kwin/lib/kdecoration.h

/*****************************************************************
This file is part of the KDE project.

Copyright (C) 2003 Lubos Lunak <l.lunak@kde.org>

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DEALINGS IN THE SOFTWARE.
******************************************************************/

#ifndef KDECORATION_H
#define KDECORATION_H

#include <QtGui/QColor>
#include <QtGui/QFont>
#include <QtCore/QObject>
#include <QtGui/QIcon>
#include <netwm_def.h>
#include <QtGui/QMouseEvent>

#define KWIN_EXPORT KDE_EXPORT

class KConfig;

/** @defgroup kdecoration KWin decorations library */

/** @addtogroup kdecoration */
/** @{ */

class KDecorationOptionsPrivate;
class KDecorationBridge;
class KDecorationPrivate;
class KDecorationFactory;

/**
 * This class provides a namespace for all decoration related classes.
 * All shared types are defined here.
 */
class KWIN_EXPORT KDecorationDefines
{
public:
    /**
     * These values represent positions inside an area
     */
    enum Position
        { // without prefix, they'd conflict with Qt::TopLeftCorner etc. :(
        PositionCenter         = 0x00,
        PositionLeft           = 0x01,
        PositionRight          = 0x02,
        PositionTop            = 0x04,
        PositionBottom         = 0x08,
        PositionTopLeft        = PositionLeft | PositionTop,
        PositionTopRight       = PositionRight | PositionTop,
        PositionBottomLeft     = PositionLeft | PositionBottom,
        PositionBottomRight    = PositionRight | PositionBottom
        };
    /**
     * Maximize mode. These values specify how a window is maximized.
     */
    // these values are written to session files, don't change the order
    enum MaximizeMode
        {
        MaximizeRestore    = 0, ///< The window is not maximized in any direction.
        MaximizeVertical   = 1, ///< The window is maximized vertically.
        MaximizeHorizontal = 2, ///< The window is maximized horizontally.
        /// Equal to @p MaximizeVertical | @p MaximizeHorizontal
        MaximizeFull = MaximizeVertical | MaximizeHorizontal
        };

    enum WindowOperation
        {
        MaximizeOp = 5000,
        RestoreOp,
        MinimizeOp,
        MoveOp,
        UnrestrictedMoveOp,
        ResizeOp,
        UnrestrictedResizeOp,
        CloseOp,
        OnAllDesktopsOp,
        ShadeOp,
        KeepAboveOp,
        KeepBelowOp,
        OperationsOp,
        WindowRulesOp,
        ToggleStoreSettingsOp = WindowRulesOp, ///< @obsolete
        HMaximizeOp,
        VMaximizeOp,
        LowerOp,
        FullScreenOp,
        NoBorderOp,
        NoOp,
        SetupWindowShortcutOp,
        ApplicationRulesOp,
        RemoveClientFromGroupOp, // Remove from group
        CloseClientGroupOp, // Close the group
        MoveClientInGroupLeftOp, // Move left in the group
        MoveClientInGroupRightOp, // Move right in the group
        ToggleClientTiledStateOp, // put a floating client into tiling
        ClientGroupDragOp
        };
    /**
     * Basic color types that should be recognized by all decoration styles.
     * Decorations are not required to implement all the colors, but for the ones that
     * are implemented the color setting for them should be obeyed.
     */
    enum ColorType
        {
        ColorTitleBar,   ///< The color for the titlebar
        ColorTitleBlend, ///< The blend color for the titlebar
        ColorFont,       ///< The titlebar text color
        ColorButtonBg,   ///< The color to use for the titlebar buttons
        ColorFrame,      ///< The color for the window frame (border)
        ColorHandle,     ///< The color for the resize handle
        NUM_COLORS       ///< @internal This value may change, do not use
        };

    /**
     * These flags specify which settings changed when rereading settings.
     * Each setting in class KDecorationOptions specifies its matching flag.
     */
    enum
        {
        SettingDecoration  = 1 << 0, ///< The decoration was changed
        SettingColors      = 1 << 1, ///< The color palette was changed
        SettingFont        = 1 << 2, ///< The titlebar font was changed
        SettingButtons     = 1 << 3, ///< The button layout was changed
        SettingTooltips    = 1 << 4, ///< The tooltip setting was changed
        SettingBorder      = 1 << 5, ///< The border size setting was changed
        SettingCompositing = 1 << 6  ///< Compositing settings was changed
        };

