Add Qt6 Support

.github/workflows/build.yml

@@ -371,10 +371,10 @@ jobs:
       - name: Install tools
         run: choco install ccache
       - name: Install Qt
-        uses: jurplel/install-qt-action@b3ea5275e37b734d027040e2c7fe7a10ea2ef946
+        uses: jurplel/install-qt-action@d325aaf2a8baeeda41ad0b5d39f84a6af9bcf005
         with:
-          version: '5.15.2'
-          arch: "win64_msvc2019_64"
+          version: '6.8.*'
+          arch: "win64_msvc2022_64"
           archives: qtbase qtsvg qttools
           cache: true
       - name: Set up build environment
@@ -391,6 +391,7 @@ jobs:
             --toolchain C:/vcpkg/scripts/buildsystems/vcpkg.cmake `
             -Werror=dev `
             -DCMAKE_BUILD_TYPE=RelWithDebInfo `
+            -DWANT_QT6=ON `
             -DUSE_COMPILE_CACHE=ON `
             -DUSE_WERROR=ON `
             -DVCPKG_TARGET_TRIPLET="x64-windows" `

CMakeLists.txt

@@ -107,6 +107,7 @@ option(WANT_DEBUG_GPROF	"Enable gprof profiler" OFF)
 OPTION(BUNDLE_QT_TRANSLATIONS	"Install Qt translation files for LMMS" OFF)
 option(WANT_DEBUG_CPACK "Show detailed logs for packaging commands" OFF)
 option(WANT_CPACK_TARBALL "Request CPack to create a tarball instead of an installer" OFF)
+option(WANT_QT6 "Build with experimental Qt6 support" OFF)
 
 
 IF(LMMS_BUILD_APPLE)
@@ -174,31 +175,45 @@ check_library_exists(rt shm_open "" LMMS_HAVE_LIBRT)
 
 LIST(APPEND CMAKE_PREFIX_PATH "${CMAKE_INSTALL_PREFIX}")
 
-FIND_PACKAGE(Qt5 5.9.0 COMPONENTS Core Gui Widgets Xml Svg REQUIRED)
-FIND_PACKAGE(Qt5 COMPONENTS LinguistTools QUIET)
+if(WANT_QT6)
+	set(QT_VERSION_MAJOR 6)
+	if(MSVC)
+		set(LMMS_QT_MIN_VERSION 6.8.0)
+	else()
+		set(LMMS_QT_MIN_VERSION 6.0.0)
+	endif()
+	set(STATUS_QT6 "Enabled")
+else()
+	set(QT_VERSION_MAJOR 5)
+	set(LMMS_QT_MIN_VERSION 5.9.0)
+	set(STATUS_QT6 "Disabled")
+endif()
+
+find_package(Qt${QT_VERSION_MAJOR} ${LMMS_QT_MIN_VERSION} COMPONENTS Core Gui Widgets Xml Svg REQUIRED)
+find_package(Qt${QT_VERSION_MAJOR} COMPONENTS LinguistTools QUIET)
 
 include_directories(SYSTEM
-	${Qt5Core_INCLUDE_DIRS}
-	${Qt5Gui_INCLUDE_DIRS}
-	${Qt5Widgets_INCLUDE_DIRS}
-	${Qt5Xml_INCLUDE_DIRS}
+	${Qt${QT_VERSION_MAJOR}Core_INCLUDE_DIRS}
+	${Qt${QT_VERSION_MAJOR}Gui_INCLUDE_DIRS}
+	${Qt${QT_VERSION_MAJOR}Widgets_INCLUDE_DIRS}
+	${Qt${QT_VERSION_MAJOR}Xml_INCLUDE_DIRS}
 )
 
-SET(QT_LIBRARIES
-	Qt5::Core
-	Qt5::Gui
-	Qt5::Widgets
-	Qt5::Xml
-	Qt5::Svg
+set(QT_LIBRARIES
+	Qt${QT_VERSION_MAJOR}::Core
+	Qt${QT_VERSION_MAJOR}::Gui
+	Qt${QT_VERSION_MAJOR}::Widgets
+	Qt${QT_VERSION_MAJOR}::Xml
+	Qt${QT_VERSION_MAJOR}::Svg
 )
 
