Odtnhj

I want to create BottomSheetDialogFragment with rounded corners.

What I've done to achieve that:

 <style name="AppTheme.TransparentBottomSheetStyle" parent="Theme.MaterialComponents.Light.BottomSheetDialog">
 <item name="android:background">@android:color/transparent</item>
 </style>

 <style name="AppTheme.BottomSheetDialogTheme" parent="Theme.MaterialComponents.Light.Dialog">
 <item name="android:windowContentOverlay">@null</item>
 <item name="android:windowBackground">@android:color/transparent</item>
 <item name="android:colorBackgroundCacheHint">@null</item>
 <item name="android:colorBackground">@android:color/transparent</item>
 <item name="android:windowIsTranslucent">true</item>
 <item name="bottomSheetStyle">@style/AppTheme.TransparentBottomSheetStyle</item>
 </style>

backdrop_shape.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

 <solid android:color="#00FF00"/>

 <corners
 android:topLeftRadius="24dp"
 android:topRightRadius="24dp"/>
</shape>

And bottom sheet layout:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:background="@drawable/backdrop_shape"
 android:paddingBottom="18dp">

And code:

override fun onActivityCreated(savedInstanceState: Bundle?) 
 super.onActivityCreated(savedInstanceState)
 setStyle(BottomSheetDialogFragment.STYLE_NORMAL, R.style.AppTheme_BottomSheetDialogTheme)
 dialog?.window?.clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND)

This works fine with AppCompat theme, but not with MaterialComponents:

As you can see, there is white background (I think, it's parent FrameLayout with id design_bottom_sheet).

And most interesting thing is that when I rotate the device (and then rotate it back), it becomes transparent as I wanted:

Is it bug or feature? How to fix it?

Note: I've tried all the solutions, that were posted on SO and other websites, they do not work on MaterialComponents too.

According to DialogFragment.setStyle:

Call to customize the basic appearance and behavior of the fragment's
dialog. This can be used for some common dialog behaviors, taking care
of selecting flags, theme, and other options for you. The same effect
can be achieve by manually setting Dialog and Window attributes
yourself. Calling this after the fragment's Dialog is created will
have no effect.

I'm guessing that maybe setStyle should be called in or before onCreate.