Terminal: Implement scroll keyboard shortcuts

Change-Id: I354e6f63f89893ca057d17fab9810ea5c3dece7d
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/libs/solutions/terminal/terminalsurface.cpp

@@ -647,6 +647,11 @@ void TerminalSurface::sendFocus(bool hasFocus)
         vterm_state_focus_out(vts);
 }
 
+bool TerminalSurface::isInAltScreen()
+{
+    return d->m_altscreen;
+}
+
 void TerminalSurface::setWriteToPty(WriteToPty writeToPty)
 {
     d->m_writeToPty = writeToPty;

src/libs/solutions/terminal/terminalsurface.h

@@ -105,6 +105,7 @@ public:
     void mouseButton(Qt::MouseButton button, bool pressed, Qt::KeyboardModifiers modifiers);
 
     void sendFocus(bool hasFocus);
+    bool isInAltScreen();
 signals:
     void invalidated(QRect grid);
     void fullSizeChanged(QSize newSize);

src/libs/solutions/terminal/terminalview.cpp

@@ -950,7 +950,33 @@ void TerminalView::keyPressEvent(QKeyEvent *event)
 
     event->accept();
 
+    if (d->m_surface->isInAltScreen()) {
         d->m_surface->sendKey(event);
+    } else {
+        switch (event->key()) {
+        case Qt::Key_PageDown:
+            verticalScrollBar()->setValue(qBound(
+                0,
+                verticalScrollBar()->value() + d->m_surface->liveSize().height(),
+                verticalScrollBar()->maximum()));
+            break;
+        case Qt::Key_PageUp:
+            verticalScrollBar()->setValue(qBound(
+                0,
+                verticalScrollBar()->value() - d->m_surface->liveSize().height(),
+                verticalScrollBar()->maximum()));
+            break;
+        case Qt::Key_End:
+            verticalScrollBar()->setValue(verticalScrollBar()->maximum());
+            break;
+        case Qt::Key_Home:
+            verticalScrollBar()->setValue(0);
+            break;
+        default:
+            d->m_surface->sendKey(event);
+            break;
+        }
+    }
 }
 
 void TerminalView::keyReleaseEvent(QKeyEvent *event)

src/plugins/terminal/terminalwidget.cpp

@@ -42,7 +42,6 @@
 #include <QPixmapCache>
 #include <QRawFont>
 #include <QRegularExpression>
-#include <QScrollBar>
 #include <QTextItem>
 #include <QTextLayout>
 #include <QToolTip>