Use loading item instead of full screen loading.

vector/src/main/java/im/vector/app/features/home/room/detail/search/SearchAction.kt

@@ -20,6 +20,6 @@ import im.vector.app.core.platform.VectorViewModelAction
 
 sealed class SearchAction : VectorViewModelAction {
     data class SearchWith(val searchTerm: String) : SearchAction()
-    object ScrolledToTop : SearchAction()
+    object LoadMore : SearchAction()
     object Retry : SearchAction()
 }

vector/src/main/java/im/vector/app/features/home/room/detail/search/SearchFragment.kt

@@ -21,14 +21,15 @@ import android.os.Parcelable
 import android.view.View
 import androidx.core.content.ContextCompat
 import androidx.recyclerview.widget.LinearLayoutManager
-import androidx.recyclerview.widget.RecyclerView
+import com.airbnb.mvrx.Fail
+import com.airbnb.mvrx.Loading
+import com.airbnb.mvrx.Success
 import com.airbnb.mvrx.args
 import com.airbnb.mvrx.fragmentViewModel
 import com.airbnb.mvrx.withState
 import im.vector.app.R
 import im.vector.app.core.extensions.cleanup
 import im.vector.app.core.extensions.configureWith
-import im.vector.app.core.extensions.exhaustive
 import im.vector.app.core.extensions.hideKeyboard
 import im.vector.app.core.extensions.trackItemsVisibilityChange
 import im.vector.app.core.platform.StateView
@@ -62,39 +63,19 @@ class SearchFragment @Inject constructor(
         stateView.eventCallback = this
 
         configureRecyclerView()
-
-        searchViewModel.observeViewEvents {
-            when (it) {
-                is SearchViewEvents.Failure -> {
-                    stateView.state = StateView.State.Error(errorFormatter.toHumanReadable(it.throwable))
-                }
-                is SearchViewEvents.Loading -> {
-                    stateView.state = StateView.State.Loading
-                }
-            }.exhaustive
-        }
     }
 
     private fun configureRecyclerView() {
         searchResultRecycler.trackItemsVisibilityChange()
         searchResultRecycler.configureWith(controller, showDivider = false)
+        (searchResultRecycler.layoutManager as? LinearLayoutManager)?.stackFromEnd = true
         controller.listener = this
 
         controller.addModelBuildListener {
             pendingScrollToPosition?.let {
-                searchResultRecycler.scrollToPosition(it)
+                searchResultRecycler.smoothScrollToPosition(it)
             }
         }
-
-        searchResultRecycler.addOnScrollListener(object : RecyclerView.OnScrollListener() {
-            override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
-                // Load next batch when scrolled to the top
-                if (newState == RecyclerView.SCROLL_STATE_IDLE
-                        && (searchResultRecycler.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition() == 0) {
-                    searchViewModel.handle(SearchAction.ScrolledToTop)
-                }
-            }
-        })
     }
 
     override fun onDestroy() {
@@ -104,18 +85,26 @@ class SearchFragment @Inject constructor(
     }
 
     override fun invalidate() = withState(searchViewModel) { state ->
-        if (state.searchResult?.results?.isNotEmpty() == true) {
+        if (state.searchResult?.results.isNullOrEmpty()) {
-            stateView.state = StateView.State.Content
+            when (state.asyncEventsRequest) {
-            controller.setData(state)
+                is Loading -> {
-
+                    stateView.state = StateView.State.Loading
-            val lastBatchSize = state.lastBatch?.results?.size ?: 0
+                }
-            val scrollPosition = if (lastBatchSize > 0) lastBatchSize - 1 else 0
+                is Fail    -> {
-            pendingScrollToPosition = scrollPosition
+                    stateView.state = StateView.State.Error(errorFormatter.toHumanReadable(state.asyncEventsRequest.error))
-        } else {
+                }
+                is Success -> {
                     stateView.state = StateView.State.Empty(
                             title = getString(R.string.search_no_results),
-                    image = ContextCompat.getDrawable(requireContext(), R.drawable.ic_search_no_results)
+                            image = ContextCompat.getDrawable(requireContext(), R.drawable.ic_search_no_results))
-            )
+                }
+            }
+        } else {
+            val lastBatchSize = state.lastBatch?.results?.size ?: 0
+            pendingScrollToPosition = if (lastBatchSize > 0) lastBatchSize - 1 else 0
+
+            stateView.state = StateView.State.Content
+            controller.setData(state)
         }
     }
 
