Add Dark mode support

src/DockManager.cpp

@@ -50,6 +50,7 @@
 #include <QWindow>
 #include <QWindowStateChangeEvent>
 #include <QVector>
+#include <QStyleHints>
 
 #include "FloatingDockContainer.h"
 #include "DockOverlay.h"
@@ -118,6 +119,7 @@ struct DockManagerPrivate
 	QMap<QString, QMenu*> ViewMenuGroups;
 	QMenu* ViewMenu;
 	CDockManager::eViewMenuInsertionOrder MenuInsertionOrder = CDockManager::MenuAlphabeticallySorted;
+	CDockManager::eStylesheetColorSchemeBehavior StylesheetColorSchemeBehavior = CDockManager::FollowApplicationPalette;
 	bool RestoringState = false;
 	QVector<CFloatingDockContainer*> UninitializedFloatingWidgets;
 	CDockFocusController* FocusController = nullptr;
@@ -129,6 +131,7 @@ struct DockManagerPrivate
 	QSize ToolBarIconSizeFloating = QSize(24, 24);
 	CDockWidget::DockWidgetFeatures LockedDockWidgetFeatures;
 	QSharedPointer<ads::CDockComponentsFactory> ComponentFactory {ads::CDockComponentsFactory::factory()};
+	bool CurrentStylesheetDark;
 
 	/**
 	 * Private data constructor
@@ -215,6 +218,12 @@ void DockManagerPrivate::loadStylesheet()
 #if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
     FileName += "_linux";
 #endif
+    if (_this->isDesiredStylesheetDark()) {
+        CurrentStylesheetDark = true;
+        FileName += "_dark";
+    }
+    else
+        CurrentStylesheetDark = false;
     FileName += ".css";
 	QFile StyleSheetFile(FileName);
 	StyleSheetFile.open(QIODevice::ReadOnly);
@@ -650,9 +659,9 @@ void CDockManager::setComponentsFactory(QSharedPointer<ads::CDockComponentsFacto
 
 
 //============================================================================
-#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
 bool CDockManager::eventFilter(QObject *obj, QEvent *e)
 {
+#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
 	// Emulate Qt:Tool behaviour.
 	// Required because on some WMs Tool windows can't be maximized.
 
@@ -725,12 +734,7 @@ bool CDockManager::eventFilter(QObject *obj, QEvent *e)
 			QApplication::setActiveWindow(window());
 		}
 	}
-	return Super::eventFilter(obj, e);
-}
 #else
-//============================================================================
-bool CDockManager::eventFilter(QObject *obj, QEvent *e)
-{
 	if (e->type() == QEvent::WindowStateChange)
 	{
 		QWindowStateChangeEvent* ev = static_cast<QWindowStateChangeEvent*>(e);
@@ -740,9 +744,15 @@ bool CDockManager::eventFilter(QObject *obj, QEvent *e)
 			QMetaObject::invokeMethod(this, "endLeavingMinimizedState", Qt::QueuedConnection);
 		}
 	}
+#endif
+	if (e->type() == QEvent::ApplicationPaletteChange && d->StylesheetColorSchemeBehavior == CDockManager::FollowApplicationPalette)
+	{
+		if (d->CurrentStylesheetDark != isDesiredStylesheetDark()) {
+			d->loadStylesheet();
+		}
+	}
 	return Super::eventFilter(obj, e);
 }
-#endif
 
 
 //============================================================================
@@ -1261,6 +1271,18 @@ void CDockManager::setViewMenuInsertionOrder(eViewMenuInsertionOrder Order)
 }
 
 
+//============================================================================
+void CDockManager::setStylesheetColorSchemeBehavior(eStylesheetColorSchemeBehavior Behavior)
+{
+	d->StylesheetColorSchemeBehavior = Behavior;
+
+	if (d->CurrentStylesheetDark != isDesiredStylesheetDark()) {
+		d->loadStylesheet();
+		ensurePolished();
+	}
+}
+
+
 //===========================================================================
 bool CDockManager::isRestoringState() const
 {
@@ -1571,6 +1593,28 @@ void CDockManager::raise()
 }
 
 
+//============================================================================
+bool CDockManager::isApplicationPaletteDark()
+{
+    QPalette appPalette = QGuiApplication::palette();
+
+    // Extract the background and foreground colors
+    QColor windowColor = appPalette.color(QPalette::Window);
+    QColor textColor = appPalette.color(QPalette::WindowText);
+
+    // Check lightness values (0.0 = black, 1.0 = white)
+    // If text is lighter than the background, the app palette is dark
+    return textColor.lightnessF() > windowColor.lightnessF();
+}
+
+
+//============================================================================
+bool CDockManager::isDesiredStylesheetDark()
+{
+    return ((isApplicationPaletteDark() && d->StylesheetColorSchemeBehavior == FollowApplicationPalette) || d->StylesheetColorSchemeBehavior == ForceDark);
+}
+
+
 } // namespace ads
 
