How to use BottomSheetDialog?

Question

I want to try BottomSheetDialog introduced in Android Support Library 23.2 but it doesn\'t seem to work correctly. Here is what the doc says:

Answer 1

Here's the issue on code.google.com https://code.google.com/p/android/issues/detail?id=201793

An issue some users are seeing boils down to the FrameLayout that wraps our content view being centered vertically. The BottomSheetBehavior only works if this view is top aligned. I haven't figured out what causes the FrameLayout to become centered vertically yet, but here's a possible workaround:

View contentView = ...
// You may have to measure your content view first.
dialog.setContentView(contentView);

// Change this to a percentage or a constant, whatever you want to do.
// The default is 1024 - any views smaller than this will be pulled off 
// the bottom of the screen.
float peekHeight = contentView.getMeasuredHeight();

View parent = (View)contentView.getParent();
BottomSheetBehavior behavior = BottomSheetBehavior.from(parent);
behavior.setPeekHeight(peekHeight);
CoordinatorLayout.LayoutParams layoutParams = 
   (CoordinatorLayout.LayoutParams)parent.getLayoutParams();
layoutParams.gravity = Gravity.TOP | Gravity.CENTER_HORIZONTAL;