Add chat history keyboard scrolling and remove unused PTT setting

tools/chatgui/src/chatview.cpp

@@ -208,7 +208,32 @@ void ChatView::mouseReleaseEvent(QMouseEvent *event) {
     QListView::mouseReleaseEvent(event);
 }
 
+bool ChatView::scrollWithKey(QKeyEvent *event) {
+    if (event->modifiers() != Qt::NoModifier) return false;
+    QAbstractSlider::SliderAction action;
+    switch (event->key()) {
+        case Qt::Key_Up: action = QAbstractSlider::SliderSingleStepSub; break;
+        case Qt::Key_Down: action = QAbstractSlider::SliderSingleStepAdd; break;
+        case Qt::Key_PageUp: action = QAbstractSlider::SliderPageStepSub; break;
+        case Qt::Key_PageDown: action = QAbstractSlider::SliderPageStepAdd; break;
+        default: return false;
+    }
+    auto* bar = verticalScrollBar();
+    const int before = bar->value();
+    bar->triggerAction(action);
+    GUI_DEBUG("history keyboard scroll: key=%d action=%d position=%d->%d range=%d..%d",
+              event->key(), int(action), before, bar->value(), bar->minimum(), bar->maximum());
+    event->accept();
+    return true;
+}
+
+bool ChatView::eventFilter(QObject *object, QEvent *event) {
+    if (event->type() == QEvent::KeyPress && isVisible() && isEnabled() && scrollWithKey(static_cast<QKeyEvent*>(event))) return true;
+    return QListView::eventFilter(object, event);
+}
+
 void ChatView::keyPressEvent(QKeyEvent *event) {
+    if (scrollWithKey(event)) return;
     if (event == QKeySequence::Copy) {
         copySelection();
         return;