Added showcase section to README.md

Added setMinimumSizeHintMode() test in demo MainWindow

README.md

@@ -48,6 +48,9 @@ of his docking system project.
     - [KDDockWidgets](#kddockwidgets)
     - [QtitanDocking](#qtitandocking)
   - [Donation](#donation)
+  - [Showcase](#showcase)
+    - [Qt Design Studio](#qt-design-studio)
+    - [QmixElements](#qmixelements)
 
 ### Docking everywhere - no central widget
 
@@ -273,3 +276,21 @@ If this project help you reduce time to develop or if you just like it, you can
 <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=85R64TMMSY9T6">
   <img src="doc/donate.png" alt="Donate with PayPal" width="160"/>
 </a>
+
+## Showcase
+
+### [Qt Design Studio](https://www.qt.io/ui-design-tools)
+
+Taken from the [Qt Blog](https://www.qt.io/blog/qt-design-studio-1.5-beta-released):
+
+> The most obvious change in [Qt Design Studio 1.5](https://www.qt.io/blog/qt-design-studio-1.5-beta-released) is the integration of dock widgets using the Qt Advanced Docking System. This allows the user to fully customize the workspace and also to undock any view into its own top level window. This especially improves the usability when using multiple screens.
+
+![Qt Design Studio](doc/qt_design_studio.png)
+
+### [QmixElements](https://www.cetoni.com/products/qmixelements/)
+
+The QmixElements software from [CETONI](https://www.cetoni.com) is a comprehensive, 
+plugin-based and modular laboratory automation software for controlling CETONI devices using a joint graphical user interface. The software features a powerful script system to automate processes. This [blog post](https://www.cetoni.com/blog/qmixelements-advanced-docking-system/) gives a nice overview about the use of the Qt
+Advanced Docking System in the QmixElements sofware.
+
+![QmixElements](doc/qmix_elements.png)

demo/MainWindow.cpp

@@ -224,11 +224,27 @@ static ads::CDockWidget* createEditorWidget(QMenu* ViewMenu)
 }
 
 
+//===========================================================================
+/**
+ * Custom QTableWidget with a minimum size hint to test CDockWidget
+ * setMinimumSizeHintMode() function of CDockWidget
+ */
+class CMinSizeTableWidget : public QTableWidget
+{
+public:
+	using QTableWidget::QTableWidget;
+	virtual QSize minimumSizeHint() const override
+	{
+		return QSize(300, 100);
+	}
+};
+
+
 //============================================================================
 static ads::CDockWidget* createTableWidget(QMenu* ViewMenu)
 {
 	static int TableCount = 0;
-	QTableWidget* w = new QTableWidget();
+	auto w = new CMinSizeTableWidget();
 	ads::CDockWidget* DockWidget = new ads::CDockWidget(QString("Table %1").arg(TableCount++));
 	static int colCount = 5;
 	static int rowCount = 30;
@@ -244,6 +260,7 @@ static ads::CDockWidget* createTableWidget(QMenu* ViewMenu)
 	}
 	DockWidget->setWidget(w);
 	DockWidget->setIcon(svgIcon(":/adsdemo/images/grid_on.svg"));
+	DockWidget->setMinimumSizeHintMode(ads::CDockWidget::MinimumSizeHintFromContent);
 	ViewMenu->addAction(DockWidget->toggleViewAction());
 	return DockWidget;
 }
@@ -488,7 +505,7 @@ CMainWindow::CMainWindow(QWidget *parent) :
 
     // uncomment the following line if you want to use opaque undocking and
 	// opaque splitter resizing
-    //CDockManager::setConfigFlags(CDockManager::DefaultOpaqueConfig);
+    // CDockManager::setConfigFlags(CDockManager::DefaultOpaqueConfig);
 
     // uncomment the following line if you want a fixed tab width that does
 	// not change if the visibility of the close button changes

sip/DockWidget.sip

@@ -50,6 +50,12 @@ public:
 		ForceScrollArea,
 		ForceNoScrollArea
 	};
+	
+    enum eMinimumSizeHintMode
+    {
+    	MinimumSizeHintFromDockWidget,
+    	MinimumSizeHintFromContent
+    };
 
 	enum eToggleViewActionMode
 	{
@@ -76,6 +82,7 @@ public:
 	bool isClosed() const;
 	QAction* toggleViewAction() const;
 	void setToggleViewActionMode(ads::CDockWidget::eToggleViewActionMode Mode);
+	void setMinimumSizeHintMode(ads::CDockWidget::eMinimumSizeHintMode Mode);
 	void setIcon(const QIcon& Icon);
 	QIcon icon() const;
 	QToolBar* toolBar() const;

src/DockAreaWidget.cpp

@@ -247,6 +247,7 @@ struct DockAreaWidgetPrivate
 	CDockManager*		DockManager		= nullptr;
 	bool UpdateTitleBarButtons = false;
 	DockWidgetAreas		AllowedAreas	= AllDockAreas;
+	QSize MinSizeHint;
 
