improved text selection handling, added text selection handling for HTML messages, clear selection on close overlay

lib/pages/chat/chat.dart

@@ -1250,7 +1250,7 @@ class ChatController extends State<ChatPageWithRoom>
 
   void pickEmojiReactionAction(Iterable<Event> allReactionEvents) async {
     // #Pangea
-    MatrixState.pAnyState.closeAllOverlays();
+    closeSelectionOverlay();
     // Pangea#
     _allReactionEvents = allReactionEvents;
     emojiPickerType = EmojiPickerType.reaction;
@@ -1271,9 +1271,19 @@ class ChatController extends State<ChatPageWithRoom>
     // Pangea#
   }
 
+  // #Pangea
+  /// Close the combined selection view overlay and clear the message
+  /// text and selection stored for the text in that overlay
+  void closeSelectionOverlay() {
+    MatrixState.pAnyState.closeAllOverlays();
+    textSelection.clearMessageText();
+    textSelection.onSelection(null);
+  }
+  // Pangea#
+
   void clearSelectedEvents() => setState(() {
         // #Pangea
-        MatrixState.pAnyState.closeAllOverlays();
+        closeSelectionOverlay();
         // Pangea#
         selectedEvents.clear();
         showEmojiPicker = false;

lib/pages/chat/events/html_message.dart

@@ -71,6 +71,9 @@ class HtmlMessage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    // #Pangea
+    controller.textSelection.setMessageText(html);
+    // Pangea#
     final fontSize = AppConfig.messageFontSize * AppConfig.fontSizeFactor;
 
     final linkColor = textColor.withAlpha(150);

lib/pangea/widgets/chat/message_text_selection.dart

@@ -1,28 +1,41 @@
 import 'dart:async';
 
+/// Contains information about the text currently being shown in a
+/// toolbar overlay message and any selection within that text.
+/// The ChatController contains one instance of this class, and it's values
+/// should be updated each time an overlay is openned or closed, or when
+/// an overlay's text selection changes.
 class MessageTextSelection {
+  /// The currently selected text in the overlay message.
   String? selectedText;
-  String messageText = "";
+
+  /// The full text displayed in the overlay message.
+  String? messageText;
+
+  /// A stream that emits the currently selected text whenever it changes.
   final StreamController<String?> selectionStream =
       StreamController<String?>.broadcast();
 
-  void setMessageText(String text) {
-    messageText = text;
-  }
+  /// Sets messageText to match the text currently being displayed in the overlay.
+  /// Text in messages is displayed in a variety of ways, i.e., direct message content,
+  /// translation, HTML rendered message, etc. This method should be called wherever the
+  /// text displayed in the overlay is determined.
+  void setMessageText(String text) => messageText = text;
 
-  void onSelection(String? text) => text == null || text.isEmpty
-      ? clearTextSelection()
-      : setTextSelection(text);
+  /// Clears the messageText value. Called when the message selection overlay is closed.
+  void clearMessageText() => messageText = null;
 
-  void setTextSelection(String selection) {
-    selectedText = selection;
+  /// Updates the selectedText value and emits it to the selectionStream.
+  void onSelection(String? text) {
+    text == null || text.isEmpty ? selectedText = null : selectedText = text;
     selectionStream.add(selectedText);
   }
 
-  void clearTextSelection() {
-    selectedText = null;
-    selectionStream.add(selectedText);
+  /// Returns the index of the selected text within the message text.
+  /// If the selected text is not found, returns null.
+  int? get offset {
+    if (selectedText == null || messageText == null) return null;
+    final index = messageText!.indexOf(selectedText!);
+    return index > -1 ? index : null;
   }
-
-  int get offset => messageText.indexOf(selectedText!);
 }

lib/pangea/widgets/chat/message_toolbar.dart

@@ -141,6 +141,7 @@ class MessageToolbarState extends State<MessageToolbar> {
   void showDefinition() {
     debugPrint("show definition");
     if (widget.textSelection.selectedText == null ||
+        widget.textSelection.messageText == null ||
         widget.textSelection.selectedText!.isEmpty) {
       toolbarContent = const SelectToDefine();
       return;
@@ -149,7 +150,7 @@ class MessageToolbarState extends State<MessageToolbar> {
     toolbarContent = WordDataCard(
       word: widget.textSelection.selectedText!,
       wordLang: widget.pangeaMessageEvent.messageDisplayLangCode,
-      fullText: widget.textSelection.messageText,
+      fullText: widget.textSelection.messageText!,
       fullTextLang: widget.pangeaMessageEvent.messageDisplayLangCode,
       hasInfo: true,
       room: widget.controller.room,

lib/pangea/widgets/chat/message_translation_card.dart

@@ -52,7 +52,8 @@ class MessageTranslationCardState extends State<MessageTranslationCard> {
   Future<void> translateSelection() async {
     if (widget.selection.selectedText == null ||
         l1Code == null ||
-        l2Code == null) {
+        l2Code == null ||
+        widget.selection.messageText == null) {
       selectionTranslation = null;
       return;
     }
@@ -64,7 +65,7 @@ class MessageTranslationCardState extends State<MessageTranslationCard> {
     final resp = await FullTextTranslationRepo.translate(
       accessToken: accessToken,
       request: FullTextTranslationRequestModel(
-        text: widget.selection.messageText,
+        text: widget.selection.messageText!,
         tgtLang: l1Code!,
         userL1: l1Code!,
         userL2: l2Code!,