@@ -133,4 +122,8 @@ class SearchFragment @Inject constructor(
 
         navigator.openRoom(requireContext(), event.roomId!!, event.eventId)
     }
+
+    override fun loadMore() {
+        searchViewModel.handle(SearchAction.LoadMore)
+    }
 }

vector/src/main/java/im/vector/app/features/home/room/detail/search/SearchResultController.kt

@@ -17,8 +17,10 @@
 package im.vector.app.features.home.room.detail.search
 
 import com.airbnb.epoxy.TypedEpoxyController
+import com.airbnb.epoxy.VisibilityState
 import im.vector.app.core.date.DateFormatKind
 import im.vector.app.core.date.VectorDateFormatter
+import im.vector.app.core.epoxy.loadingItem
 import im.vector.app.core.ui.list.genericItemHeader
 import im.vector.app.features.home.AvatarRenderer
 import org.matrix.android.sdk.api.session.Session
@@ -34,8 +36,11 @@ class SearchResultController @Inject constructor(
 
     var listener: Listener? = null
 
+    private var idx = 0
+
     interface Listener {
         fun onItemClicked(event: Event)
+        fun loadMore()
     }
 
     init {
@@ -45,6 +50,18 @@ class SearchResultController @Inject constructor(
     override fun buildModels(data: SearchViewState?) {
         data?.searchResult?.results ?: return
 
+        if (!data.searchResult.nextBatch.isNullOrEmpty()) {
+            loadingItem {
+                // Always use a different id, because we can be notified several times of visibility state changed
+                id("loadMore${idx++}")
+                onVisibilityStateChanged { _, _, visibilityState ->
+                    if (visibilityState == VisibilityState.VISIBLE) {
+                        listener?.loadMore()
+                    }
+                }
+            }
+        }
+
         buildSearchResultItems(data.searchResult.results!!)
     }
 

vector/src/main/java/im/vector/app/features/home/room/detail/search/SearchViewEvents.kt

@@ -20,5 +20,4 @@ import im.vector.app.core.platform.VectorViewEvents
 
 sealed class SearchViewEvents : VectorViewEvents {
     data class Failure(val throwable: Throwable) : SearchViewEvents()
-    data class Loading(val message: CharSequence? = null) : SearchViewEvents()
 }

vector/src/main/java/im/vector/app/features/home/room/detail/search/SearchViewModel.kt

@@ -16,16 +16,21 @@
 
 package im.vector.app.features.home.room.detail.search
 
+import androidx.lifecycle.viewModelScope
+import com.airbnb.mvrx.Fail
 import com.airbnb.mvrx.FragmentViewModelContext
+import com.airbnb.mvrx.Loading
 import com.airbnb.mvrx.MvRxViewModelFactory
+import com.airbnb.mvrx.Success
 import com.airbnb.mvrx.ViewModelContext
 import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
 import im.vector.app.core.extensions.exhaustive
 import im.vector.app.core.platform.VectorViewModel
-import org.matrix.android.sdk.api.MatrixCallback
+import kotlinx.coroutines.launch
 import org.matrix.android.sdk.api.session.Session
 import org.matrix.android.sdk.api.session.search.SearchResult
+import org.matrix.android.sdk.internal.util.awaitCallback
 
 class SearchViewModel @AssistedInject constructor(
         @Assisted private val initialState: SearchViewState,
@@ -49,7 +54,7 @@ class SearchViewModel @AssistedInject constructor(
     override fun handle(action: SearchAction) {
         when (action) {
             is SearchAction.SearchWith -> handleSearchWith(action)
-            is SearchAction.ScrolledToTop -> handleScrolledToTop()
+            is SearchAction.LoadMore   -> handleLoadMore()
             is SearchAction.Retry      -> handleRetry()
         }.exhaustive
     }
@@ -57,17 +62,13 @@ class SearchViewModel @AssistedInject constructor(
     private fun handleSearchWith(action: SearchAction.SearchWith) {
         if (action.searchTerm.length > 1) {
             setState {
-                copy(searchTerm = action.searchTerm, isNextBatch = false)
+                copy(searchTerm = action.searchTerm)
             }
-
             startSearching()
         }
     }
 