    /**
     * Border size. KDecorationOptions::preferredBorderSize() returns
     * one of these values.
     */
    enum BorderSize
        {
        BorderTiny,      ///< Minimal borders
        BorderNormal,    ///< Standard size borders, the default setting
        BorderLarge,     ///< Larger borders
        BorderVeryLarge, ///< Very large borders
        BorderHuge,      ///< Huge borders
        BorderVeryHuge,  ///< Very huge borders
        BorderOversized, ///< Oversized borders
        BordersCount     ///< @internal
        };

    /**
     * Used to find out which features the decoration supports.
     * @see KDecorationFactory::supports()
     */
    enum Ability
        {
        // announce
        AbilityAnnounceButtons = 0, ///< decoration supports AbilityButton* values (always use)
        AbilityAnnounceColors = 1, ///< decoration supports AbilityColor* values (always use)
        // buttons
        AbilityButtonMenu = 1000,   ///< decoration supports the menu button
        AbilityButtonOnAllDesktops = 1001, ///< decoration supports the on all desktops button
        AbilityButtonSpacer = 1002, ///< decoration supports inserting spacers between buttons
        AbilityButtonHelp = 1003,   ///< decoration supports what's this help button
        AbilityButtonMinimize = 1004,  ///< decoration supports a minimize button
        AbilityButtonMaximize = 1005, ///< decoration supports a maximize button
        AbilityButtonClose = 1006, ///< decoration supports a close button
        AbilityButtonAboveOthers = 1007, ///< decoration supports an above button
        AbilityButtonBelowOthers = 1008, ///< decoration supports a below button
        AbilityButtonShade = 1009, ///< decoration supports a shade button
        AbilityButtonResize = 1010, ///< decoration supports a resize button
        // colors
        AbilityColorTitleBack = 2000, ///< decoration supports titlebar background color
        ABILITYCOLOR_FIRST = AbilityColorTitleBack, ///< @internal
        AbilityColorTitleFore = 2001, ///< decoration supports titlebar foreground color
        AbilityColorTitleBlend = 2002, ///< decoration supports second titlebar background color
        AbilityColorFrame = 2010, ///< decoration supports frame color
        AbilityColorHandle = 2011, ///< decoration supports resize handle color
        AbilityColorButtonBack = 2020, ///< decoration supports button background color
        AbilityColorButtonFore = 2021, ///< decoration supports button foreground color
        ABILITYCOLOR_END, ///< @internal
        // compositing
        AbilityProvidesShadow = 3000, ///< The decoration draws its own shadows.
                                      ///  @since 4.3
        AbilityUsesAlphaChannel = 3001, ///< The decoration isn't clipped to the mask when compositing is enabled.
                                        ///  The mask is still used to define the input region and the blurred
                                        ///  region, when the blur plugin is enabled.
                                        ///  @since 4.3
        AbilityExtendIntoClientArea = 3002, ///< The decoration respects transparentRect()
                                            ///  @since 4.4
        // Tabbing
        AbilityClientGrouping = 4000, ///< The decoration supports tabbing
        // TODO colors for individual button types
        ABILITY_DUMMY = 10000000
        };

    enum Requirement { REQUIREMENT_DUMMY = 1000000 };
    
    /**
    *
    * Returns mimeType used to drag and drop clientGroupItems 
    */
    
    static QString clientGroupItemDragMimeType();

};

class KWIN_EXPORT ClientGroupItem
    {
    public:
        ClientGroupItem( QString t, QIcon i )
            {
            title_ = t;
            icon_ = i;
            }
        inline QIcon icon() const
            {
            return icon_;
            }
        inline QString title() const
            {
            return title_;
            }
    private:
        QString title_;
        QIcon icon_;
    };

class KDecorationProvides
    : public KDecorationDefines
    {
    public:
        virtual ~KDecorationProvides(){}
        virtual bool provides( Requirement req ) = 0;
    };

