[Teacher][MBL-14841] Empty state added for modules with no items (#1066)

* [Teacher] Empty state added for modules with no items

refs: MBL-14829
affects: Teacher
release note: Empty state added for modules with no items.

apps/teacher/src/main/java/com/instructure/teacher/features/modules/list/ModuleListPresenter.kt

@@ -39,21 +39,25 @@ object ModuleListPresenter : Presenter<ModuleListModel, ModuleListViewState> {
         val courseColor = model.course.color
 
         items += model.modules.map { module ->
-            val moduleItems = module.items.map { item ->
-                if (item.type.equals(ModuleItem.Type.SubHeader.name, ignoreCase = true)) {
-                    ModuleListItemData.ModuleItemData(
-                        id = item.id,
-                        title = null,
-                        subtitle = item.title,
-                        iconResId = null,
-                        isPublished = item.published,
-                        indent = item.indent * indentWidth,
-                        tintColor = 0,
-                        enabled = false
-                    )
-                } else {
-                    createModuleItemData(item, context, indentWidth, courseColor, item.id in model.loadingModuleItemIds)
+            val moduleItems: List<ModuleListItemData> = if (module.items.isNotEmpty()) {
+                module.items.map { item ->
+                    if (item.type.equals(ModuleItem.Type.SubHeader.name, ignoreCase = true)) {
+                        ModuleListItemData.ModuleItemData(
+                                id = item.id,
+                                title = null,
+                                subtitle = item.title,
+                                iconResId = null,
+                                isPublished = item.published,
+                                indent = item.indent * indentWidth,
+                                tintColor = 0,
+                                enabled = false
+                        )
+                    } else {
+                        createModuleItemData(item, context, indentWidth, courseColor, item.id in model.loadingModuleItemIds)
+                    }
                 }
+            } else {
+                listOf(ModuleListItemData.EmptyItem(module.id))
             }
             ModuleListItemData.ModuleData(
                 id = module.id,

apps/teacher/src/main/java/com/instructure/teacher/features/modules/list/ui/ModuleListRecyclerAdapter.kt

@@ -48,6 +48,7 @@ class ModuleListRecyclerAdapter(
         register(ModuleListModuleBinder())
         register(ModuleListItemBinder())
         register(ModuleListLoadingBinder())
+        register(ModuleListEmptyItemBinder())
     }
 
     fun setData(items: List<ModuleListItemData>, collapsedModuleIds: Set<Long>) {

apps/teacher/src/main/java/com/instructure/teacher/features/modules/list/ui/ModuleListViewState.kt

@@ -30,6 +30,8 @@ sealed class ModuleListItemData {
 
     object Loading : ModuleListItemData()
 
+    data class EmptyItem(val moduleId: Long) : ModuleListItemData()
+
     data class FullError(val buttonColor: Int): ModuleListItemData()
 
     data class InlineError(val buttonColor: Int): ModuleListItemData()
@@ -38,7 +40,7 @@ sealed class ModuleListItemData {
         val id: Long,
         val name: String,
         val isPublished: Boolean?,
-        val moduleItems: List<ModuleItemData>
+        val moduleItems: List<ModuleListItemData>
     ): ModuleListItemData()
 
     data class ModuleItemData(

apps/teacher/src/main/java/com/instructure/teacher/features/modules/list/ui/binders/ModuleListEmptyItemBinder.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2019 - present Instructure, Inc.
+ *
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, version 3 of the License.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+package com.instructure.teacher.features.modules.list.ui.binders
+
+import com.instructure.teacher.R
+import com.instructure.teacher.adapters.ListItemBinder
+import com.instructure.teacher.features.modules.list.ui.ModuleListCallback
+import com.instructure.teacher.features.modules.list.ui.ModuleListItemData
+
+class ModuleListEmptyItemBinder : ListItemBinder<ModuleListItemData.EmptyItem, ModuleListCallback>() {
+
+    override val layoutResId: Int
+        get() = R.layout.adapter_module_empty_item
+
+    override val bindBehavior = NoBind()
+
+    override fun getItemId(item: ModuleListItemData.EmptyItem): Long = item.moduleId
+}

apps/teacher/src/main/res/layout/adapter_module_empty_item.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright (C) 2019 - present Instructure, Inc.
+  ~
+  ~     This program is free software: you can redistribute it and/or modify
+  ~     it under the terms of the GNU General Public License as published by
+  ~     the Free Software Foundation, version 3 of the License.
+  ~
+  ~     This program is distributed in the hope that it will be useful,
+  ~     but WITHOUT ANY WARRANTY; without even the implied warranty of
+  ~     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  ~     GNU General Public License for more details.
+  ~
+  ~     You should have received a copy of the GNU General Public License
+  ~     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+  -->
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:minHeight="48dp"
+    android:paddingStart="16dp"
+    android:paddingTop="8dp"
+    android:paddingEnd="16dp"
+    android:paddingBottom="8dp">
+
+    <TextView
+        android:id="@+id/emptyModuleItemTitle"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:text="@string/noItemsToDisplayShort" />
+
+</FrameLayout>

apps/teacher/src/test/java/com/instructure/teacher/unit/modules/ModuleListPresenterTest.kt

@@ -63,7 +63,7 @@ class ModuleListPresenterTest : Assert() {
             id = 1L,
             name = "Module 1",
             isPublished = true,
-            moduleItems = emptyList()
+            moduleItems = listOf(ModuleListItemData.EmptyItem(1L))
         )
         moduleItemTemplate = ModuleItem(
             id = 1000L,