 	/**
 	 * Private data constructor
@@ -303,6 +304,20 @@ struct DockAreaWidgetPrivate
 	 * Udpates the enable state of the close and detach button
 	 */
 	void updateTitleBarButtonStates();
+
+	/**
+	 * Scans all contained dock widgets for the max. minimum size hint
+	 */
+	void updateMinimumSizeHint()
+	{
+		MinSizeHint = QSize();
+		for (int i = 0; i < ContentsLayout->count(); ++i)
+		{
+			auto Widget = ContentsLayout->widget(i);
+			MinSizeHint.setHeight(qMax(MinSizeHint.height(), Widget->minimumSizeHint().height()));
+			MinSizeHint.setWidth(qMax(MinSizeHint.width(), Widget->minimumSizeHint().width()));
+		}
+	}
 };
 // struct DockAreaWidgetPrivate
 
@@ -407,6 +422,8 @@ void CDockAreaWidget::insertDockWidget(int index, CDockWidget* DockWidget,
 	d->tabBar()->blockSignals(false);
 	TabWidget->setVisible(!DockWidget->isClosed());
 	DockWidget->setProperty(INDEX_PROPERTY, index);
+	d->MinSizeHint.setHeight(qMax(d->MinSizeHint.height(), DockWidget->minimumSizeHint().height()));
+	d->MinSizeHint.setWidth(qMax(d->MinSizeHint.width(), DockWidget->minimumSizeHint().width()));
 	if (Activate)
 	{
 		setCurrentIndex(index);
@@ -447,6 +464,7 @@ void CDockAreaWidget::removeDockWidget(CDockWidget* DockWidget)
 
 	d->updateTitleBarButtonStates();
 	updateTitleBarVisibility();
+	d->updateMinimumSizeHint();
 	auto TopLevelDockWidget = DockContainer->topLevelDockWidget();
 	if (TopLevelDockWidget)
 	{
@@ -863,6 +881,13 @@ CDockAreaTitleBar* CDockAreaWidget::titleBar() const
 {
 	return d->TitleBar;
 }
+
+
+//============================================================================
+QSize CDockAreaWidget::minimumSizeHint() const
+{
+	return d->MinSizeHint.isValid() ? d->MinSizeHint : Super::minimumSizeHint();
+}
 } // namespace ads
 
 //---------------------------------------------------------------------------

src/DockAreaWidget.h

@@ -164,6 +164,13 @@ public:
 	 */
 	CDockContainerWidget* dockContainer() const;
 
+    /**
+     * Returns the largest minimumSizeHint() of the dock widgets in this
+     * area.
+     * The minimum size hint is updated if a dock widget is removed or added.
+     */
+    virtual QSize minimumSizeHint() const override;
+
 	/**
 	 * Returns the rectangle of the title area
 	 */

src/DockManager.h

@@ -30,18 +30,11 @@
 //============================================================================
 //                                   INCLUDES
 //============================================================================
-#include <ads_globals.h>
-#include <DockContainerWidget.h>
-#include <DockWidget.h>
-#include <FloatingDockContainer.h>
-#include <qbytearray.h>
-#include <qflags.h>
-#include <qlist.h>
-#include <qmap.h>
-#include <qobjectdefs.h>
-#include <qstring.h>
-#include <qstringlist.h>
-#include <QtGui/qicon.h>
+#include "ads_globals.h"
+#include "DockContainerWidget.h"
+#include "DockWidget.h"
+#include "FloatingDockContainer.h"
+
 
 class QSettings;
 class QMenu;

src/DockWidget.cpp

@@ -82,6 +82,7 @@ struct DockWidgetPrivate
 	QSize ToolBarIconSizeFloating = QSize(24, 24);
 	bool IsFloatingTopLevel = false;
 	QList<QAction*> TitleBarActions;
+	CDockWidget::eMinimumSizeHintMode MinimumSizeHintMode = CDockWidget::MinimumSizeHintFromDockWidget;
 
 	/**
 	 * Private data constructor
@@ -424,6 +425,13 @@ void CDockWidget::setToggleViewActionMode(eToggleViewActionMode Mode)
 }
 
