From 106259f6e6b3e896ee2190195747df753ed308c8 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Fri, 10 Jul 2020 09:28:03 -0700
Subject: [PATCH] Set DoubleBuffering to reduce flicker

This sets double buffering for GTK and MSW to minimize flicker when
redrawing window elements.

Fixes https://gitlab.com/kicad/code/kicad/issues/4785
---
 eeschema/sch_draw_panel.cpp          | 2 ++
 eeschema/sch_preview_panel.cpp       | 2 ++
 gerbview/gerbview_draw_panel_gal.cpp | 1 +
 pcbnew/pcb_draw_panel_gal.cpp        | 1 +
 4 files changed, 6 insertions(+)

diff --git a/eeschema/sch_draw_panel.cpp b/eeschema/sch_draw_panel.cpp
index 5991d1278f..69ee6aa1a6 100644
--- a/eeschema/sch_draw_panel.cpp
+++ b/eeschema/sch_draw_panel.cpp
@@ -197,6 +197,8 @@ void SCH_DRAW_PANEL::OnShow()
         if( frame )
             frame->ActivateGalCanvas();
     }
+
+    m_parent->SetDoubleBuffered( true );
 }
 
 
diff --git a/eeschema/sch_preview_panel.cpp b/eeschema/sch_preview_panel.cpp
index da6a3e240e..02da8dfbbe 100644
--- a/eeschema/sch_preview_panel.cpp
+++ b/eeschema/sch_preview_panel.cpp
@@ -87,6 +87,8 @@ SCH_PREVIEW_PANEL::~SCH_PREVIEW_PANEL()
 
 void SCH_PREVIEW_PANEL::OnShow()
 {
+    m_parent->SetDoubleBuffered( true );
+
     //m_view->RecacheAllItems();
 }
 
diff --git a/gerbview/gerbview_draw_panel_gal.cpp b/gerbview/gerbview_draw_panel_gal.cpp
index 28b541c806..59ce9eac36 100644
--- a/gerbview/gerbview_draw_panel_gal.cpp
+++ b/gerbview/gerbview_draw_panel_gal.cpp
@@ -100,6 +100,7 @@ void GERBVIEW_DRAW_PANEL_GAL::OnShow()
 
     if( frame )
     {
+        m_parent->SetDoubleBuffered( true );
         SetTopLayer( frame->GetActiveLayer() );
         auto& displ_opts = frame->GetDisplayOptions();
         static_cast<KIGFX::GERBVIEW_RENDER_SETTINGS*>(
diff --git a/pcbnew/pcb_draw_panel_gal.cpp b/pcbnew/pcb_draw_panel_gal.cpp
index 077373c719..3ec08a70c2 100644
--- a/pcbnew/pcb_draw_panel_gal.cpp
+++ b/pcbnew/pcb_draw_panel_gal.cpp
@@ -416,6 +416,7 @@ void PCB_DRAW_PANEL_GAL::OnShow()
 
     if( frame )
     {
+        m_parent->SetDoubleBuffered( true );
         SetTopLayer( frame->GetActiveLayer() );
         KIGFX::PAINTER* painter = m_view->GetPainter();
         auto settings = static_cast<KIGFX::PCB_RENDER_SETTINGS*>( painter->GetSettings() );