Keep return-to-latest action available in historical message windows

tools/chatgui/src/chatview.cpp

@@ -49,6 +49,7 @@ ChatView::ChatView(QWidget *parent)
     m_scrollDownBtn->setVisible(false);
 
     connect(m_scrollDownBtn, &QPushButton::clicked, this, [this]() {
+        emit latestRequested();
         scrollToBottom();
     });
     connect(verticalScrollBar(), &QScrollBar::valueChanged, this, &ChatView::updateScrollDownBtn);
@@ -65,6 +66,11 @@ void ChatView::setBackgroundImage(const QString &path) {
     viewport()->update();
 }
 
+void ChatView::setHistoricalWindow(bool enabled) {
+    m_historicalWindow = enabled;
+    updateScrollDownBtn();
+}
+
 void ChatView::resizeEvent(QResizeEvent *event) {
     QListView::resizeEvent(event);
     scheduleDelayedItemsLayout();
@@ -241,7 +247,7 @@ void ChatView::copySelection() {
 void ChatView::updateScrollDownBtn() {
     QScrollBar* sb = verticalScrollBar();
     bool atBottom = sb && (sb->value() >= sb->maximum());
-    m_scrollDownBtn->setVisible(!atBottom);
+    m_scrollDownBtn->setVisible(m_historicalWindow || !atBottom);
     if (!atBottom) {
         QRect vr = viewport()->geometry();
         m_scrollDownBtn->move(vr.right() - 44, vr.bottom() - 44);

tools/chatgui/src/chatview.h

@@ -24,6 +24,7 @@ public:
     explicit ChatView(QWidget *parent = nullptr);
 
     void setBackgroundImage(const QString &path);
+    void setHistoricalWindow(bool enabled);
 
     bool hasSelection() const { return m_selStart.isValid(); }
     QModelIndex selStart() const { return QModelIndex(m_selStart); }
@@ -38,6 +39,7 @@ public:
 signals:
     void animationTriggered();
     void linkActivated(const QString& link);
+    void latestRequested();
 
 protected:
     bool viewportEvent(QEvent *event) override;
@@ -62,6 +64,7 @@ private:
     QPersistentModelIndex m_pressIndex;
     QPoint m_pressPos;
     bool m_selecting = false;
+    bool m_historicalWindow = false;
     std::function<QString(const QModelIndex&, const QPoint&)> m_linkHitTest;
     QPushButton *m_scrollDownBtn = nullptr;
 };