Add open auto-hide dock on hover from drag and drop (#663)

doc/user-guide.md

@@ -49,6 +49,7 @@
   - [`AutoHideCloseButtonCollapsesDock`](#autohideclosebuttoncollapsesdock)
   - [`AutoHideHasCloseButton`](#autohidehasclosebutton)
   - [`AutoHideHasMinimizeButton`](#autohidehasminimizebutton)
+  - [`AutoHideOpenOnDragHover`](#autohideopenondraghover)
 - [DockWidget Feature Flags](#dockwidget-feature-flags)
   - [`DockWidgetClosable`](#dockwidgetclosable)
   - [`DockWidgetMovable`](#dockwidgetmovable)
@@ -704,6 +705,15 @@ If this flag is set (disabled by default), then each auto hide widget has a mini
 
 ![AutoHideHasMinimizeButton](cfg_flag_AutoHideHasMinimizeButton.png)
 
+
+### `AutoHideOpenOnDragHover`
+
+If this flag is set (disabled by default), then holding a dragging cursor hover an auto-hide collapsed dock's tab will open said dock:
+
+![AutoHideOpenOnDragHover](cfg_flag_AutoHideOpenOnDragHover.gif)
+
+Said dock must be set to accept drops to hide when cursor leaves its scope.
+
 ## DockWidget Feature Flags
 
 ### `DockWidgetClosable`

src/AutoHideDockContainer.h

@@ -18,7 +18,6 @@
 ** License along with this library; If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
 
-
 //============================================================================
 /// \file   AutoHideDockContainer.h
 /// \author Syarif Fakhri
@@ -29,10 +28,10 @@
 //============================================================================
 //                                   INCLUDES
 //============================================================================
-#include "ads_globals.h"
-
 #include <QSplitter>
+
 #include "AutoHideTab.h"
+#include "ads_globals.h"
 
 QT_FORWARD_DECLARE_CLASS(QXmlStreamWriter)
 
@@ -52,151 +51,153 @@ struct SideTabBarPrivate;
  */
 class ADS_EXPORT CAutoHideDockContainer : public QFrame
 {
-	Q_OBJECT
+    Q_OBJECT
     Q_PROPERTY(int sideBarLocation READ sideBarLocation)
 private:
-	AutoHideDockContainerPrivate* d; ///< private data (pimpl)
-	friend struct AutoHideDockContainerPrivate;
-	friend CAutoHideSideBar;
-	friend SideTabBarPrivate;
+    AutoHideDockContainerPrivate* d;  ///< private data (pimpl)
+    friend struct AutoHideDockContainerPrivate;
+    friend CAutoHideSideBar;
+    friend SideTabBarPrivate;
 
 protected:
-	virtual bool eventFilter(QObject* watched, QEvent* event) override;
-	virtual void resizeEvent(QResizeEvent* event) override;
-	virtual void leaveEvent(QEvent *event) override;
-	virtual bool event(QEvent* event) override;
+    virtual bool eventFilter(QObject* watched, QEvent* event) override;
+    virtual void resizeEvent(QResizeEvent* event) override;
+    virtual void leaveEvent(QEvent* event) override;
+    virtual bool event(QEvent* event) override;
+    virtual void dragLeaveEvent(QDragLeaveEvent* ev) override;
 
-	/**
-	 * Updates the size considering the size limits and the resize margins
-	 */
-	void updateSize();
+    /**
+     * Updates the size considering the size limits and the resize margins
+     */
+    void updateSize();
 
-	/*
-	 * Saves the state and size
-	 */
-	void saveState(QXmlStreamWriter& Stream);
+    /*
+     * Saves the state and size
+     */
+    void saveState(QXmlStreamWriter& Stream);
 
 public:
-	using Super = QFrame;
+    using Super = QFrame;
 
     /**
-	 * Create Auto Hide widget with the given dock widget
-	 */
-	CAutoHideDockContainer(CDockWidget* DockWidget, SideBarLocation area,
-		CDockContainerWidget* parent);
-
-	/**
-	 * Virtual Destructor
-	 */
-	virtual ~CAutoHideDockContainer();
-
-	/**
-	 * Gets the side tab bar
-	 */
-	CAutoHideSideBar* autoHideSideBar() const;
-
-	/**
-	 * Returns the side tab
-	 */
-	CAutoHideTab* autoHideTab() const;
-
-	/**
-	 * Gets the dock widget in this dock container
-	 */
-	CDockWidget* dockWidget() const;
-
-	/**
-	 * Returns the index of this container in the sidebar
-	 */
-	int tabIndex() const;
-
-	/**
-	 * Adds a dock widget and removes the previous dock widget
-	 */
-	void addDockWidget(CDockWidget* DockWidget);
+     * Create Auto Hide widget with the given dock widget
+     */
+    CAutoHideDockContainer(CDockWidget* DockWidget, SideBarLocation area,
+                           CDockContainerWidget* parent);
 
