Prevents losing all entered text when a new message arrives on the chat room. Also,

Keeps the keyboard open after sending a message.
Shows the entire new message when it arrives on the chat room.
Adds a widget to easily show the latest messages when moving the list up.

app/src/main/java/chat/rocket/android/chatroom/presentation/ChatRoomPresenter.kt

@@ -39,7 +39,6 @@ class ChatRoomPresenter @Inject constructor(private val view: ChatRoomView,
     private val client = factory.create(serverInteractor.get()!!)
     private var subId: String? = null
     private var settings: Map<String, Value<Any>> = getSettingsInteractor.get(serverInteractor.get()!!)!!
-
     private val stateChannel = Channel<State>()
 
     fun loadMessages(chatRoomId: String, chatRoomType: String, offset: Long = 0) {
@@ -72,23 +71,23 @@ class ChatRoomPresenter @Inject constructor(private val view: ChatRoomView,
 
     fun sendMessage(chatRoomId: String, text: String, messageId: String?) {
         launchUI(strategy) {
-            view.disableMessageInput()
+            view.disableSendMessageButton()
             try {
+                // ignore message for now, will receive it on the stream
                 val message = if (messageId == null) {
                     client.sendMessage(chatRoomId, text)
                 } else {
                     client.updateMessage(chatRoomId, messageId, text)
                 }
-                // ignore message for now, will receive it on the stream
-                view.enableMessageInput(clear = true)
+                view.clearMessageComposition()
             } catch (ex: Exception) {
-                ex.printStackTrace()
                 ex.message?.let {
                     view.showMessage(it)
                 }.ifNull {
                     view.showGenericErrorMessage()
                 }
-                view.enableMessageInput()
+            } finally {
+                view.enableSendMessageButton()
             }
         }
     }

app/src/main/java/chat/rocket/android/chatroom/presentation/ChatRoomView.kt

@@ -75,7 +75,19 @@ interface ChatRoomView : LoadingView, MessageView {
      */
     fun showEditingAction(roomId: String, messageId: String, text: String)
 
-    fun disableMessageInput()
+    /**
+     * Disabling the send message button avoids the user tap this button multiple
+     * times to send a same message.
+     */
+    fun disableSendMessageButton()
 
-    fun enableMessageInput(clear: Boolean = false)
+    /**
+     * Enables the send message button.
+     */
+    fun enableSendMessageButton()
+
+    /**
+     * Clears the message composition.
+     */
+    fun clearMessageComposition()
 }
\ No newline at end of file

app/src/main/java/chat/rocket/android/chatroom/ui/ChatRoomFragment.kt

@@ -24,6 +24,8 @@ import dagger.android.support.AndroidSupportInjection
 import kotlinx.android.synthetic.main.fragment_chat_room.*
 import kotlinx.android.synthetic.main.message_attachment_options.*
 import kotlinx.android.synthetic.main.message_composer.*
+import kotlinx.android.synthetic.main.message_list.*
+import timber.log.Timber
 import javax.inject.Inject
 
 fun newInstance(chatRoomId: String, chatRoomName: String, chatRoomType: String, isChatRoomReadOnly: Boolean): Fragment {
@@ -85,7 +87,10 @@ class ChatRoomFragment : Fragment(), ChatRoomView {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         presenter.loadMessages(chatRoomId, chatRoomType)
-        setupComposer()
+
+        setupRecyclerView()
+        setupFab()
+        setupMessageComposer()
         setupActionSnackbar()
     }
 
@@ -156,20 +161,23 @@ class ChatRoomFragment : Fragment(), ChatRoomView {
     override fun showInvalidFileMessage() = showMessage(getString(R.string.msg_invalid_file))
 
     override fun showNewMessage(message: MessageViewModel) {
-        text_message.textContent = ""
         adapter.addItem(message)
-        recycler_view.smoothScrollToPosition(0)
+        recycler_view.scrollToPosition(0)
     }
 
