From 0b50ee097449961bd39cbf3aee0cb110c8b60021 Mon Sep 17 00:00:00 2001
From: ganfra <francois.ganard@gmail.com>
Date: Fri, 2 Nov 2018 10:17:37 +0100
Subject: [PATCH] Timeline : scroll to show new message

---
 .../platform/DefaultListUpdateCallback.kt     | 22 +++++++++++++++++++
 .../home/room/detail/RoomDetailFragment.kt    |  5 ++++-
 .../room/detail/ScrollOnNewMessageCallback.kt | 14 ++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/im/vector/riotredesign/core/platform/DefaultListUpdateCallback.kt
 create mode 100644 app/src/main/java/im/vector/riotredesign/features/home/room/detail/ScrollOnNewMessageCallback.kt

diff --git a/app/src/main/java/im/vector/riotredesign/core/platform/DefaultListUpdateCallback.kt b/app/src/main/java/im/vector/riotredesign/core/platform/DefaultListUpdateCallback.kt
new file mode 100644
index 0000000000..53ec2c0472
--- /dev/null
+++ b/app/src/main/java/im/vector/riotredesign/core/platform/DefaultListUpdateCallback.kt
@@ -0,0 +1,22 @@
+package im.vector.riotredesign.core.platform
+
+import android.support.v7.util.ListUpdateCallback
+
+interface DefaultListUpdateCallback : ListUpdateCallback {
+
+    override fun onChanged(position: Int, count: Int, tag: Any?) {
+        //no-op
+    }
+
+    override fun onMoved(position: Int, count: Int) {
+        //no-op
+    }
+
+    override fun onInserted(position: Int, count: Int) {
+        //no-op
+    }
+
+    override fun onRemoved(position: Int, count: Int) {
+        //no-op
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/im/vector/riotredesign/features/home/room/detail/RoomDetailFragment.kt b/app/src/main/java/im/vector/riotredesign/features/home/room/detail/RoomDetailFragment.kt
index 2e942dacf1..ae77d50f01 100644
--- a/app/src/main/java/im/vector/riotredesign/features/home/room/detail/RoomDetailFragment.kt
+++ b/app/src/main/java/im/vector/riotredesign/features/home/room/detail/RoomDetailFragment.kt
@@ -33,6 +33,7 @@ class RoomDetailFragment : RiotFragment() {
     private val matrix by inject<Matrix>()
     private val currentSession = matrix.currentSession
     private var roomId by FragmentArgumentDelegate<String>()
+
     private lateinit var timelineEventController: TimelineEventController
     private lateinit var room: Room
 
@@ -59,8 +60,10 @@ class RoomDetailFragment : RiotFragment() {
 
     private fun setupRecyclerView() {
         val layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, true)
+        val listUpdateCallback = ScrollOnNewMessageCallback(layoutManager)
         recyclerView.layoutManager = layoutManager
         timelineEventController = TimelineEventController(riotActivity)
+        timelineEventController.addModelBuildListener { it.dispatchTo(listUpdateCallback) }
         recyclerView.setController(timelineEventController)
     }
 
@@ -82,4 +85,4 @@ class RoomDetailFragment : RiotFragment() {
         timelineEventController.requestModelBuild()
     }
 
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/im/vector/riotredesign/features/home/room/detail/ScrollOnNewMessageCallback.kt b/app/src/main/java/im/vector/riotredesign/features/home/room/detail/ScrollOnNewMessageCallback.kt
new file mode 100644
index 0000000000..3328d8b408
--- /dev/null
+++ b/app/src/main/java/im/vector/riotredesign/features/home/room/detail/ScrollOnNewMessageCallback.kt
@@ -0,0 +1,14 @@
+package im.vector.riotredesign.features.home.room.detail
+
+import android.support.v7.widget.LinearLayoutManager
+import im.vector.riotredesign.core.platform.DefaultListUpdateCallback
+
+class ScrollOnNewMessageCallback(private val layoutManager: LinearLayoutManager) : DefaultListUpdateCallback {
+
+    override fun onInserted(position: Int, count: Int) {
+        if (layoutManager.findFirstVisibleItemPosition() == 0) {
+            layoutManager.scrollToPosition(0)
+        }
+    }
+
+}
\ No newline at end of file