/*
   This file is part of the KDE project

   Copyright © 2006-2007, 2008 Fredrik Höglund <fredrik@kde.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#ifndef KFILEITEMDELEGATE_H
#define KFILEITEMDELEGATE_H

#include <QtGui/QAbstractItemDelegate>
#include <QtGui/QTextOption>
#include <kio/global.h>


class QAbstractItemModel;
class QAbstractItemView;
class QHelpEvent;
class QModelIndex;
class QPainter;


/**
 * KFileItemDelegate is intended to be used to provide a KDE file system
 * view, when using one of the standard item views in Qt with KDirModel.
 *
 * While primarily intended to be used with KDirModel, it uses
 * Qt::DecorationRole and Qt::DisplayRole for the icons and text labels,
 * just like QItemDelegate, and can thus be used with any standard model.
 *
 * When used with KDirModel however, KFileItemDelegate can change the way
 * the display and/or decoration roles are drawn, based on properties
 * of the file items. For example, if the file item is a symbolic link,
 * it will use an italic font to draw the file name.
 *
 * KFileItemDelegate also supports showing additional information about
 * the file items below the icon labels.
 *
 * Which information should be shown, if any, is controlled by the
 * @ref information property, which is a list that can be set by calling
 * setShowInformation(), and read by calling showInformation().
 * By default this list is empty.
 *
 * To use KFileItemDelegate, instantiate an object from the delegate,
 * and call setItemDelegate() in one of the standard item views in Qt:
 *
 * @code
 * QListView *listview = new QListView(this);
 * KFileItemDelegate *delegate = new KFileItemDelegate(this);
 * listview->setItemDelegate(delegate);
 * @endcode
 */
class KIO_EXPORT KFileItemDelegate : public QAbstractItemDelegate
{
    Q_OBJECT

    /**
     * This property holds which additional information (if any) should be shown below
     * items in icon views.
     *
     * Access functions:
     * @li void setShownformation(InformationList information)
     * @li InformationList showInformation() const
     */
    Q_PROPERTY(InformationList information READ showInformation WRITE setShowInformation)

    /**
     * This property holds the color used for the text shadow.
     *
     * The alpha value in the color determines the opacity of the shadow.
     * Shadows are only rendered when the alpha value is non-zero.
     * The default value for this property is Qt::transparent.
     *
     * Access functions:
     * @li void setShadowColor(const QColor &color)
     * @li QColor shadowColor() const
     */
    Q_PROPERTY(QColor shadowColor READ shadowColor WRITE setShadowColor)

    /**
     * This property holds the horizontal and vertical offset for the text shadow.
     * The default value for this property is (1, 1).
     *
     * Access functions:
     * @li void setShadowOffset(const QPointF &offset)
     * @li QPointF shadowOffset() const
     */
    Q_PROPERTY(QPointF shadowOffset READ shadowOffset WRITE setShadowOffset)

    /**
     * This property holds the blur radius for the text shadow.
     * The default value for this property is 2.
     *
     * Access functions:
     * @li void setShadowBlur(qreal radius)
     * @li qreal shadowBlur() const
     */
    Q_PROPERTY(qreal shadowBlur READ shadowBlur WRITE setShadowBlur)

    /**
     * This property holds the maximum size that can be returned
     * by KFileItemDelegate::sizeHint(). If the maximum size is empty,
     * it will be ignored.
     */
    Q_PROPERTY(QSize maximumSize READ maximumSize WRITE setMaximumSize)

    /**
     * This property determines whether a tooltip will be shown by the delegate
     * if the display role is elided. This tooltip will contain the full display
     * role information. The tooltip will only be shown if the Qt::ToolTipRole differs
     * from Qt::DisplayRole, or if they match, showToolTipWhenElided flag is set and
     * the display role information is elided.
     */
    Q_PROPERTY(bool showToolTipWhenElided READ showToolTipWhenElided WRITE setShowToolTipWhenElided)

    /**
     * This property determines if there are KIO jobs on a destination URL visible, then
     * they will have a small animation overlay displayed on them.
     * @since 4.5
     */
    Q_PROPERTY(bool jobTransfersVisible READ jobTransfersVisible WRITE setJobTransfersVisible)

