GTK3: Force scrollbars visible

GTK3 does a fade in/fade out routine for scrollbars by default.  This
was problematic as it caused a cascade of full-screen repaint events on
each mouse event.  Instead of disabling scrollbars (which only helped
the full canvas), we force the old scrollbar behavior is environmental
variables.

Revert "gtk3: Remove scrollbars"

This reverts commit db43bd82a7.

common/draw_panel_gal.cpp

@@ -72,13 +72,7 @@ EDA_DRAW_PANEL_GAL::EDA_DRAW_PANEL_GAL( wxWindow* aParentWindow, wxWindowID aWin
     SwitchBackend( aGalType );
     SetBackgroundStyle( wxBG_STYLE_CUSTOM );
 
-#ifdef __WXGTK3__
-    // Until we can handle the repaint events from scroll bar hide/show
-    // todo: Implement area mapping for re-painting scrollbars
-    ShowScrollbars( wxSHOW_SB_NEVER, wxSHOW_SB_NEVER );
-#else
     ShowScrollbars( wxSHOW_SB_ALWAYS, wxSHOW_SB_ALWAYS );
-#endif
     EnableScrolling( false, false );    // otherwise Zoom Auto disables GAL canvas
 
     Connect( wxEVT_SIZE, wxSizeEventHandler( EDA_DRAW_PANEL_GAL::onSize ), NULL, this );

common/single_top.cpp

@@ -134,6 +134,10 @@ struct APP_SINGLE_TOP : public wxApp
         {
             wxSetEnv ( wxT("UBUNTU_MENUPROXY" ), wxT( "0" ) );
         }
+
+        // Disable overlay scrollbars as they mess up wxWidgets window sizing and cause excessive redraw requests
+        wxSetEnv( wxT( "GTK_OVERLAY_SCROLLING" ), wxT( "0" ) );
+
     }
 #endif
 

common/view/wx_view_controls.cpp

@@ -646,12 +646,6 @@ wxPoint WX_VIEW_CONTROLS::getMouseScreenPosition() const
 
 void WX_VIEW_CONTROLS::UpdateScrollbars()
 {
-#ifdef __WXGTK3__
-    // Until we can handle the repaint events from scroll bar hide/show
-    // todo: Implement area mapping for re-painting scrollbars
-    return;
-#endif
-
     const BOX2D viewport = m_view->GetViewport();
     const BOX2D& boundary = m_view->GetBoundary();
 

kicad/kicad.cpp

@@ -229,6 +229,9 @@ struct APP_KICAD : public wxApp
         {
             wxSetEnv ( wxT("UBUNTU_MENUPROXY" ), wxT( "0" ) );
         }
+
+        // Disable overlay scrollbars as they mess up wxWidgets window sizing and cause excessive redraw requests
+        wxSetEnv( wxT( "GTK_OVERLAY_SCROLLING" ), wxT( "0" ) );
     }
 #endif