while dockManager.removeDockWidget , the dockManager() returns null (#399)

This adds a `addDockWidgetToContainer()` method to `CDockManager`, which allows a dock widget to be registered with the dock manager, and added to a specific container, even if that container doesn't currently have any `DockAreaWidget`s.

This is pretty much just a clone of `addDockWidget()`, but with the ability to specify a container widget instead of a dock area.

CMakeLists.txt

@@ -1,20 +1,41 @@
 cmake_minimum_required(VERSION 3.5)
-set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules ${CMAKE_MODULE_PATH})
-include(GetGitRevisionDescription)
-git_describe(GitTagVersion --tags)
-string(REGEX REPLACE "^([0-9]+)\\..*" "\\1" VERSION_MAJOR "${GitTagVersion}")
-string(REGEX REPLACE "^[0-9]+\\.([0-9]+).*" "\\1" VERSION_MINOR "${GitTagVersion}")
-string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" VERSION_PATCH "${GitTagVersion}")
-set(VERSION_SHORT "${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}")
+
+# By default, the version information is extracted from the git index. However,
+# we can override this behavior by explicitly setting ADS_VERSION and
+# skipping the git checks. This is useful for cases where this project is being
+# used independently of its original git repo (e.g. vendored in another project)
+if(NOT ADS_VERSION)
+    set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules ${CMAKE_MODULE_PATH})
+    include(GetGitRevisionDescription)
+    git_describe(GitTagVersion --tags)
+    string(REGEX REPLACE "^([0-9]+)\\..*" "\\1" VERSION_MAJOR "${GitTagVersion}")
+    string(REGEX REPLACE "^[0-9]+\\.([0-9]+).*" "\\1" VERSION_MINOR "${GitTagVersion}")
+    string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" VERSION_PATCH "${GitTagVersion}")
+    set(VERSION_SHORT "${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}")
+else()
+    string(REGEX MATCHALL "[\.]" VERSION_DOT_MATCHES ${ADS_VERSION})
+    list(LENGTH VERSION_DOT_MATCHES VERSION_DOT_COUNT)
+    if(VERSION_DOT_COUNT EQUAL 2)
+        set(VERSION_SHORT ${ADS_VERSION})
+    else()
+        message(FATAL_ERROR "ADS_VERSION must be in major.minor.patch format, e.g. 3.8.1. Got ${ADS_VERSION}")
+    endif()
+endif()
+
+
 project(QtADS LANGUAGES CXX VERSION ${VERSION_SHORT})
+
 option(BUILD_STATIC "Build the static library" OFF)
 option(BUILD_EXAMPLES "Build the examples" ON)
+
 if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "4")
     set(ads_PlatformDir "x86")
 else()
     set(ads_PlatformDir "x64")
 endif()
+
 add_subdirectory(src)
+
 if(BUILD_EXAMPLES)
     add_subdirectory(examples)
     add_subdirectory(demo)

README.md

@@ -15,13 +15,20 @@ integrated development environments (IDEs) such as Visual Studio.
 
 ## New and Noteworthy
 
-The [release 3.7](https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System/releases/tag/3.7.0)
+The [release 3.8](https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System/releases/tag/3.8.1)
+adds the following features:
+
+- option to close tabs with the middle mouse button
+- `DeleteContentOnClose` flag for dynamic deletion and creation of dock widget
+  content
+
+The [release 3.7](https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System/releases/tag/3.7.2)
 adds the following features:
 
 - support for **Qt6.**
 - support for [empty dock area](doc/user-guide.md#empty-dock-area)
 
-The [release 3.6](https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System/releases/tag/3.6.0)
+The [release 3.6](https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System/releases/tag/3.6.3)
 adds some nice new features:
 
 - support for [central widget](doc/user-guide.md#central-widget) concept
@@ -82,6 +89,8 @@ know it from Visual Studio.
   - [D-Tect X](#d-tect-x)
   - [HiveWE](#hivewe)
   - [Ramses Composer](#ramses-composer)
+  - [Plot Juggler](#plot-juggler)
+  - [Notepad Next](#notepad-next)
 
 ### Docking everywhere - no central widget
 
@@ -363,13 +372,13 @@ Taken from the [Qt Blog](https://www.qt.io/blog/qt-design-studio-1.5-beta-releas
 
 [![Qt Design Studio](doc/showcase_qt_design_studio_video.png)](https://youtu.be/za9KBWcFXEw?t=84)
 
-### [QmixElements](https://www.cetoni.com/products/qmixelements/)
+### [CETONI Elements](https://www.cetoni.com/products/qmixelements/)
 
-The QmixElements software from [CETONI](https://www.cetoni.com) is a comprehensive, 
+The CETONI Elements 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.
+Advanced Docking System in the CETONI Elements sofware.
 
