#ifndef FloatingDockContainerH
#define FloatingDockContainerH
/*******************************************************************************
** Qt Advanced Docking System
** Copyright (C) 2017 Uwe Kindler
**
** This library is free software; you can redistribute it and/or
** modify it under the terms of the GNU Lesser General Public
** License as published by the Free Software Foundation; either
** version 2.1 of the License, or (at your option) any later version.
**
** This library is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** Lesser General Public License for more details.
**
** You should have received a copy of the GNU Lesser General Public
** License along with this library; If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/


//============================================================================
/// \file   FloatingDockContainer.h
/// \author Uwe Kindler
/// \date   01.03.2017
/// \brief  Declaration of CFloatingDockContainer class
//============================================================================

//============================================================================
//                                   INCLUDES
//============================================================================
#include "ads_globals.h"

#include <QRubberBand>

#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
#include <QDockWidget>
#define tFloatingWidgetBase QDockWidget
#else
#include <QWidget>
#define tFloatingWidgetBase QWidget
#endif

class CDockingStateReader;
QT_FORWARD_DECLARE_CLASS(QMimeData)

namespace ads
{
struct FloatingDockContainerPrivate;
class CDockManager;
struct DockManagerPrivate;
class CDockAreaWidget;
class CDockContainerWidget;
class CDockWidget;
class CDockManager;
class CDockAreaTabBar;
class CDockWidgetTab;
struct DockWidgetTabPrivate;
class CDockAreaTitleBar;
struct DockAreaTitleBarPrivate;
class CFloatingWidgetTitleBar;
class CDockingStateReader;
class CFloatingDragPreview;

/**
 * Pure virtual interface for floating widgets.
 * This interface is used for opaque and non-opaque undocking. If opaque
 * undocking is used, the a real CFloatingDockContainer widget will be created
 */
class ADS_EXPORT IFloatingWidget
{
public:
    virtual ~IFloatingWidget() = default;

	/**
	 * Starts floating.
	 * This function should get called typically from a mouse press event
	 * handler
	 */
	virtual void startFloating(const QPoint& DragStartMousePos, const QSize& Size,
        eDragState DragState, QWidget* MouseEventHandler) = 0;

	/**
	 * Moves the widget to a new position relative to the position given when
	 * startFloating() was called.
	 * This function should be called from a mouse mouve event handler to
	 * move the floating widget on mouse move events.
	 */
	virtual void moveFloating() = 0;

	/**
	 * Tells the widget that to finish dragging if the mouse is released.
	 * This function should be called from a mouse release event handler
	 * to finish the dragging
	 */
	virtual void finishDragging() = 0;
};


/**
 * This implements a floating widget that is a dock container that accepts
 * docking of dock widgets like the main window and that can be docked into
 * another dock container.
 * Every floating window of the docking system is a FloatingDockContainer.
 */
class ADS_EXPORT CFloatingDockContainer : public tFloatingWidgetBase, public IFloatingWidget
{
	Q_OBJECT
private:
	FloatingDockContainerPrivate* d; ///< private data (pimpl)
	friend struct FloatingDockContainerPrivate;
	friend class CDockManager;
	friend struct DockManagerPrivate;
	friend class CDockAreaTabBar;
	friend struct DockWidgetTabPrivate;
	friend class CDockWidgetTab;
	friend class CDockAreaTitleBar;
	friend struct DockAreaTitleBarPrivate;
	friend class CDockWidget;
	friend class CDockAreaWidget;
    friend class CFloatingWidgetTitleBar;
	friend class CDockContainerWidget;

	/**
	 * Returns the floating widget that is transported in the mime data of
	 * a drag and drop operation started by startPlatformDrag() and nullptr,
	 * if the mime data does not contain a floating widget
	 */
	static CFloatingDockContainer* floatingWidgetFromMimeData(const QMimeData* MimeData);

	/**
	 * Records the drop candidate while a platform drag is hovering over a
	 * dock container. Called from CDockContainerWidget::dragMoveEvent().
	 * Some compositors (e.g. Mutter) do not deliver a drop event when the
	 * dragged window overlaps the drop target. startPlatformDrag() then docks
	 * the floating widget into the last recorded candidate, if the drag ended
	 * over a valid drop area
	 */
	static void platformDragUpdateDropCandidate(CDockContainerWidget* Container,
		const QPoint& GlobalPos, bool ValidDropArea);

	/**
	 * Marks the platform drag drop as handled by a delivered drop event, so
	 * that startPlatformDrag() does not dock the floating widget a second time
	 */
	static void platformDragNotifyDropHandled();

