Set the mention and error color according to colorscheme

Use kirigami to set the proper link and error color for mentions and error underlining in chatbox

This is with my own colorscheme:

![image](/uploads/6269b85f936a98b02f42a9ce01da76b1/image.png)

src/chatdocumenthandler.cpp

@@ -324,3 +324,35 @@ void ChatDocumentHandler::pushMention(const Mention mention) const
         m_room->mentions()->push_back(mention);
     }
 }
+
+QColor ChatDocumentHandler::mentionColor() const
+{
+    return m_mentionColor;
+}
+
+void ChatDocumentHandler::setMentionColor(const QColor &color)
+{
+    if (m_mentionColor == color) {
+        return;
+    }
+    m_mentionColor = color;
+    m_highlighter->mentionFormat.setForeground(m_mentionColor);
+    m_highlighter->rehighlight();
+    Q_EMIT mentionColorChanged();
+}
+
+QColor ChatDocumentHandler::errorColor() const
+{
+    return m_errorColor;
+}
+
+void ChatDocumentHandler::setErrorColor(const QColor &color)
+{
+    if (m_errorColor == color) {
+        return;
+    }
+    m_errorColor = color;
+    m_highlighter->errorFormat.setForeground(m_errorColor);
+    m_highlighter->rehighlight();
+    Q_EMIT errorColorChanged();
+}

src/chatdocumenthandler.h

@@ -35,6 +35,9 @@ class ChatDocumentHandler : public QObject
 
     Q_PROPERTY(NeoChatRoom *room READ room WRITE setRoom NOTIFY roomChanged)
 
+    Q_PROPERTY(QColor mentionColor READ mentionColor WRITE setMentionColor NOTIFY mentionColorChanged);
+    Q_PROPERTY(QColor errorColor READ errorColor WRITE setErrorColor NOTIFY errorColorChanged);
+
 public:
     explicit ChatDocumentHandler(QObject *parent = nullptr);
 
@@ -60,6 +63,13 @@ public:
 
     void updateCompletions();
     CompletionModel *completionModel() const;
+
+    [[nodiscard]] QColor mentionColor() const;
+    void setMentionColor(const QColor &color);
+
+    [[nodiscard]] QColor errorColor() const;
+    void setErrorColor(const QColor &color);
+
 Q_SIGNALS:
     void isEditChanged();
     void documentChanged();
@@ -68,6 +78,8 @@ Q_SIGNALS:
     void completionModelChanged();
     void selectionStartChanged();
     void selectionEndChanged();
+    void errorColorChanged();
+    void mentionColorChanged();
 
 private:
     int completionStartIndex() const;
@@ -79,6 +91,9 @@ private:
     NeoChatRoom *m_room = nullptr;
     bool completionVisible = false;
 
+    QColor m_mentionColor;
+    QColor m_errorColor;
+
     int m_cursorPosition;
     int m_selectionStart;
     int m_selectionEnd;

src/qml/Component/ChatBox/ChatBar.qml

@@ -394,6 +394,8 @@ QQC2.Control {
         cursorPosition: textField.cursorPosition
         selectionStart: textField.selectionStart
         selectionEnd: textField.selectionEnd
+        mentionColor: Kirigami.Theme.linkColor
+        errorColor: Kirigami.Theme.negativeTextColor
         Component.onCompleted: {
             RoomManager.chatDocumentHandler = documentHandler;
         }

src/qml/Component/Timeline/MessageEditComponent.qml

@@ -119,6 +119,8 @@ QQC2.TextArea {
         selectionStart: root.selectionStart
         selectionEnd: root.selectionEnd
         room: root.room // We don't care about saving for edits so this is OK.
+        mentionColor: Kirigami.Theme.linkColor
+        errorColor: Kirigami.Theme.negativeTextColor
     }
 
     TextMetrics {