-![QmixElements](doc/showcase_qmix_elements.png)
+![CETONI_Elements](doc/showcase_qmix_elements.png)
 
 ### [ezEditor](https://github.com/ezEngine/ezEngine)
 
@@ -413,3 +422,32 @@ and digital portfolio.
 [learn more...](https://github.com/GENIVI/ramses-composer)
 
 ![RamsesComposer](doc/showcase_ramses_composer.png)
+
+### [Plot Juggler](https://github.com/facontidavide/PlotJuggler)
+
+PlotJuggler is a fast, powerful and intuitive tool to visualize time series.
+It makes it easy to visualize data but also to analyze it. You can manipulate
+your time series using a simple and extendable Transform Editor. Some of the
+highlights are:
+
+- Simple Drag & Drop user interface.
+- Load data from file.
+- Connect to live streaming of data.
+- Save the visualization layout and configurations to re-use them later.
+- Fast OpenGL visualization.
+- Can handle thousands of timeseries and millions of data points.
+- Transform your data using a simple editor: derivative, moving average, integral, etc…
+- PlotJuggler can be easily extended using plugins.
+
+[read more...](https://github.com/facontidavide/PlotJuggler)
+
+[![Plot Juggler](doc/showcase_plot_juggler.png)](https://vimeo.com/480588113#t=46s)
+
+### [Notepad Next](https://github.com/dail8859/NotepadNext)
+
+Notepad Next is a cross-platform reimplementation of Notepad++ that uses the 
+Advanced Docking System to arrange the open source files on the screen.
+
+[learn more...](https://github.com/dail8859/NotepadNext)
+
+![NotepadNext](doc/showcase_notepad_next.png)

demo/MainWindow.cpp

@@ -466,6 +466,15 @@ void MainWindowPrivate::createContent()
     Action = ui.menuTests->addAction(QString("Raise %1").arg(DockWidget->windowTitle()));
     DockWidget->connect(Action, SIGNAL(triggered()), SLOT(raise()));
 
+    // Test hidden floating dock widget
+    DockWidget = createLongTextLabelDockWidget();
+    DockManager->addDockWidgetFloating(DockWidget);
+    DockWidget->toggleView(false);
+
+    // Test visible floating dock widget
+    DockWidget = createCalendarDockWidget();
+    DockManager->addDockWidgetFloating(DockWidget);
+
 
 #ifdef Q_OS_WIN
 #if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))

doc/user-guide.md

@@ -27,6 +27,17 @@
   - [`EqualSplitOnInsertion`](#equalsplitoninsertion)
   - [`FloatingContainerForceNativeTitleBar` (Linux only)](#floatingcontainerforcenativetitlebar-linux-only)
   - [`FloatingContainerForceQWidgetTitleBar` (Linux only)](#floatingcontainerforceqwidgettitlebar-linux-only)
+  - [`MiddleMouseButtonClosesTab`](#middlemousebuttonclosestab)
+- [DockWidget Feature Flags](#dockwidget-feature-flags)
+  - [`DockWidgetClosable`](#dockwidgetclosable)
+  - [`DockWidgetMovable`](#dockwidgetmovable)
+  - [`DockWidgetFloatable`](#dockwidgetfloatable)
+  - [`DockWidgetDeleteOnClose`](#dockwidgetdeleteonclose)
+  - [`CustomCloseHandling`](#customclosehandling)
+  - [`DockWidgetFocusable`](#dockwidgetfocusable)
+  - [`DockWidgetForceCloseWithArea`](#dockwidgetforceclosewitharea)
+  - [`NoTab`](#notab)
+  - [`DeleteContentOnClose`](#deletecontentonclose)
 - [Central Widget](#central-widget)
 - [Empty Dock Area](#empty-dock-area)
 - [Custom Close Handling](#custom-close-handling)
@@ -464,6 +475,69 @@ If you would like to overwrite autodetection, then you can activate this flag
 to force QWidget based title bars. You can overwrite autodetection and this
 flag, if you set the environment variable `ADS_UseNativeTitle` to 0 or 1.
 