-IF(LMMS_BUILD_LINUX AND WANT_VST)
+IF(LMMS_BUILD_LINUX AND WANT_VST AND NOT WANT_QT6)
     FIND_PACKAGE(Qt5 COMPONENTS X11Extras REQUIRED)
     LIST(APPEND QT_LIBRARIES Qt5::X11Extras)
 ENDIF()
 
-# Resolve Qt5::qmake to full path for use in packaging scripts
-GET_TARGET_PROPERTY(QT_QMAKE_EXECUTABLE "${Qt5Core_QMAKE_EXECUTABLE}" IMPORTED_LOCATION)
+# Resolve qmake to full path for use in packaging scripts
+get_target_property(QT_QMAKE_EXECUTABLE Qt${QT_VERSION_MAJOR}::qmake IMPORTED_LOCATION)
 
 # Find the location of Qt translation files
 execute_process(COMMAND ${QT_QMAKE_EXECUTABLE} -query QT_INSTALL_TRANSLATIONS
@@ -211,8 +226,8 @@ IF(EXISTS "${QT_TRANSLATIONS_DIR}")
 	ADD_DEFINITIONS("-DQT_TRANSLATIONS_DIR=\"${QT_TRANSLATIONS_DIR}\"")
 ENDIF()
 
-FIND_PACKAGE(Qt5Test)
-SET(QT_QTTEST_LIBRARY Qt5::Test)
+FIND_PACKAGE(Qt${QT_VERSION_MAJOR}Test)
+SET(QT_QTTEST_LIBRARY Qt${QT_VERSION_MAJOR}::Test)
 
 # check for libsndfile
 FIND_PACKAGE(SndFile REQUIRED)
@@ -875,6 +890,7 @@ MESSAGE(
 "* Debug packaging commands          : ${STATUS_DEBUG_CPACK}\n"
 "* Profile using GNU profiler        : ${STATUS_GPROF}\n"
 "* Debug assertions                  : ${STATUS_ASSERTIONS}\n"
+"* Experimental Qt6 support          : ${STATUS_QT6}\n"
 )
 
 MESSAGE(

cmake/install/CMakeLists.txt

@@ -1,9 +1,9 @@
 SET(PLUGIN_FILES "")
 IF(LMMS_BUILD_WIN32)
-        INSTALL(FILES $<TARGET_FILE:Qt5::QWindowsIntegrationPlugin> DESTINATION platforms)
-        INSTALL(FILES $<TARGET_FILE:Qt5::QSvgIconPlugin> DESTINATION iconengines)
-        INSTALL(FILES $<TARGET_FILE:Qt5::QSvgPlugin> DESTINATION imageformats)
-        INSTALL(FILES $<TARGET_FILE:Qt5::Svg> DESTINATION .)
+        INSTALL(FILES $<TARGET_FILE:Qt${QT_VERSION_MAJOR}::QWindowsIntegrationPlugin> DESTINATION platforms)
+        INSTALL(FILES $<TARGET_FILE:Qt${QT_VERSION_MAJOR}::QSvgIconPlugin> DESTINATION iconengines)
+        INSTALL(FILES $<TARGET_FILE:Qt${QT_VERSION_MAJOR}::QSvgPlugin> DESTINATION imageformats)
+        INSTALL(FILES $<TARGET_FILE:Qt${QT_VERSION_MAJOR}::Svg> DESTINATION .)
 ENDIF()
 
 IF(LMMS_BUILD_WIN32 OR LMMS_INSTALL_DEPENDENCIES)

cmake/linux/LinuxDeploy.cmake

@@ -109,6 +109,10 @@ set(ENV{PATH} "${QTBIN}:$ENV{PATH}")
 # Promote finding our own libraries first
 set(ENV{LD_LIBRARY_PATH} "${APP}/usr/lib/${lmms}/:${APP}/usr/lib/${lmms}/optional:$ENV{LD_LIBRARY_PATH}")
 
