From 552d0fe072a79cc66928782bebbb16a6c9022316 Mon Sep 17 00:00:00 2001
From: Gary Wang <wzc782970009@gmail.com>
Date: Mon, 1 Mar 2021 13:11:17 +0800
Subject: [PATCH] fix: compat for older Qt (lower than 5.13)

---
 app/graphicsview.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/app/graphicsview.cpp b/app/graphicsview.cpp
index ce64369..dcc6009 100644
--- a/app/graphicsview.cpp
+++ b/app/graphicsview.cpp
@@ -9,6 +9,13 @@
 #include <QImageReader>
 #include <QStyleOptionGraphicsItem>
 
+// TODO: remove this once we drop older Qt support.
+#if QT_VERSION_CHECK(5, 13, 0)
+#define COMPAT_CONSTCOLOR constexpr
+#else
+#define COMPAT_CONSTCOLOR const
+#endif
+
 GraphicsView::GraphicsView(QWidget *parent)
     : QGraphicsView (parent)
 {
@@ -303,8 +310,8 @@ void GraphicsView::setCheckerboardEnabled(bool enabled, bool invertColor)
         QPixmap tilePixmap(0x20, 0x20);
         tilePixmap.fill(invertColor ? QColor(220, 220, 220, 170) : QColor(35, 35, 35, 170));
         QPainter tilePainter(&tilePixmap);
-        constexpr QColor color(45, 45, 45, 170);
-        constexpr QColor invertedColor(210, 210, 210, 170);
+        COMPAT_CONSTCOLOR QColor color(45, 45, 45, 170);
+        COMPAT_CONSTCOLOR QColor invertedColor(210, 210, 210, 170);
         tilePainter.fillRect(0, 0, 0x10, 0x10, invertColor ? invertedColor : color);
         tilePainter.fillRect(0x10, 0x10, 0x10, 0x10, invertColor ? invertedColor : color);
         tilePainter.end();