+### `MiddleMouseButtonClosesTab`
+
+If the flag is set, the user can use the mouse middle button to close the tab
+under the mouse. So you do not need to exactly hit the tab close button to
+close tab. Just click with the middle mouse button on a tab like this is
+possible in various web browsers.
+
+![MiddleMouseButtonClosesTab true](cfg_flag_MiddleMouseButtonClosesTab.gif)
+
+## DockWidget Feature Flags
+
+### `DockWidgetClosable`
+
+If set, the dock widget will have a close button.
+
+### `DockWidgetMovable`
+
+If a dock widget is movable, then it and can be moved to a new position in the
+current dock container. Disable this flag to prevent moving of a dock widget
+via mouse. If the `OpaqueUndocking` configuration flag is set, then dock widgets
+are immediately undocked into floating widgets. That means, moving is only
+possible in this case, if the dock widget is also floatable (feature flag
+`DockWidgetFloatable` is set).
+
+### `DockWidgetFloatable`
+
+If set, a dock widget can be dragged into a floating window.
+
+### `DockWidgetDeleteOnClose`
+
+Deletes the dock widget and its content when it is closed.
+
+### `CustomCloseHandling`
+
+Clicking the close button will not close the dock widget but emits the
+`closeRequested()` signal instead. This allows the application to implement
+a custom close handling.
+
+### `DockWidgetFocusable`
+
+If this is enabled, a dock widget can get focus highlighting.
+
+### `DockWidgetForceCloseWithArea`
+
+A dock widget will be closed when the dock area hosting it is closed. If the
+`DockWidgetDeleteOnClose` feature is enabled for a dock widget, then it will
+be deleted, if the user clicks the close button of this dock widget. If the
+user clicks the close button of the dock area that contains this widget,
+then only the visibility of the dock widget is toggled. If this feature flag
+is set, the closing the dock area also closes the dock widget. That means, if
+the dock widget feature `DockWidgetDeleteOnClose` is set for the dock widgets
+in a dock area, then all dock widgets will be deleted if the dock area is closed.
+
+### `NoTab`
+
+A dock widget tab will never be shown if this flag is set.
+
+### `DeleteContentOnClose`
+
+Deletes only the contained widget on close, keeping the dock widget intact and
+in place. Attempts to rebuild the contents widget on show if there is a widget
+factory set. See [issue #365](https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System/pull/365) for more details.
+
 ## Central Widget
 
 The Advanced Docking System has been developed to overcome the limitations of

examples/CMakeLists.txt

@@ -1,6 +1,7 @@
 cmake_minimum_required(VERSION 3.5)
 project(QtADSExamples LANGUAGES CXX VERSION ${VERSION_SHORT})
 add_subdirectory(simple)
+add_subdirectory(hideshow)
 add_subdirectory(sidebar)
 add_subdirectory(deleteonclose)
 add_subdirectory(centralwidget)

examples/examples.pro

@@ -3,6 +3,7 @@ TEMPLATE = subdirs
 SUBDIRS = \
     centralwidget \
 	simple \
+	hideshow \
 	sidebar \
 	deleteonclose \
 	emptydockarea \

examples/hideshow/CMakeLists.txt

@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 3.5)
+project(ads_example_hideshow VERSION ${VERSION_SHORT}) 
+find_package(QT NAMES Qt6 Qt5 COMPONENTS Core REQUIRED)
+find_package(Qt${QT_VERSION_MAJOR} 5.5 COMPONENTS Core Gui Widgets REQUIRED)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+add_executable(HideShowExample WIN32 
+    main.cpp
+    MainWindow.cpp
+    MainWindow.ui
+)
+target_include_directories(HideShowExample PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/../../src")
+target_link_libraries(HideShowExample PRIVATE qtadvanceddocking)
+target_link_libraries(HideShowExample PUBLIC Qt${QT_VERSION_MAJOR}::Core 
+                                             Qt${QT_VERSION_MAJOR}::Gui 
+                                             Qt${QT_VERSION_MAJOR}::Widgets)
+set_target_properties(HideShowExample PROPERTIES 
+    AUTOMOC ON
+    AUTORCC ON
+    AUTOUIC ON
+    CXX_STANDARD 14
+    CXX_STANDARD_REQUIRED ON
+    CXX_EXTENSIONS OFF
+    VERSION ${VERSION_SHORT}
+    EXPORT_NAME "Qt Advanced Docking System Hide,Show Example"
+    ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${ads_PlatformDir}/lib"
+    LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${ads_PlatformDir}/lib"
+    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${ads_PlatformDir}/bin"
+)

