Allow overriding fonts by (family,style).

CMakeLists.txt

@@ -90,6 +90,8 @@ PRIVATE
     ui/style/style_core.h
     ui/style/style_core_color.cpp
     ui/style/style_core_color.h
+    ui/style/style_core_custom_font.cpp
+    ui/style/style_core_custom_font.h
     ui/style/style_core_direction.cpp
     ui/style/style_core_direction.h
     ui/style/style_core_font.cpp

ui/style/style_core_custom_font.cpp

@@ -0,0 +1,73 @@
+// This file is part of Desktop App Toolkit,
+// a set of libraries for developing nice desktop applications.
+//
+// For license and copyright information please follow this link:
+// https://github.com/desktop-app/legal/blob/master/LEGAL
+//
+#include "ui/style/style_core_custom_font.h"
+
+#include "ui/style/style_core_font.h"
+
+#include <QFontDatabase>
+
+namespace style {
+namespace {
+
+using namespace internal;
+
+auto RegularFont = CustomFont();
+auto BoldFont = CustomFont();
+
+} // namespace
+
+void SetCustomFonts(const CustomFont &regular, const CustomFont &bold) {
+	RegularFont = regular;
+	BoldFont = bold;
+}
+
+QFont ResolveFont(uint32 flags, int size) {
+	static auto Database = QFontDatabase();
+
+	const auto bold = ((flags & FontBold) || (flags & FontSemibold));
+	const auto italic = (flags & FontItalic);
+	const auto &custom = bold ? BoldFont : RegularFont;
+	const auto useCustom = !custom.family.isEmpty();
+
+	auto result = QFont();
+	if (flags & FontMonospace) {
+		result.setFamily(MonospaceFont());
+	} else if (useCustom) {
+		const auto sizes = Database.smoothSizes(custom.family, custom.style);
+		const auto good = sizes.isEmpty()
+			? Database.pointSizes(custom.family, custom.style)
+			: sizes;
+		const auto point = good.isEmpty() ? size : good.front();
+		result = Database.font(custom.family, custom.style, point);
+	} else {
+		result.setFamily(GetFontOverride(flags));
+		if (bold) {
+#ifdef DESKTOP_APP_USE_PACKAGED_FONTS
+			result.setWeight(QFont::DemiBold);
+#else // DESKTOP_APP_USE_PACKAGED_FONTS
+			result.setBold(true);
+#endif // !DESKTOP_APP_USE_PACKAGED_FONTS
+
+			if (flags & FontItalic) {
+				result.setStyleName("Semibold Italic");
+			} else {
+				result.setStyleName("Semibold");
+			}
+		}
+	}
+	if (italic) {
+		result.setItalic(true);
+	}
+
+	result.setUnderline(flags & FontUnderline);
+	result.setStrikeOut(flags & FontStrikeOut);
+	result.setPixelSize(size);
+
+	return result;
+}
+
+} // namespace style

ui/style/style_core_custom_font.h

@@ -0,0 +1,45 @@
+// This file is part of Desktop App Toolkit,
+// a set of libraries for developing nice desktop applications.
+//
+// For license and copyright information please follow this link:
+// https://github.com/desktop-app/legal/blob/master/LEGAL
+//
+#pragma once
+
+namespace style {
+
+struct CustomFont {
+	QString family;
+	QString style;
+};
+
+inline bool operator==(const CustomFont &a, const CustomFont &b) {
+	return (a.family == b.family) && (a.style == b.style);
+}
+
+inline bool operator<(const CustomFont &a, const CustomFont &b) {
+	return (a.family < b.family)
+		|| (a.family == b.family && a.style < b.style);
+}
+
+inline bool operator!=(const CustomFont &a, const CustomFont &b) {
+	return !(a == b);
+}
+
+inline bool operator>(const CustomFont &a, const CustomFont &b) {
+	return (b < a);
+}
+
+inline bool operator<=(const CustomFont &a, const CustomFont &b) {
+	return !(b < a);
+}
+
+inline bool operator>=(const CustomFont &a, const CustomFont &b) {
+	return !(a < b);
+}
+
+void SetCustomFonts(const CustomFont &regular, const CustomFont &bold);
+
+[[nodiscard]] QFont ResolveFont(uint32 flags, int size);
+
+} // namespace style

ui/style/style_core_font.cpp

@@ -6,6 +6,7 @@
 //
 #include "ui/style/style_core_font.h"
 
+#include "ui/style/style_core_custom_font.h"
 #include "ui/ui_log.h"
 #include "base/algorithm.h"
 #include "ui/integration.h"
@@ -106,26 +107,6 @@ bool LoadCustomFont(const QString &filePath, const QString &familyName, int flag
 	return QString();
 }
 
