Introduce epoxy in demo app

app/build.gradle

@@ -1,6 +1,11 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-kapt'
+
+kapt {
+    correctErrorTypes = true
+}
 
 android {
     compileSdkVersion 28
@@ -20,7 +25,20 @@ android {
     }
 }
 
+
+configurations.all { strategy ->
+    strategy.resolutionStrategy.eachDependency { details ->
+        if (details.requested.group == 'com.android.support') {
+            details.useVersion "28.0.0"
+        }
+    }
+}
+
 dependencies {
+
+    def epoxy_version = "2.19.0"
+
+
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation project(":matrix-sdk-android")
 
@@ -30,6 +48,9 @@ dependencies {
 
     implementation 'com.jakewharton.timber:timber:4.7.1'
 
+    implementation("com.airbnb.android:epoxy:$epoxy_version")
+    kapt "com.airbnb.android:epoxy-processor:$epoxy_version"
+
     implementation "org.koin:koin-android:$koin_version"
     implementation "org.koin:koin-android-scope:$koin_version"
     implementation "org.koin:koin-android-viewmodel:$koin_version"
@@ -38,3 +59,5 @@ dependencies {
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 }
+
+

app/src/main/java/im/vector/riotredesign/core/helpers/KotlinEpoxyHolder.kt

@@ -0,0 +1,45 @@
+package im.vector.riotredesign.core.helpers
+
+import android.view.View
+import com.airbnb.epoxy.EpoxyHolder
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
+/**
+ * A pattern for easier view binding with an [EpoxyHolder]
+ *
+ * See [SampleKotlinModelWithHolder] for a usage example.
+ */
+abstract class KotlinEpoxyHolder : EpoxyHolder() {
+    private lateinit var view: View
+
+    override fun bindView(itemView: View) {
+        view = itemView
+    }
+
+    protected fun <V : View> bind(id: Int): ReadOnlyProperty<KotlinEpoxyHolder, V> =
+            Lazy { holder: KotlinEpoxyHolder, prop ->
+                holder.view.findViewById(id) as V?
+                ?: throw IllegalStateException("View ID $id for '${prop.name}' not found.")
+            }
+
+    /**
+     * Taken from Kotterknife.
+     * https://github.com/JakeWharton/kotterknife
+     */
+    private class Lazy<V>(
+            private val initializer: (KotlinEpoxyHolder, KProperty<*>) -> V
+    ) : ReadOnlyProperty<KotlinEpoxyHolder, V> {
+        private object EMPTY
+
+        private var value: Any? = EMPTY
+
+        override fun getValue(thisRef: KotlinEpoxyHolder, property: KProperty<*>): V {
+            if (value == EMPTY) {
+                value = initializer(thisRef, property)
+            }
+            @Suppress("UNCHECKED_CAST")
+            return value as V
+        }
+    }
+}

app/src/main/java/im/vector/riotredesign/core/helpers/KotlinModel.kt

@@ -0,0 +1,39 @@
+package im.vector.riotredesign.core.helpers
+
+import android.support.annotation.IdRes
+import android.support.annotation.LayoutRes
+import android.view.View
+import com.airbnb.epoxy.EpoxyModel
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
+abstract class KotlinModel(
+        @LayoutRes private val layoutRes: Int
+) : EpoxyModel<View>() {
+
+    private var view: View? = null
+
+    abstract fun bind()
+
+    override fun bind(view: View) {
+        this.view = view
+        bind()
+    }
+
+    override fun unbind(view: View) {
+        this.view = null
+    }
+
+    override fun getDefaultLayout() = layoutRes
+
+    protected fun <V : View> bind(@IdRes id: Int) = object : ReadOnlyProperty<KotlinModel, V> {
+        override fun getValue(thisRef: KotlinModel, property: KProperty<*>): V {
+            // This is not efficient because it looks up the view by id every time (it loses
+            // the pattern of a "holder" to cache that look up). But it is simple to use and could
+            // be optimized with a map
+            @Suppress("UNCHECKED_CAST")
+            return view?.findViewById(id) as V?
+                   ?: throw IllegalStateException("View ID $id for '${property.name}' not found.")
+        }
+    }
+}

app/src/main/java/im/vector/riotredesign/core/platform/RiotFragment.kt

@@ -2,5 +2,5 @@ package im.vector.riotredesign.core.platform
 
 import android.support.v4.app.Fragment
 
-class RiotFragment : Fragment() {
+open class RiotFragment : Fragment() {
 }

app/src/main/java/im/vector/riotredesign/features/home/HomeActivity.kt

@@ -1,31 +1,24 @@
 package im.vector.riotredesign.features.home
 
-import android.arch.lifecycle.Observer
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
-import im.vector.matrix.android.api.Matrix
-import im.vector.matrix.android.api.session.room.Room
 import im.vector.riotredesign.R
 import im.vector.riotredesign.core.platform.RiotActivity
-import org.koin.android.ext.android.inject
-import timber.log.Timber
 
