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  *                                                                         *
   6  *   This program is free software; you can redistribute it and/or modify  *
   7  *   it under the terms of the GNU General Public License as published by  *
   8  *   the Free Software Foundation; either version 2 of the License, or     *
   9  *   (at your option) any later version.                                   *
  10  *                                                                         *
  11  *   This program is distributed in the hope that it will be useful,       *
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  14  *   GNU General Public License for more details.                          *
  15  *                                                                         *
  16  *   You should have received a copy of the GNU General Public License     *
  17  *   along with this program; if not, write to the                         *
  18  *   Free Software Foundation, Inc.,                                       *
  19  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  20  ***************************************************************************/
  21
  22 #include "kstandarditemlistgroupheader.h"
  23
  24 #include "kitemlistview.h"
  25
  26 #include <QGraphicsSceneResizeEvent>
  27 #include <QPainter>
  28 #include <QStyleOptionGraphicsItem>
  29
  30 KItemListGroupHeader::KItemListGroupHeader(QGraphicsWidget* parent) :
  31     QGraphicsWidget(parent),
  32     m_dirtyCache(true),
  33     m_role(),
  34     m_data(),
  35     m_styleOption(),
  36     m_scrollOrientation(Qt::Vertical),
  37     m_itemIndex(-1),
  38     m_separatorColor(),
  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     if (m_styleOption == option) {
  81         return;
  82     }
  83
  84     const KItemListStyleOption previous = m_styleOption;
  85     m_styleOption = option;
  86     m_dirtyCache = true;
  87     styleOptionChanged(option, previous);
  88 }
  89
  90 const KItemListStyleOption& KItemListGroupHeader::styleOption() const
  91 {
  92     return m_styleOption;
  93 }
  94
  95 void KItemListGroupHeader::setScrollOrientation(Qt::Orientation orientation)
  96 {
  97     if (m_scrollOrientation != orientation) {
  98         const Qt::Orientation previous = m_scrollOrientation;
  99         m_scrollOrientation = orientation;
 100         if (orientation == Qt::Vertical) {
 101             m_dirtyCache = true;
 102         }
 103         scrollOrientationChanged(orientation, previous);
 104     }
 105 }
 106
 107 void KItemListGroupHeader::setItemIndex(int index)
 108 {
 109     if (m_itemIndex != index) {
 110         const int previous = m_itemIndex;
 111         m_itemIndex = index;
 112         m_dirtyCache = true;
 113         itemIndexChanged(m_itemIndex, previous);
 114     }
 115 }
 116
 117 int KItemListGroupHeader::itemIndex() const
 118 {
 119     return m_itemIndex;
 120 }
 121
 122 Qt::Orientation KItemListGroupHeader::scrollOrientation() const
 123 {
 124     return m_scrollOrientation;
 125 }
 126
 127 void KItemListGroupHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 128 {
 129     Q_UNUSED(painter)
 130     Q_UNUSED(option)
 131     Q_UNUSED(widget)
 132
 133     if (m_dirtyCache) {
 134         updateCache();
 135     }
 136
 137     paintSeparator(painter, m_separatorColor);
 138     paintRole(painter, m_roleBounds, m_roleColor);
 139 }
 140
 141 void KItemListGroupHeader::roleChanged(const QByteArray& current, const QByteArray& previous)
 142 {
 143     Q_UNUSED(current)
 144     Q_UNUSED(previous)
 145 }
 146
 147 void KItemListGroupHeader::dataChanged(const QVariant& current, const QVariant& previous)
 148 {
 149     Q_UNUSED(current)
 150     Q_UNUSED(previous)
 151 }
 152
 153 void KItemListGroupHeader::styleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 154 {
 155     Q_UNUSED(current)
 156     Q_UNUSED(previous)
 157 }
 158
 159 void KItemListGroupHeader::scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 160 {
 161     Q_UNUSED(current)
 162     Q_UNUSED(previous)
 163 }
 164
 165 void KItemListGroupHeader::itemIndexChanged(int current, int previous)
 166 {
 167     Q_UNUSED(current)
 168     Q_UNUSED(previous)
 169 }
 170
 171 void KItemListGroupHeader::resizeEvent(QGraphicsSceneResizeEvent* event)
 172 {
 173     QGraphicsWidget::resizeEvent(event);
 174     if (event->oldSize().height() != event->newSize().height()) {
 175         m_dirtyCache = true;
 176     }
 177 }
 178
 179 void KItemListGroupHeader::updateCache()
 180 {
 181     Q_ASSERT(m_dirtyCache);
 182
 183     // Calculate the role- and line-color. No alphablending is used for
 184     // performance reasons.
 185     const QColor c1 = textColor();
 186     const QColor c2 = baseColor();
 187     m_separatorColor = mixedColor(c1, c2, 10);
 188     m_roleColor = mixedColor(c1, c2, 60);
 189
 190     const int padding = qMax(1, m_styleOption.padding);
 191     const int horizontalMargin = qMax(2, m_styleOption.horizontalMargin);
 192
 193     const QFontMetrics fontMetrics(m_styleOption.font);
 194     const qreal roleHeight = fontMetrics.height();
 195
 196     const int y = (m_scrollOrientation == Qt::Vertical) ? padding : horizontalMargin;
 197
 198     m_roleBounds = QRectF(horizontalMargin + padding,
 199                           y,
 200                           size().width() - 2 * padding - horizontalMargin,
 201                           roleHeight);
 202
 203     m_dirtyCache = false;
 204 }
 205
 206 QColor KItemListGroupHeader::mixedColor(const QColor& c1, const QColor& c2, int c1Percent)
 207 {
 208     Q_ASSERT(c1Percent >= 0 && c1Percent <= 100);
 209
 210     const int c2Percent = 100 - c1Percent;
 211     return QColor((c1.red()   * c1Percent + c2.red()   * c2Percent) / 100,
 212                   (c1.green() * c1Percent + c2.green() * c2Percent) / 100,
 213                   (c1.blue()  * c1Percent + c2.blue()  * c2Percent) / 100);
 214 }
 215
 216 QPalette::ColorRole KItemListGroupHeader::normalTextColorRole() const
 217 {
 218     return QPalette::Text;
 219 }
 220
 221 QPalette::ColorRole KItemListGroupHeader::normalBaseColorRole() const
 222 {
 223     return QPalette::Window;
 224 }
 225
 226 QColor KItemListGroupHeader::textColor() const
 227 {
 228     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 229     return styleOption().palette.color(group, normalTextColorRole());
 230 }
 231
 232 QColor KItemListGroupHeader::baseColor() const
 233 {
 234     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 235     return styleOption().palette.color(group, normalBaseColorRole());
 236 }
 237