/**
 * This class holds various configuration settings for the decoration.
 * It is accessible from the decorations either as KDecoration::options()
 * or KDecorationFactory::options().
 */
class KWIN_EXPORT KDecorationOptions : public KDecorationDefines
    {
public:
    KDecorationOptions();
    virtual ~KDecorationOptions();
    /**
     * Call to update settings when the config changes. Return value is
     * a combination of Setting* (SettingColors, etc.) that have changed.
     * @since 4.0.1
     */
    unsigned long updateSettings( KConfig* config );
    /**
     * Returns the color that should be used for the given part of the decoration.
     * The changed flags for this setting is SettingColors.
     *
     * @param type   The requested color type.
     * @param active Whether the color should be for active or inactive windows.
     */
    QColor color(ColorType type, bool active=true) const;
    /**
     * Returns a palette using the given decoration color as the background.
     * The changed flags for this setting is SettingColors.
     *
     * @param type   The requested color type.
     * @param active Whether to return the color for active or inactive windows.
     */
    QPalette palette(ColorType type, bool active=true) const;
    /**
     * Returns the active or inactive decoration font.
     * The changed flags for this setting is SettingFont.
     *
     * @param active Whether to return the color for active or inactive windows.
     * @param small  If @a true, returns a font that's suitable for tool windows.
     */
    QFont font(bool active=true, bool small = false) const;
    /**
     * Returns @a true if the style should use custom button positions
     * The changed flags for this setting is SettingButtons.
     *
     * @see titleButtonsLeft
     * @see titleButtonsRight
     */
    bool customButtonPositions() const;
    /**
     * If customButtonPositions() returns true, titleButtonsLeft
     * returns which buttons should be on the left side of the titlebar from left
     * to right. Characters in the returned string have this meaning :
     * @li 'M' menu button
     * @li 'S' on_all_desktops button
     * @li 'H' quickhelp button
     * @li 'I' minimize ( iconify ) button
     * @li 'A' maximize button
     * @li 'X' close button
     * @li 'F' keep_above_others button
     * @li 'B' keep_below_others button
     * @li 'L' shade button
     * @li 'R' resize button
     * @li '_' spacer
     *
     * The default ( which is also returned if customButtonPositions returns false )
     * is "MS".
     * Unknown buttons in the returned string must be ignored.
     * The changed flags for this setting is SettingButtons.
     */
    QString titleButtonsLeft() const;
    /**
     * Returns the default left button sequence
     */
    static QString defaultTitleButtonsLeft();
    /**
     * If customButtonPositions() returns true, titleButtonsRight
     * returns which buttons should be on the right side of the titlebar from left
     * to right. Characters in the return string have the same meaning like
     * in titleButtonsLeft().
     *
     * The default ( which is also returned if customButtonPositions returns false )
     * is "HIA__X".
     * Unknown buttons in the returned string must be ignored.
     * The changed flags for this setting is SettingButtons.
     */
    QString titleButtonsRight() const;
    /**
     * Returns the default right button sequence.
     */
    static QString defaultTitleButtonsRight();
    /**
     * @returns true if the style should use tooltips for window buttons
     * The changed flags for this setting is SettingTooltips.
     */
    bool showTooltips() const;

    /**
     * The preferred border size selected by the user, e.g. for accessibility
     * reasons, or when using high resolution displays. It's up to the decoration
     * to decide which borders or if any borders at all will obey this setting.
     * It is guaranteed that the returned value will be one of those
     * returned by KDecorationFactory::borderSizes(), so if that one hasn't been
     * reimplemented, BorderNormal is always returned.
     * The changed flags for this setting is SettingBorder.
     * @param factory the decoration factory used
     */
    BorderSize preferredBorderSize( KDecorationFactory* factory ) const;

    /*
    * When this functions returns false, moving and resizing of maximized windows
    * is not allowed, and therefore the decoration is allowed to turn off (some of)
    * its borders.
    * The changed flags for this setting is SettingButtons.
    */
    bool moveResizeMaximizedWindows() const;

    /**
     * @internal
     */
    WindowOperation operationMaxButtonClick( Qt::MouseButtons button ) const;