-    override fun disableMessageInput() {
+    override fun disableSendMessageButton() {
         button_send.isEnabled = false
-        text_message.isEnabled = false
     }
 
-    override fun enableMessageInput(clear: Boolean) {
+    override fun enableSendMessageButton() {
         button_send.isEnabled = true
-        text_message.isEnabled = true
-        if (clear) text_message.textContent = ""
+    }
+
+    override fun clearMessageComposition() {
+        citation = null
+        editingMessageId = null
+        text_message.textContent = ""
+        actionSnackbar.dismiss()
     }
 
     override fun dispatchUpdateMessage(index: Int, message: MessageViewModel) {
@@ -217,7 +225,32 @@ class ChatRoomFragment : Fragment(), ChatRoomView {
 
     }
 
-    private fun setupComposer() {
+    private fun setupRecyclerView() {
+        recycler_view.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                super.onScrolled(recyclerView, dx, dy)
+                Timber.i("Scrolling vertically: $dy")
+                if (!recyclerView.canScrollVertically(1)) {
+                    button_fab.hide()
+                } else {
+                    if (dy > 0 && !button_fab.isVisible()) {
+                        button_fab.show()
+                    } else if (dy < 0 && button_fab.isVisible()) {
+                        button_fab.hide()
+                    }
+                }
+            }
+        })
+    }
+
+    private fun setupFab() {
+        button_fab.setOnClickListener {
+            recycler_view.scrollToPosition(0)
+            button_fab.hide()
+        }
+    }
+
+    private fun setupMessageComposer() {
         if (isChatRoomReadOnly) {
             text_room_is_read_only.setVisible(true)
             input_container.setVisible(false)
@@ -239,10 +272,9 @@ class ChatRoomFragment : Fragment(), ChatRoomView {
                 })
 
             button_send.setOnClickListener {
-                var textMessage = citation ?: ""
-                textMessage += text_message.textContent
-                sendMessage(textMessage)
-                clearActionMessage()
+                var message = citation ?: ""
+                message += text_message.textContent
+                sendMessage(message)
             }
 
 
@@ -271,17 +303,10 @@ class ChatRoomFragment : Fragment(), ChatRoomView {
     private fun setupActionSnackbar() {
         actionSnackbar = ActionSnackbar.make(message_list_container, parser = parser)
         actionSnackbar.cancelView.setOnClickListener({
-            clearActionMessage()
+            clearMessageComposition()
         })
     }
 
-    private fun clearActionMessage() {
-        citation = null
-        editingMessageId = null
-        text_message.text.clear()
-        actionSnackbar.dismiss()
-    }
-
     private fun showAttachmentOptions() {
         view_dim.setVisible(true)
 

app/src/main/java/chat/rocket/android/chatrooms/ui/ChatRoomsAdapter.kt

@@ -18,6 +18,7 @@ import chat.rocket.core.model.ChatRoom
 import com.facebook.drawee.view.SimpleDraweeView
 import kotlinx.android.synthetic.main.avatar.view.*
 import kotlinx.android.synthetic.main.item_chat.view.*
+import kotlinx.android.synthetic.main.unread_messages_badge.view.*
 
 class ChatRoomsAdapter(private val context: Context,
                        private val listener: (ChatRoom) -> Unit) : RecyclerView.Adapter<ChatRoomsAdapter.ViewHolder>() {

app/src/main/java/chat/rocket/android/util/extensions/Ui.kt

@@ -21,6 +21,10 @@ fun View.setVisible(visible: Boolean) {
     }
 }
 
+fun View.isVisible(): Boolean {
+    return visibility == View.VISIBLE
+}
+
 fun ViewGroup.inflate(@LayoutRes resource: Int): View = LayoutInflater.from(context).inflate(resource, this, false)
 
 fun AppCompatActivity.addFragment(tag: String, layoutId: Int, newInstance: () -> Fragment) {

app/src/main/res/drawable/ic_arrow_downward_black_24dp.xml

+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportHeight="24.0"
+    android:viewportWidth="24.0">
+
+    <path
+        android:fillColor="#010101"
+        android:pathData="M20,12l-1.41,-1.41L13,16.17V4h-2v12.17l-5.58,-5.59L4,12l8,8 8,-8z" />
+
+</vector>
\ No newline at end of file

