[LyX/master] Also change pdf module highlighting on the fly on mode change

[Juergen Spitzmueller]

commit 7c8c3657fdebf38d35a44c0e7e50a092d106addf
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Tue Sep 5 11:48:53 2023 +0200

    Also change pdf module highlighting on the fly on mode change
---
 src/frontends/qt/GuiDocument.cpp |   28 ++++++++++++++++++++++++++--
 src/frontends/qt/GuiDocument.h   |    6 ++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/frontends/qt/GuiDocument.cpp b/src/frontends/qt/GuiDocument.cpp
index bd72195..46f2a9c 100644
--- a/src/frontends/qt/GuiDocument.cpp
+++ b/src/frontends/qt/GuiDocument.cpp
@@ -1782,8 +1782,11 @@ GuiDocument::GuiDocument(GuiView & lv)
 		pdfSupportModule->subjectLE));
 	pdfSupportModule->keywordsLE->setValidator(new NoNewLineValidator(
 		pdfSupportModule->keywordsLE));
-	(void) new LaTeXHighlighter(pdfSupportModule->optionsTE->document(), true, true);
-	(void) new LaTeXHighlighter(pdfSupportModule->metadataTE->document(), true, true);
+
+	pdf_options_highlighter_ = new LaTeXHighlighter(
+				pdfSupportModule->optionsTE->document(), true, true);
+	pdf_metadata_highlighter_ = new LaTeXHighlighter(
+				pdfSupportModule->metadataTE->document(), true, true);
 
 	for (int i = 0; backref_opts[i][0]; ++i)
 		pdfSupportModule->backrefCO->addItem(qt_(backref_opts_gui[i]));
@@ -1840,6 +1843,9 @@ GuiDocument::GuiDocument(GuiView & lv)
 	docPS->addPanel(outputModule, N_("Output"));
 	docPS->addPanel(preambleModule, N_("LaTeX Preamble"));
 	docPS->setCurrentPanel("Document Class");
+
+	// Filter out (dark/light) mode changes
+	installEventFilter(this);
 }
 
 
@@ -5391,6 +5397,24 @@ void GuiDocument::setOutputSync(bool on)
 }
 
 
+bool GuiDocument::eventFilter(QObject * sender, QEvent * event)
+{
+	if (event->type() == QEvent::ApplicationPaletteChange) {
+		// mode switch: colors need to be updated
+		// and the highlighting redone
+		if (pdf_options_highlighter_) {
+			pdf_options_highlighter_->setupColors();
+			pdf_options_highlighter_->rehighlight();
+		}
+		if (pdf_metadata_highlighter_) {
+			pdf_metadata_highlighter_->setupColors();
+			pdf_metadata_highlighter_->rehighlight();
+		}
+	}
+	return QWidget::eventFilter(sender, event);
+}
+
+
 } // namespace frontend
 } // namespace lyx
 
diff --git a/src/frontends/qt/GuiDocument.h b/src/frontends/qt/GuiDocument.h
index 12f1cd7..c99345c 100644
--- a/src/frontends/qt/GuiDocument.h
+++ b/src/frontends/qt/GuiDocument.h
@@ -360,6 +360,12 @@ private:
 	/// Track whether we prompted the user about unapplied
 	/// changes
 	bool prompted_;
+	
+	/// LaTeX syntax highlighter
+	LaTeXHighlighter * pdf_options_highlighter_;
+	LaTeXHighlighter * pdf_metadata_highlighter_;
+protected:
+	bool eventFilter(QObject * sender, QEvent * event) override;
 };