Add handlers for scrollbar events

Fixes: lp:1776120
* https://bugs.launchpad.net/kicad/+bug/1776120

common/view/wx_view_controls.cpp

@@ -67,6 +67,14 @@ WX_VIEW_CONTROLS::WX_VIEW_CONTROLS( VIEW* aView, wxScrolledCanvas* aParentPanel
                             wxMouseEventHandler( WX_VIEW_CONTROLS::onLeave ), NULL, this );
     m_parentPanel->Connect( wxEVT_SCROLLWIN_THUMBTRACK,
                             wxScrollWinEventHandler( WX_VIEW_CONTROLS::onScroll ), NULL, this );
+    m_parentPanel->Connect( wxEVT_SCROLLWIN_PAGEUP,
+                            wxScrollWinEventHandler( WX_VIEW_CONTROLS::onScroll ), NULL, this );
+    m_parentPanel->Connect( wxEVT_SCROLLWIN_PAGEDOWN,
+                            wxScrollWinEventHandler( WX_VIEW_CONTROLS::onScroll ), NULL, this );
+    m_parentPanel->Connect( wxEVT_SCROLLWIN_LINEUP,
+                            wxScrollWinEventHandler( WX_VIEW_CONTROLS::onScroll ), NULL, this );
+    m_parentPanel->Connect( wxEVT_SCROLLWIN_LINEDOWN,
+                            wxScrollWinEventHandler( WX_VIEW_CONTROLS::onScroll ), NULL, this );
 
     m_panTimer.SetOwner( this );
     this->Connect( wxEVT_TIMER,