examples/hideshow/MainWindow.cpp

@@ -0,0 +1,78 @@
+#include "../../examples/hideshow/MainWindow.h"
+
+#include "ui_MainWindow.h"
+
+#include <QLabel>
+#include <QPushButton>
+
+MainWindow::MainWindow(QWidget *parent) :
+    QMainWindow(parent),
+    ui(new Ui::MainWindow)
+{
+    ui->setupUi(this);
+
+    ui->centralWidget->setLayout( m_layout = new QStackedLayout() );
+
+    m_welcomeWidget = new QWidget(this);
+    auto welcomeLayout = new QVBoxLayout(m_welcomeWidget);
+    welcomeLayout->addStretch();
+    QPushButton* openButton = new QPushButton("Open project");
+    welcomeLayout->addWidget( openButton );
+    welcomeLayout->addStretch();
+
+    connect( openButton, SIGNAL(clicked()), this, SLOT(openProject()) );
+
+    m_DockManager = new ads::CDockManager(ui->centralWidget);
+
+    // Create example content label - this can be any application specific
+	// widget
+	QLabel* l = new QLabel();
+	l->setWordWrap(true);
+	l->setAlignment(Qt::AlignTop | Qt::AlignLeft);
+	l->setText("Lorem ipsum dolor sit amet, consectetuer adipiscing elit. ");
+
+	// Create a dock widget with the title Label 1 and set the created label
+	// as the dock widget content
+	ads::CDockWidget* DockWidget = new ads::CDockWidget("Label 1");
+	DockWidget->setWidget(l);
+
+	// Add the toggleViewAction of the dock widget to the menu to give
+	// the user the possibility to show the dock widget if it has been closed
+	ui->menuView->addAction(DockWidget->toggleViewAction());
+
+    connect( ui->actionOpen, SIGNAL(triggered()), this, SLOT(openProject()) );
+    connect( ui->actionClose, SIGNAL(triggered()), this, SLOT(closeProject()) );
+
+	// Add the dock widget to the top dock widget area
+	m_DockManager->addDockWidget(ads::TopDockWidgetArea, DockWidget);
+
+    ui->centralWidget->layout()->addWidget( m_welcomeWidget );
+    ui->centralWidget->layout()->addWidget( m_DockManager );
+
+    closeProject();
+}
+
+MainWindow::~MainWindow()
+{
+    delete ui;
+}
+
+void MainWindow::openProject()
+{
+    ui->actionOpen->setEnabled(false);
+    ui->actionClose->setEnabled(true);
+    ui->menuView->setEnabled(true);
+
+    m_layout->setCurrentWidget( m_DockManager );
+}
+
+void MainWindow::closeProject()
+{
+    ui->actionOpen->setEnabled(true);
+    ui->actionClose->setEnabled(false);
+    ui->menuView->setEnabled(false);
+
+    m_DockManager->hideManagerAndFloatingWidgets();
+    m_layout->setCurrentWidget( m_welcomeWidget );
+}
+

examples/hideshow/MainWindow.h

@@ -0,0 +1,33 @@
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QStackedLayout>
+#include "DockManager.h"
+
+QT_BEGIN_NAMESPACE
+namespace Ui {
+class MainWindow;
+}
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    explicit MainWindow(QWidget *parent = 0);
+    ~MainWindow();
+
+private slots:
+    void openProject();
+    void closeProject();
+
+private:
+    Ui::MainWindow *ui;
+    QWidget* m_welcomeWidget;
+    ads::CDockManager* m_DockManager;
+    QStackedLayout* m_layout;
+};
+
+#endif // MAINWINDOW_H

examples/hideshow/MainWindow.ui

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralWidget"/>
+  <widget class="QMenuBar" name="menuBar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>400</width>
+     <height>26</height>
+    </rect>
+   </property>
+   <widget class="QMenu" name="menuView">
+    <property name="title">
+     <string>View</string>
+    </property>
+   </widget>
+   <widget class="QMenu" name="menuFile">
+    <property name="title">
+     <string>File</string>
+    </property>
+    <addaction name="actionOpen"/>
+    <addaction name="actionClose"/>
+   </widget>
+   <addaction name="menuFile"/>
+   <addaction name="menuView"/>
+  </widget>
+  <widget class="QStatusBar" name="statusBar"/>
+  <action name="actionOpen">
+   <property name="text">
+    <string>Open project</string>
+   </property>
+  </action>
+  <action name="actionClose">
+   <property name="text">
+    <string>Close project</string>
+   </property>
+  </action>
+ </widget>
+ <layoutdefault spacing="6" margin="11"/>
+ <resources/>
+ <connections/>
+</ui>

