How do their APIs compare?

Comparing "APIs" across these two repos means comparing quite different kinds of surfaces, since they solve unrelated problems (a UI widget library vs. a barcode scanning library). Here's what the retrieved data actually shows:

cymcsg/ultimaterecyclerview — a widget/adapter API

• The core public surface is a custom RecyclerView subclass (UltimateRecyclerView) meant to be dropped into XML layouts as shown in the README, used "just like RecyclerView" but with added behaviors (refresh, load-more, animations, drag/drop, sticky headers).
• On top of that, it exposes an adapter-helper API modeled after Joan Zapata's QuickAdapter pattern:
  • BaseQuickAdapter<T> — abstract adapter where you only implement convert(), using a BaseAdapterHelper to minimize boilerplate [UltimateRecyclerView/ultimaterecyclerview/src/main/java/com/marshalchen/ultimaterecyclerview/quickAdapter/extBaseAdapter/BaseQuickAdapter.java:L1-L39].
  • EnhancedQuickAdapter<T> — extends that pattern by adding an itemChanged boolean to convert(), letting you distinguish "adapting to same item" vs. dataset invalidated [UltimateRecyclerView/ultimaterecyclerview/src/main/java/com/marshalchen/ultimaterecyclerview/quickAdapter/extBaseAdapter/EnhancedQuickAdapter.java:L1-L33].
• Supporting interfaces/callbacks extend the API for specific interactions:
  • ItemTouchHelperViewHolder — callback interface for swipe/drag ViewHolders, mirroring Android's ItemTouchHelper.Callback [UltimateRecyclerView/ultimaterecyclerview/src/main/java/com/marshalchen/ultimaterecyclerview/itemTouchHelper/ItemTouchHelperViewHolder.java:L1-L26].
  • ObservableScrollViewCallbacks — callback interface for scroll-driven behaviors like hide/show toolbar [UltimateRecyclerView/ultimaterecyclerview/src/main/java/com/marshalchen/ultimaterecyclerview/ObservableScrollViewCallbacks.java:L1-L21].
  • DragSortShadowBuilder supports drag-and-drop visuals [UltimateRecyclerView/ultimaterecyclerview/src/main/java/com/marshalchen/ultimaterecyclerview/dragsortadapter/DragSortShadowBuilder.java:L1-L27].
• There's also a logging utility, URLogs, offering leveled log calls (e.g. v(String msg)) with stack-trace-aware tagging for debugging [UltimateRecyclerView/ultimaterecyclerview/src/main/java/com/marshalchen/ultimaterecyclerview/URLogs.java:L48-L87].
• Overall shape: inheritance/composition-based Android UI API — you subclass adapters, implement interfaces, and configure a View subclass declaratively in XML.

zxing/zxing — a scanning/decoding + platform-integration API

• The Android client module exposes helper/utility classes rather than one central widget:
  • LocaleManager — static utility methods like getCountryTLD, getProductSearchCountryTLD, getBookSearchCountryTLD, isBookSearchUrl for localizing search URLs based on device locale [android/src/com/google/zxing/client/android/LocaleManager.java:L114-L153].
  • OpenCameraInterface / OpenCamera — abstraction over Android's Camera API for opening a camera and reporting metadata like facing direction and orientation [android/src/com/google/zxing/client/android/camera/open/OpenCameraInterface.java:L1-L25, android/src/com/google/zxing/client/android/camera/open/OpenCamera.java:L1-L24].
  • PreviewCallback — camera preview frame callback, built on Camera and Handler/Message [android/src/com/google/zxing/client/android/camera/PreviewCallback.java:L1-L24].
  • ProductResultInfoRetriever — retrieves product