 
+//============================================================================
+void CDockWidget::setMinimumSizeHintMode(eMinimumSizeHintMode Mode)
+{
+	d->MinimumSizeHintMode = Mode;
+}
+
+
 //============================================================================
 void CDockWidget::toggleView(bool Open)
 {
@@ -753,7 +761,14 @@ void CDockWidget::setClosedState(bool Closed)
 //============================================================================
 QSize CDockWidget::minimumSizeHint() const
 {
-	return QSize(60, 40);
+	if (d->MinimumSizeHintMode == CDockWidget::MinimumSizeHintFromDockWidget || !d->Widget)
+	{
+		return QSize(60, 40);
+	}
+	else
+	{
+		return d->Widget->minimumSizeHint();
+	}
 }
 
 

src/DockWidget.h

@@ -189,6 +189,23 @@ public:
         ForceNoScrollArea
     };
 
+
+    /**
+     * The mode of the minimumSizeHint() that is returned by the DockWidget
+     * minimumSizeHint() function.
+     * To ensure, that a dock widget does not block resizing, the dock widget
+     * reimplements minimumSizeHint() function to return a very small minimum
+     * size hint. If you would like to adhere the minimumSizeHint() from the
+     * content widget, the set the minimumSizeHintMode() to
+     * MinimumSizeHintFromContent.
+     */
+    enum eMinimumSizeHintMode
+    {
+    	MinimumSizeHintFromDockWidget,
+    	MinimumSizeHintFromContent
+    };
+
+
     /**
      * This mode configures the behavior of the toggle view action.
      * If the mode if ActionModeToggle, then the toggle view action is
@@ -225,7 +242,8 @@ public:
     virtual ~CDockWidget();
 
     /**
-     * We return a fixed minimum size hint for all dock widgets
+     * We return a fixed minimum size hint or the size hint of the content
+     * widget if minimum size hint mode is MinimumSizeHintFromContent
      */
     virtual QSize minimumSizeHint() const override;
 
@@ -334,6 +352,13 @@ public:
      */
     void setToggleViewActionMode(eToggleViewActionMode Mode);
 
+    /**
+     * Configures the minimum size hint that is returned by the
+     * minimumSizeHint() function.
+     * \see eMinimumSizeHintMode for a detailed description
+     */
+    void setMinimumSizeHintMode(eMinimumSizeHintMode Mode);
+
     /**
      * Sets the dock widget icon that is shown in tabs and in toggle view
      * actions

src/FloatingDockContainer.cpp

@@ -38,6 +38,7 @@
 #include <QDebug>
 #include <QAbstractButton>
 #include <QElapsedTimer>
+#include <QTime>
 
 #include "DockContainerWidget.h"
 #include "DockAreaWidget.h"
@@ -66,6 +67,7 @@ struct FloatingDockContainerPrivate
 	QPoint DragStartMousePosition;
 	CDockContainerWidget *DropContainer = nullptr;
 	CDockAreaWidget *SingleDockArea = nullptr;
+	QPoint DragStartPos;
 #ifdef Q_OS_LINUX
     QWidget* MouseEventHandler = nullptr;
     CFloatingWidgetTitleBar* TitleBar = nullptr;
@@ -109,6 +111,10 @@ struct FloatingDockContainerPrivate
 #endif
 	}
 
+	/**
+	 * Reflect the current dock widget title in the floating widget windowTitle()
+	 * depending on the CDockManager::FloatingContainerHasWidgetTitle flag
+	 */
 	void reflectCurrentWidget(CDockWidget* CurrentWidget)
 	{
 		// reflect CurrentWidget's title if configured to do so, otherwise display application name as window title
@@ -133,6 +139,11 @@ struct FloatingDockContainerPrivate
 			_this->setWindowIcon(QApplication::windowIcon());
 		}
 	}
+
+	/**
+	 * Handles escape key press when dragging around the floating widget
+	 */
+	void handleEscapeKey();
 };
 // struct FloatingDockContainerPrivate
 
@@ -264,6 +275,17 @@ void FloatingDockContainerPrivate::updateDropOverlays(const QPoint &GlobalPos)
 	}
 }
 
+
+//============================================================================
+void FloatingDockContainerPrivate::handleEscapeKey()
+{
+	ADS_PRINT("FloatingDockContainerPrivate::handleEscapeKey()");
+	setState(DraggingInactive);
+	DockManager->containerOverlay()->hideOverlay();
+	DockManager->dockAreaOverlay()->hideOverlay();
+}
+
+
 //============================================================================
 CFloatingDockContainer::CFloatingDockContainer(CDockManager *DockManager) :
 	tFloatingWidgetBase(DockManager),
@@ -363,6 +385,9 @@ void CFloatingDockContainer::moveEvent(QMoveEvent *event)
 	switch (d->DraggingState)
 	{
 	case DraggingMousePressed:
+#ifdef Q_OS_WIN
+		qApp->installEventFilter(this);
+#endif
 		d->setState(DraggingFloatingWidget);
 		d->updateDropOverlays(QCursor::pos());
 		break;
@@ -380,6 +405,8 @@ void CFloatingDockContainer::moveEvent(QMoveEvent *event)
 	default:
 		break;
 	}
+
+
 }
 
