Feature/loadmore recyclerview

flowbinding-recyclerview/README.md

@@ -20,4 +20,6 @@ fun RecyclerView.childAttachStateChangeEvents(): Flow<RecyclerViewChildAttachSta
 fun RecyclerView.flingEvents(handled: (FlingEvent) -> Boolean = { true }): Flow<FlingEvent>
 fun RecyclerView.scrollEvents(): Flow<RecyclerViewScrollEvent>
 fun RecyclerView.scrollStateChanges(): Flow<Int>
+fun RecyclerView.loadMoreFlowVertically(): Flow<Boolean>
+fun RecyclerView.loadMoreFlowHorizontally(): Flow<Boolean>
 ```

flowbinding-recyclerview/src/main/java/reactivecircus/flowbinding/recyclerview/RecyclerViewLoadMoreFlow.kt

@@ -0,0 +1,60 @@
+package reactivecircus.flowbinding.recyclerview
+
+import androidx.annotation.CheckResult
+import androidx.recyclerview.widget.RecyclerView
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.conflate
+import reactivecircus.flowbinding.common.checkMainThread
+
+/**
+ * Create a [Flow] of scroll events on the [RecyclerView] instance.
+ *
+ * Note: create a extension for loading more in different directions
+ *
+ * Example of usage:
+ *
+ * ```
+ * recyclerView.loadMoreFlowVertically()
+ *     .onEach { loadMore ->
+ *          // handle data changed
+ *     }
+ *     .launchIn(uiScope)
+ * ```
+ */
+@CheckResult
+@OptIn(ExperimentalCoroutinesApi::class)
+public fun RecyclerView.loadMoreFlowVertically(): Flow<Boolean> = callbackFlow {
+    checkMainThread()
+    val listener = object : RecyclerView.OnScrollListener() {
+        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
+            if (!recyclerView.canScrollVertically(1) && newState == RecyclerView.SCROLL_STATE_IDLE) {
+                trySend(true)
+            } else {
+                trySend(false)
+            }
+        }
+    }
+    addOnScrollListener(listener)
+    awaitClose { removeOnScrollListener(listener) }
+}.conflate()
+
+
+@CheckResult
+@OptIn(ExperimentalCoroutinesApi::class)
+public fun RecyclerView.loadMoreFlowHorizontally(): Flow<Boolean> = callbackFlow {
+    checkMainThread()
+    val listener = object : RecyclerView.OnScrollListener() {
+        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
+            if (!recyclerView.canScrollHorizontally(1) && newState == RecyclerView.SCROLL_STATE_IDLE) {
+                trySend(true)
+            } else {
+                trySend(false)
+            }
+        }
+    }
+    addOnScrollListener(listener)
+    awaitClose { removeOnScrollListener(listener) }
+}.conflate()