    /**
     * @internal
     */
    virtual unsigned long updateSettings() = 0; // returns SettingXYZ mask

protected:
    /** @internal */
    void setOpMaxButtonLeftClick( WindowOperation op );
    /** @internal */
    void setOpMaxButtonRightClick( WindowOperation op );
    /** @internal */
    void setOpMaxButtonMiddleClick( WindowOperation op );
    /** @internal */
    void setBorderSize( BorderSize bs );
    /** @internal */
    void setCustomButtonPositions( bool b );
    /** @internal */
    void setTitleButtonsLeft( const QString& b );
    /** @internal */
    void setTitleButtonsRight( const QString& b );
private:
    /**
     * @internal
     */
    KDecorationOptionsPrivate* d;
    };


/**
 * This is the base class for a decoration object. It provides functions
 * that give various information about the decorated window, and also
 * provides pure virtual functions for controlling the decoration that
 * every decoration should implement.
 */
class KWIN_EXPORT KDecoration
    : public QObject, public KDecorationDefines
    {
    Q_OBJECT
    public:
        /**
         * Constructs a KDecoration object. Both the arguments are passed from
         * KDecorationFactory. Note that the initialization code of the decoration
         * should be done in the init() method.
         */
        KDecoration( KDecorationBridge* bridge, KDecorationFactory* factory );
        /**
         * Destroys the KDecoration.
         */
        virtual ~KDecoration();

        // requests from decoration

        /**
         * Returns the KDecorationOptions object, which is used to access
         * configuration settings for the decoration.
         */
        static const KDecorationOptions* options();
        /**
         * Returns @a true if the decorated window is currently active.
         */
        bool isActive() const;
        /**
         * Returns @a true if the decoration window can be closed by the user.
         */
        bool isCloseable() const;
        /**
         * Returns @a true if the decorated window can be maximized.
         */
        bool isMaximizable() const;
        /**
         * Returns the current maximization mode of the decorated window.
         * Note that only fully maximized windows should be treated
         * as "maximized" (e.g. if the maximize button has only two states).
         */
        MaximizeMode maximizeMode() const;
        /**
         * Returns @a true if the decorated window can be minimized by the user.
         */
        bool isMinimizable() const;
        /**
         * Return @a true if the decorated window can show context help
         * (i.e. the decoration should provide the context help button).
         */
        bool providesContextHelp() const;
        /**
         * Returns the number of the virtual desktop the decorated window
         * is currently on (including NET::OnAllDesktops for being on all
         * desktops).
         */
        int desktop() const;
        /**
         * Convenience function that returns @a true if the window is on all
         * virtual desktops.
         */
        bool isOnAllDesktops() const; // convenience
        /**
         * Returns @a true if the decoration window is modal (usually a modal dialog).
         */
        bool isModal() const;
        /**
         * Returns @a true if the decorated window can be shaded.
         */
        bool isShadeable() const;
        /**
         * Returns @a true if the decorated window is currently shaded.
         * If the window is e.g. hover unshaded, it's not considered to be shaded.
         * This function should not be used for the shade titlebar button, use
         * @ref isSetShade() instead.
         *
         * @see isSetShade
         */
        bool isShade() const;
        /**
         * Returns @a true if the decorated window was set to be shaded. This function
         * returns also true if the window is e.g. hover unshaded, so it doesn't
         * always correspond to the actual window state.
         *
         * @see isShade
         */
        bool isSetShade() const;
        /**
         * Returns @a true if the decorated window should be kept above other windows.
         */
        bool keepAbove() const;
        /**
         * Returns @a true if the decorated window should be kept below other windows.
         */
        bool keepBelow() const;
        /**
         * Returns @a true if the decorated window can be moved by the user.
         */
        bool isMovable() const;
        /**
         * Returns @a true if the decorated window can be resized by the user.
         */
        bool isResizable() const;
        /**
         * This function returns the window type of the decorated window.
         * The argument to this function is a mask of all window types
         * the decoration knows about (as the list of valid window types
         * is extended over time, and fallback types are specified in order
         * to support older code). For a description of all window types,
         * see the definition of the NET::WindowType type. Note that
         * some window types never have decorated windows.
         *
         * An example of usage:
         * @code
         * const unsigned long supported_types = NET::NormalMask | NET::DesktopMask
         * 	| NET::DockMask | NET::ToolbarMask | NET::MenuMask | NET::DialogMask
         * 	| NET::OverrideMask | NET::TopMenuMask | NET::UtilityMask | NET::SplashMask;
         *
         * NET::WindowType type = windowType( supported_types );
         *
         * if( type == NET::Utility || type == NET::Menu || type == NET::Toolbar )
         *    // ... use smaller decorations for tool window types
         * else
         *    // ... use normal decorations
         * @endcode
         */
        NET::WindowType windowType( unsigned long supported_types ) const;
        /**
         * Returns an icon set with the decorated window's icon.
         */
        QIcon icon() const;
        /**
         * Returns the decorated window's caption that should be shown in the titlebar.
         */
        QString caption() const;
        /**
         * This function invokes the window operations menu.
         * \param pos specifies the place on the screen where the menu should
         * show up. The menu pops up at the bottom-left corner of the specified
         * rectangle, unless there is no space, in which case the menu is
         * displayed above the rectangle.
         *
         * \note Decorations that enable a double-click operation for the menu
         * button must ensure to call \a showWindowMenu() with the \a pos
         * rectangle set to the menu button geometry.
         * IMPORTANT: As a result of this function, the decoration object that
         * called it may be destroyed after the function returns. This means
         * that the decoration object must either return immediately after
         * calling showWindowMenu(), or it must use
         * KDecorationFactory::exists() to check it's still valid. For example,
         * the code handling clicks on the menu button should look similarly
         * like this:
         *
         * \code
         * KDecorationFactory* f = factory(); // needs to be saved before
         * showWindowMenu( button[MenuButton]->mapToGlobal( menuPoint ));
         * if( !f->exists( this )) // destroyed, return immediately
         *     return;
         * button[MenuButton]->setDown(false);
         * \endcode
         */
        void showWindowMenu( const QRect &pos );