	/**
	 * Wayland: returns the concatenated style sheets along the dock manager
	 * parent chain. A floating widget has no parent widget on Wayland, so it
	 * does not inherit the dock manager's effective style sheet through the
	 * widget hierarchy and gets this style sheet applied explicitly instead
	 * (an application wide qApp style sheet is still applied automatically by
	 * Qt and is therefore not included here). Used at construction and when
	 * the dock manager re-applies the style sheet after a style change.
	 */
	static QString waylandInheritedStyleSheet(QWidget* DockManager);

private Q_SLOTS:
	void onDockAreasAddedOrRemoved();
	void onDockAreaCurrentChanged(int Index);

protected:
	/**
	 * Starts floating at the given global position.
	 * Use moveToGlobalPos() to move the widget to a new position
	 * depending on the start position given in Pos parameter
	 */
	virtual void startFloating(const QPoint& DragStartMousePos, const QSize& Size,
        eDragState DragState, QWidget* MouseEventHandler) override;

	/**
	 * Call this function if you explicitly want to signal that dragging has
	 * finished
	 */
	virtual void finishDragging() override;

	/**
	 * This function deletes all dock widgets in it.
	 * This functions should be called only from dock manager in its
	 * destructor before deleting the floating widget
     */
	void deleteContent();

	/**
	 * Call this function if you just want to initialize the position
	 * and size of the floating widget
	 */
	void initFloatingGeometry(const QPoint& DragStartMousePos, const QSize& Size)
	{
        startFloating(DragStartMousePos, Size, DraggingInactive, nullptr);
	}

	/**
	 * Moves the widget to a new position relative to the position given when
	 * startFloating() was called
	 */
	void moveFloating() override;

	/**
	 * Restores the state from given stream.
	 * If Testing is true, the function only parses the data from the given
	 * stream but does not restore anything. You can use this check for
	 * faulty files before you start restoring the state
	 */
	bool restoreState(CDockingStateReader& Stream, bool Testing);

	/**
	 * Call this function to update the window title
	 */
    void updateWindowTitle();

protected: // reimplements QWidget
	virtual void changeEvent(QEvent *event) override;
	virtual void closeEvent(QCloseEvent *event) override;
	virtual void hideEvent(QHideEvent *event) override;
	virtual void showEvent(QShowEvent *event) override;

#ifdef Q_OS_MACOS
	virtual bool event(QEvent *e) override;
    virtual void moveEvent(QMoveEvent *event) override;
#elif defined(Q_OS_UNIX)
	virtual void moveEvent(QMoveEvent *event) override;
	virtual void resizeEvent(QResizeEvent *event) override;
	virtual bool event(QEvent *e) override;
#endif

#ifdef Q_OS_WIN
	/**
	 * Native event filter for handling WM_MOVING messages on Windows
	 */
#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
    virtual bool nativeEvent(const QByteArray &eventType, void *message, long *result) override;
#else
    virtual bool nativeEvent(const QByteArray &eventType, void *message, qintptr *result) override;
#endif
#endif


public:
	using Super = tFloatingWidgetBase;

	/**
	 * Create empty floating widget - required for restore state
	 */
	CFloatingDockContainer(CDockManager* DockManager);

	/**
	 * Create floating widget with the given dock area
	 */
	CFloatingDockContainer(CDockAreaWidget* DockArea);

	/**
	 * Create floating widget with the given dock widget
	 */
	CFloatingDockContainer(CDockWidget* DockWidget);

	/**
	 * Virtual Destructor
	 */
	~CFloatingDockContainer() override;

	/**
	 * Access function for the internal dock container
	 */
	CDockContainerWidget* dockContainer() const;

	/**
	 * Call this function to start dragging the floating widget
	 */
    void startDragging(const QPoint& DragStartMousePos, const QSize& Size,
        QWidget* MouseEventHandler)
	{
        startFloating(DragStartMousePos, Size, DraggingFloatingWidget, MouseEventHandler);
	}