-    private fun handleScrolledToTop() {
+    private fun handleLoadMore() {
-        setState {
-            copy(isNextBatch = true)
-        }
         startSearching(true)
     }
 
@@ -75,14 +76,24 @@ class SearchViewModel @AssistedInject constructor(
         startSearching()
     }
 
-    private fun startSearching(scrolledToTop: Boolean = false) = withState { state ->
+    private fun startSearching(isNextBatch: Boolean = false) = withState { state ->
         if (state.roomId == null || state.searchTerm == null) return@withState
 
         // There is no batch to retrieve
-        if (scrolledToTop && state.searchResult?.nextBatch == null) return@withState
+        if (isNextBatch && state.searchResult?.nextBatch == null) return@withState
 
-        _viewEvents.post(SearchViewEvents.Loading())
+        // Show full screen loading just for the clean search
+        if (!isNextBatch) {
+            setState {
+                copy(
+                        asyncEventsRequest = Loading()
+                )
+            }
+        }
 
+        viewModelScope.launch {
+            try {
+                val result = awaitCallback<SearchResult> {
                     session
                             .getRoom(state.roomId)
                             ?.search(
@@ -93,26 +104,23 @@ class SearchViewModel @AssistedInject constructor(
                                     afterLimit = 0,
                                     includeProfile = true,
                                     limit = 20,
-                        callback = object : MatrixCallback<SearchResult> {
+                                    callback = it
-                            override fun onFailure(failure: Throwable) {
-                                onSearchFailure(failure)
-                            }
-
-                            override fun onSuccess(data: SearchResult) {
-                                onSearchResultSuccess(data)
-                            }
-                        }
                             )
                 }
-
+                onSearchResultSuccess(result, isNextBatch)
-    private fun onSearchFailure(failure: Throwable) {
+            } catch (failure: Throwable) {
-        setState {
-            copy(searchResult = null)
-        }
                 _viewEvents.post(SearchViewEvents.Failure(failure))
+                setState {
+                    copy(
+                            asyncEventsRequest = Fail(failure),
+                            searchResult = null
+                    )
+                }
+            }
+        }
     }
 
-    private fun onSearchResultSuccess(searchResult: SearchResult) = withState { state ->
+    private fun onSearchResultSuccess(searchResult: SearchResult, isNextBatch: Boolean) = withState { state ->
         val accumulatedResult = SearchResult(
                 nextBatch = searchResult.nextBatch,
                 results = searchResult.results,
@@ -120,7 +128,7 @@ class SearchViewModel @AssistedInject constructor(
         )
 
         // Accumulate results if it is the next batch
-        if (state.isNextBatch) {
+        if (isNextBatch) {
             if (state.searchResult != null) {
                 accumulatedResult.results = accumulatedResult.results?.plus(state.searchResult.results!!)
             }
@@ -130,7 +138,11 @@ class SearchViewModel @AssistedInject constructor(
         }
 
         setState {
-            copy(searchResult = accumulatedResult, lastBatch = searchResult)
+            copy(
+                    searchResult = accumulatedResult,
+                    lastBatch = searchResult,
+                    asyncEventsRequest = Success(Unit)
+            )
         }
     }
 }

vector/src/main/java/im/vector/app/features/home/room/detail/search/SearchViewState.kt

@@ -16,7 +16,9 @@
 
 package im.vector.app.features.home.room.detail.search
 
+import com.airbnb.mvrx.Async
 import com.airbnb.mvrx.MvRxState
+import com.airbnb.mvrx.Uninitialized
 import org.matrix.android.sdk.api.session.search.SearchResult
 
 data class SearchViewState(
@@ -26,7 +28,8 @@ data class SearchViewState(
         val lastBatch: SearchResult? = null,
         val searchTerm: String? = null,
         val roomId: String? = null,
-        val isNextBatch: Boolean = false
+        // Current pagination request
+        val asyncEventsRequest: Async<Unit> = Uninitialized
 ) : MvRxState {
 
     constructor(args: SearchArgs) : this(roomId = args.roomId)

vector/src/main/res/layout/fragment_search.xml

@@ -2,8 +2,7 @@
 <im.vector.app.core.platform.StateView xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/stateView"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
+    android:layout_height="match_parent">
-    android:background="?riotx_header_panel_background">
 
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/searchResultRecycler"