examples/hideshow/hideshow.pro

@@ -0,0 +1,31 @@
+ADS_OUT_ROOT = $${OUT_PWD}/../..
+
+QT += core gui widgets
+
+TARGET = HideShowExample
+DESTDIR = $${ADS_OUT_ROOT}/lib
+TEMPLATE = app
+CONFIG += c++14
+CONFIG += debug_and_release
+adsBuildStatic {
+    DEFINES += ADS_STATIC
+}
+
+DEFINES += QT_DEPRECATED_WARNINGS
+
+SOURCES += \
+        main.cpp \
+        MainWindow.cpp
+
+HEADERS += \
+        MainWindow.h
+
+FORMS += \
+        MainWindow.ui
+        
+
+LIBS += -L$${ADS_OUT_ROOT}/lib
+include(../../ads.pri)
+INCLUDEPATH += ../../src
+DEPENDPATH += ../../src    
+

examples/hideshow/main.cpp

@@ -0,0 +1,11 @@
+#include <QApplication>
+#include "../../examples/hideshow/MainWindow.h"
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    MainWindow w;
+    w.show();
+
+    return a.exec();
+}

src/DockAreaWidget.h

@@ -367,7 +367,8 @@ Q_SIGNALS:
 	 */
 	void viewToggled(bool Open);
 }; // class DockAreaWidget
-}
- // namespace ads
+} // namespace ads
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(ads::CDockAreaWidget::DockAreaFlags)
 //-----------------------------------------------------------------------------
 #endif // DockAreaWidgetH

src/DockContainerWidget.cpp

@@ -1286,7 +1286,7 @@ CDockContainerWidget::CDockContainerWidget(CDockManager* DockManager, QWidget *p
 	d->isFloating = floatingWidget() != nullptr;
 
 	d->Layout = new QGridLayout();
-	d->Layout->setContentsMargins(0, 1, 0, 1);
+	d->Layout->setContentsMargins(0, 0, 0, 0);
 	d->Layout->setSpacing(0);
 	setLayout(d->Layout);
 
@@ -1625,6 +1625,21 @@ QList<CDockAreaWidget*> CDockContainerWidget::openedDockAreas() const
 }
 
 
+//============================================================================
+bool CDockContainerWidget::hasOpenDockAreas() const
+{
+	for (auto DockArea : d->DockAreas)
+	{
+		if (!DockArea->isHidden())
+		{
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
 //============================================================================
 void CDockContainerWidget::saveState(QXmlStreamWriter& s) const
 {
@@ -1680,7 +1695,10 @@ bool CDockContainerWidget::restoreState(CDockingStateReader& s, bool Testing)
 		if (!Testing)
 		{
 			CFloatingDockContainer* FloatingWidget = floatingWidget();
-			FloatingWidget->restoreGeometry(Geometry);
+			if (FloatingWidget)
+			{
+				FloatingWidget->restoreGeometry(Geometry);
+			}
 		}
 	}
 

src/DockContainerWidget.h

@@ -216,6 +216,13 @@ public:
 	 */
 	QList<CDockAreaWidget*> openedDockAreas() const;
 
+	/**
+	 * This function returns true, if the container has open dock areas.
+	 * This functions is a little bit faster than calling openedDockAreas().isEmpty()
+	 * because it returns as soon as it finds an open dock area
+	 */
+	bool hasOpenDockAreas() const;
+
     /**
      * This function returns true if this dock area has only one single
      * visible dock widget.

src/DockFocusController.cpp

@@ -32,6 +32,8 @@
 
 namespace ads
 {
+static const char* const FocusedDockWidgetProperty = "FocusedDockWidget";
+
 /**
  * Private data class of CDockFocusController class (pimpl)
  */
@@ -57,8 +59,8 @@ struct DockFocusControllerPrivate
 	 * the dock area that it belongs to
 	 */
 	void updateDockWidgetFocus(CDockWidget* DockWidget);
-};
-// struct DockFocusControllerPrivate
+}; // struct DockFocusControllerPrivate
+
 
