[LyX/master] Move function

[Juergen Spitzmueller]

commit c316f29b42d48ae85d14bcd5ddcfa79cc96b7798
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Sun May 10 10:16:00 2026 +0200

    Move function
---
 src/RowPainter.cpp                  | 34 +---------------------------------
 src/frontends/Application.h         |  6 ++++++
 src/frontends/qt/ColorCache.cpp     | 27 +++++++++++++++++++++++++++
 src/frontends/qt/ColorCache.h       |  7 +++++++
 src/frontends/qt/GuiApplication.cpp |  6 ++++++
 src/frontends/qt/GuiApplication.h   |  1 +
 6 files changed, 48 insertions(+), 33 deletions(-)

diff --git a/src/RowPainter.cpp b/src/RowPainter.cpp
index cced976d6f..fd45245ea7 100644
--- a/src/RowPainter.cpp
+++ b/src/RowPainter.cpp
@@ -41,7 +41,6 @@
 #include "support/lassert.h"
 
 #include <algorithm>
-#include <cmath>
 
 using namespace std;
 
@@ -248,37 +247,6 @@ void RowPainter::paintMisspelledMark(Row::Element const & e) const
 }
 
 
-namespace {
-
-// check whether a color is relatively light (i.e., needs
-// a dark one as contrast) depending on relative luminance
-// (cf. https://www.w3.org/TR/WCAG20/#relativeluminancedef)
-bool isLightColor(RGBColor const & rgb)
-{
-	// RGB to sRGB
-	double r = rgb.r / 255.0;
-	if (r <= 0.04045)
-		r = r / 12.92;
-	else
-		r = pow((r + 0.055) / 1.055, 2.4);
-	double g = rgb.g / 255.0;
-	if (g <= 0.04045)
-		g = g / 12.92;
-	else
-		g = pow((g + 0.055) / 1.055, 2.4);
-	double b = rgb.b / 255.0;
-	if (b <= 0.04045)
-		b = b / 12.92;
-	else
-		b = pow((b + 0.055) / 1.055, 2.4);
-	// Calculate luminance
-	double L = 0.2126 * r + 0.7152 * g + 0.0722 * b;
-
-	return (L + 0.05) / (0.0 + 0.05) > (1.0 + 0.05) / (L + 0.05);
-}
-} // namespace anon
-
-
 void RowPainter::paintStringAndSel(Row::Element const & e) const
 {
 	// at least part of text selected?
@@ -290,7 +258,7 @@ void RowPainter::paintStringAndSel(Row::Element const & e) const
 
 	bool invert = false;
 	if (theApp() && theApp()->isInDarkMode()
-	    && isLightColor(rgbFromHexName(lcolor.getX11HexName(pi_.background_color, true))))
+	    && theApp()->isLightColor(rgbFromHexName(lcolor.getX11HexName(pi_.background_color, true))))
 		invert = true;
 
 	if (e.type == Row::PREEDIT) {
diff --git a/src/frontends/Application.h b/src/frontends/Application.h
index f52b124e2c..615cca5150 100644
--- a/src/frontends/Application.h
+++ b/src/frontends/Application.h
@@ -214,6 +214,12 @@ public:
 	 */
 	virtual bool isInDarkMode() = 0;
 
+	/**
+	 * @return true this is a relatively light color
+	 * depending on relative luminance
+	 */
+	virtual bool isLightColor(RGBColor const & rgb) = 0;
+
 	/** Eg, passing Color_black returns "000000",
 	*      passing Color_white returns "ffffff".
 	*/
diff --git a/src/frontends/qt/ColorCache.cpp b/src/frontends/qt/ColorCache.cpp
index bdf4ab1d8b..dbc9a72040 100644
--- a/src/frontends/qt/ColorCache.cpp
+++ b/src/frontends/qt/ColorCache.cpp
@@ -17,6 +17,8 @@
 
 #include "Color.h"
 
+#include <cmath>
+
 namespace lyx {
 
 namespace{
@@ -155,6 +157,31 @@ bool ColorCache::isDarkMode() const
 }
 
 
+bool ColorCache::isLightColor(RGBColor const & rgb)
+{
+	// RGB to sRGB
+	double r = rgb.r / 255.0;
+	if (r <= 0.04045)
+		r = r / 12.92;
+	else
+		r = pow((r + 0.055) / 1.055, 2.4);
+	double g = rgb.g / 255.0;
+	if (g <= 0.04045)
+		g = g / 12.92;
+	else
+		g = pow((g + 0.055) / 1.055, 2.4);
+	double b = rgb.b / 255.0;
+	if (b <= 0.04045)
+		b = b / 12.92;
+	else
+		b = pow((b + 0.055) / 1.055, 2.4);
+	// Calculate luminance
+	double L = 0.2126 * r + 0.7152 * g + 0.0722 * b;
+
+	return (L + 0.05) / (0.0 + 0.05) > (1.0 + 0.05) / (L + 0.05);
+}
+
+
 QColor const rgb2qcolor(RGBColor const & rgb)
 {
 	return QColor(rgb.r, rgb.g, rgb.b);
diff --git a/src/frontends/qt/ColorCache.h b/src/frontends/qt/ColorCache.h
index 105a97df87..ced8177b87 100644
--- a/src/frontends/qt/ColorCache.h
+++ b/src/frontends/qt/ColorCache.h
@@ -47,6 +47,13 @@ public:
 	/// guess whether we are in dark mode
 	bool isDarkMode() const;
 
+	/**
+	 * check whether a color is relatively light (i.e., needs
+	 * a dark one as contrast) depending on relative luminance
+	 * (cf. https://www.w3.org/TR/WCAG20/#relativeluminancedef)
+	*/
+	bool isLightColor(RGBColor const & rgb);
+
 	/// change the undelying palette
 	void setPalette(QPalette const pal) { pal_ = pal; clear(); }
 
diff --git a/src/frontends/qt/GuiApplication.cpp b/src/frontends/qt/GuiApplication.cpp
index e786fea150..f3070c525d 100644
--- a/src/frontends/qt/GuiApplication.cpp
+++ b/src/frontends/qt/GuiApplication.cpp
@@ -3091,6 +3091,12 @@ bool GuiApplication::isInDarkMode()
 }
 
 
+bool GuiApplication::isLightColor(RGBColor const & rgb)
+{
+	return colorCache().isLightColor(rgb);
+}
+
+
 bool GuiApplication::getRgbColor(ColorCode col, RGBColor & rgbcol)
 {
 	QColor const & qcol = d->color_cache_.get(col);
diff --git a/src/frontends/qt/GuiApplication.h b/src/frontends/qt/GuiApplication.h
index 2b8040eff9..db84925ca9 100644
--- a/src/frontends/qt/GuiApplication.h
+++ b/src/frontends/qt/GuiApplication.h
@@ -75,6 +75,7 @@ public:
 	bool event(QEvent * e) override;
 	bool getRgbColor(ColorCode col, RGBColor & rgbcol) override;
 	bool isInDarkMode() override;
+	bool isLightColor(RGBColor const & rgb) override;
 	std::string const hexName(ColorCode col) override;
 	void registerSocketCallback(int fd, SocketCallback func) override;
 	void unregisterSocketCallback(int fd) override;