Improved transparent docking

demo/MainWindow.cpp

@@ -322,7 +322,9 @@ CMainWindow::CMainWindow(QWidget *parent) :
 
 	// uncomment the following line if you wand a fixed tab width that does
 	// not change if the visibility of the close button changes
-	CDockManager::setConfigFlag(CDockManager::OpaqueUndocking, false);
+	//CDockManager::setConfigFlag(CDockManager::OpaqueUndocking, false);
+	//CDockManager::setConfigFlag(CDockManager::DragPreviewIsDynamic, false);
+	CDockManager::setConfigFlags(CDockManager::NonOpaqueWithWindowFrame);
 
 	// Now create the dock manager and its content
 	d->DockManager = new CDockManager(this);

src/DockManager.h

@@ -152,12 +152,24 @@ public:
 		TabCloseButtonIsToolButton = 0x0040,//! If enabled the tab close buttons will be QToolButtons instead of QPushButtons - disabled by default
 		AllTabsHaveCloseButton = 0x0080, //!< if this flag is set, then all tabs that are closable show a close button
 		RetainTabSizeWhenCloseButtonHidden = 0x0100, //!< if this flag is set, the space for the close button is reserved even if the close button is not visible
-		OpaqueUndocking = 0x0200,
+		OpaqueUndocking = 0x0200,///< If enabled, the widgets are immediately undocked into floating widgets, if disabled, only a draw preview is undocked and the real undocking is deferred until the mouse is released
+		DragPreviewIsDynamic = 0x0400,///< If opaque undocking is disabled, this flag defines the behavior of the drag preview window, if this flag is enabled, the preview will be adjusted dynamically to the drop area
+		DragPreviewShowsContentPixmap = 0x0800,///< If opaque undocking is disabled, the created drag preview window shows a copy of the content of the dock widget / dock are that is dragged
+		DragPreviewHasWindowFrame = 0x1000,///< If opaque undocking is disabled, then this flag configures if the drag preview is frameless or looks like a real window
 		DefaultConfig = ActiveTabHasCloseButton
 		              | DockAreaHasCloseButton
 		              | OpaqueSplitterResize
 		              | XmlCompressionEnabled
 		              | OpaqueUndocking, ///< the default configuration
+		DefaultNonOpaqueConfig = ActiveTabHasCloseButton
+		              | DockAreaHasCloseButton
+		              | XmlCompressionEnabled
+		              | DragPreviewShowsContentPixmap, ///< the default configuration for non opaque operations
+		NonOpaqueWithWindowFrame = ActiveTabHasCloseButton
+		              | DockAreaHasCloseButton
+		              | XmlCompressionEnabled
+		              | DragPreviewShowsContentPixmap
+		              | DragPreviewHasWindowFrame ///< the default configuration for non opaque operations that show a real window with frame
 	};
 	Q_DECLARE_FLAGS(ConfigFlags, eConfigFlag)
 

src/FloatingOverlay.cpp

@@ -40,6 +40,7 @@ struct FloatingOverlayPrivate
 	qreal WindowOpacity;
 	bool Hidden = false;
 	bool IgnoreMouseEvents = false;
+	QPixmap ContentPreviewPixmap;
 
 
 	/**
@@ -99,7 +100,10 @@ void FloatingOverlayPrivate::updateDropOverlays(const QPoint &GlobalPos)
 	{
 		ContainerOverlay->hideOverlay();
 		DockAreaOverlay->hideOverlay();
+		if (CDockManager::configFlags().testFlag(CDockManager::DragPreviewIsDynamic))
+		{
 			setHidden(false);
+		}
 		return;
 	}
 
@@ -140,7 +144,10 @@ void FloatingOverlayPrivate::updateDropOverlays(const QPoint &GlobalPos)
 		}
 	}
 
+	if (CDockManager::configFlags().testFlag(CDockManager::DragPreviewIsDynamic))
+	{
 		setHidden(DockDropArea != InvalidDockWidgetArea || ContainerDropArea != InvalidDockWidgetArea);
+	}
 }
 
 
@@ -153,21 +160,37 @@ FloatingOverlayPrivate::FloatingOverlayPrivate(CFloatingOverlay *_public) :
 
 //============================================================================
 CFloatingOverlay::CFloatingOverlay(QWidget* Content, QWidget* parent) :
-	QFrame(parent),
+	QWidget(parent),
 	d(new FloatingOverlayPrivate(this))
 {
 	d->Content = Content;
 	setAttribute(Qt::WA_DeleteOnClose);
-
+	if (CDockManager::configFlags().testFlag(CDockManager::DragPreviewHasWindowFrame))
+	{
+		setWindowFlags(
+			Qt::Window | Qt::WindowMaximizeButtonHint | Qt::WindowCloseButtonHint);
+	}
+	else
+	{
 		setWindowFlags(Qt::Tool | Qt::FramelessWindowHint);
-	setWindowOpacity(1);
-	setWindowTitle("FloatingOverlay");
 		setAttribute(Qt::WA_NoSystemBackground);
 		setAttribute(Qt::WA_TranslucentBackground);
+	}
+
+	setWindowOpacity(0.6);
 	// We install an event filter to detect mouse release events because we
 	// do not receive mouse release event if the floating widget is behind
 	// the drop overlay cross
 	qApp->installEventFilter(this);
+
+	// Create a static image of the widget that should get undocked
+	// This is like some kind preview image like it is uses in drag and drop
+	// operations
+	if (CDockManager::configFlags().testFlag(CDockManager::DragPreviewShowsContentPixmap))
+	{
+		d->ContentPreviewPixmap = QPixmap(Content->size());
+		Content->render(&d->ContentPreviewPixmap);
+	}
 }
 
