Show/hide save action button dynamically.

vector/src/main/java/im/vector/riotx/features/roomprofile/settings/RoomSettingsAction.kt

@@ -23,4 +23,5 @@ sealed class RoomSettingsAction : VectorViewModelAction {
     data class SetRoomTopic(val newTopic: String) : RoomSettingsAction()
     data class SetRoomAvatar(val newAvatarUrl: String) : RoomSettingsAction()
     object EnableEncryption : RoomSettingsAction()
+    object Save : RoomSettingsAction()
 }

vector/src/main/java/im/vector/riotx/features/roomprofile/settings/RoomSettingsController.kt

@@ -52,6 +52,28 @@ class RoomSettingsController @Inject constructor(
                 stringProvider.getString(R.string.settings)
         )
 
+        formEditTextItem {
+            id("name")
+            /*enabled(enableFormElement)*/
+            value(data.newName ?: roomSummary.displayName)
+            hint(stringProvider.getString(R.string.room_settings_name_hint))
+
+            onTextChange { text ->
+                callback?.onNameChanged(text)
+            }
+        }
+
+        formEditTextItem {
+            id("topic")
+            /*enabled(enableFormElement)*/
+            value(data.newTopic ?: roomSummary.topic)
+            hint(stringProvider.getString(R.string.room_settings_topic_hint))
+
+            onTextChange { text ->
+                callback?.onTopicChanged(text)
+            }
+        }
+
         if (roomSummary.isEncrypted) {
             buildProfileAction(
                     id = "encryption",
@@ -71,27 +93,5 @@ class RoomSettingsController @Inject constructor(
                     action = { callback?.onEnableEncryptionClicked() }
             )
         }
-
-        formEditTextItem {
-            id("name")
-            /*enabled(enableFormElement)*/
-            value(roomSummary.displayName)
-            hint(stringProvider.getString(R.string.room_settings_name_hint))
-
-            onTextChange { text ->
-                callback?.onNameChanged(text)
-            }
-        }
-
-        formEditTextItem {
-            id("topic")
-            /*enabled(enableFormElement)*/
-            value(roomSummary.topic)
-            hint(stringProvider.getString(R.string.room_settings_topic_hint))
-
-            onTextChange { text ->
-                callback?.onTopicChanged(text)
-            }
-        }
     }
 }

vector/src/main/java/im/vector/riotx/features/roomprofile/settings/RoomSettingsFragment.kt

@@ -17,6 +17,8 @@
 package im.vector.riotx.features.roomprofile.settings
 
 import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
 import android.view.View
 import androidx.appcompat.app.AlertDialog
 import androidx.core.view.isVisible
@@ -46,6 +48,8 @@ class RoomSettingsFragment @Inject constructor(
 
     override fun getLayoutResId() = R.layout.fragment_room_setting_generic
 
+    override fun getMenuRes() = R.menu.vector_room_settings
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         controller.callback = this
@@ -66,6 +70,20 @@ class RoomSettingsFragment @Inject constructor(
         super.onDestroyView()
     }
 
+    override fun onPrepareOptionsMenu(menu: Menu) {
+        withState(viewModel) { state ->
+            menu.findItem(R.id.roomSettingsSaveAction).isVisible = state.showSaveAction
+        }
+        super.onPrepareOptionsMenu(menu)
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        if (item.itemId == R.id.roomSettingsSaveAction) {
+            viewModel.handle(RoomSettingsAction.Save)
+        }
+        return super.onOptionsItemSelected(item)
+    }
+
     override fun invalidate() = withState(viewModel) { viewState ->
         controller.setData(viewState)
         renderRoomSummary(viewState)
@@ -97,5 +115,7 @@ class RoomSettingsFragment @Inject constructor(
             roomSettingsToolbarTitleView.text = it.displayName
             avatarRenderer.render(it.toMatrixItem(), roomSettingsToolbarAvatarImageView)
         }
+
+        invalidateOptionsMenu()
     }
 }

vector/src/main/java/im/vector/riotx/features/roomprofile/settings/RoomSettingsViewModel.kt

@@ -55,18 +55,43 @@ class RoomSettingsViewModel @AssistedInject constructor(@Assisted initialState:
         room.rx().liveRoomSummary()
                 .unwrap()
                 .execute { async ->
-                    copy(roomSummary = async)
+                    val roomSummary = async.invoke()
+                    copy(
+                            roomSummary = async,
+                            newName = roomSummary?.displayName,
+                            newTopic = roomSummary?.topic
+                    )
                 }
     }
 
     override fun handle(action: RoomSettingsAction) {
         when (action) {
             is RoomSettingsAction.EnableEncryption -> handleEnableEncryption()
-            is RoomSettingsAction.SetRoomName -> setState { copy(newName = action.newName) }
+            is RoomSettingsAction.SetRoomName      -> setState {
-            is RoomSettingsAction.SetRoomTopic -> setState { copy(newTopic = action.newTopic) }
+                copy(
+                        newName = action.newName,
+                        showSaveAction = shouldShowSaveAction(this)
+                )
+            }
+            is RoomSettingsAction.SetRoomTopic     -> setState {
+                copy(
+                        newTopic = action.newTopic,
+                        showSaveAction = shouldShowSaveAction(this)
+                )
+            }
+            is RoomSettingsAction.Save             -> saveSettings()
         }
     }
 
+    private fun shouldShowSaveAction(state: RoomSettingsViewState): Boolean {
+        val summary = state.roomSummary.invoke()
+        return summary?.displayName != state.newName ||
+                summary?.topic != state.newTopic
+    }
+
+    private fun saveSettings() {
+    }
+
     private fun handleEnableEncryption() {
         setState {
             copy(isLoading = true)

vector/src/main/java/im/vector/riotx/features/roomprofile/settings/RoomSettingsViewState.kt

@@ -27,7 +27,8 @@ data class RoomSettingsViewState(
         val roomSummary: Async<RoomSummary> = Uninitialized,
         val isLoading: Boolean = false,
         val newName: String? = null,
-        val newTopic: String? = null
+        val newTopic: String? = null,
+        val showSaveAction: Boolean = false
 ) : MvRxState {
 
     constructor(args: RoomProfileArgs) : this(roomId = args.roomId)

vector/src/main/res/menu/vector_room_settings.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/roomSettingsSaveAction"
+        android:title="@string/save"
+        app:iconTint="?attr/colorAccent"
+        app:showAsAction="ifRoom" />
+</menu>