How to Allow outside touch for BottomSheetDialog?

Try code below in your BottomSheetDialog:

 override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
     return (super.onCreateDialog(savedInstanceState) as BottomSheetDialog).apply {
         setCanceledOnTouchOutside(false)
     }
 }

or wrap by <CoordinatorLayout> for instance your <ConstraintLayout> and implement <layout /> and attach to BottomSheetBehavior.

This is not possible till you are using BottomSheetDialogFragment. BottomSheetDialogFragment is a dialog and as behaviour of every dialog, it does not allow user interception on any view behind the dialog, although that is visible to user.

So to achieve this you need to use Fragment instead of BottomSheetDialogFragment. And yes it will require lot of code changes :) and you have to live without BottomSheetDialogFragment if you want to intercept views behind.

you should use android.support.design.widget.BottomSheetBehavior.

but if you want to have a bottomSheet in other class I suggest you use a Fragment and in this fragment open your bottomSheet

open your fragment in this way.

And in your fragment, open your bottomSheet in the following code:

in onInitViews

var mBottomSheetBehavior = BottomSheetBehavior.from(bottomSheetCoordinatorLayout)
mBottomSheetBehavior!!.state = BottomSheetBehavior.STATE_HIDDEN

mBottomSheetBehavior!!.setBottomSheetCallback(object : BottomSheetBehavior.BottomSheetCallback() {
     override fun onStateChanged(bottomSheet: View, newState: Int) {
          when (newState) {
             BottomSheetBehavior.STATE_HIDDEN -> {
                  fragmentManager?.popBackStack()
             }
             //BottomSheetBehavior.STATE_COLLAPSED -> "Collapsed"
             //BottomSheetBehavior.STATE_DRAGGING -> "Dragging..."
             //BottomSheetBehavior.STATE_EXPANDED -> "Expanded"
             //BottomSheetBehavior.STATE_SETTLING -> "Settling..."
           }
      }

      override fun onSlide(bottomSheet: View, slideOffset: Float) {
          //text_view_state!!.text = "Sliding..."
      }
})

And your layout should be like this:

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layoutDirection="ltr">

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/bottomSheetCoordinatorLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:behavior_hideable="true"
        app:behavior_peekHeight="55dp"
        app:layout_behavior="@string/bottom_sheet_behavior">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/top_radius_primary_color"
            android:paddingStart="@dimen/material_size_32"
            android:paddingEnd="@dimen/material_size_32">

        </RelativeLayout>
    </android.support.design.widget.CoordinatorLayout>
</android.support.design.widget.CoordinatorLayout>

I hope it helps you