/StickyHeaders

Adapter and LayoutManager for Android RecyclerView which enables sticky header positioning.

Primary LanguageJavaMIT LicenseMIT

StickyHeaders

Adapter and LayoutManager for Android RecyclerView which enables sticky header positioning.

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minSdkVersion: 14

compile 'org.zakariya.stickyheaders:stickyheaders:0.7.10'

StickyHeaders are section headers in a RecyclerView which are positioned "stickily" to the top of the scrollview during scrolling. A common use-case is an address book where the list of people's last names are grouped into sections by the first letter of the last name, and the header for each section shows that letter.

For example:

AddressBookSample

StickyHeaders also supports a callback (org.zakariya.stickyheaders.StickyHeaderLayoutManager.HeaderPositionChangedCallback) when a header becomes "sticky" or returns to normal positioning. For example, it is used here to set the elevation on the header to cast a subtle drop shadow when the header is in sticky position.

For example:

CallbacksSample

Usage

To use StickyHeaders, you need to do two things.

  1. Implement an adapter by subclassing org.zakariya.stickyheaders.SectioningAdapter
  2. Assign a org.zakariya.stickyheaders.StickyHeaderLayoutManager to your recyclerview.
  3. When handling modifications to your dataset, never call the RecyclerView.Adapter::notify* methods, instead, call the corresponding methods in org.zakariya.stickyheaders.SectioningAdapter::notifySection*. The reason for this is SectioningAdapter maintains internal state, and the notifySection* methods are tailored for adding and removing sections, adding and removing items from sections, etc.

Notes

  1. StickyHeaders uses androidx.recyclerview.*
  2. You can use sectioning adapter with a normal androidx.recyclerview.widget.LinearLayoutManager. it works fine, and could be a good way to implement a list like at the root of Android's Settings app.