 
 //===========================================================================
@@ -125,7 +127,7 @@ void DockFocusControllerPrivate::updateDockWidgetFocus(CDockWidget* DockWidget)
 
 	if (Window)
 	{
-		Window->setProperty("FocusedDockWidget", QVariant::fromValue<CDockWidget*>(DockWidget));
+        Window->setProperty(FocusedDockWidgetProperty, QVariant::fromValue(QPointer<CDockWidget>(DockWidget)));
 	}
 	CDockAreaWidget* NewFocusedDockArea = nullptr;
 	if (FocusedDockWidget)
@@ -161,7 +163,7 @@ void DockFocusControllerPrivate::updateDockWidgetFocus(CDockWidget* DockWidget)
 
     if (NewFloatingWidget)
     {
-    	NewFloatingWidget->setProperty("FocusedDockWidget", QVariant::fromValue(DockWidget));
+        NewFloatingWidget->setProperty(FocusedDockWidgetProperty, QVariant::fromValue(QPointer<CDockWidget>(DockWidget)));
     }
 
 
@@ -243,13 +245,13 @@ void CDockFocusController::onFocusWindowChanged(QWindow *focusWindow)
 		return;
 	}
 
-	auto vDockWidget = focusWindow->property("FocusedDockWidget");
+    auto vDockWidget = focusWindow->property(FocusedDockWidgetProperty);
 	if (!vDockWidget.isValid())
 	{
 		return;
 	}
 
-	auto DockWidget = vDockWidget.value<CDockWidget*>();
+    auto DockWidget = vDockWidget.value<QPointer<CDockWidget>>();
 	if (!DockWidget)
 	{
 		return;
@@ -376,13 +378,13 @@ void CDockFocusController::notifyFloatingWidgetDrop(CFloatingDockContainer* Floa
 		return;
 	}
 
-	auto vDockWidget = FloatingWidget->property("FocusedDockWidget");
+    auto vDockWidget = FloatingWidget->property(FocusedDockWidgetProperty);
 	if (!vDockWidget.isValid())
 	{
 		return;
 	}
 
-	auto DockWidget = vDockWidget.value<CDockWidget*>();
+    auto DockWidget = vDockWidget.value<QPointer<CDockWidget>>();
 	if (DockWidget)
 	{
 		DockWidget->dockAreaWidget()->setCurrentDockWidget(DockWidget);

src/DockManager.cpp

@@ -98,6 +98,7 @@ struct DockManagerPrivate
 {
 	CDockManager* _this;
 	QList<CFloatingDockContainer*> FloatingWidgets;
+	QList<CFloatingDockContainer*> HiddenFloatingWidgets;
 	QList<CDockContainerWidget*> Containers;
 	CDockOverlay* ContainerOverlay;
 	CDockOverlay* DockAreaOverlay;
@@ -755,6 +756,9 @@ CFloatingDockContainer* CDockManager::addDockWidgetFloating(CDockWidget* Dockwid
 void CDockManager::showEvent(QShowEvent *event)
 {
 	Super::showEvent(event);
+
+	// Fix Issue #380
+	restoreHiddenFloatingWidgets();
 	if (d->UninitializedFloatingWidgets.empty())
 	{
 		return;
@@ -762,12 +766,52 @@ void CDockManager::showEvent(QShowEvent *event)
 
 	for (auto FloatingWidget : d->UninitializedFloatingWidgets)
 	{
-		FloatingWidget->show();
+		// Check, if someone closed a floating dock widget before the dock
+		// manager is shown
+		if (FloatingWidget->dockContainer()->hasOpenDockAreas())
+		{
+			FloatingWidget->show();
+		}
 	}
 	d->UninitializedFloatingWidgets.clear();
 }
 
 
+//============================================================================
+void CDockManager::restoreHiddenFloatingWidgets()
+{
+	if (d->HiddenFloatingWidgets.isEmpty())
+	{
+		return;
+	}
+
+	// Restore floating widgets that were hidden upon hideManagerAndFloatingWidgets
+	for (auto FloatingWidget : d->HiddenFloatingWidgets)
+	{
+		bool hasDockWidgetVisible = false;
+
+		// Needed to prevent CFloatingDockContainer being shown empty
+		// Could make sense to move this to CFloatingDockContainer::showEvent(QShowEvent *event)
+		// if experiencing CFloatingDockContainer being shown empty in other situations, but let's keep
+		// it here for now to make sure changes to fix Issue #380 does not impact existing behaviours
+		for (auto dockWidget : FloatingWidget->dockWidgets())
+		{
+			if (dockWidget->toggleViewAction()->isChecked())
+			{
+				dockWidget->toggleView(true);
+				hasDockWidgetVisible = true;
+			}
+		}
+
+		if (hasDockWidgetVisible)
+		{
+			FloatingWidget->show();
+		}
+	}
+
+	d->HiddenFloatingWidgets.clear();
+}
+
 //============================================================================
 CDockAreaWidget* CDockManager::addDockWidget(DockWidgetArea area,
 	CDockWidget* Dockwidget, CDockAreaWidget* DockAreaWidget)
@@ -779,6 +823,16 @@ CDockAreaWidget* CDockManager::addDockWidget(DockWidgetArea area,
 	return AreaOfAddedDockWidget;
 }
 
