Android Question Best practice for Android Dark theme?

jo1234 · Sep 17, 2019

Hi all,

I have a question concerning the Dark theme that has been introduced with Android 10.
What is the best practice to support Dark themes in B4A?
How can I select an image based on the night mode flag?

thanks a lot,
Johannes

Erel · Sep 18, 2019

You can use AppCompat for this and set the theme to be:

B4X:

CreateResource(values, theme.xml,
<resources>
    <style name="MyAppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
    </style>
</resources>
)

If you use the default colors then most views will look properly automatically.

You can check whether night mode is active:

B4X:

Sub IsNightMode As Boolean
   Dim ctxt As JavaObject
   ctxt.InitializeContext
   Log(ctxt.RunMethodJO("getResources", Null).RunMethodJO("getConfiguration", Null).GetField("uiMode"))
   Return Bit.And(ctxt.RunMethodJO("getResources", Null).RunMethodJO("getConfiguration", Null).GetField("uiMode"), 0x30) = 0x20
End Sub

You can set the default night mode if you don't want it to be based on the system default:

B4X:

Sub SetDefaultNightMode (Mode As Int)
   Dim jo As JavaObject
   jo.InitializeStatic("androidx.appcompat.app.AppCompatDelegate").RunMethod("setDefaultNightMode", Array(Mode))
End Sub

The constants are listed here: https://developer.android.com/refer...at/app/AppCompatDelegate.html#MODE_NIGHT_AUTO

Note that the activity will be recreated if the theme changes.

Android Question Best practice for Android Dark theme?

jo1234

Active Member

Erel

B4X founder

Similar Threads

Android Question Best practice for Android Dark theme?

jo1234

Active Member

Erel

B4X founder

Similar Threads

Privacy & Transparency

Privacy & Transparency