    Q_ENUMS(Information)


    public:
        /**
         * This enum defines the additional information that can be displayed below item
         * labels in icon views.
         *
         * The information will only be shown for indexes for which the model provides
         * a valid value for KDirModel::FileItemRole, and only when there's sufficient vertical
         * space to display at least one line of the information, along with the display label.
         *
         * For the number of items to be shown for folders, the model must provide a valid
         * value for KDirMode::ChildCountRole, in addition to KDirModel::FileItemRole.
         *
         * Note that KFileItemDelegate will not call KFileItem::determineMimeType() if
         * KFileItem::isMimeTypeKnown() returns false, so if you want to display mime types
         * you should use a KMimeTypeResolver with the model and the view, to ensure that mime
         * types are resolved. If the mime type isn't known, "Unknown" will be displayed until
         * the mime type has been successfully resolved.
         *
         * @see setShowInformation()
         * @see showInformation()
         * @see information
         */
        enum Information {
            NoInformation,     ///< No additional information will be shown for items.
            Size,              ///< The file size for files, and the number of items for folders.
            Permissions,       ///< A UNIX permissions string, e.g. -rwxr-xr-x.
            OctalPermissions,  ///< The permissions as an octal value, e.g. 0644.
            Owner,             ///< The user name of the file owner, e.g. root
            OwnerAndGroup,     ///< The user and group that owns the file, e.g. root:root
            CreationTime,      ///< The date and time the file/folder was created.
            ModificationTime,  ///< The date and time the file/folder was last modified.
            AccessTime,        ///< The date and time the file/folder was last accessed.
            MimeType,          ///< The mime type for the item, e.g. text/html.
            FriendlyMimeType,  ///< The descriptive name for the mime type, e.g. HTML Document.
            LinkDest,          ///< The destination of a symbolic link. @since 4.5
            LocalPathOrUrl,    ///< The local path to the file or the URL in case it is not a local file. @since 4.5
            Comment            ///< A simple comment that can be displayed to the user as is. @since 4.6
        };

        typedef QList<Information> InformationList;


        /**
         * Constructs a new KFileItemDelegate.
         *
         * @param parent The parent object for the delegate.
         */
        explicit KFileItemDelegate(QObject *parent = 0);


        /**
         * Destroys the item delegate.
         */
        virtual ~KFileItemDelegate();


        /**
         * Returns the nominal size for the item referred to by @p index, given the
         * provided options.
         *
         * If the model provides a valid Qt::FontRole and/or Qt::AlignmentRole for the item,
         * those will be used instead of the ones specified in the style options.
         *
         * This function is reimplemented from @ref QAbstractItemDelegate.
         *
         * @param option  The style options that should be used when painting the item.
         * @param index   The index to the item for which to return the size hint.
         */
        virtual QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const;


        /**
         * Paints the item indicated by @p index, using @p painter.
         *
         * The item will be drawn in the rectangle specified by option.rect.
         * The correct size for that rectangle can be obtained by calling
         * @ref sizeHint().
         *
         * This function will use the following data values if the model provides
         * them for the item, in place of the values in @p option:
         *
         * @li Qt::FontRole        The font that should be used for the display role.
         * @li Qt::AlignmentRole   The alignment of the display role.
         * @li Qt::ForegroundRole  The text color for the display role.
         * @li Qt::BackgroundRole  The background color for the item.
         *
         * This function is reimplemented from @ref QAbstractItemDelegate.
         *
         * @param painter The painter with which to draw the item.
         * @param option  The style options that should be used when painting the item.
         * @param index   The index to the item that should be painted.
         */
        virtual void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;


        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        virtual QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const;


        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        virtual bool editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem & option, const QModelIndex &index);


        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        virtual void setEditorData(QWidget *editor, const QModelIndex &index) const;


        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        virtual void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const;


        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        virtual void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option,const QModelIndex &index) const;


        /**
         * Sets the list of information lines that are shown below the icon label in list views.
         *
         * You will typically construct the list like this:
         * @code
         * KFileItemDelegate::InformationList list;
         * list << KFileItemDelegate::FriendlyMimeType << KFileItemDelegate::Size;
         * delegate->setShowInformation(list);
         * @endcode
         *
         * The information lines will be displayed in the list order.
         * The delegate will first draw the item label, and then as many information
         * lines as will fit in the available space.
         *
         * @param list A list of information items that should be shown
         */
        void setShowInformation(const InformationList &list);


        /**
         * Sets a single information line that is shown below the icon label in list views.
         *
         * This is a convenience function for when you only want to show a single line
         * of information.
         *
         * @param information The information that should be shown
         */
        void setShowInformation(Information information);