+# Workaround for finding libs from online installer
+# https://github.com/linuxdeploy/linuxdeploy-plugin-qt/issues/193
+set(ENV{LD_LIBRARY_PATH} "${QTBIN}/../lib:$ENV{LD_LIBRARY_PATH}")
+
 # Skip slow searching of copyright files https://github.com/linuxdeploy/linuxdeploy/issues/278
 set(ENV{DISABLE_COPYRIGHT_FILES_DEPLOYMENT} 1)
 

cmake/modules/BuildPlugin.cmake

@@ -30,7 +30,7 @@ MACRO(BUILD_PLUGIN PLUGIN_NAME)
 		ADD_GEN_QRC(RCC_OUT "${PLUGIN_NAME}.qrc" PREFIX artwork/${PLUGIN_NAME} ${PLUGIN_EMBEDDED_RESOURCES})
 	ENDIF(ER_LEN)
 
-	QT5_WRAP_CPP(plugin_MOC_out ${PLUGIN_MOCFILES})
+	cmake_language(CALL QT${QT_VERSION_MAJOR}_WRAP_CPP plugin_MOC_out ${PLUGIN_MOCFILES})
 
 	FOREACH(f ${PLUGIN_SOURCES})
 		ADD_FILE_DEPENDENCIES(${f} ${RCC_OUT})
@@ -51,7 +51,7 @@ MACRO(BUILD_PLUGIN PLUGIN_NAME)
 
 	ADD_LIBRARY(${PLUGIN_NAME} ${PLUGIN_LINK} ${PLUGIN_SOURCES} ${plugin_MOC_out} ${RCC_OUT})
 
-	target_link_libraries("${PLUGIN_NAME}" lmms Qt5::Widgets Qt5::Xml)
+	target_link_libraries("${PLUGIN_NAME}" lmms Qt${QT_VERSION_MAJOR}::Widgets Qt${QT_VERSION_MAJOR}::Xml)
 
 	INSTALL(TARGETS ${PLUGIN_NAME}
 		LIBRARY DESTINATION "${PLUGIN_DIR}"

cmake/modules/GenQrc.cmake

@@ -58,7 +58,7 @@ function(add_gen_qrc RCC_OUT QRC_NAME)
 	# generators. See issue #6177.
 	add_custom_command(
 		OUTPUT "${CPP_FILE}"
-		COMMAND Qt5::rcc
+		COMMAND Qt${QT_VERSION_MAJOR}::rcc
 			--name "${RESOURCE_NAME}"
 			--output "${CPP_FILE}"
 			"${QRC_FILE}"

data/locale/CMakeLists.txt

@@ -1,5 +1,5 @@
-SET(QT_LUPDATE_EXECUTABLE "${Qt5_LUPDATE_EXECUTABLE}")
-SET(QT_LRELEASE_EXECUTABLE "${Qt5_LRELEASE_EXECUTABLE}")
+SET(QT_LUPDATE_EXECUTABLE "${Qt${QT_VERSION_MAJOR}_LUPDATE_EXECUTABLE}")
+SET(QT_LRELEASE_EXECUTABLE "${Qt${QT_VERSION_MAJOR}_LRELEASE_EXECUTABLE}")
 
