Merge pull request 'unread messages scrollposition: fix dualpane and performance issues' (#145) from erinn48 into trunk

Reviewed-on: cwtch.im/cwtch-ui#145
Reviewed-by: Sarah Jamie Lewis <sarah@openprivacy.ca>

lib/main.dart

@@ -169,7 +169,7 @@ class FlwtchState extends State<Flwtch> {
     var args = jsonDecode(call.arguments);
     var profile = profs.getProfile(args["ProfileOnion"])!;
     var convo = profile.contactList.getContact(args["Handle"])!;
-    var initialIndex = convo.unreadMessages;
+    Provider.of<AppState>(navKey.currentContext!, listen: false).initialScrollIndex = convo.unreadMessages;
     convo.unreadMessages = 0;
 
     // single pane mode pushes; double pane mode reads AppState.selectedProfile/Conversation
@@ -187,7 +187,7 @@ class FlwtchState extends State<Flwtch> {
                 ChangeNotifierProvider.value(value: profile),
                 ChangeNotifierProvider.value(value: convo),
               ],
-              builder: (context, child) => MessageView(initialIndex),
+              builder: (context, child) => MessageView(),
             );
           },
         ),

lib/model.dart

@@ -30,6 +30,7 @@ class AppState extends ChangeNotifier {
   String appError = "";
   String? _selectedProfile;
   String? _selectedConversation;
+  int _initialScrollIndex = 0;
   int? _selectedIndex;
   bool _unreadMessagesBelow = false;
 
@@ -67,6 +68,12 @@ class AppState extends ChangeNotifier {
     notifyListeners();
   }
 
+  int get initialScrollIndex => _initialScrollIndex;
+  set initialScrollIndex(int newVal) {
+    this._initialScrollIndex = newVal;
+    notifyListeners();
+  }
+
   bool isLandscape(BuildContext c) => MediaQuery.of(c).size.width > MediaQuery.of(c).size.height;
 }
 

lib/views/contactsview.dart

@@ -23,18 +23,19 @@ class ContactsView extends StatefulWidget {
 
 // selectConversation can be called from anywhere to set the active conversation
 void selectConversation(BuildContext context, String handle) {
-  var initialIndex = Provider.of<ProfileInfoState>(context, listen: false).contactList.getContact(handle)!.unreadMessages;
   // requery instead of using contactinfostate directly because sometimes listview gets confused about data that resorts
+  var initialIndex = Provider.of<ProfileInfoState>(context, listen: false).contactList.getContact(handle)!.unreadMessages;
   Provider.of<ProfileInfoState>(context, listen: false).contactList.getContact(handle)!.unreadMessages = 0;
   // triggers update in Double/TripleColumnView
+  Provider.of<AppState>(context, listen: false).initialScrollIndex = initialIndex;
   Provider.of<AppState>(context, listen: false).selectedConversation = handle;
   Provider.of<AppState>(context, listen: false).selectedIndex = null;
   // if in singlepane mode, push to the stack
   var isLandscape = Provider.of<AppState>(context, listen: false).isLandscape(context);
-  if (Provider.of<Settings>(context, listen: false).uiColumns(isLandscape).length == 1) _pushMessageView(context, handle, initialIndex);
+  if (Provider.of<Settings>(context, listen: false).uiColumns(isLandscape).length == 1) _pushMessageView(context, handle);
 }
 
-void _pushMessageView(BuildContext context, String handle, int initialIndex) {
+void _pushMessageView(BuildContext context, String handle) {
   var profileOnion = Provider.of<ProfileInfoState>(context, listen: false).onion;
   Navigator.of(context).push(
     MaterialPageRoute<void>(
@@ -47,7 +48,7 @@ void _pushMessageView(BuildContext context, String handle, int initialIndex) {
             ChangeNotifierProvider.value(value: profile),
             ChangeNotifierProvider.value(value: profile.contactList.getContact(handle)!),
           ],
-          builder: (context, child) => MessageView(initialIndex),
+          builder: (context, child) => MessageView(),
         );
       },
     ),

lib/views/doublecolview.dart

@@ -17,7 +17,6 @@ class _DoubleColumnViewState extends State<DoubleColumnView> {
   Widget build(BuildContext context) {
     var flwtch = Provider.of<AppState>(context);
     var cols = Provider.of<Settings>(context).uiColumns(true);
-    var initialIndex = flwtch.selectedConversation == null ? 0 : Provider.of<ProfileInfoState>(context, listen: false).contactList.getContact(flwtch.selectedConversation!)!.unreadMessages;
     return Flex(
       direction: Axis.horizontal,
       children: <Widget>[
@@ -36,7 +35,7 @@ class _DoubleColumnViewState extends State<DoubleColumnView> {
                   ChangeNotifierProvider.value(value: Provider.of<ProfileInfoState>(context)),
                   ChangeNotifierProvider.value(
                       value: flwtch.selectedConversation != null ? Provider.of<ProfileInfoState>(context).contactList.getContact(flwtch.selectedConversation!)! : ContactInfoState("", "")),
-                ], child: Container(child: MessageView(initialIndex))),
+                ], child: Container(child: MessageView())),
         ),
       ],
     );

lib/views/messageview.dart

@@ -22,9 +22,6 @@ import '../widgets/messagelist.dart';
 import 'groupsettingsview.dart';
 
 class MessageView extends StatefulWidget {
-  int initialIndex;
-  MessageView(this.initialIndex);
-
   @override
   _MessageViewState createState() => _MessageViewState();
 }
@@ -38,24 +35,31 @@ class _MessageViewState extends State<MessageView> {
 