 //============================================================================
@@ -443,6 +470,7 @@ void CFloatingDockContainer::showEvent(QShowEvent *event)
 	Super::showEvent(event);
 }
 
+
 //============================================================================
 bool CFloatingDockContainer::event(QEvent *e)
 {
@@ -458,21 +486,17 @@ bool CFloatingDockContainer::event(QEvent *e)
 		// It is really great to work around the whole NonClientMouseArea
 		// bugs
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 2))
-		if (e->type()
-		    == QEvent::NonClientAreaMouseButtonPress /*&& QGuiApplication::mouseButtons().testFlag(Qt::LeftButton)*/)
-		{
-			ADS_PRINT("FloatingWidget::event Event::NonClientAreaMouseButtonPress" << e->type());
-			d->setState(DraggingMousePressed);
-		}
+		if (e->type() == QEvent::NonClientAreaMouseButtonPress /*&& QGuiApplication::mouseButtons().testFlag(Qt::LeftButton)*/)
 #else
 		if (e->type() == QEvent::NonClientAreaMouseButtonPress && QGuiApplication::mouseButtons().testFlag(Qt::LeftButton))
+#endif
 		{
-            ADS_PRINT("FloatingWidget::event Event::NonClientAreaMouseButtonPress" << e->type());
+			ADS_PRINT("FloatingWidget::event Event::NonClientAreaMouseButtonPress" << e->type());
+			d->DragStartPos = pos();
 			d->setState(DraggingMousePressed);
 		}
-#endif
 	}
-		break;
+	break;
 
 	case DraggingMousePressed:
 		switch (e->type())
@@ -515,12 +539,49 @@ bool CFloatingDockContainer::event(QEvent *e)
 	}
 
 #if (ADS_DEBUG_LEVEL > 0)
-	qDebug() << "CFloatingDockContainer::event " << e->type();
+	qDebug() << QTime::currentTime() << "CFloatingDockContainer::event " << e->type();
 #endif
 	return QWidget::event(e);
 }
 
 
+//============================================================================
+bool CFloatingDockContainer::eventFilter(QObject *watched, QEvent *e)
+{
+	Q_UNUSED(watched);
+	// I have not found a way to detect non client area key press events to
+	// handle escape key presses. On Windows, if the escape key is pressed while
+	// dragging around a widget, the widget position is reset to its start position
+	// which in turn generates a QEvent::NonClientAreaMouseButtonRelease event
+	// if the mouse is outside of the widget after the move to its initial position
+	// or a QEvent::MouseButtonRelease event, if the mouse is inside of teh widget
+	// after the position has been reset.
+	// So we can install an event filter on the application to get these events
+	// here to properly cancel dragging and hide the overlays.
+	// If we are in DraggingFloatingWidget state, it means the widget
+	// has been dragged already but if the position is the same like
+	// the start position, then this is an indication that the escape
+	// key has been pressed.
+	if (e->type() == QEvent::MouseButtonRelease || e->type() == QEvent::NonClientAreaMouseButtonRelease)
+	{
+		ADS_PRINT("CFloatingDockContainer::eventFilter QEvent::MouseButtonRelease or"
+			"QEvent::NonClientAreaMouseButtonRelease" << "d->DragggingState " << d->DraggingState);
+		qApp->removeEventFilter(this);
+		if (d->DragStartPos == pos())
+		{
+			d->handleEscapeKey();
+			return true;
+		}
+		return false;
+	}
+
+#if (ADS_DEBUG_LEVEL > 0)
+	qDebug() << QTime::currentTime() << "CFloatingDockContainer::eventFilter " << e->type();
+#endif
+	return false;
+}
+
+
 //============================================================================
 void CFloatingDockContainer::startFloating(const QPoint &DragStartMousePos,
     const QSize &Size, eDragState DragState, QWidget *MouseEventHandler)

src/FloatingDockContainer.h

@@ -180,6 +180,7 @@ protected: // reimplements QWidget
 	virtual void closeEvent(QCloseEvent *event) override;
 	virtual void hideEvent(QHideEvent *event) override;
 	virtual void showEvent(QShowEvent *event) override;
+	virtual bool eventFilter(QObject *watched, QEvent *event) override;
 
 public:
 	using Super = QWidget;