highlight tabs only on unviewed messages (#5649)

src/widgets/helper/ChannelView.hpp

@@ -212,6 +212,14 @@ public:
 
     Scrollbar *scrollbar();
 
+    using ChannelViewID = std::size_t;
+    ///
+    /// \brief Get the ID of this ChannelView
+    ///
+    /// The ID is made of the underlying channel's name
+    /// combined with the filter set IDs
+    ChannelViewID getID() const;
+
     pajlada::Signals::Signal<QMouseEvent *> mouseDown;
     pajlada::Signals::NoArgSignal selectionChanged;
     pajlada::Signals::Signal<HighlightState> tabHighlightRequested;
@@ -315,6 +323,9 @@ private:
     void showReplyThreadPopup(const MessagePtr &message);
     bool canReplyToMessages() const;
 
+    void updateID();
+    ChannelViewID id_{};
+
     bool layoutQueued_ = false;
     bool bufferInvalidationQueued_ = false;
 
@@ -376,7 +387,7 @@ private:
     FilterSetPtr channelFilters_;
 
     // Returns true if message should be included
-    bool shouldIncludeMessage(const MessagePtr &m) const;
+    bool shouldIncludeMessage(const MessagePtr &message) const;
 
     // Returns whether the scrollbar should have highlights
     bool showScrollbarHighlights() const;