Make LimitedQueueSnapshot usages in ChannelView const (#4223)

src/widgets/helper/ChannelView.cpp

@@ -426,7 +426,7 @@ void ChannelView::performLayout(bool causedByScrollbar)
     // BenchmarkGuard benchmark("layout");
 
     /// Get messages and check if there are at least 1
-    auto &messages = this->getMessagesSnapshot();
+    const auto &messages = this->getMessagesSnapshot();
 
     this->showingLatestMessages_ =
         this->scrollBar_->isAtBottom() ||
@@ -444,7 +444,7 @@ void ChannelView::performLayout(bool causedByScrollbar)
 }
 
 void ChannelView::layoutVisibleMessages(
-    LimitedQueueSnapshot<MessageLayoutPtr> &messages)
+    const LimitedQueueSnapshot<MessageLayoutPtr> &messages)
 {
     const auto start = size_t(this->scrollBar_->getCurrentValue());
     const auto layoutWidth = this->getLayoutWidth();
@@ -468,11 +468,14 @@ void ChannelView::layoutVisibleMessages(
     }
 
     if (redrawRequired)
+    {
         this->queueUpdate();
+    }
 }
 
 void ChannelView::updateScrollbar(
-    LimitedQueueSnapshot<MessageLayoutPtr> &messages, bool causedByScrollbar)
+    const LimitedQueueSnapshot<MessageLayoutPtr> &messages,
+    bool causedByScrollbar)
 {
     if (messages.size() == 0)
     {

src/widgets/helper/ChannelView.hpp

@@ -195,8 +195,8 @@ private:
 
     void performLayout(bool causedByScrollbar = false);
     void layoutVisibleMessages(
-        LimitedQueueSnapshot<MessageLayoutPtr> &messages);
-    void updateScrollbar(LimitedQueueSnapshot<MessageLayoutPtr> &messages,
+        const LimitedQueueSnapshot<MessageLayoutPtr> &messages);
+    void updateScrollbar(const LimitedQueueSnapshot<MessageLayoutPtr> &messages,
                          bool causedByScrollbar);
 
     void drawMessages(QPainter &painter);