   @override
   void initState() {
-    // using "8" because "# of messages that fit on one screen" isnt trivial to calculate at this point
-    if (widget.initialIndex > 8) {
-      WidgetsFlutterBinding.ensureInitialized().addPostFrameCallback((timeStamp) {
-        Provider.of<AppState>(context, listen: false).unreadMessagesBelow = true;
-      });
-    }
-
     scrollListener.itemPositions.addListener(() {
       var first = scrollListener.itemPositions.value.first.index;
       var last = scrollListener.itemPositions.value.last.index;
       // sometimes these go hi->lo and sometimes they go lo->hi because [who tf knows]
-      if (first == 0 || last == 0) {
+      if ((first == 0 || last == 0) && Provider.of<AppState>(context, listen: false).unreadMessagesBelow == true) {
+        Provider.of<AppState>(context, listen: false).initialScrollIndex = 0;
         Provider.of<AppState>(context, listen: false).unreadMessagesBelow = false;
       }
     });
     super.initState();
   }
 
+  @override
+  void didChangeDependencies() {
+    var appState = Provider.of<AppState>(context, listen: false);
+
+    // using "8" because "# of messages that fit on one screen" isnt trivial to calculate at this point
+    if (appState.initialScrollIndex > 8 && appState.unreadMessagesBelow == false) {
+      WidgetsFlutterBinding.ensureInitialized().addPostFrameCallback((timeStamp) {
+        appState.unreadMessagesBelow = true;
+      });
+    }
+    super.didChangeDependencies();
+  }
+
   @override
   void dispose() {
     focusNode.dispose();
@@ -107,7 +111,7 @@ class _MessageViewState extends State<MessageView> {
                   onPressed: _pushContactSettings),
             ],
           ),
-          body: Padding(padding: EdgeInsets.fromLTRB(8.0, 8.0, 8.0, 108.0), child: MessageList(widget.initialIndex, scrollController, scrollListener)),
+          body: Padding(padding: EdgeInsets.fromLTRB(8.0, 8.0, 8.0, 108.0), child: MessageList(scrollController, scrollListener)),
           bottomSheet: _buildComposeBox(),
         ));
   }

lib/views/triplecolview.dart

@@ -35,7 +35,7 @@ class _TripleColumnViewState extends State<TripleColumnView> {
         child: appState.selectedConversation == null
             ? Center(child: Text(AppLocalizations.of(context)!.addContactFirst))
             : //dev
-            Container(child: MessageView(0/*todo:setme*/)),
+            Container(child: MessageView()),
       ),
     ]);
   }

lib/widgets/messagelist.dart

@@ -9,10 +9,9 @@ import '../model.dart';
 import '../settings.dart';
 
 class MessageList extends StatefulWidget {
-  int initialIndex;
   ItemScrollController scrollController;
   ItemPositionsListener scrollListener;
-  MessageList(this.initialIndex, this.scrollController, this.scrollListener);
+  MessageList(this.scrollController, this.scrollListener);
 
   @override
   _MessageListState createState() => _MessageListState();
@@ -21,6 +20,7 @@ class MessageList extends StatefulWidget {
 class _MessageListState extends State<MessageList> {
   @override
   Widget build(BuildContext outerContext) {
+    var initi = Provider.of<AppState>(outerContext, listen: false).initialScrollIndex;
     bool isP2P = !Provider.of<ContactInfoState>(context).isGroup;
     bool isGroupAndSyncing = Provider.of<ContactInfoState>(context).isGroup == true && Provider.of<ContactInfoState>(context).status == "Authenticated";
     bool isGroupAndSynced = Provider.of<ContactInfoState>(context).isGroup && Provider.of<ContactInfoState>(context).status == "Synced";
@@ -72,7 +72,7 @@ class _MessageListState extends State<MessageList> {
                       ? ScrollablePositionedList.builder(
                           itemPositionsListener: widget.scrollListener,
                           itemScrollController: widget.scrollController,
-                          initialScrollIndex: widget.initialIndex,
+                          initialScrollIndex: Provider.of<AppState>(outerContext, listen: false).initialScrollIndex,
                           itemCount: Provider.of<ContactInfoState>(outerContext).totalMessages,
                           reverse: true, // NOTE: There seems to be a bug in flutter that corrects the mouse wheel scroll, but not the drag direction...
                           itemBuilder: (itemBuilderContext, index) {