In my video play app, I use this flag: SYSTEM_UI_FLAG_HIDE_NAVIGATION to make the navigation bar disappear, but when I touch the screen, the navigation bar appears, after the first touch, my touch events and other events work fine.
My question is how can I take over the first touch?
You can't really take over the first event. You could implement View.OnSystemUiVisibilityChangeListener and be notified when the navigation bar is shown or hidden again, and then depending on its current state do what you wanted on the first touch, if possible.
However, there is no way you can completely take over the first touch, as stated in the documentation for SYSTEM_UI_FLAG_HIDE_NAVIGATION:
There is a limitation: because navigation controls are so important, the least user interaction will cause them to reappear immediately. When this happens, both this flag and SYSTEM_UI_FLAG_FULLSCREEN will be cleared automatically, so that both elements reappear at the same time.
For anyone coming across this post, if your intention is to hide the navigation/status bar and not have it come back up when you touch the screen, take a look at the different "immersive" configurations as described here: https://developer.android.com/training/system-ui/immersive
for example:
currentActivity?.window?.decorView?.systemUiVisibility = View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY or
View.SYSTEM_UI_FLAG_FULLSCREEN or
View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
That would effectively put your screen in "Full Screen" Mode regardless of any interaction the user has with the screen
To show the navigation/status bar again, simply change it back to:
currentActivity?.window?.decorView?.systemUiVisibility = View.SYSTEM_UI_FLAG_VISIBLE
Related
I recently added the following code to my app to remove the navigation bar (soft buttons) from some phones. This caused some resizing issues with my app so getting rid of the navigation bar was ideal.
getWindow().requestFeature(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
See more: https://developer.android.com/training/system-ui/navigation.html
This does exactly what I wanted. The soft buttons are no longer present on devices such as the Nexus 5. However, this caused the side effect of disabling and touch or gestures until there is at least one touch event first. For example, I have some buttons on the home screen. With the above code, tapping on the button the first time does nothing. From the second time onwards, the app behaves like normal. My app also uses a viewpager, and swiping to other tabs or selecting another tab from the action bar also has no effect until I tap somewhere on the screen first.
Obviously, this behaviour is not wanted. When the user opens the app and selects one of the buttons, they expect the button to be clicked. Instead, they'd have to tap the button twice (and then everything works fine from that point on).
I'm testing this on the Samsung Galaxy S3 (which does not have the navigation bar along the bottom) and the Nexus 5 (which does have the navigation bar along the bottom).
Edit: Further research - Hiding the navigation bar is only temporary. The navigation bar is requesting focus for the first touch event, since the navigation bar is meant to pop back up as soon as there is any kind of ui event. So even on the Galaxy S3, which has no navigation bar in the first place, the touch event is being sucked up by the navigation bar. For devices that really do have a navigation bar, the bar will reappear on every interaction and you must tell the device to hide it again. As far as I can tell, there is no way to permanently hide the navigation bar.
My next question is to find out how it is possible to query the device to see if there is a navigation bar. If I know that the device does not have the navigation bar, then there is no need to try to hide it and have the OS absorb the first touch event.
SYSTEM_UI_FLAG_HIDE_NAVIGATION is designed for passive activities like watching videos and maybe reading books. For your purposes, immersive mode is a better choice. https://developer.android.com/training/system-ui/immersive.html
More specifically you may want to add the SYSTEM_UI_FLAG_IMMERSIVE_STICKY flag together with SYSTEM_UI_FLAG_HIDE_NAVIGATION, so that the navigation bar is hidden and will stay hidden until user swipes from top or bottom.
Note that a "reminder bubble" will appear the first time a user enters this mode in your app.
Hello,
I need do fullscreen in android 4.0 (I must hide back button, home...)
I used android:theme="#android:style/Theme.NoTitleBar.Fullscreen"
but it doesn't work.
Homebutton and backbutton cannot be hidden...
Users always need to have access to these buttons, so the black bar will always be on the screen
Like write K_Anas in a relative question, it is not possible hide Homebutton and backbutton in Android 4.0, for security reasons and because is a simply anti-pattern solution.
