Fix headerHeight and multiline or empty title sections in search result sections (#442)

Axel · web-flow · commit 132707724234 · 2021-07-15T13:25:55.000+02:00
diff --git a/test-app/r2-testapp/src/main/java/org/readium/r2/testapp/reader/ReaderViewModel.kt b/test-app/r2-testapp/src/main/java/org/readium/r2/testapp/reader/ReaderViewModel.kt
@@ -14,6 +14,8 @@ import androidx.lifecycle.viewModelScope
 import androidx.paging.*
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.launch
 import org.readium.r2.shared.Search
 import org.readium.r2.shared.UserException
@@ -89,25 +91,27 @@ class ReaderViewModel(context: Context, arguments: ReaderContract.Input) : ViewM
     }
 
     fun search(query: String) = viewModelScope.launch {
-        _searchLocators.clear()
+        if (query == lastSearchQuery) return@launch
+        lastSearchQuery = query
+        _searchLocators.value = emptyList()
         searchIterator = publication.search(query)
             .onFailure { channel.send(Event.Failure(it)) }
             .getOrNull()
-
         pagingSourceFactory.invalidate()
         channel.send(Event.StartNewSearch)
     }
 
-    fun cancelSearch() {
-        viewModelScope.launch {
-            searchIterator?.close()
-            searchIterator = null
-            pagingSourceFactory.invalidate()
-        }
+    fun cancelSearch() = viewModelScope.launch {
+        _searchLocators.value = emptyList()
+        searchIterator?.close()
+        searchIterator = null
+        pagingSourceFactory.invalidate()
     }
 
-    val searchLocators: List<Locator> get() = _searchLocators
-    private var _searchLocators = mutableListOf<Locator>()
+    val searchLocators: StateFlow<List<Locator>> get() = _searchLocators
+    private var _searchLocators = MutableStateFlow<List<Locator>>(emptyList())
+
+    private var lastSearchQuery: String? = null
 
     private var searchIterator: SearchIterator? = null
 
@@ -119,7 +123,7 @@ class ReaderViewModel(context: Context, arguments: ReaderContract.Input) : ViewM
         override suspend fun next(): SearchTry<LocatorCollection?> {
             val iterator = searchIterator ?: return Try.success(null)
             return iterator.next().onSuccess {
-                _searchLocators.addAll(it?.locators ?: emptyList())
+                _searchLocators.value += (it?.locators ?: emptyList())
             }
         }
     }
diff --git a/test-app/r2-testapp/src/main/java/org/readium/r2/testapp/search/SearchFragment.kt b/test-app/r2-testapp/src/main/java/org/readium/r2/testapp/search/SearchFragment.kt
@@ -10,6 +10,7 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.core.view.isVisible
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.fragment.app.setFragmentResult
@@ -49,6 +50,10 @@ class SearchFragment : Fragment(R.layout.fragment_search) {
             .onEach { searchAdapter.submitData(it) }
             .launchIn(viewScope)
 
+        viewModel.searchLocators
+            .onEach { binding.noResultLabel.isVisible = it.isEmpty() }
+            .launchIn(viewScope)
+
         viewModel.channel
             .receive(viewLifecycleOwner) { event ->
                 when (event) {
@@ -63,7 +68,7 @@ class SearchFragment : Fragment(R.layout.fragment_search) {
             layoutManager = LinearLayoutManager(activity)
             addItemDecoration(SectionDecoration(context, object : SectionDecoration.Listener {
                 override fun isStartOfSection(itemPos: Int): Boolean =
-                    viewModel.searchLocators.run {
+                    viewModel.searchLocators.value.run {
                         when {
                             itemPos == 0 -> true
                             itemPos < 0 -> false
@@ -73,7 +78,7 @@ class SearchFragment : Fragment(R.layout.fragment_search) {
                     }
 
                 override fun sectionTitle(itemPos: Int): String =
-                    viewModel.searchLocators.getOrNull(itemPos)?.title ?: ""
+                    viewModel.searchLocators.value.getOrNull(itemPos)?.title ?: ""
             }))
             addItemDecoration(DividerItemDecoration(context, DividerItemDecoration.VERTICAL))
         }
diff --git a/test-app/r2-testapp/src/main/java/org/readium/r2/testapp/utils/SectionDecoration.kt b/test-app/r2-testapp/src/main/java/org/readium/r2/testapp/utils/SectionDecoration.kt
@@ -29,9 +29,7 @@ class SectionDecoration(
     }
 
