plasma/delegate.h

   1 /*
   2     Copyright 2007 Robert Knight <robertknight@gmail.com>
   3     Copyright 2008 Marco Martin <notmart@gmail.com>
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Library General Public
   7     License as published by the Free Software Foundation; either
   8     version 2 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Library General Public License for more details.
  14
  15     You should have received a copy of the GNU Library General Public License
  16     along with this library; see the file COPYING.LIB.  If not, write to
  17     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18     Boston, MA 02110-1301, USA.
  19 */
  20
  21 #ifndef PLASMA_DELEGATE_H
  22 #define PLASMA_DELEGATE_H
  23
  24 // Qt
  25 #include <QtGui/QAbstractItemDelegate>
  26
  27 // Plasma
  28 #include <plasma/plasma_export.h>
  29
  30 namespace Plasma
  31 {
  32
  33 class DelegatePrivate;
  34
  35 /**
  36  * @class Delegate plasma/delegate.h <Plasma/Delegate>
  37  *
  38  * Item delegate for rendering items in Plasma menus implemented with item views.
  39  *
  40  * The delegate makes use of its own data roles that are:
  41  * SubTitleRole: the text of the subtitle
  42  * SubTitleMandatoryRole: if the subtitle is to always be displayed
  43  *   (as default the subtitle is displayed only on mouse over)
  44  * ColumnTypeRole: if the column is a main column (with title and subtitle)
  45  * or a secondary action column (only a little icon that appears on mouse
  46  * over is displayed)
  47  */
  48 class PLASMA_EXPORT Delegate : public QAbstractItemDelegate
  49 {
  50     Q_OBJECT
  51 public:
  52
  53     enum SpecificRoles {
  54         SubTitleRole = Qt::UserRole + 1,
  55         SubTitleMandatoryRole = Qt::UserRole + 2,
  56         ColumnTypeRole = Qt::UserRole + 3
  57     };
  58
  59     enum ColumnType {
  60         MainColumn = 1,
  61         SecondaryActionColumn = 2
  62     };
  63
  64     Delegate(QObject *parent = 0);
  65     ~Delegate();
  66
  67     /**
  68      * Maps an arbitrary role to a role belonging to SpecificRoles.
  69      * Using this function you can use any model with this delegate.
  70      *
  71      * @param role a role belonging to SpecificRoles
  72      * @param actual an arbitrary role of the model we are using
  73      */
  74     void setRoleMapping(SpecificRoles role, int actual);
  75
  76     int roleMapping(SpecificRoles role) const;
  77
  78     //Reimplemented
  79     virtual void paint(QPainter *painter, const QStyleOptionViewItem &option,
  80                        const QModelIndex &index) const;
  81
  82     /**
  83      * @return true if a tooltip should be shown
  84      */
  85     bool showToolTip() const;
  86
  87 protected:
  88     /**
  89      * Returns the empty area after the title.
  90      * The height is the height of the subtitle.
  91      * It can be used by subclasses that wants to paint additional data after
  92      * calling the paint function of the superclass.
  93      *
  94      * @param option options for the title text
  95      * @param index model index that we want to compute the free area
  96      */
  97     QRect rectAfterTitle(const QStyleOptionViewItem &option, const QModelIndex &index) const;
  98
  99     /**
 100      * Returns the empty area after the subtitle.
 101      * The height is the height of the subtitle.
 102      * It can be used by subclasses, that wants to paint additional data.
 103      *
 104      * @param option options for the subtitle text
 105      * @param index model index that we want to compute the free area
 106      */
 107     QRect rectAfterSubTitle(const QStyleOptionViewItem &option, const QModelIndex &index) const;
 108
 109     /**
 110      * Returns the empty area after both the title and the subtitle.
 111      * The height is the height of the item.
 112      * It can be used by subclasses that wants to paint additional data
 113      *
 114      * @param option options for the title and subtitle text
 115      * @param index model index that we want to compute the free area
 116      */
 117     QRect emptyRect(const QStyleOptionViewItem &option, const QModelIndex &index) const;
 118
 119     virtual QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const;
 120
 121 private:
 122     DelegatePrivate *const d;
 123 };
 124
 125 }
 126
 127 #endif // PLASMA_DELEGATE_H