 
@@ -181,6 +204,7 @@ CFloatingOverlay::CFloatingOverlay(CDockWidget* Content)
 		d->ContentSourceArea = Content->dockAreaWidget();
 		d->ContenSourceContainer = Content->dockContainer();
 	}
+	setWindowTitle(Content->windowTitle());
 }
 
 
@@ -191,6 +215,7 @@ CFloatingOverlay::CFloatingOverlay(CDockAreaWidget* Content)
 	d->DockManager = Content->dockManager();
 	d->ContentSourceArea = Content;
 	d->ContenSourceContainer = Content->dockContainer();
+	setWindowTitle(Content->currentDockWidget()->windowTitle());
 }
 
 
@@ -241,7 +266,6 @@ bool CFloatingOverlay::eventFilter(QObject *watched, QEvent *event)
 	if (event->type() == QEvent::MouseButtonRelease && !d->IgnoreMouseEvents)
 	{
 		ADS_PRINT("FloatingWidget::eventFilter QEvent::MouseButtonRelease");
-		std::cout << "CFloatingOverlay::eventFilter QEvent::MouseButtonRelease" << std::endl;
 
 		auto DockDropArea = d->DockManager->dockAreaOverlay()->dropAreaUnderCursor();
 		auto ContainerDropArea = d->DockManager->containerOverlay()->dropAreaUnderCursor();
@@ -265,16 +289,22 @@ bool CFloatingOverlay::eventFilter(QObject *watched, QEvent *event)
 			}
 			FloatingWidget->setGeometry(this->geometry());
 			FloatingWidget->show();
+			if (!CDockManager::configFlags().testFlag(CDockManager::DragPreviewHasWindowFrame))
+			{
 				QApplication::processEvents();
 				int FrameHeight = FloatingWidget->frameGeometry().height() - FloatingWidget->geometry().height();
 				QRect FixedGeometry = this->geometry();
 				FixedGeometry.adjust(0, FrameHeight, 0, 0);
 				FloatingWidget->setGeometry(FixedGeometry);
 			}
+		}
 
 		this->close();
 		d->DockManager->containerOverlay()->hideOverlay();
 		d->DockManager->dockAreaOverlay()->hideOverlay();
+		// Because we use the event filter, we receive multiple mouse release
+		// events. To prevent multiple code execution, we ignore all mouse
+		// events after the first mouse event
 		d->IgnoreMouseEvents = true;
 	}
 
@@ -286,14 +316,19 @@ bool CFloatingOverlay::eventFilter(QObject *watched, QEvent *event)
 void CFloatingOverlay::paintEvent(QPaintEvent* event)
 {
 	Q_UNUSED(event);
-
 	if (d->Hidden)
 	{
 		return;
 	}
 
-	QRect r = rect();
 	QPainter painter(this);
+	if (CDockManager::configFlags().testFlag(CDockManager::DragPreviewShowsContentPixmap))
+	{
+		painter.drawPixmap(QPoint(0, 0), d->ContentPreviewPixmap);
+	}
+
+	if (!CDockManager::configFlags().testFlag(CDockManager::DragPreviewHasWindowFrame))
+	{
 		QColor Color = palette().color(QPalette::Active, QPalette::Highlight);
 		QPen Pen = painter.pen();
 		Pen.setColor(Color.darker(120));
@@ -304,7 +339,8 @@ void CFloatingOverlay::paintEvent(QPaintEvent* event)
 		Color = Color.lighter(130);
 		Color.setAlpha(64);
 		painter.setBrush(Color);
-	painter.drawRect(r.adjusted(0, 0, -1, -1));
+		painter.drawRect(rect().adjusted(0, 0, -1, -1));
+	}
 }
 
 

src/FloatingOverlay.h

@@ -10,7 +10,7 @@
 //============================================================================
 //                                   INCLUDES
 //============================================================================
-#include <QFrame>
+#include <QWidget>
 #include "FloatingDockContainer.h"
 
 namespace ads
@@ -23,7 +23,7 @@ struct FloatingOverlayPrivate;
  * A floating overlay is a temporary floating widget that is just used to
  * indicate the floating widget movement
  */
-class CFloatingOverlay : public QFrame, public IFloatingWidget
+class CFloatingOverlay : public QWidget, public IFloatingWidget
 {
 private:
 	FloatingOverlayPrivate* d;
@@ -40,7 +40,7 @@ protected:
 	CFloatingOverlay(QWidget* Content, QWidget* parent);
 
 public:
-	using Super = QRubberBand;
+	using Super = QWidget;
 	CFloatingOverlay(CDockWidget* Content);
 	CFloatingOverlay(CDockAreaWidget* Content);