        /**
         * Overloaded version of the above.
         */
        void showWindowMenu( QPoint pos );
        /**
         * This function performs the given window operation. This function may destroy
         * the current decoration object, just like showWindowMenu().
         */
        void performWindowOperation( WindowOperation op );
        /**
         * If the decoration is non-rectangular, this function needs to be called
         * to set the shape of the decoration.
         *
         * @param reg  The shape of the decoration.
         * @param mode The X11 values Unsorted, YSorted, YXSorted and YXBanded that specify
         *             the sorting of the rectangles, default value is Unsorted.
         */
        void setMask( const QRegion& reg, int mode = 0 );
        /**
         * This convenience function resets the shape mask.
         */
        void clearMask(); // convenience
        /**
         * If this function returns @a true, the decorated window is used as a preview
         * e.g. in the configuration module. In such case, the decoration can e.g.
         * show some information in the window area.
         */
        bool isPreview() const;
        /**
         * Returns the geometry of the decoration.
         */
        QRect geometry() const;
        /**
         * Returns the icon geometry for the window, i.e. the geometry of the taskbar
         * entry. This is used mainly for window minimize animations. Note that
         * the geometry may be null.
         */
        QRect iconGeometry() const;
        /**
         * Returns the intersection of the given region with the region left
         * unobscured by the windows stacked above the current one. You can use
         * this function to, for example, try to keep the titlebar visible if
         * there is a hole available. The region returned is in the coordinate
         * space of the decoration.
         * @param r The region you want to check for holes
         */
        QRegion unobscuredRegion( const QRegion& r ) const;
        /**
         * Returns the handle of the window that is being decorated. It is possible
         * the returned value will be 0.
         * IMPORTANT: This function is meant for special purposes, and it
         * usually should not be used. The main purpose is finding out additional
         * information about the window's state. Also note that different kinds
         * of windows are decorated: Toplevel windows managed by the window manager,
         * test window in the window manager decoration module, and possibly also
         * other cases.
         * Careless abuse of this function will usually sooner or later lead
         * to problems.
         */
        WId windowId() const;
        /**
         * Convenience function that returns the width of the decoration.
         */
        int width() const; // convenience
        /**
         * Convenience function that returns the height of the decoration.
         */
        int height() const;  // convenience
        /**
         * Returns the rectangle within the window frame that should be transparent.
         * Usually this rectangle is the same as the client area, and it is never
         * larger.
         *
         * If the client has requested that the window frame is extended into the
         * client area, this rectangle is smaller than the client area.
         *
         * If the window frame should cover the whole client area, a null rectangle
         * is returned.
         *
         * @since 4.4
         */
        QRect transparentRect() const;
        /**
         * This function is the default handler for mouse events. All mouse events
         * that are not handled by the decoration itself should be passed to it
         * in order to make work operations like window resizing by dragging borders etc.
         */
        void processMousePressEvent( QMouseEvent* e );