 
 class HomeActivity : RiotActivity() {
 
-    private val matrix by inject<Matrix>()
-    private val currentSession = matrix.currentSession!!
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_home)
-        currentSession.rooms().observe(this, Observer<List<Room>> { roomList ->
-            if (roomList == null) {
-                return@Observer
+
+        if (savedInstanceState == null) {
+            val roomListFragment = RoomListFragment.newInstance()
+            val ft = supportFragmentManager.beginTransaction()
+            ft.replace(R.id.homeFragmentContainer, roomListFragment)
+            ft.commit()
         }
-            Timber.v("Observe rooms: %d", roomList.size)
-        })
     }
 
     companion object {

app/src/main/java/im/vector/riotredesign/features/home/RoomController.kt

@@ -0,0 +1,20 @@
+package im.vector.riotredesign.features.home
+
+import com.airbnb.epoxy.TypedEpoxyController
+import im.vector.matrix.android.api.session.room.Room
+
+class RoomController(private val callback: Callback? = null) : TypedEpoxyController<List<Room>>() {
+
+    override fun buildModels(data: List<Room>?) {
+        data?.forEach {
+            RoomItem(it.roomId, listener = { callback?.onRoomSelected(it) })
+                    .id(it.roomId)
+                    .addTo(this)
+        }
+    }
+
+    interface Callback {
+        fun onRoomSelected(room: Room)
+    }
+
+}

app/src/main/java/im/vector/riotredesign/features/home/RoomItem.kt

@@ -0,0 +1,18 @@
+package im.vector.riotredesign.features.home
+
+import android.widget.TextView
+import im.vector.riotredesign.R
+import im.vector.riotredesign.core.helpers.KotlinModel
+
+data class RoomItem(
+        val title: String,
+        val listener: (() -> Unit)? = null
+) : KotlinModel(R.layout.item_room) {
+
+    val titleView by bind<TextView>(R.id.titleView)
+
+    override fun bind() {
+        titleView.setOnClickListener { listener?.invoke() }
+        titleView.text = title
+    }
+}

app/src/main/java/im/vector/riotredesign/features/home/RoomListFragment.kt

@@ -0,0 +1,49 @@
+package im.vector.riotredesign.features.home
+
+import android.arch.lifecycle.Observer
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.Toast
+import im.vector.matrix.android.api.Matrix
+import im.vector.matrix.android.api.session.room.Room
+import im.vector.riotredesign.R
+import im.vector.riotredesign.core.platform.RiotFragment
+import kotlinx.android.synthetic.main.fragment_room_list.*
+import org.koin.android.ext.android.inject
+
+class RoomListFragment : RiotFragment(), RoomController.Callback {
+
+    companion object {
+
+        fun newInstance(): RoomListFragment {
+            return RoomListFragment()
+        }
+
+    }
+
+    private val matrix by inject<Matrix>()
+    private val currentSession = matrix.currentSession!!
+    private val roomController = RoomController(this)
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        return inflater.inflate(R.layout.fragment_room_list, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        epoxyRecyclerView.setController(roomController)
+        currentSession.rooms().observe(this, Observer<List<Room>> { renderRooms(it) })
+    }
+
+    private fun renderRooms(rooms: List<Room>?) {
+        roomController.setData(rooms)
+    }
+
+    override fun onRoomSelected(room: Room) {
+        Toast.makeText(context, "Room ${room.roomId} clicked", Toast.LENGTH_SHORT).show()
+    }
+
+
+}

app/src/main/res/layout/activity_home.xml

@@ -1,40 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
     tools:context=".features.login.LoginActivity">
 
-    <Button
-        android:id="@+id/startSyncButton"
-        android:layout_width="0dp"
-        android:layout_height="0dp"
-        android:layout_marginBottom="8dp"
-        android:layout_marginEnd="8dp"
-        android:layout_marginStart="8dp"
-        android:layout_marginTop="8dp"
-        android:text="Start sync"
-        app:layout_constraintBottom_toTopOf="@+id/stopSyncButton"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
-
-    <Button
-        android:id="@+id/stopSyncButton"
-        android:layout_width="0dp"
-        android:layout_height="0dp"
-        android:layout_marginBottom="8dp"
-        android:layout_marginEnd="8dp"
-        android:layout_marginStart="8dp"
-        android:layout_marginTop="8dp"
-        android:text="stop sync"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintHorizontal_bias="0.5"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/startSyncButton" />
+    <FrameLayout
+        android:id="@+id/homeFragmentContainer"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
 
 
 </android.support.constraint.ConstraintLayout>

app/src/main/res/layout/fragment_room_detail.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+</android.support.constraint.ConstraintLayout>

app/src/main/res/layout/fragment_room_list.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.airbnb.epoxy.EpoxyRecyclerView
+        android:id="@+id/epoxyRecyclerView"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+</FrameLayout>

app/src/main/res/layout/item_event.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.constraint.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+</android.support.constraint.ConstraintLayout>

app/src/main/res/layout/item_room.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/titleView"
+    android:layout_width="match_parent"
+    android:layout_height="80dp"
+    android:gravity="center_vertical"
+    android:padding="16dp"
+    android:textSize="14sp"
+    tools:text="Room name" />