+//============================================================================
+CDockAreaWidget* CDockManager::addDockWidgetToContainer(DockWidgetArea area,
+	CDockWidget* Dockwidget, CDockContainerWidget* DockContainerWidget)
+{
+	d->DockWidgetsMap.insert(Dockwidget->objectName(), Dockwidget);
+	auto AreaOfAddedDockWidget = DockContainerWidget->addDockWidget(area, Dockwidget);
+	Q_EMIT dockWidgetAdded(Dockwidget);
+	return AreaOfAddedDockWidget;
+}
+
 
 //============================================================================
 CDockAreaWidget* CDockManager::addDockWidgetTab(DockWidgetArea area,
@@ -1097,6 +1151,38 @@ void CDockManager::setDockWidgetFocused(CDockWidget* DockWidget)
 	}
 }
 
+//===========================================================================
+void CDockManager::hideManagerAndFloatingWidgets()
+{
+	hide();
+
+	d->HiddenFloatingWidgets.clear();
+	// Hide updates of floating widgets from user
+	for (auto FloatingWidget : d->FloatingWidgets)
+	{
+		if ( FloatingWidget->isVisible() )
+		{
+			QList<CDockWidget*> VisibleWidgets;
+			for ( auto dockWidget : FloatingWidget->dockWidgets() )
+			{
+				if ( dockWidget->toggleViewAction()->isChecked() )
+					VisibleWidgets.push_back( dockWidget );
+			}
+
+			// save as floating widget to be shown when CDockManager will be shown back
+			d->HiddenFloatingWidgets.push_back( FloatingWidget );
+			FloatingWidget->hide();
+
+			// hidding floating widget automatically marked contained CDockWidgets as hidden
+			// but they must remain marked as visible as we want them to be restored visible
+			// when CDockManager will be shown back
+			for ( auto dockWidget : VisibleWidgets )
+			{
+				dockWidget->toggleViewAction()->setChecked(true);
+			}
+		}
+		}
+}
 
 //===========================================================================
 CDockWidget* CDockManager::focusedDockWidget() const

src/DockManager.h

@@ -147,6 +147,11 @@ protected:
 	 */
 	CDockFocusController* dockFocusController() const;
 
+    /**
+     * Restore floating widgets hidden by an earlier call to hideManagerAndFloatingWidgets.
+     */
+    void restoreHiddenFloatingWidgets();
+
 public:
 	using Super = CDockContainerWidget;
 
@@ -278,6 +283,15 @@ public:
 	CDockAreaWidget* addDockWidget(DockWidgetArea area, CDockWidget* Dockwidget,
 		CDockAreaWidget* DockAreaWidget = nullptr);
 
+	/**
+	 * Adds dockwidget into the given container.
+	 * This allows you to place the dock widget into a container, even if that
+	 * container does not yet contain a DockAreaWidget.
+	 * \return Returns the dock area widget that contains the new DockWidget
+	 */
+	CDockAreaWidget* addDockWidgetToContainer(DockWidgetArea area, CDockWidget* Dockwidget,
+		CDockContainerWidget* DockContainerWidget);
+
 	/**
 	 * This function will add the given Dockwidget to the given dock area as
 	 * a new tab.
@@ -527,6 +541,12 @@ public Q_SLOTS:
 	 */
 	void setDockWidgetFocused(CDockWidget* DockWidget);
 
+    /**
+     * hide CDockManager and all floating widgets (See Issue #380). Calling regular QWidget::hide()
+     * hides the CDockManager but not the floating widgets;
+     */
+    void hideManagerAndFloatingWidgets();
+
 Q_SIGNALS:
 	/**
 	 * This signal is emitted if the list of perspectives changed.
@@ -617,5 +637,7 @@ Q_SIGNALS:
     void focusedDockWidgetChanged(ads::CDockWidget* old, ads::CDockWidget* now);
 }; // class DockManager
 } // namespace ads
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(ads::CDockManager::ConfigFlags)
 //-----------------------------------------------------------------------------
 #endif // DockManagerH