     /**
-	 * Returns the side tab bar area of this Auto Hide dock container
-	 */
-	SideBarLocation sideBarLocation() const;
+     * Virtual Destructor
+     */
+    virtual ~CAutoHideDockContainer();
 
-	/**
-	 * Sets a new SideBarLocation.
-	 * If a new side bar location is set, the auto hide dock container needs
-	 * to update its resize handle position
-	 */
-	void setSideBarLocation(SideBarLocation SideBarLocation);
+    /**
+     * Gets the side tab bar
+     */
+    CAutoHideSideBar* autoHideSideBar() const;
 
-	/**
-	 * Returns the dock area widget of this Auto Hide dock container
-	 */
-	CDockAreaWidget* dockAreaWidget() const;
+    /**
+     * Returns the side tab
+     */
+    CAutoHideTab* autoHideTab() const;
 
-	/**
-	 * Returns the parent container that hosts this auto hide container
-	 */
-	CDockContainerWidget* dockContainer() const;
+    /**
+     * Gets the dock widget in this dock container
+     */
+    CDockWidget* dockWidget() const;
 
-	/**
-	 * Moves the contents to the parent container widget
-	 * Used before removing this Auto Hide dock container 
-	 */
+    /**
+     * Returns the index of this container in the sidebar
+     */
+    int tabIndex() const;
+
+    /**
+     * Adds a dock widget and removes the previous dock widget
+     */
+    void addDockWidget(CDockWidget* DockWidget);
+
+    /**
+     * Returns the side tab bar area of this Auto Hide dock container
+     */
+    SideBarLocation sideBarLocation() const;
+
+    /**
+     * Sets a new SideBarLocation.
+     * If a new side bar location is set, the auto hide dock container needs
+     * to update its resize handle position
+     */
+    void setSideBarLocation(SideBarLocation SideBarLocation);
+
+    /**
+     * Returns the dock area widget of this Auto Hide dock container
+     */
+    CDockAreaWidget* dockAreaWidget() const;
+
+    /**
+     * Returns the parent container that hosts this auto hide container
+     */
+    CDockContainerWidget* dockContainer() const;
+
+    /**
+     * Moves the contents to the parent container widget
+     * Used before removing this Auto Hide dock container
+     */
     void moveContentsToParent();
 
-	/**
-	 * Cleanups up the side tab widget and then deletes itself
-	 */
-	void cleanupAndDelete();
+    /**
+     * Cleanups up the side tab widget and then deletes itself
+     */
+    void cleanupAndDelete();
 
-	/*
-	 * Toggles the auto Hide dock container widget
-	 * This will also hide the side tab widget
-	 */
-	void toggleView(bool Enable);
+    /*
+     * Toggles the auto Hide dock container widget
+     * This will also hide the side tab widget
+     */
+    void toggleView(bool Enable);
 
-	/*
-	 * Collapses the auto hide dock container widget
-	 * Does not hide the side tab widget
-	 */
-	void collapseView(bool Enable);
+    /*
+     * Collapses the auto hide dock container widget
+     * Does not hide the side tab widget
+     */
+    void collapseView(bool Enable);
 
-	/**
-	 * Toggles the current collapse state
-	 */
-	void toggleCollapseState();
+    /**
+     * Toggles the current collapse state
+     */
+    void toggleCollapseState();
 
-	/**
-	 * Use this instead of resize.
-	 * Depending on the sidebar location this will set the width or height
-	 * of this auto hide container.
-	 */
-	void setSize(int Size);
+    /**
+     * Use this instead of resize.
+     * Depending on the sidebar location this will set the width or height
+     * of this auto hide container.
+     */
+    void setSize(int Size);
 
-	/**
-	 * Resets the width or height to the initial dock widget size dependinng on
-	 * the orientation.
-	 * If the orientation is Qt::Horizontal, then the height is reset to
-	 * the initial size and if orientation is Qt::Vertical, then the width is
-	 * reset to the initial size
-	 */
-	void resetToInitialDockWidgetSize();
+    /**
+     * Resets the width or height to the initial dock widget size dependinng on
+     * the orientation.
+     * If the orientation is Qt::Horizontal, then the height is reset to
+     * the initial size and if orientation is Qt::Vertical, then the width is
+     * reset to the initial size
+     */
+    void resetToInitialDockWidgetSize();
 
-	/**
-	 * Returns orientation of this container.
-	 * Left and right containers have a Qt::Vertical orientation and top / bottom
-	 * containers have a Qt::Horizontal orientation.
-	 * The function returns the orientation of the corresponding auto hide
-	 * side bar.
-	 */
-	Qt::Orientation orientation() const;
+    /**
+     * Returns orientation of this container.
+     * Left and right containers have a Qt::Vertical orientation and top / bottom
+     * containers have a Qt::Horizontal orientation.
+     * The function returns the orientation of the corresponding auto hide
+     * side bar.
+     */
+    Qt::Orientation orientation() const;
 