 //---------------------------------------------------------------------------

src/DockManager.h

@@ -179,6 +179,13 @@ public Q_SLOTS:
 		MenuAlphabeticallySorted
 	};
 
+	enum eStylesheetColorSchemeBehavior
+	{
+		ForceLight,
+		ForceDark,
+		FollowApplicationPalette
+	};
+
 	/**
 	 * These global configuration flags configure some global dock manager
 	 * settings.
@@ -397,6 +404,16 @@ public Q_SLOTS:
 	 */
 	static CIconProvider& iconProvider();
 
+	/**
+	 * Returns if current application palette is dark
+	 */
+	static bool isApplicationPaletteDark();
+
+	/**
+	 * Returns if currently applied stylesheet is supposed to be dark
+	 */
+	bool isDesiredStylesheetDark();
+
 	/**
 	 * Adds dockwidget into the given area.
 	 * If DockAreaWidget is not null, then the area parameter indicates the area
@@ -617,6 +634,17 @@ public Q_SLOTS:
 	 */
 	void setViewMenuInsertionOrder(eViewMenuInsertionOrder Order);
 
+	/**
+	 * Define the behavior of stylesheet color scheme selection.
+	 * The stylesheet can be fixed to either light or dark scheme,
+	 * or it can follow the current application palette (default).
+	 * Note: The fixed settings implement legacy behavior (before
+	 * dark scheme was implemented) including problems like missing
+	 * palette change propagation. They are implemented solely
+	 * for compatibility reasons and manual stylesheet switching.
+	 */
+	void setStylesheetColorSchemeBehavior(eStylesheetColorSchemeBehavior Behavior);
+
 	/**
 	 * This function returns true between the restoringState() and
 	 * stateRestored() signals.

src/DockOverlay.cpp

@@ -129,7 +129,14 @@ struct DockOverlayCrossPrivate
 			 break;
 
 		case CDockOverlayCross::ArrowColor: return pal.color(QPalette::Active, QPalette::Base);
-		case CDockOverlayCross::ShadowColor: return QColor(0, 0, 0, 64);
+		case CDockOverlayCross::ShadowColor:
+			 {
+				 QColor Color = pal.color(QPalette::Active, QPalette::Text);
+				 Color.setAlpha(64);
+				 return Color;
+			 }
+			 break;
+
 		default:
 			return QColor();
 		}
@@ -146,7 +153,6 @@ struct DockOverlayCrossPrivate
 		if (!Color.isValid())
 		{
 			Color = defaultIconColor(ColorIndex);
-			IconColors[ColorIndex] = Color;
 		}
 		return Color;
 	}
@@ -907,6 +913,20 @@ void CDockOverlayCross::showEvent(QShowEvent*)
 }
 
 
+//============================================================================
+bool CDockOverlayCross::event(QEvent *e)
+{
+	bool Result = QWidget::event(e);
+
+	if (e->type() == QEvent::ApplicationPaletteChange)
+	{
+		d->UpdateRequired = true;
+	}
+
+	return Result;
+}
+
+
 //============================================================================
 void CDockOverlayCross::updatePosition()
 {

src/DockOverlay.h

@@ -273,6 +273,7 @@ class CDockOverlayCross : public QWidget
 
 protected:
 	virtual void showEvent(QShowEvent* e) override;
+	virtual bool event(QEvent* e) override;
 	void setAreaWidgets(const QHash<DockWidgetArea, QWidget*>& widgets);
 }; // CDockOverlayCross
 

src/ads.qrc

@@ -23,5 +23,28 @@
         <file>images/minimize-button.svg</file>
         <file>images/minimize-button-focused.svg</file>
         <file>images/vs-pin-button-disabled.svg</file>
+        <file>stylesheets/default_dark.css</file>
+        <file>images/close-button_dark.svg</file>
+        <file>images/pin-button_dark.svg</file>
+        <file>images/close-button-disabled_dark.svg</file>
+        <file>stylesheets/default_linux_dark.css</file>
+        <file>images/close-button-focused_dark.svg</file>
+        <file>stylesheets/focus_highlighting_dark.css</file>
+        <file>stylesheets/focus_highlighting_linux_dark.css</file>
+        <file>images/tabs-menu-button_dark.svg</file>
+        <file>images/detach-button_dark.svg</file>
+        <file>images/detach-button-disabled_dark.svg</file>
+        <file>images/maximize-button_dark.svg</file>
+        <file>images/maximize-button-focused_dark.svg</file>
+        <file>images/restore-button_dark.svg</file>
+        <file>images/restore-button-focused_dark.svg</file>
+        <file>images/vs-pin-button_dark.svg</file>
+        <file>images/vs-pin-button-pinned_dark.svg</file>
+        <file>images/vs-pin-button-pinned-focused_dark.svg</file>
+        <file>images/vs-pin-button_45_dark.svg</file>
+        <file>images/pin-button-big_dark.svg</file>
+        <file>images/minimize-button_dark.svg</file>
+        <file>images/minimize-button-focused_dark.svg</file>
+        <file>images/vs-pin-button-disabled_dark.svg</file>
     </qresource>
 </RCC>