        // requests to decoration

        /**
         * This function is called immediately after the decoration object is created.
         * Due to some technical reasons, initialization should be done here
         * instead of in the constructor.
         */
        virtual void init() = 0; // called once right after created

        /**
         * This function should return mouse cursor position in the decoration.
         * Positions at the edge will result in window resizing with mouse button
         * pressed, center position will result in moving.
         */
        virtual Position mousePosition( const QPoint& p ) const = 0;

        /**
         * This function should return the distance from each window side to the inner
         * window. The sizes may depend on the state of the decorated window, such as
         * whether it's shaded. Decorations often turn off their bottom border when the
         * window is shaded, and turn off their left/right/bottom borders when
         * the window is maximized and moving and resizing of maximized windows is disabled.
         * This function mustn't do any repaints or resizes. Also, if the sizes returned
         * by this function don't match the real values, this may result in drawing errors
         * or other problems.
         *
         * @see KDecorationOptions::moveResizeMaximizedWindows()
         */
        // mustn't do any repaints, resizes or anything like that
        virtual void borders( int& left, int& right, int& top, int& bottom ) const = 0;
        /**
         * This method is called by kwin when the style should resize the decoration window.
         * The usual implementation is to resize the main widget of the decoration to the
         * given size.
         *
         * @param s Specifies the new size of the decoration window.
         */
        virtual void resize( const QSize& s ) = 0;
        /**
         * This function should return the minimum required size for the decoration.
         * Note that the returned size shouldn't be too large, because it will be
         * used to keep the decorated window at least as large.
         */
        virtual QSize minimumSize() const = 0;
        /**
         * This function is called whenever the window either becomes or stops being active.
         * Use isActive() to find out the current state.
         */
        virtual void activeChange() = 0;
        /**
         * This function is called whenever the caption changes. Use caption() to get it.
         */
        virtual void captionChange() = 0;
        /**
         * This function is called whenever the window icon changes. Use icon() to get it.
         */
        virtual void iconChange() = 0;
        /**
         * This function is called whenever the maximalization state of the window changes.
         * Use maximizeMode() to get the current state.
         */
        virtual void maximizeChange() = 0;
        /**
         * This function is called whenever the desktop for the window changes. Use
         * desktop() or isOnAllDesktops() to find out the current desktop
         * on which the window is.
         */
        virtual void desktopChange() = 0;
        /**
         * This function is called whenever the window is shaded or unshaded. Use
         * isShade() to get the current state.
         */
        virtual void shadeChange() = 0;

    Q_SIGNALS:
        /**
         * This signal is emitted whenever the window's keep-above state changes.
         */
        void keepAboveChanged( bool );
        /**
         * This signal is emitted whenever the window's keep-below state changes.
         */
        void keepBelowChanged( bool );

    public:
        /**
         * This function may be reimplemented to provide custom bound drawing
         * for transparent moving or resizing of the window.
         * @a False should be returned if the default implementation should be used.
         * Note that if you e.g. paint the outline using a 5 pixels wide line,
         * you should compensate for the 2 pixels that would make the window
         * look larger.
         * It is the decoration's responsibility to do the painting, using
         * e.g. code like:
         * @code
         *     Display* dpy = QX11Info::display();
         *     XGCValues xgc;
         *     xgc.function = GXxor;
         *     xgc.foreground = WhitePixel( dpy, DefaultScreen( dpy ));
         *     xgc.line_width = width;
         *     xgc.subwindow_mode = IncludeInferiors;
         *     GC gc = XCreateGC( dpy, DefaultRootWindow( dpy ),
         *         GCFunction | GCForeground | GCLineWidth | GCSubwindowMode, &xgc );
         *     XDrawRectangle( dpy, DefaultRootWindow( dpy ), gc, r.x(), r.y(), r.width(), r.height());
         *     XFreeGC( dpy, gc );
         * @endcode
         *
         * @param geom  The geometry at this the bound should be drawn
         * @param clear @a true if the bound should be cleared (when doing the usual XOR
         *              painting this argument can be simply ignored)
         *
         * @see geometry()
         */
        virtual bool drawbound( const QRect& geom, bool clear );
        /**
         * @internal Reserved.
         */
        // TODO position will need also values for top+left+bottom etc. docking ?
        virtual bool windowDocked( Position side );
        /**
         * This function is called to reset the decoration on settings changes.
         * It is usually invoked by calling KDecorationFactory::resetDecorations().
         *
         * @param changed Specifies which settings were changed, given by the SettingXXX masks
         */
        virtual void reset( unsigned long changed );

