Legacy RecyclerView header/footer support and AndroidX migration examples.

简体中文 · Legacy examples · Development

This project originally made it easier to add headers, footers and loading-state examples to RecyclerView. Today, it preserves that implementation as a buildable migration reference alongside an AndroidX example.

For new projects, use AndroidX ConcatAdapter for headers and footers. Add Paging when you need managed pagination. Existing integrations can migrate incrementally; this branch is not a drop-in update for the old Android Support library.

Choose your path

Your situation	Start here
Building a new RecyclerView screen	Run ConcatAdapter (AndroidX) in samplePlus; its page uses no API from this library.
Maintaining an existing integration	Review compatibility and maintenance and the legacy usage notes.
Looking for the original examples	See legacy usage and screenshots.
Contributing or working with an AI agent	Read CONTRIBUTING.md, architecture and AGENTS.md.

What replaces the original features?

Need	Current AndroidX approach
Header + data + footer	ConcatAdapter(headerAdapter, dataAdapter, footerAdapter)
Data-row click positions	getBindingAdapterPosition(), checking NO_POSITION
Incremental list updates	ListAdapter / DiffUtil
Managed pagination and retry UI	Paging + PagingDataAdapter + LoadStateAdapter
Full-width grid / staggered-grid decorations	Explicit span lookup / full-span layout parameters

ConcatAdapter handles adapter composition, notification offsets and view-type isolation; it does not choose layout spans. Paging migration also requires moving data requests and pagination state, not just replacing a scroll listener. See the official ConcatAdapter reference and Paging loading-state guide.

Run the examples

Use JDK 17 or 21, Android SDK 36, and Build Tools 35.0.0. Set ANDROID_HOME or configure an untracked local.properties; see setup details.

sdkmanager "platforms;android-36" "build-tools;35.0.0" "platform-tools"
./gradlew testDebugUnitTest assembleDebug lintDebug --console=plain

Use gradlew.bat on Windows. First builds download dependencies. Tests run on the host without an emulator. The build pins Gradle 8.13, AGP 8.11.1, RecyclerView 1.4.0 and AppCompat 1.7.1; all modules require Android API 21+.

Module	Purpose
library	Legacy wrapper, position/span helpers and scroll callbacks; retained for migration and regression coverage.
sample	Minimal legacy header/footer example.
samplePlus	AndroidX grid example first, followed by legacy linear/grid/staggered paging demos.

Open the root project in Android Studio and run samplePlus. In ConcatAdapter (AndroidX), headers and footers span both columns; tapping an item reports its position within the data adapter. The two demo apps have different application IDs and can be installed together.

The modern page is ConcatExampleActivity.java. samplePlus still depends on library for its other demos; copying the modern page does not require the legacy wrapper. This repository does not include a complete Paging or Compose app.

Compatibility and maintenance

• This branch migrates android.support types to AndroidX and raises the minimum SDK from 14 to 21 for library and sample. Legacy Support consumers must update their imports and rebuild.
• The original Support-era source remains in Git history. This branch does not publish or replace Maven artifacts.
• Work is focused on reproducible builds, confirmed defects, necessary compatibility fixes and documentation/examples. New general-purpose adapter features are outside the maintenance scope.
• Regression tests and CI cover documented paths, not every historical edge case. See the architecture notes for known limits and the device smoke-test checklist in CONTRIBUTING.md.