RecyclerView Bindings

How to Use

val callback = RecyclerViewScrollCallback
 .Builder(visibleThreshold, recyclerView.layoutManager)
 .resetLoadingState(resetLoadingState)
 .onScrolledToBottom(onScrolledToBottom)
 .build()
recyclerView.clearOnScrollListeners()
recyclerView.addOnScrollListener(callback)

How to Bind

 dataBinding {
 enabled = true
 }

/**
 * @param recyclerView RecyclerView to bind to RecyclerViewScrollCallback
 * @param visibleThreshold The minimum number of items to have below your current scroll position before loading more.
 * @param resetLoadingState Reset endless scroll listener when performing a new search
 * @param onScrolledToBottom OnScrolledListener for RecyclerView scrolled
 */
@BindingAdapter(value = *arrayOf("visibleThreshold", "resetLoadingState", "onScrolledToBottom"), requireAll = false)
fun setRecyclerViewScrollCallback(recyclerView: RecyclerView, visibleThreshold: Int, resetLoadingState: Boolean,
 onScrolledToBottom: RecyclerViewScrollCallback.OnScrolledListener) {
 ... // add addOnScrollListener to RecyclerView using OnScrolledListener as above
}
/**
 * @param swipeRefreshLayout Bind swipeRefreshLayout with OnRefreshListener
 * @param onRefresh Listener for onRefresh when swiped
 */
@BindingAdapter("onPulledToRefresh")
fun setOnSwipeRefreshListener(swipeRefreshLayout: SwipeRefreshLayout, onPulledToRefresh: Runnable) {
 swipeRefreshLayout.setOnRefreshListener { onPulledToRefresh.run() }
}

<android.support.v4.widget.SwipeRefreshLayout
 android:id="@+id/srl"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 bind:onPulledToRefresh="@{() -> presenter.initialize()}">
 <android.support.v7.widget.RecyclerView
 android:id="@+id/rv"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:background="@color/grey"
 app:layoutManager="android.support.v7.widget.LinearLayoutManager"
 bind:onScrolledToBottom="@{(page) -> presenter.onLoadMore(page)}"
 bind:resetLoadingState="@{model.resetLoadingState}"
 bind:spaceItemDecoration="@{@dimen/space_very_low}"
 bind:visibleThreshold="@{model.visibleThreshold}"
 tools:listitem="@layout/item_main" />
</android.support.v4.widget.SwipeRefreshLayout>

Pagination using RxJava (using Subjects)

/**
 * initialize all resources
 * set current page to 1
 * create paginator and subscribe to events
 */
override fun initialize() {
 currentPage = 1 // set page = 1
 paginator = PublishProcessor.create() // create PublishProcessor
 val d = paginator.onBackpressureDrop()
 .filter { !loading } // return if it is still loading
 .doOnNext { loading = view.showProgress() } // loading = true
 .concatMap { contract.getUsersFromServer(it) } // API call
 .observeOn(AndroidSchedulers.mainThread())
 .subscribe({
 loading = view.hideProgress() // loading = false
 view.showItems(it) // show items
 currentPage++ // increment page
 }, {
 loading = view.hideProgress() // loading = false
 view.showError(it.localizedMessage) // show error
 })
 disposables.add(d)
 onLoadMore(currentPage)
}
/**
 * called when list is scrolled to its bottom
 * @param page current page (not used)
 */
override fun onLoadMore(page: Int) {
 paginator.onNext(currentPage) // increment page if not loading
}

Library used

dependencies {
 compile 'com.android.support:design:{latest_version}'
 compile 'io.reactivex.rxjava2:rxandroid:{latest_version}'
 compile 'io.reactivex.rxjava2:rxjava:{latest_version}'
}

Also try

Reference