-QString MonospaceFont() {
-	static const auto family = [&]() -> QString {
-		const auto manual = ManualMonospaceFont();
-		const auto system = SystemMonospaceFont();
-
-#if defined Q_OS_WIN || defined Q_OS_MAC
-		// Prefer our monospace font.
-		const auto useSystem = manual.isEmpty();
-#else // Q_OS_WIN || Q_OS_MAC
-		// Prefer system monospace font.
-		const auto metrics = QFontMetrics(QFont(system));
-		const auto useSystem = manual.isEmpty()
-			|| (metrics.charWidth("i", 0) == metrics.charWidth("W", 0));
-#endif // Q_OS_WIN || Q_OS_MAC
-		return useSystem ? system : manual;
-	}();
-
-	return family;
-}
-
 enum {
 	FontTypeRegular = 0,
 	FontTypeRegularItalic,
@@ -277,6 +258,26 @@ QString GetFontOverride(int32 flags) {
 	return result.isEmpty() ? "Open Sans" : result;
 }
 
+QString MonospaceFont() {
+	static const auto family = [&]() -> QString {
+		const auto manual = ManualMonospaceFont();
+		const auto system = SystemMonospaceFont();
+
+#if defined Q_OS_WIN || defined Q_OS_MAC
+		// Prefer our monospace font.
+		const auto useSystem = manual.isEmpty();
+#else // Q_OS_WIN || Q_OS_MAC
+		// Prefer system monospace font.
+		const auto metrics = QFontMetrics(QFont(system));
+		const auto useSystem = manual.isEmpty()
+			|| (metrics.charWidth("i", 0) == metrics.charWidth("W", 0));
+#endif // Q_OS_WIN || Q_OS_MAC
+		return useSystem ? system : manual;
+	}();
+
+	return family;
+}
+
 void destroyFonts() {
 	for (auto fontData : fontsMap) {
 		delete fontData;
@@ -295,7 +296,8 @@ int registerFontFamily(const QString &family) {
 }
 
 FontData::FontData(int size, uint32 flags, int family, Font *other)
-: m(f)
+: f(ResolveFont(flags, size))
+, m(f)
 , _size(size)
 , _flags(flags)
 , _family(family) {
@@ -306,32 +308,6 @@ FontData::FontData(int size, uint32 flags, int family, Font *other)
 	}
 	modified[_flags] = Font(this);
 
-	if (_flags & FontMonospace) {
-		f.setFamily(MonospaceFont());
-	} else {
-		f.setFamily(GetFontOverride(flags));
-	}
-
-	f.setPixelSize(size);
-	f.setItalic(_flags & FontItalic);
-	f.setUnderline(_flags & FontUnderline);
-	f.setStrikeOut(_flags & FontStrikeOut);
-
-	if ((_flags & FontBold) || (_flags & FontSemibold)) {
-#ifdef DESKTOP_APP_USE_PACKAGED_FONTS
-		f.setWeight(QFont::DemiBold);
-#else // DESKTOP_APP_USE_PACKAGED_FONTS
-		f.setBold(true);
-#endif // !DESKTOP_APP_USE_PACKAGED_FONTS
-
-		if (_flags & FontItalic) {
-			f.setStyleName("Semibold Italic");
-		} else {
-			f.setStyleName("Semibold");
-		}
-	}
-
-	m = QFontMetrics(f);
 	height = m.height();
 	ascent = m.ascent();
 	descent = m.descent();

ui/style/style_core_font.h

@@ -16,6 +16,7 @@ namespace internal {
 
 void StartFonts();
 [[nodiscard]] QString GetFontOverride(int32 flags = 0);
+[[nodiscard]] QString MonospaceFont();
 
 void destroyFonts();
 int registerFontFamily(const QString &family);
@@ -67,17 +68,19 @@ enum FontFlags {
 
 class FontData {
 public:
-
+	int width(const QString &str) const {
-	int32 width(const QString &str) const {
 		return m.width(str);
 	}
-	int32 width(const QString &str, int32 from, int32 to) const {
+	int width(const QString &str, int32 from, int32 to) const {
 		return width(str.mid(from, to));
 	}
-	int32 width(QChar ch) const {
+	int width(QChar ch) const {
 		return m.width(ch);
 	}
-	QString elided(const QString &str, int32 width, Qt::TextElideMode mode = Qt::ElideRight) const {
+	QString elided(
+			const QString &str,
+			int width,
+			Qt::TextElideMode mode = Qt::ElideRight) const {
 		return m.elidedText(str, mode, width);
 	}