From 65008c5c0bbc2672f13f7603ee8ba8bd64c25333 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Tue, 10 Dec 2019 08:00:42 -0800
Subject: [PATCH] Eeschema: Check twice before using GAL

The windows display may through an error which we need to catch when
starting GAL under windows.  This is a reimplementation of
e39586e15 which cannot be cherry-picked into v5

Fixes #2620 | https://gitlab.com/kicad/code/kicad/issues/2620
---
 eeschema/sch_draw_panel.cpp | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/eeschema/sch_draw_panel.cpp b/eeschema/sch_draw_panel.cpp
index 0ad1f53bd2..80c4f7514b 100644
--- a/eeschema/sch_draw_panel.cpp
+++ b/eeschema/sch_draw_panel.cpp
@@ -23,10 +23,11 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  */
 
-
+#include <functional>
 #include <view/wx_view_controls.h>
 #include <worksheet_viewitem.h>
 
+#include <confirm.h>
 #include <gal/graphics_abstraction_layer.h>
 #include <sch_draw_panel.h>
 #include <sch_view.h>
@@ -34,8 +35,6 @@
 #include <sch_edit_frame.h>
 #include <preview_items/selection_area.h>
 
-#include <functional>
-
 #include <sch_sheet.h>
 #include <pgm_base.h>
 
@@ -174,7 +173,19 @@ void SCH_DRAW_PANEL::DisplaySheet( const SCH_SCREEN *aScreen )
 
 void SCH_DRAW_PANEL::OnShow()
 {
-    //m_view->RecacheAllItems();
+    SCH_BASE_FRAME* frame = dynamic_cast<SCH_BASE_FRAME*>( GetParent() );
+
+    try
+    {
+        // Check if the current rendering backend can be properly initialized
+        m_view->UpdateItems();
+    }
+    catch( const std::runtime_error& e )
+    {
+        // Fallback to software renderer
+        DisplayInfoMessage( frame, e.what() );
+        SwitchBackend( GAL_TYPE_CAIRO );
+    }
 }