src/kitemviews/kitemlistgroupheader.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   Based on the Itemviews NG project from Trolltech Labs:                *
   5  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   6  *                                                                         *
   7  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  21  ***************************************************************************/
  22
  23 #include "kitemlistgroupheader.h"
  24
  25 #include "kitemlistview.h"
  26
  27 #include <QGraphicsSceneResizeEvent>
  28 #include <QPainter>
  29 #include <QStyleOptionGraphicsItem>
  30 #include <KDebug>
  31
  32 KItemListGroupHeader::KItemListGroupHeader(QGraphicsWidget* parent) :
  33     QGraphicsWidget(parent, 0),
  34     m_dirtyCache(true),
  35     m_role(),
  36     m_data(),
  37     m_styleOption(),
  38     m_scrollOrientation(Qt::Vertical),
  39     m_roleColor(),
  40     m_roleBounds()
  41 {
  42 }
  43
  44 KItemListGroupHeader::~KItemListGroupHeader()
  45 {
  46 }
  47
  48 void KItemListGroupHeader::setRole(const QByteArray& role)
  49 {
  50     if (m_role != role) {
  51         const QByteArray previous = m_role;
  52         m_role = role;
  53         update();
  54         roleChanged(role, previous);
  55     }
  56 }
  57
  58 QByteArray KItemListGroupHeader::role() const
  59 {
  60     return m_role;
  61 }
  62
  63 void KItemListGroupHeader::setData(const QVariant& data)
  64 {
  65     if (m_data != data) {
  66         const QVariant previous = m_data;
  67         m_data = data;
  68         update();
  69         dataChanged(data, previous);
  70     }
  71 }
  72
  73 QVariant KItemListGroupHeader::data() const
  74 {
  75     return m_data;
  76 }
  77
  78 void KItemListGroupHeader::setStyleOption(const KItemListStyleOption& option)
  79 {
  80     const KItemListStyleOption previous = m_styleOption;
  81     m_styleOption = option;
  82     m_dirtyCache = true;
  83     styleOptionChanged(option, previous);
  84 }
  85
  86 const KItemListStyleOption& KItemListGroupHeader::styleOption() const
  87 {
  88     return m_styleOption;
  89 }
  90
  91 void KItemListGroupHeader::setScrollOrientation(Qt::Orientation orientation)
  92 {
  93     if (m_scrollOrientation != orientation) {
  94         const Qt::Orientation previous = m_scrollOrientation;
  95         m_scrollOrientation = orientation;
  96         if (orientation == Qt::Vertical) {
  97             m_dirtyCache = true;
  98         }
  99         scrollOrientationChanged(orientation, previous);
 100     }
 101 }
 102
 103 Qt::Orientation KItemListGroupHeader::scrollOrientation() const
 104 {
 105     return m_scrollOrientation;
 106 }
 107
 108 void KItemListGroupHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 109 {
 110     Q_UNUSED(option);
 111     Q_UNUSED(widget);
 112
 113     if (m_dirtyCache) {
 114         updateCache();
 115     }
 116
 117     if (m_scrollOrientation != Qt::Horizontal) {
 118         painter->setPen(m_roleColor);
 119         const qreal y = m_roleBounds.y() - m_styleOption.margin;
 120         painter->drawLine(0, y, size().width() - 1, y);
 121     }
 122 }
 123
 124 QRectF KItemListGroupHeader::roleBounds() const
 125 {
 126     return m_roleBounds;
 127 }
 128
 129 QColor KItemListGroupHeader::roleColor() const
 130 {
 131     return m_roleColor;
 132 }
 133
 134 void KItemListGroupHeader::roleChanged(const QByteArray& current, const QByteArray& previous)
 135 {
 136     Q_UNUSED(current);
 137     Q_UNUSED(previous);
 138 }
 139
 140 void KItemListGroupHeader::dataChanged(const QVariant& current, const QVariant& previous)
 141 {
 142     Q_UNUSED(current);
 143     Q_UNUSED(previous);
 144 }
 145
 146 void KItemListGroupHeader::styleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 147 {
 148     Q_UNUSED(current);
 149     Q_UNUSED(previous);
 150 }
 151
 152 void KItemListGroupHeader::scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 153 {
 154     Q_UNUSED(current);
 155     Q_UNUSED(previous);
 156 }
 157
 158 void KItemListGroupHeader::resizeEvent(QGraphicsSceneResizeEvent* event)
 159 {
 160     QGraphicsWidget::resizeEvent(event);
 161     if (event->oldSize().height() != event->newSize().height()) {
 162         m_dirtyCache = true;
 163     }
 164 }
 165
 166 void KItemListGroupHeader::updateCache()
 167 {
 168     Q_ASSERT(m_dirtyCache);
 169
 170     // Calculate the outline color. No alphablending is used for
 171     // performance reasons.
 172     const QColor c1 = m_styleOption.palette.text().color();
 173     const QColor c2 = m_styleOption.palette.background().color();
 174     const int p1 = 35;
 175     const int p2 = 100 - p1;
 176     m_roleColor = QColor((c1.red()   * p1 + c2.red()   * p2) / 100,
 177                          (c1.green() * p1 + c2.green() * p2) / 100,
 178                          (c1.blue()  * p1 + c2.blue()  * p2) / 100);
 179
 180     const int margin = m_styleOption.margin;
 181     const QFontMetrics fontMetrics(m_styleOption.font);
 182     const qreal roleHeight = fontMetrics.height();
 183
 184     m_roleBounds = QRectF(margin,
 185                           size().height() - roleHeight - margin,
 186                           size().width() - 2 * margin,
 187                           roleHeight);
 188
 189     m_dirtyCache = false;
 190 }
 191
 192 #include "kitemlistgroupheader.moc"