 IF(QT_LUPDATE_EXECUTABLE STREQUAL "")
 	EXECUTE_PROCESS(COMMAND "lupdate" "-help" RESULT_VARIABLE LUPDATE_FALLBACK OUTPUT_QUIET)

include/ColorChooser.h

@@ -55,8 +55,7 @@ class ColorChooser : public QColorDialog
 	//! Forward key events to the parent to prevent stuck notes when the dialog gets focus
 	void keyReleaseEvent(QKeyEvent *event) override
 	{
-		QKeyEvent ke(*event);
-		QApplication::sendEvent(parentWidget(), &ke);
+		QApplication::sendEvent(parentWidget(), event);
 	}
 private:
 	//! Copy the current QColorDialog palette into an array

include/ColorHelper.h

@@ -35,17 +35,23 @@ class ColorHelper
 public:
 	static QColor interpolateInRgb(const QColor& a, const QColor& b, float t)
 	{
-		qreal ar, ag, ab, aa;
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+		using ColorType = float;
+#else
+		using ColorType = qreal;
+#endif
+
+		ColorType ar, ag, ab, aa;
 		a.getRgbF(&ar, &ag, &ab, &aa);
 
-		qreal br, bg, bb, ba;
+		ColorType br, bg, bb, ba;
 		b.getRgbF(&br, &bg, &bb, &ba);
 
-		const auto t2 = static_cast<qreal>(t);
-		const float interH = std::lerp(ar, br, t2);
-		const float interS = std::lerp(ag, bg, t2);
-		const float interV = std::lerp(ab, bb, t2);
-		const float interA = std::lerp(aa, ba, t2);
+		const auto t2 = static_cast<ColorType>(t);
+		const auto interH = std::lerp(ar, br, t2);
+		const auto interS = std::lerp(ag, bg, t2);
+		const auto interV = std::lerp(ab, bb, t2);
+		const auto interA = std::lerp(aa, ba, t2);
 
 		return QColor::fromRgbF(interH, interS, interV, interA);
 	}

include/ControlLayout.h

@@ -98,6 +98,14 @@ class ControlLayout : public QLayout
 {
 	Q_OBJECT
 
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	using ControlLayoutMap = QMultiMap<QString, QLayoutItem*>;
+	using ControlLayoutMapIterator = QMultiMapIterator<QString, QLayoutItem*>;
+#else
+	using ControlLayoutMap = QMap<QString, QLayoutItem*>;
+	using ControlLayoutMapIterator = QMapIterator<QString, QLayoutItem*>;
+#endif
+
 public:
 	explicit ControlLayout(QWidget *parent,
 		int margin = -1, int hSpacing = -1, int vSpacing = -1);
@@ -126,9 +134,9 @@ private slots:
 private:
 	int doLayout(const QRect &rect, bool testOnly) const;
 	int smartSpacing(QStyle::PixelMetric pm) const;
-	QMap<QString, QLayoutItem *>::const_iterator pairAt(int index) const;
+	ControlLayoutMap::const_iterator pairAt(int index) const;
 
-	QMultiMap<QString, QLayoutItem *> m_itemMap;
+	ControlLayoutMap m_itemMap;
 	int m_hSpace;
 	int m_vSpace;
 	// relevant dimension is width, as later, heightForWidth() will be called

include/DeprecationHelper.h

@@ -29,8 +29,10 @@
 
 #include <type_traits>
 
+#include <QDomDocument>
 #include <QFontMetrics>
 #include <QKeySequence>
+#include <QVariant>
 #include <QWheelEvent>
 
 namespace lmms
@@ -58,15 +60,74 @@ inline int horizontalAdvance(const QFontMetrics& metrics, const QString& text)
  * @param wheelEvent
  * @return the position of wheelEvent
  */
-inline QPoint position(QWheelEvent *wheelEvent)
+inline QPoint position(const QWheelEvent* wheelEvent)
 {
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
 	return wheelEvent->position().toPoint();
 #else
 	return wheelEvent->pos();
 #endif
 }
 
