From 812b6f7d69e691a04ba22477d4e443d3fb4f8757 Mon Sep 17 00:00:00 2001
From: Juergen Spitzmueller <spitz@lyx.org>
Date: Thu, 4 Mar 2021 12:35:38 +0100
Subject: [PATCH] Allow for runtime (dark/light) mode switch

---
 src/frontends/qt/GuiToolbar.cpp |  8 ++++++++
 src/frontends/qt/GuiToolbar.h   |  3 +++
 src/frontends/qt/GuiView.cpp    | 13 +++++++++++++
 src/frontends/qt/GuiView.h      |  2 ++
 4 files changed, 26 insertions(+)

diff --git a/src/frontends/qt/GuiToolbar.cpp b/src/frontends/qt/GuiToolbar.cpp
index 5600f4a74f..8057d84a70 100644
--- a/src/frontends/qt/GuiToolbar.cpp
+++ b/src/frontends/qt/GuiToolbar.cpp
@@ -116,6 +116,14 @@ void GuiToolbar::fill()
 }
 
 
+void GuiToolbar::refill()
+{
+	filled_ = false;
+	clear();
+	fill();
+}
+
+
 void GuiToolbar::showEvent(QShowEvent * ev)
 {
 	fill();
diff --git a/src/frontends/qt/GuiToolbar.h b/src/frontends/qt/GuiToolbar.h
index 262b09ef07..d658f3f51b 100644
--- a/src/frontends/qt/GuiToolbar.h
+++ b/src/frontends/qt/GuiToolbar.h
@@ -152,6 +152,9 @@ public:
 	///
 	void toggle();
 
+	///
+	void refill();
+
 	/// toggles movability
 	void movable(bool silent = false);
 
diff --git a/src/frontends/qt/GuiView.cpp b/src/frontends/qt/GuiView.cpp
index a48540d28c..c226968c5c 100644
--- a/src/frontends/qt/GuiView.cpp
+++ b/src/frontends/qt/GuiView.cpp
@@ -1470,6 +1470,12 @@ bool GuiView::event(QEvent * e)
 		return QMainWindow::event(e);
 	}
 
+	case QEvent::ApplicationPaletteChange: {
+		// runtime switch from/to dark mode
+		refillToolbars();
+		return QMainWindow::event(e);
+	}
+
 	default:
 		return QMainWindow::event(e);
 	}
@@ -1739,6 +1745,13 @@ void GuiView::updateToolbars()
 }
 
 
+void GuiView::refillToolbars()
+{
+	for (auto const & tb_p : d.toolbars_)
+		tb_p.second->refill();
+}
+
+
 void GuiView::setBuffer(Buffer * newBuffer, bool switch_to)
 {
 	LYXERR(Debug::DEBUG, "Setting buffer: " << newBuffer << endl);
diff --git a/src/frontends/qt/GuiView.h b/src/frontends/qt/GuiView.h
index 4c610e0ef9..f5024e5ef4 100644
--- a/src/frontends/qt/GuiView.h
+++ b/src/frontends/qt/GuiView.h
@@ -149,6 +149,8 @@ public:
 	/// updates the possible layouts selectable
 	void updateLayoutList();
 	void updateToolbars();
+	/// refill the toolbars (dark mode switch)
+	void refillToolbars();
 
 	///
 	LayoutBox * getLayoutDialog() const;
-- 
2.39.5