src/DockWidget.cpp

@@ -893,7 +893,10 @@ void CDockWidget::setFloating()
 //============================================================================
 void CDockWidget::deleteDockWidget()
 {
-	dockManager()->removeDockWidget(this);
+	auto manager=dockManager();
+	if(manager){
+		manager->removeDockWidget(this);
+	}
 	deleteLater();
 	d->Closed = true;
 }

src/DockWidget.h

@@ -600,7 +600,8 @@ Q_SIGNALS:
      */
     void featuresChanged(ads::CDockWidget::DockWidgetFeatures features);
 }; // class DockWidget
-}
- // namespace ads
+} // namespace ads
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(ads::CDockWidget::DockWidgetFeatures)
 //-----------------------------------------------------------------------------
 #endif // DockWidgetH

src/DockWidgetTab.cpp

@@ -407,7 +407,7 @@ void CDockWidgetTab::mouseReleaseEvent(QMouseEvent* ev)
 	} 
 	else if (ev->button() == Qt::MiddleButton)
 	{
-		if (CDockManager::testConfigFlag(CDockManager::MiddleMouseButtonClosesTab))
+		if (CDockManager::testConfigFlag(CDockManager::MiddleMouseButtonClosesTab) && d->DockWidget->features().testFlag(CDockWidget::DockWidgetClosable))
 		{
 			// Only attempt to close if the mouse is still
 			// on top of the widget, to allow the user to cancel.

src/ElidingLabel.cpp

@@ -163,8 +163,8 @@ void CElidingLabel::resizeEvent(QResizeEvent *event)
 //============================================================================
 QSize CElidingLabel::minimumSizeHint() const
 {
-#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
-    bool HasPixmap = !pixmap().isNull();
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+    bool HasPixmap = !pixmap(Qt::ReturnByValue).isNull();
 #else
     bool HasPixmap = (pixmap() != nullptr);
 #endif
@@ -185,8 +185,8 @@ QSize CElidingLabel::minimumSizeHint() const
 //============================================================================
 QSize CElidingLabel::sizeHint() const
 {
-#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
-    bool HasPixmap = !pixmap().isNull();
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+    bool HasPixmap = !pixmap(Qt::ReturnByValue).isNull();
 #else
     bool HasPixmap = (pixmap() != nullptr);
 #endif

src/ads_globals.h

@@ -308,5 +308,6 @@ void repolishStyle(QWidget* w, eRepolishChildOptions Options = RepolishIgnoreChi
 } // namespace internal
 } // namespace ads
 
+Q_DECLARE_OPERATORS_FOR_FLAGS(ads::DockWidgetAreas)
 //---------------------------------------------------------------------------
 #endif // ads_globalsH

src/stylesheets/default.css

@@ -4,6 +4,9 @@
 ads--CDockContainerWidget {
 	background: palette(dark);
 }
+ads--CDockContainerWidget > QSplitter{
+        padding: 1 0 1 0;
+}
 
 ads--CDockContainerWidget ads--CDockSplitter::handle {
 	background: palette(dark);
@@ -90,4 +93,4 @@ QScrollArea#dockWidgetScrollArea {
 	qproperty-icon: url(:/ads/images/detach-button.svg),
 		url(:/ads/images/detach-button-disabled.svg) disabled;
 	qproperty-iconSize: 16px;	
-}
+}

src/stylesheets/default_linux.css

@@ -4,6 +4,9 @@
 ads--CDockContainerWidget {
 	background: palette(dark);
 }
+ads--CDockContainerWidget > QSplitter{
+        padding: 1 0 1 0;
+}
 
 ads--CDockContainerWidget ads--CDockSplitter::handle {
 	background: palette(dark);

src/stylesheets/focus_highlighting.css

@@ -4,6 +4,9 @@
 ads--CDockContainerWidget {
 	background: palette(dark);
 }
+ads--CDockContainerWidget > QSplitter{
+        padding: 1 0 1 0;
+}
 
 ads--CDockAreaWidget {
 	background: palette(window);
@@ -123,4 +126,4 @@ ads--CDockAreaWidget[focused="true"] ads--CDockAreaTitleBar {
 	background: transparent;
 	border-bottom: 2px solid palette(highlight);
 	padding-bottom: 0px;
-}
+}

src/stylesheets/focus_highlighting_linux.css

@@ -4,6 +4,10 @@
 ads--CDockContainerWidget {
         background: palette(dark);
 }
+ads--CDockContainerWidget > QSplitter{
+        padding: 1 0 1 0;
+}
+
 
 ads--CDockContainerWidget ads--CDockSplitter::handle {
         background: palette(dark);