You can use SYSTEM_UI_FLAG_HIDE_NAVIGATION to hide the system navigation temporarily, but it will always reappear when the user touches the screen. Even the notification bar will reappear when the screen is touched.
You are not allowed to hide the system bar with the home button completely for security reasons.
I'm currently working on an app for blind people. What I need is to prevent users from accidentally going outside of my app, so I'm trying to overlay/replace/hide soft buttons in Android 4. I know this must be possible because it is used for example in MXPlayer (you can "lock" screen when playing video).
I've tried to override all three buttons (back,home,recent apps). No problem with back and home, but I couldn't figure out how to override(disable) recent apps. I've tried solution described here without success.
Next idea was to overlay the entire screen. I've successfully created system overlay mentioned in this question, but I didn't find out how to overlay my soft buttons.
Do you have any idea how to solve this problem without rooting the phone and using custom ROM?
edit: I've also tried hiding the buttons with SYSTEM_UI_FLAG_LOW_PROFILE(turns buttons into dots) and SYSTEM_UI_FLAG_HIDE_NAVIGATION(hides buttons till next touch). Unfortunately this also doesn't solve my problem because after touch buttons work as usual. Maybe there's a way how to catch "unhiding" a override showing them again?
From Android docs :
The SYSTEM_UI_FLAG_LOW_PROFILE flag replaces the STATUS_BAR_HIDDEN flag. When set, this flag enables “low profile" mode for the system bar or navigation bar. Navigation buttons dim and other elements in the system bar also hide. Enabling this is useful for creating more immersive games without distraction for the system navigation buttons.
The SYSTEM_UI_FLAG_VISIBLE flag replaces the STATUS_BAR_VISIBLE flag to request the system bar or navigation bar be visible.
The SYSTEM_UI_FLAG_HIDE_NAVIGATION is a new flag that requests the navigation bar hide completely. Be aware that this works only for the navigation bar used by some handsets (it does not hide the system bar on tablets). The navigation bar returns to view as soon as the system receives user input. As such, this mode is useful primarily for video playback or other cases in which the whole screen is needed but user input is not required.
In Samsung Galaxy S3, even though my app is set to be full screen, and this makes the notification bar not to be visible, if I swipe from the very edge of the screen side, this action will make the notification bar to appear again, allowing the user to expand it over the full screen app.
Is there any way to disable this, or to cancel the expand of the notification bar?
The problem is that I have a listview covering the whole screen, and if I swipe to scroll the items, every time I do it from the very edge due to the instinctive action of scrolling faster, then the notification bar appears again.
I've tried tricks such as creating an overlay window on the edge, but not working at all for SG3.
Thanks
If you haven't tried already, you might attempt to use the View flag for hiding navigation, SYSTEM_UI_FLAG_HIDE_NAVIGATION, documented here.
However it may be important to note this found at the bottom of their description :
There is a limitation: because navigation controls are so important, the least user interaction will cause them to reappear immediately. When this happens, both this flag and SYSTEM_UI_FLAG_FULLSCREEN will be cleared automatically, so that both elements reappear at the same time.
which is probably related to what you're seeing. I find it hard to believe there's a way around this... I just tried and every fullscreen app I have on my S3 behaves this exact same way.
I suspect that if there was a way around it (assuming the above doesn't work, which I don't expect it to), it would be considered to be a bug by the Android team, and I would advise against it.
i want make Fullscreen in android 4.0, i use android:theme="#android:style/Theme.NoTitleBar.Fullscreen"
the action bar is disappear, but the status bar isn't appear
i use
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
before "setContentView()"
OK, FullScreen!! however, when the dialog or popupwindow show, the status bar appear again,
i read the source code and find the word :
There is a limitation: because navigation controls are so important,
the least user interaction will cause them to reappear immediately.
can i make fullscreen anytime? help me!
There is a limitation: because navigation controls are so important, the least user * interaction will cause them to reappear immediately.
In other words, Android is telling you that the limitation exists because it would be a bad idea to prevent the user from accessing the navigation controls. Doing so would surely disrupt the user experience and would probably piss off a lot of users. That said, unless you have a very good reason for doing so, you should leave it the way it is.