     private lateinit var headerView: View
-    private lateinit var sectionTitle: TextView
-
-    private val headerHeight get() = headerView.height
+    private lateinit var sectionTitleView: TextView
 
     override fun getItemOffsets(
         outRect: Rect,
@@ -41,32 +39,42 @@ class SectionDecoration(
     ) {
         super.getItemOffsets(outRect, view, parent, state)
         val pos = parent.getChildAdapterPosition(view)
-        if (listener.isStartOfSection(pos))
-            outRect.top = headerHeight
+        initHeaderViewIfNeeded(parent)
+        if (listener.sectionTitle(pos) != "" && listener.isStartOfSection(pos)) {
+            sectionTitleView.text = listener.sectionTitle(pos)
+            fixLayoutSize(headerView, parent)
+            outRect.top = headerView.height
+        }
     }
 
     override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
         super.onDrawOver(c, parent, state)
-        SectionHeaderBinding.inflate(
-            LayoutInflater.from(context),
-            parent,
-            false
-        ).apply {
-            headerView = root
-            sectionTitle = header
-        }
-        fixLayoutSize(headerView, parent)
+        initHeaderViewIfNeeded(parent)
 
         val children = parent.children.toList()
         children.forEach { child ->
             val pos = parent.getChildAdapterPosition(child)
-            if (pos != NO_POSITION && (listener.isStartOfSection(pos) || isTopChild(child, children))) {
-                sectionTitle.text = listener.sectionTitle(pos)
+            if (pos != NO_POSITION && listener.sectionTitle(pos) != "" &&
+                (listener.isStartOfSection(pos) || isTopChild(child, children))) {
+                sectionTitleView.text = listener.sectionTitle(pos)
+                fixLayoutSize(headerView, parent)
                 drawHeader(c, child, headerView)
             }
         }
     }
 
+    private fun initHeaderViewIfNeeded(parent: RecyclerView) {
+        if (::headerView.isInitialized) return
+        SectionHeaderBinding.inflate(
+            LayoutInflater.from(context),
+            parent,
+            false
+        ).apply {
+            headerView = root
+            sectionTitleView = header
+        }
+    }
+
     private fun fixLayoutSize(v: View, parent: ViewGroup) {
         val widthSpec = View.MeasureSpec.makeMeasureSpec(parent.width, View.MeasureSpec.EXACTLY)
         val heightSpec = View.MeasureSpec.makeMeasureSpec(parent.height, View.MeasureSpec.UNSPECIFIED)
diff --git a/test-app/r2-testapp/src/main/res/layout/fragment_search.xml b/test-app/r2-testapp/src/main/res/layout/fragment_search.xml
@@ -24,4 +24,16 @@
         app:layout_constraintEnd_toEndOf="@id/search_overlay"
         app:layout_constraintStart_toStartOf="@id/search_overlay"
         app:layout_constraintTop_toTopOf="@id/search_overlay" />
-</androidx.constraintlayout.widget.ConstraintLayout>
+
+    <TextView
+        android:id="@+id/noResultLabel"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="24dp"
+        android:text="@string/no_result"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        android:visibility="gone"/>
+
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/test-app/r2-testapp/src/main/res/layout/section_header.xml b/test-app/r2-testapp/src/main/res/layout/section_header.xml
@@ -9,21 +9,17 @@
   ~ LICENSE file present in the project repository where this source code is maintained.
   -->
 
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/header"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
+    android:layout_height="wrap_content"
     android:background="@color/colorAccent"
-    android:orientation="vertical">
-
-    <TextView
-        android:id="@+id/header"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:paddingBottom="10dp"
-        android:paddingEnd="20dp"
-        android:paddingStart="20dp"
-        android:paddingTop="10dp"
-        android:textAllCaps="true"
-        android:textStyle="bold" />
-
-</LinearLayout>
+    android:orientation="vertical"
+    android:ellipsize="end"
+    android:maxLines="3"
+    android:paddingStart="20dp"
+    android:paddingTop="10dp"
+    android:paddingEnd="20dp"
+    android:paddingBottom="10dp"
+    android:textAllCaps="true"
+    android:textStyle="bold" />
diff --git a/test-app/r2-testapp/src/main/res/values/strings.xml b/test-app/r2-testapp/src/main/res/values/strings.xml
@@ -191,4 +191,5 @@
     <string name="brightness_higher">Brightness higher</string>
     <string name="tts_slower">TTS slower</string>
     <string name="tts_faster">TTS faster</string>
+    <string name="no_result">No result</string>
 </resources>