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

@@ -4,8 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/root_layout"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:orientation="vertical">
+    android:layout_height="match_parent">
 
     <com.wang.avi.AVLoadingIndicatorView
         android:id="@+id/view_loading"
@@ -20,16 +19,23 @@
     <FrameLayout
         android:id="@+id/message_list_container"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
+        android:layout_height="match_parent"
         android:layout_above="@+id/layout_message_composer">
 
-        <android.support.v7.widget.RecyclerView
-            android:id="@+id/recycler_view"
+        <include
+            android:id="@+id/layout_message_list"
+            layout="@layout/message_list"
             android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:scrollbars="vertical" />
+            android:layout_height="match_parent" />
     </FrameLayout>
 
+    <include
+        android:id="@+id/layout_message_composer"
+        layout="@layout/message_composer"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true" />
+
     <View
         android:id="@+id/view_dim"
         android:layout_width="match_parent"
@@ -45,14 +51,6 @@
         android:layout_height="wrap_content"
         android:layout_above="@+id/layout_message_composer"
         android:layout_margin="5dp"
-        android:visibility="gone"
-        tools:visibility="visible" />
-
-    <include
-        android:id="@+id/layout_message_composer"
-        layout="@layout/message_composer"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:layout_alignParentBottom="true" />
+        android:visibility="gone" />
 
 </RelativeLayout>

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

@@ -78,23 +78,16 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             app:layout_constraintBottom_toTopOf="@+id/guideline_one"
-            app:layout_constraintRight_toRightOf="@+id/text_total_unread_messages"
+            app:layout_constraintRight_toRightOf="@+id/layout_unread_messages_badge"
             tools:text="11:45" />
 
-        <TextView
-            android:id="@+id/text_total_unread_messages"
-            style="@style/TextAppearance.AppCompat.Caption"
+        <include
+            android:id="@+id/layout_unread_messages_badge"
+            layout="@layout/unread_messages_badge"
             android:layout_width="20dp"
             android:layout_height="20dp"
-            android:background="@drawable/style_total_unread_messages"
-            android:gravity="center"
-            android:textColor="@color/white"
-            android:textSize="10sp"
-            android:visibility="gone"
             app:layout_constraintBottom_toTopOf="@+id/guideline_two"
-            app:layout_constraintRight_toRightOf="parent"
-            tools:text="99+"
-            tools:visibility="visible" />
+            app:layout_constraintRight_toRightOf="parent" />
 
         <android.support.constraint.Guideline
             android:id="@+id/guideline_one"

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

+<?xml version="1.0" encoding="utf-8"?>
+<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <android.support.v7.widget.RecyclerView
+        android:id="@+id/recycler_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:scrollbars="vertical" />
+
+    <android.support.design.widget.FloatingActionButton
+        android:id="@+id/button_fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="16dp"
+        android:src="@drawable/ic_arrow_downward_black_24dp"
+        android:theme="@style/Theme.AppCompat"
+        android:tint="@color/gray_material"
+        android:visibility="invisible"
+        app:backgroundTint="@color/white"
+        app:fabSize="mini"
+        app:layout_anchor="@id/recycler_view"
+        app:layout_anchorGravity="bottom|end" />
+
+</android.support.design.widget.CoordinatorLayout>
\ No newline at end of file

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

+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <TextView
+        android:id="@+id/text_total_unread_messages"
+        style="@style/TextAppearance.AppCompat.Caption"
+        android:layout_width="20dp"
+        android:layout_height="20dp"
+        android:background="@drawable/style_total_unread_messages"
+        android:gravity="center"
+        android:textColor="@color/white"
+        android:textSize="10sp"
+        android:visibility="gone"
+        tools:text="99+"
+        tools:visibility="visible" />
+
+</LinearLayout>
\ No newline at end of file