        // special

        /**
         * This should be the first function called in init() to specify
         * the main widget of the decoration. The widget should be created
         * with parent specified by initialParentWidget() and flags
         * specified by initialWFlags().
         */
        void setMainWidget( QWidget* );
        /**
         * Convenience functions that creates and sets a main widget as necessary.
         * In such case, it's usually needed to install an event filter
         * on the main widget to receive important events on it.
         *
         * @param flags Additional widget flags for the main widget. Note that only
         *              flags that affect widget drawing are allowed. Window type flags
         *              like WX11BypassWM or WStyle_NoBorder are forbidden.
         */
        void createMainWidget( Qt::WFlags flags = 0 );
        /**
         * The parent widget that should be used for the main widget.
         */
        QWidget* initialParentWidget() const;
        /**
         * The flags that should be used when creating the main widget.
         * It is possible to add more flags when creating the main widget, but only flags
         * that affect widget drawing are allowed. Window type flags like WX11BypassWM
         * or WStyle_NoBorder are forbidden.
         */
        Qt::WFlags initialWFlags() const;
        /**
         * Returns the main widget for the decoration.
         */
        QWidget* widget();
        /**
         * Returns the main widget for the decoration.
         */
        const QWidget* widget() const;
        /**
         * Returns the factory that created this decoration.
         */
        KDecorationFactory* factory() const;
        /**
         * Performs X server grab. It is safe to call it several times in a row.
         */
        void grabXServer();
        /**
         * Ungrabs X server (if the number of ungrab attempts matches the number of grab attempts).
         */
        void ungrabXServer();
    public Q_SLOTS:
        // requests from decoration

        /**
         * This function can be called by the decoration to request
         * closing of the decorated window. Note that closing the window
         * also involves destroying the decoration.
         * IMPORTANT: This function may destroy the current decoration object,
         * just like showWindowMenu().
         */
        void closeWindow();
        /**
         * Changes the maximize mode of the decorated window. This function should
         * be preferred to the other maximize() overload for reacting on clicks
         * on the maximize titlebar button.
         */
        void maximize( Qt::MouseButtons button );
        /**
         * Set the maximize mode of the decorated window.
         * @param mode The maximization mode to be set.
         */
        void maximize( MaximizeMode mode );
        /**
         * Minimize the decorated window.
         */
        void minimize();
        /**
         * Start showing context help in the window (i.e. the mouse will enter
         * the what's this mode).
         */
        void showContextHelp();
        /**
         * Moves the window to the given desktop. Use NET::OnAllDesktops for making
         * the window appear on all desktops.
         */
        void setDesktop( int desktop );
        /**
         * This function toggles the on-all-desktops state of the decorated window.
         */
        void toggleOnAllDesktops(); // convenience
        /**
         * This function performs the operation configured as titlebar double click
         * operation.
         */
        void titlebarDblClickOperation();
        /**
         * This function performs the operation configured as titlebar wheel mouse
         * operation.
         * @param delta the mouse wheel delta
         */
        void titlebarMouseWheelOperation( int delta );
        /**
         * Shades or unshades the decorated window.
         * @param set Whether the window should be shaded
         */
        void setShade( bool set );
        /**
         * Sets or reset keeping this window above others.
         * @param set Whether to keep the window above others
         */
        void setKeepAbove( bool set );
        /**
         * Sets or reset keeping this window below others.
         * @param set Whether to keep the window below others
         */
        void setKeepBelow( bool set );
        /**
         * @internal
         */
        void emitKeepAboveChanged( bool above );
        /**
         * @internal
         */
        void emitKeepBelowChanged( bool below );

    private:
        KDecorationBridge* bridge_;
        QWidget* w_;
        KDecorationFactory* factory_;
        friend class KDecorationOptions; // for options_
        friend class KDecorationUnstable; // for bridge_
        static KDecorationOptions* options_;
        KDecorationPrivate* d;

