This library offers a simple way to add sticky side headers to RecyclerViews. Without touching your list adapter, headers will scroll in with the first item in a group, stick to the top of the list, then scroll out with the last item in a group.
implementation 'com.github.7shifts:SideHeaderDecorator:0.2.0'
Using SideHeaderDecorator requires only two steps. First, use the HeaderProvider interface to map items to header data. Sequential items mapping to the same header data are considered a group. For example, consider a list of name Strings where the headers' data is a name's first initial.
val headerProvider = object : SideHeaderDecorator.HeaderProvider<Char> {
override fun getHeader(position: Int): Char {
return names[position].first()
}
}Second, given your header data from HeaderProvider::getHeader, implement SideHeaderDecorator's single abstract method to create header views. Pass your HeaderProvider to SideHeaderDecorator's constructor. For example, given the first initial of a name, return an inflated header view.
val headerDecorator = object : SideHeaderDecorator<Char>(headerProvider) {
override fun getHeaderView(header: Char, parent: RecyclerView): View {
val textView = LayoutInflater.from(parent.context).inflate(R.layout.header_view, parent, false) as TextView
textView.text = header.toString()
return textView
}
}That's it! Apply the decorator to your RecyclerView and get sticky side headers!
names_recycler_view.addItemDecoration(headerDecorator)
List Item Padding
- To make room for the header view, SideHeaderDecorator steals the left padding from your list item views.
Header Placement
- The header view is placed (at first) in the top-left corner of your list item view. The header view retains its own padding.
Copyright (c) 2019 7shifts
SideHeaderDecorator is licensed under the MIT License.