lp = getWindow().getAttributes();
lp.screenBrightness = 1; // 0f - no backlight ... 1f - full backlight
getWindow().setAttributes(lp);
But it has no effect if you have automatic backlight level enabled in the system settings. This solution should help to turn off automatic backlight.
I've been trying to set the brightness under the limit of Android settings. There are two similar apps in Google Play doing this:
Shades
Screen Filter
The second one, even allows to use the phone with a black screen, just what I need in my app.
There are a lot of other questions about brightness but not to set it under this system limit, and I've found one question asking almost the same but not helping me:
Brightness Screen Filter
So after a lot of search I've got following code:
int brightness=0; //0 to 255, so I set it to a low level (not enough for me)
ContentResolver cResolver = getContentResolver();
//set the system brightness value, and if active, disable auto mode.
System.putInt(cResolver, System.SCREEN_BRIGHTNESS, brightness);
System.putInt(cResolver, System.SCREEN_BRIGHTNESS_MODE, System.SCREEN_BRIGHTNESS_MODE_MANUAL);
//previous lines don't set the brightness to the current screen so we set it like this:
LayoutParams layoutpars = getWindow().getAttributes();
layoutpars.screenBrightness = brightness / (float)255;
//Now we have brightness to the minimum allowed by Android but
//to achieve what these apps do, I have to reduce alpha of the window to the min
//then the screen is black like I want, and totally usable!
layoutpars.alpha=0.05f;
window.setAttributes(layoutpars);
Here the alpha is the key, this is doing what I want, but only for current window/screen, and I need to save to the system this alpha as default, like I'm doing with the brightness and the Manual mode for applying everywhere.
Do you know how I should do this? I'm unable to find a value "System.SCREEN_ALPHA" to set it with System.putInt or another way to do this.
In the other question I linked before, pheelicks replied with a suggestion of using a transparent non-touchable over screen, but this is not working for me, and the result does not give the feeling of a turned off screen like previous apps.
Thanks.
I decided to implemented this feature just inside my app with alpha. So I couldn't solve the initial question at all....
Anyways, in the end seems that the solution to this question is the one Pheelicks replied here: https://stackoverflow.com/a/4287597/1667990
-This is launching an activity to be always on top,
-with alpha to 0.0f so it be transparent,
-that redirects the touch to the activity behind:
//Let touches go through to apps/activities underneath.
Window window = activity.getWindow();
window.addFlags(FLAG_NOT_TOUCHABLE);
-And most important thing not explained in the previous link, is to set the dim behind our window to 1 (like the dim in a messagebox, but setting to the max to be black behind :D )
window.setDimAmount ((float)1.0) ;
window.setFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND,
WindowManager.LayoutParams.FLAG_DIM_BEHIND);
I haven't tried that and decided not to do it in my app as it could bring unexpected behavior in my circumstances, but I think it should definitely work, if anyone try please add your feedback!
Can screen brightness changes be tested in the Android emulator? I've tried various examples that all use the following code snippet:
WindowManager.LayoutParams lp = window.getAttributes();
lp.screenBrightness = (*some float percentage*);
window.setAttributes(lp);
But I don't see any change in brightness in the emulator. I've tested it in cupcake and 2.2.
Brightness changes do not get reflected in the emulator. To confirm, you can check the phone settings in the emulator (Settings > Display > Brightness) and changing the brightness from there. It will not change.
To see the effects of changing the brightness, you'll need an actual device running android.