Setting maximum expanded height for bottomsheet dynamically

Question

How to set maximum expanded height in android support design bottom sheet?

The question is an extension to the above question, i want to set the max expanded height of the sheet but dynamically according to the screen size.

I have tried setting new layout params to the view implementing bottomsheet behaviour but it does nothing good.

Answer 1

Please use this and chill :)

1. const val BOTTOMSHEET_HEIGHT_TO_SCREEN_HEIGHT_RATIO = 0.80 //change according to your requirement
2. override onCreateDialog() in your bottomsheetFragment

---

override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val dialog = super.onCreateDialog(savedInstanceState) as BottomSheetDialog
        dialog.setOnShowListener {
            dialog.findViewById<FrameLayout>(com.google.android.material.R.id.design_bottom_sheet)
                ?.apply {
                    val maxDesiredHeight =
                        (resources.displayMetrics.heightPixels * BOTTOMSHEET_HEIGHT_TO_SCREEN_HEIGHT_RATIO).toInt()
                    if (this.height > maxDesiredHeight) {
                        val bottomSheetLayoutParams = this.layoutParams
                        bottomSheetLayoutParams.height = maxDesiredHeight
                        this.layoutParams = bottomSheetLayoutParams
                    }
                    BottomSheetBehavior.from(this)?.apply {
                        this.state = BottomSheetBehavior.STATE_EXPANDED
                        this.skipCollapsed = true
                    }
                }
        }
        return dialog
    }

Answer 2

2021 I'm late but someone will need Kotlin extenxion:

fun View.setupFullHeight(maxHeight: Double = 0.3) {
val displayMetrics = context?.resources?.displayMetrics
val height = displayMetrics?.heightPixels
val maximalHeight = (height?.times(maxHeight))?.toInt()
val layoutParams = this.layoutParams
maximalHeight?.let {
    layoutParams.height = it
}
this.layoutParams = layoutParams

}

How to use:

override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
    return object : BottomSheetDialog(requireContext(), R.style.DialogRoundedCornerStyle) {

        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)

            dialog?.setOnShowListener {
                val bottomSheetDialog = it as BottomSheetDialog
                val parentLayout =
                    bottomSheetDialog.findViewById<View>(R.id.design_bottom_sheet)
                parentLayout?.let { view ->
                    val behavior = BottomSheetBehavior.from(view)
                    view.setupFullHeight()
                    behavior.apply {
                        state = BottomSheetBehavior.STATE_EXPANDED
                        isDraggable = false
                        isCancelable = false
                    }
                }
            }
        }

        override fun onBackPressed() {
            super.onBackPressed()
            dialog?.dismiss()
        }
    }
}

Answer 3

The simplest solution is to set the maxHeight property of the bottom sheet like this.

DisplayMetrics displayMetrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
 bottomSheet.setMaxHeight((int) (displayMetrics.heightPixels * 0.65));

Answer 4

Finally found it,

This question troubled me a lot with no solution reported anywhere, and the answer lies in the behavior itself.

The minimum offset is the max value upto which the bottomsheet should move and we set the lower cap of the value to our desired height upto which we want the bottomsheet to move. You can expose a function to set the value or do it direclty in our behavior.

To dynamically set the max expanded height for bottomsheet we need to increase the minimum offset value from 0 to our desired value in BottomSheetBehavior class, let me show the code.

Happy coding!!

         // The minimum offset value upto which your bottomsheet to move
         private int mMinOffset;

        /**
          * Called when the parent CoordinatorLayout is about the layout the given child view.
          */
        @Override
        public boolean onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection) {
               int dynamicHeight = Utils.dpToPx(parent.getContext(), **your_value_in_dp**);
               mMinOffset = Math.max(dynamicHeight, mParentHeight - child.getHeight());
               mMaxOffset = Math.max(mParentHeight - mPeekHeight, mMinOffset);
               mAnchorOffset = Math.min(mParentHeight - mAnchorHeight, mMaxOffset);

               if (mState == STATE_EXPANDED) {
                    ViewCompat.offsetTopAndBottom(child, mMinOffset);
                    anchorViews(mMinOffset);
               } 
        }