	/**
	 * Starts a compositor driven drag of the given floating widget on
	 * Wayland.
	 * Wayland neither reports the global cursor position nor allows clients
	 * to move top level windows, so the mouse tracked dragging that is used
	 * on the other platforms cannot work. Instead, this function executes a
	 * QDrag with the MIME types that QWaylandDataDevice translates into an
	 * xdg_toplevel_drag_v1 request, so the compositor moves the floating
	 * widget with the cursor. The CDockContainerWidget drag and drop event
	 * handlers show the drop overlays and dock the widget on drop.
	 * GlobalPressPos is the mouse press position in global coordinates and
	 * DragSource is the widget that received the mouse press event.
	 * DragOffset, when non-null, is the surface-local point of the floating
	 * widget that should stay under the cursor (the xdg_toplevel_drag attach
	 * offset). It must be supplied for a freshly created floating window: on
	 * Wayland such a window has no meaningful geometry yet, so deriving the
	 * offset from GlobalPressPos via mapFromGlobal() would place it randomly.
	 * When null (e.g. dragging an already-mapped floating window) the offset is
	 * derived from GlobalPressPos.
	 * The function blocks until the user drops or cancels the drag. It
	 * returns Qt::MoveAction, if the floating widget was docked into a
	 * drop area and Qt::IgnoreAction, if the floating widget was dropped
	 * outside of any drop area and remains floating.
	 */
	static Qt::DropAction startPlatformDrag(CFloatingDockContainer* FloatingWidget,
		const QPoint& GlobalPressPos, QWidget* DragSource,
		const QPoint* DragOffset = nullptr);

	/**
	 * Wayland hybrid drag helper, shared by the tab and the title bar drag
	 * paths. While the cursor stays inside SourceWindow the in-window Preview
	 * is moved to GlobalPos and this returns true. Once the cursor leaves
	 * SourceWindow the Preview is torn down without performing a drop and this
	 * returns false - the caller then creates the real floating widget and
	 * hands it to startPlatformDragForFloatingWidget(). Preview may be null.
	 */
	static bool waylandMoveOrLeaveInWindowPreview(CFloatingDragPreview* Preview,
		QWidget* SourceWindow, const QPoint& GlobalPos);

	/**
	 * Wayland hybrid drag helper, shared by the tab and the title bar drag
	 * paths. Floats the freshly created FloatingWidget at the given Size and
	 * starts the compositor driven platform drag, keeping GrabOffset (the
	 * surface-local grab point) under the cursor. See startPlatformDrag() for
	 * why the offset is passed explicitly instead of being derived from the
	 * press position on Wayland.
	 */
	static Qt::DropAction startPlatformDragForFloatingWidget(
		IFloatingWidget* FloatingWidget, const QPoint& GrabOffset,
		const QSize& Size, const QPoint& GlobalGrabPos, QWidget* DragSource);

	/**
	 * This function returns true, if it can be closed.
	 * It can be closed, if all dock widgets in all dock areas can be closed
	 */
    bool isClosable() const;

    /**
     * This function returns true, if this floating widget has only one single
     * visible dock widget in a single visible dock area.
     * The single dock widget is a real top level floating widget because no
     * other widgets are docked.
     */
    bool hasTopLevelDockWidget() const;

    /**
     * This function returns the first dock widget in the first dock area.
     * If the function hasSingleDockWidget() returns true, then this function
     * returns this single dock widget.
     */
    CDockWidget* topLevelDockWidget() const;

    /**
     * This function returns a list of all dock widget in this floating widget.
     * This is a simple convenience function that simply calls the dockWidgets()
     * function of the internal container widget.
     */
    QList<CDockWidget*> dockWidgets() const;

	/**
	 * This function hides the floating widget instantly and delete it later.
	 */
	void finishDropOperation();

	/**
	 * Returns true while this floating widget is actively being dragged.
	 */
	bool isDraggingActive() const;

#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
    /**
	 * This is a function that responds to FloatingWidgetTitleBar::maximizeRequest()
	 * Maximize or normalize the container size.
     */
    void onMaximizeRequest();

	/**
	 * Normalize (Unmaximize) the window.
	 *	fixGeometry parameter fixes a "bug" in QT where immediately after calling showNormal
	 *	geometry is not set properly.
	 *	Set this true when moving the window immediately after normalizing.
	 */
	void showNormal(bool fixGeometry=false);

	/**
	 * Maximizes the window.
	 */
	void showMaximized();

	/**
	 * Returns if the window is currently maximized or not.
	 */
	bool isMaximized() const;

	/**
	 * Patched show to prevent the window from appearing in the taskbar.
	 */
	void show();

	/**
	 * Returns true if the floating widget has a native titlebar or false if
	 * the floating widget has a QWidget based title bar
	 */
	bool hasNativeTitleBar();
#endif
}; // class FloatingDockContainer
}
 // namespace ads
//-----------------------------------------------------------------------------
#endif // FloatingDockContainerH