        /**
         * Returns the file item information that should be shown below item labels in list views.
         */
        InformationList showInformation() const;


        /**
         * Sets the color used for drawing the text shadow.
         *
         * To enable text shadows, set the shadow color to a non-transparent color.
         * To disable text shadows, set the color to Qt::transparent.
         *
         * @see shadowColor()
         */
        void setShadowColor(const QColor &color);


        /**
         * Returns the color used for the text shadow.
         *
         * @see setShadowColor()
         */
        QColor shadowColor() const;


        /**
         * Sets the horizontal and vertical offset for the text shadow.
         *
         * @see shadowOffset()
         */
        void setShadowOffset(const QPointF &offset);


        /**
         * Returns the offset used for the text shadow.
         *
         * @see setShadowOffset()
         */
        QPointF shadowOffset() const;


        /**
         * Sets the blur radius for the text shadow.
         *
         * @see shadowBlur()
         */
        void setShadowBlur(qreal radius);


        /**
         * Returns the blur radius for the text shadow.
         *
         * @see setShadowBlur()
         */
        qreal shadowBlur() const;

        /**
         * Sets the maximum size for KFileItemDelegate::sizeHint().
         *
         * @see maximumSize()
         * @since 4.1
         */
        void setMaximumSize(const QSize &size);

        /**
         * Returns the maximum size for KFileItemDelegate::sizeHint().
         *
         * @see setMaximumSize()
         * @since 4.1
         */
        QSize maximumSize() const;

        /**
         * Sets whether a tooltip should be shown if the display role is
         * elided containing the full display role information.
         *
         * @note The tooltip will only be shown if the Qt::ToolTipRole differs
         *       from Qt::DisplayRole, or if they match, showToolTipWhenElided
         *       flag is set and the display role information is elided.
         * @see showToolTipWhenElided()
         * @since 4.2
         */
        void setShowToolTipWhenElided(bool showToolTip);

        /**
         * Returns whether a tooltip should be shown if the display role
         * is elided containing the full display role information.
         *
         * @note The tooltip will only be shown if the Qt::ToolTipRole differs
         *       from Qt::DisplayRole, or if they match, showToolTipWhenElided
         *       flag is set and the display role information is elided.
         * @see setShowToolTipWhenElided()
         * @since 4.2
         */
        bool showToolTipWhenElided() const;

        /**
         * Returns the rectangle of the icon that is aligned inside the decoration
         * rectangle.
         * @since 4.4
         */
        QRect iconRect(const QStyleOptionViewItem &option, const QModelIndex &index) const;

        /**
         * When the contents text needs to be wrapped, @p wrapMode strategy
         * will be followed.
         *
         * @since 4.4
         */
        void setWrapMode(QTextOption::WrapMode wrapMode);

        /**
         * Returns the wrapping strategy followed to show text when it needs
         * wrapping.
         *
         * @since 4.4
         */
        QTextOption::WrapMode wrapMode() const;

        /**
         * Enable/Disable the displaying of an animated overlay that is shown for any destination
         * urls (in the view). When enabled, the animations (if any) will be drawn automatically.
         *
         * Only the files/folders that are visible and have jobs associated with them
         * will display the animation.
         * You would likely not want this enabled if you perform some kind of custom painting
         * that takes up a whole item, and will just make this(and what you paint) look funky.
         *
         * Default is disabled.
         *
         * Note: The model (KDirModel) needs to have it's method called with the same
         * value, when you make the call to this method.
         *
         * @since 4.5
         */
        void setJobTransfersVisible(bool jobTransfersVisible);

        /**
         * Returns whether or not the displaying of job transfers is enabled.
         * @see setJobTransfersVisible()
         * @since 4.5
         */
        bool jobTransfersVisible() const;

        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        virtual bool eventFilter(QObject *object, QEvent *event);

    public Q_SLOTS:
        /**
         * Reimplemented from @ref QAbstractItemDelegate.
         */
        bool helpEvent(QHelpEvent * event, QAbstractItemView *view, const QStyleOptionViewItem &option, const QModelIndex &index);

        /**
         * Returns the shape of the item as a region.
         * The returned region can be used for precise hit testing of the item.
         */
        QRegion shape(const QStyleOptionViewItem &option, const QModelIndex &index);

    private:
        class Private;
        Private * const d; /// @internal
        Q_DISABLE_COPY(KFileItemDelegate)
};

#endif // KFILEITEMDELEGATE_H

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