+/**
+ * @brief position is a backwards-compatible adapter for
+ * QDropEvent::position and pos functions.
+ * @param me
+ * @return the position of the drop event
+ */
+inline QPoint position(const QDropEvent* de)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	return de->position().toPoint();
+#else
+	return de->pos();
+#endif
+}
+
+/**
+ * @brief position is a backwards-compatible adapter for
+ * QMouseEvent::position and pos functions.
+ * @param me
+ * @return the position of the mouse event
+ */
+inline QPoint position(const QMouseEvent* me)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	return me->position().toPoint();
+#else
+	return me->pos();
+#endif
+}
+
+/**
+ * @brief positionF is a backwards-compatible adapter for
+ * QMouseEvent::position and localPos functions.
+ * @param me
+ * @return the position of the mouse event
+ */
+inline QPointF positionF(const QMouseEvent* me)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	return me->position();
+#else
+	return me->localPos();
+#endif
+}
+
+/**
+ * @brief globalPosition is a backwards-compatible adapter for
+ * QMouseEvent::globalPosition and globalPos functions.
+ * @param me
+ * @return the global position of the mouse event
+ */
+inline QPoint globalPosition(const QMouseEvent* me)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	return me->globalPosition().toPoint();
+#else
+	return me->globalPos();
+#endif
+}
 
 namespace detail
 {
@@ -77,20 +138,67 @@ inline constexpr bool IsKeyOrModifier = std::is_same_v<T, Qt::Key>
 
 } // namespace detail
 
-
 /**
  * @brief Combines Qt key and modifier arguments together,
  * replacing `A | B` which was deprecated in C++20
  * due to the enums being different types. (P1120R0)
  * @param args Any number of Qt::Key, Qt::Modifier, or Qt::KeyboardModifier
- * @return The combination of the given keys/modifiers as an int
+ * @return The combination of the given keys/modifiers as a QKeySequence
  */
-template<typename... Args, std::enable_if_t<(detail::IsKeyOrModifier<Args> && ...), bool> = true>
-constexpr int combine(Args... args)
+template<typename... Args> requires (detail::IsKeyOrModifier<Args> && ...)
+inline QKeySequence keySequence(Args... args)
 {
 	return (0 | ... | static_cast<int>(args));
 }
 
+/**
+ * @brief typeId is a backwards-compatible adapter for
+ * QVariant::typeId and type functions.
+ * @param variant
+ * @return the type id of the variant
+ */
+inline QMetaType::Type typeId(const QVariant& variant)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+	return static_cast<QMetaType::Type>(variant.typeId());
+#else
+	return static_cast<QMetaType::Type>(variant.type());
+#endif
+}
+
+//! Backwards-compatible adapter for QDomDocument::setContent
+inline bool setContent(QDomDocument& doc, const QByteArray& text,
+	QString* errorMsg = nullptr, int* errorLine = nullptr, int* errorColumn = nullptr)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 5, 0))
+	auto result = doc.setContent(text, QDomDocument::ParseOption::Default);
+	if (errorMsg) { *errorMsg = std::move(result.errorMessage); }
+	if (errorLine) { *errorLine = static_cast<int>(result.errorLine); }
+	if (errorColumn) { *errorColumn = static_cast<int>(result.errorColumn); }
+	return static_cast<bool>(result);
+#else
+	return doc.setContent(text, errorMsg, errorLine, errorColumn);
+#endif
+}
+
+//! Backwards-compatible adapter for QDomDocument::setContent
+inline bool setContent(QDomDocument& doc, QIODevice* dev, bool namespaceProcessing,
+	QString* errorMsg = nullptr, int* errorLine = nullptr, int* errorColumn = nullptr)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 5, 0))
+	const auto options = namespaceProcessing
+		? QDomDocument::ParseOption::UseNamespaceProcessing
+		: QDomDocument::ParseOption::Default;
+	auto result = doc.setContent(dev, options);
+	if (errorMsg) { *errorMsg = std::move(result.errorMessage); }
+	if (errorLine) { *errorLine = static_cast<int>(result.errorLine); }
+	if (errorColumn) { *errorColumn = static_cast<int>(result.errorColumn); }
+	return static_cast<bool>(result);
+#else
+	return doc.setContent(dev, namespaceProcessing, errorMsg, errorLine, errorColumn);
+#endif
+}
+
 } // namespace lmms
 
 #endif // LMMS_DEPRECATIONHELPER_H