-	/**
-	 * Removes the AutoHide container from the current side bar and adds
-	 * it to the new side bar given in SideBarLocation
-	 */
-	void moveToNewSideBarLocation(SideBarLocation SideBarLocation, int TabIndex = -1);
+    /**
+     * Removes the AutoHide container from the current side bar and adds
+     * it to the new side bar given in SideBarLocation
+     */
+    void moveToNewSideBarLocation(SideBarLocation SideBarLocation,
+                                  int TabIndex = -1);
 };
-} // namespace ads
+}  // namespace ads
 
 //-----------------------------------------------------------------------------
 #endif

src/AutoHideTab.cpp

@@ -33,6 +33,8 @@
 #include <QApplication>
 #include <QElapsedTimer>
 #include <QMenu>
+#include <qevent.h>
+#include <qnamespace.h>
 
 #include "AutoHideDockContainer.h"
 #include "AutoHideSideBar.h"
@@ -41,6 +43,7 @@
 #include "DockWidget.h"
 #include "FloatingDragPreview.h"
 #include "DockOverlay.h"
+#include "ads_globals.h"
 
 namespace ads
 {
@@ -55,6 +58,7 @@ struct AutoHideTabPrivate
     CAutoHideSideBar* SideBar = nullptr;
 	Qt::Orientation Orientation{Qt::Vertical};
 	QElapsedTimer TimeSinceHoverMousePress;
+	QElapsedTimer TimeSinceDragOver;
 	bool MousePressed = false;
 	eDragState DragState = DraggingInactive;
 	QPoint GlobalDragStartMousePosition;
@@ -252,6 +256,9 @@ CAutoHideTab::CAutoHideTab(QWidget* parent) :
 {
 	setAttribute(Qt::WA_NoMousePropagation);
 	setFocusPolicy(Qt::NoFocus);
+    if (CDockManager::testAutoHideConfigFlag(CDockManager::AutoHideOpenOnDragHover)) {
+        setAcceptDrops(true);
+    }
 }
 
 
@@ -355,7 +362,6 @@ bool CAutoHideTab::event(QEvent* event)
 	case QEvent::Leave:
 		 d->forwardEventToDockContainer(event);
 		 break;
-
 	default:
 		break;
 	}
@@ -537,6 +543,37 @@ void CAutoHideTab::mouseMoveEvent(QMouseEvent* ev)
     Super::mouseMoveEvent(ev);
 }
 
+//============================================================================
+void CAutoHideTab::dragEnterEvent(QDragEnterEvent* ev) {
+    if (CDockManager::testAutoHideConfigFlag(CDockManager::AutoHideOpenOnDragHover)) {
+        if (!d->TimeSinceDragOver.isValid()) {
+            d->TimeSinceDragOver.restart();
+            ev->accept();
+        }
+        else if (d->TimeSinceDragOver.hasExpired(500)) {
+            ev->accept();
+        }
+    }
+}
+
+//============================================================================
+void CAutoHideTab::dragLeaveEvent(QDragLeaveEvent* ev) {
+    if (CDockManager::testAutoHideConfigFlag(CDockManager::AutoHideOpenOnDragHover)) {
+        d->TimeSinceDragOver.invalidate();
+        d->forwardEventToDockContainer(ev);
+    }
+}
+
+//============================================================================
+void CAutoHideTab::dragMoveEvent(QDragMoveEvent* ev) {
+    if (CDockManager::testAutoHideConfigFlag(CDockManager::AutoHideOpenOnDragHover)
+        && d->TimeSinceDragOver.isValid()
+        && d->TimeSinceDragOver.hasExpired(500)) {
+        d->TimeSinceDragOver.invalidate();
+        d->DockWidget->autoHideDockContainer()->collapseView(false);
+        ev->accept();
+    }
+}
 
 //============================================================================
 void CAutoHideTab::requestCloseDockWidget()

src/AutoHideTab.h

@@ -76,6 +76,9 @@ protected:
 	virtual void mousePressEvent(QMouseEvent* ev) override;
 	virtual void mouseReleaseEvent(QMouseEvent* ev) override;
 	virtual void mouseMoveEvent(QMouseEvent* ev) override;
+    virtual void dragEnterEvent(QDragEnterEvent* ev) override;
+    virtual void dragLeaveEvent(QDragLeaveEvent* ev) override;
+    virtual void dragMoveEvent(QDragMoveEvent* ev) override;
 
 public:
     using Super = CPushButton;

src/DockManager.h

@@ -254,6 +254,7 @@ public:
 		AutoHideCloseButtonCollapsesDock = 0x40, ///< Close button of an auto hide container collapses the dock instead of hiding it completely
 		AutoHideHasCloseButton = 0x80, //< If the flag is set an auto hide title bar has a close button
 		AutoHideHasMinimizeButton = 0x100, ///< if this flag is set, the auto hide title bar has a minimize button to collapse the dock widget
+        AutoHideOpenOnDragHover = 0x200,  ///< if this flag is set, dragging hover the tab bar will open the dock
 
 		DefaultAutoHideConfig = AutoHideFeatureEnabled
 			                  | DockAreaHasAutoHideButton