    };

/**
 * @warning THIS CLASS IS UNSTABLE!
 */
class KWIN_EXPORT KDecorationUnstable
    : public KDecoration
    {
    Q_OBJECT

    public:
        KDecorationUnstable( KDecorationBridge* bridge, KDecorationFactory* factory );
        virtual ~KDecorationUnstable();
        /**
         * This function can return additional padding values that are added outside the
         * borders of the window, and can be used by the decoration if it wants to paint
         * outside the frame.
         *
         * The typical use case is for drawing a drop shadow or glowing effect around the window.
         *
         * The area outside the frame cannot receive input, and when compositing is disabled,
         * painting is clipped to the mask, or the window frame if no mask is defined.
         */
        virtual void padding(int &left, int &right, int &top, int &bottom) const;
        /**
         * Returns @a true if compositing--and therefore ARGB--is enabled.
         */
        bool compositingActive() const;

        // Window tabbing

        /**
         * Returns whether or not this client group contains the active client.
         */
        bool isClientGroupActive();
        /**
         * Return a list of all the clients in the group that contains the client that this
         * decoration is attached to.
         */
        QList< ClientGroupItem > clientGroupItems() const;
        /**
         * Returns a unique identifier for the client at index \p index of the client group list.
         * \see moveItemToClientGroup()
         */
        long itemId( int index );
        /**
         * Returns the list index of the currently visible client in this group.
         */
        int visibleClientGroupItem();
        /**
         * Switch the currently visible client to the one at list index \p index.
         */
        void setVisibleClientGroupItem( int index );
        /**
         * Move the client at index \p index to the position before the client at index \p before.
         */
        void moveItemInClientGroup( int index, int before );
        /**
         * Move the client that's unique identifier is \p itemId to the position before the client
         * at index \p before if set, otherwise the end of the list. This call is to move clients
         * between two different groups, if moving in the same group then use
         * moveItemInClientGroup() instead.
         * \see itemId()
         */
        void moveItemToClientGroup( long itemId, int before = -1 );
        /**
         * Remove the client at index \p index from the group. If \p newGeom is set then the client
         * will move and resize to the specified geometry, otherwise it will stay where the group
         * is located.
         */
        void removeFromClientGroup( int index, const QRect& newGeom = QRect() );
        /**
         * Close the client at index \p index.
         */
        void closeClientGroupItem( int index );
        /**
         * Close all windows in this group.
         */
        void closeAllInClientGroup();
        /**
         * Display the right-click client menu belonging to the client at index \p index at the
         * global coordinates specified by \p pos.
         */
        void displayClientMenu( int index, const QPoint& pos );
        /**
         * Determine which action the user has mapped \p button to. Useful for determining whether
         * a button press was for window tab dragging or for displaying the client menu.
         */
        WindowOperation buttonToWindowOperation( Qt::MouseButtons button );
    };

inline
KDecorationDefines::MaximizeMode operator^( KDecorationDefines::MaximizeMode m1, KDecorationDefines::MaximizeMode m2 )
    {
    return KDecorationDefines::MaximizeMode( int(m1) ^ int(m2) );
    }

inline
KDecorationDefines::MaximizeMode operator&( KDecorationDefines::MaximizeMode m1, KDecorationDefines::MaximizeMode m2 )
    {
    return KDecorationDefines::MaximizeMode( int(m1) & int(m2) );
    }

inline
KDecorationDefines::MaximizeMode operator|( KDecorationDefines::MaximizeMode m1, KDecorationDefines::MaximizeMode m2 )
    {
    return KDecorationDefines::MaximizeMode( int(m1) | int(m2) );
    }

inline QWidget* KDecoration::widget()
    {
    return w_;
    }

inline const QWidget* KDecoration::widget() const
    {
    return w_;
    }

inline KDecorationFactory* KDecoration::factory() const
    {
    return factory_;
    }

inline bool KDecoration::isOnAllDesktops() const
    {
    return desktop() == NET::OnAllDesktops;
    }

inline int KDecoration::width() const
    {
    return geometry().width();
    }

inline int KDecoration::height() const
    {
    return geometry().height();
    }

/** @} */

#endif