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_itemIndex(-1),
  40     m_lineColor(),
  41     m_roleColor(),
  42     m_roleBounds()
  43 {
  44 }
  45
  46 KItemListGroupHeader::~KItemListGroupHeader()
  47 {
  48 }
  49
  50 void KItemListGroupHeader::setRole(const QByteArray& role)
  51 {
  52     if (m_role != role) {
  53         const QByteArray previous = m_role;
  54         m_role = role;
  55         update();
  56         roleChanged(role, previous);
  57     }
  58 }
  59
  60 QByteArray KItemListGroupHeader::role() const
  61 {
  62     return m_role;
  63 }
  64
  65 void KItemListGroupHeader::setData(const QVariant& data)
  66 {
  67     if (m_data != data) {
  68         const QVariant previous = m_data;
  69         m_data = data;
  70         update();
  71         dataChanged(data, previous);
  72     }
  73 }
  74
  75 QVariant KItemListGroupHeader::data() const
  76 {
  77     return m_data;
  78 }
  79
  80 void KItemListGroupHeader::setStyleOption(const KItemListStyleOption& option)
  81 {
  82     const KItemListStyleOption previous = m_styleOption;
  83     m_styleOption = option;
  84     m_dirtyCache = true;
  85     styleOptionChanged(option, previous);
  86 }
  87
  88 const KItemListStyleOption& KItemListGroupHeader::styleOption() const
  89 {
  90     return m_styleOption;
  91 }
  92
  93 void KItemListGroupHeader::setScrollOrientation(Qt::Orientation orientation)
  94 {
  95     if (m_scrollOrientation != orientation) {
  96         const Qt::Orientation previous = m_scrollOrientation;
  97         m_scrollOrientation = orientation;
  98         if (orientation == Qt::Vertical) {
  99             m_dirtyCache = true;
 100         }
 101         scrollOrientationChanged(orientation, previous);
 102     }
 103 }
 104
 105 void KItemListGroupHeader::setItemIndex(int index)
 106 {
 107     if (m_itemIndex != index) {
 108         const int previous = m_itemIndex;
 109         m_itemIndex = index;
 110         m_dirtyCache = true;
 111         itemIndexChanged(m_itemIndex, previous);
 112     }
 113 }
 114
 115 int KItemListGroupHeader::itemIndex() const
 116 {
 117     return m_itemIndex;
 118 }
 119
 120 Qt::Orientation KItemListGroupHeader::scrollOrientation() const
 121 {
 122     return m_scrollOrientation;
 123 }
 124
 125 void KItemListGroupHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 126 {
 127     Q_UNUSED(option);
 128     Q_UNUSED(widget);
 129
 130     if (m_dirtyCache) {
 131         updateCache();
 132     }
 133
 134     if (m_itemIndex == 0) {
 135         // No top- or left-line should be drawn for the first group-header
 136         return;
 137     }
 138
 139     painter->setPen(m_lineColor);
 140
 141     if (m_scrollOrientation == Qt::Horizontal) {
 142         painter->drawLine(0, 0, 0, size().height() - 1);
 143     } else {
 144         painter->drawLine(0, 0, size().width() - 1, 0);
 145     }
 146 }
 147
 148 QRectF KItemListGroupHeader::roleBounds() const
 149 {
 150     return m_roleBounds;
 151 }
 152
 153 QColor KItemListGroupHeader::roleColor() const
 154 {
 155     return m_roleColor;
 156 }
 157
 158 void KItemListGroupHeader::roleChanged(const QByteArray& current, const QByteArray& previous)
 159 {
 160     Q_UNUSED(current);
 161     Q_UNUSED(previous);
 162 }
 163
 164 void KItemListGroupHeader::dataChanged(const QVariant& current, const QVariant& previous)
 165 {
 166     Q_UNUSED(current);
 167     Q_UNUSED(previous);
 168 }
 169
 170 void KItemListGroupHeader::styleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 171 {
 172     Q_UNUSED(current);
 173     Q_UNUSED(previous);
 174 }
 175
 176 void KItemListGroupHeader::scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 177 {
 178     Q_UNUSED(current);
 179     Q_UNUSED(previous);
 180 }
 181
 182 void KItemListGroupHeader::itemIndexChanged(int current, int previous)
 183 {
 184     Q_UNUSED(current);
 185     Q_UNUSED(previous);
 186 }
 187
 188 void KItemListGroupHeader::resizeEvent(QGraphicsSceneResizeEvent* event)
 189 {
 190     QGraphicsWidget::resizeEvent(event);
 191     if (event->oldSize().height() != event->newSize().height()) {
 192         m_dirtyCache = true;
 193     }
 194 }
 195
 196 void KItemListGroupHeader::updateCache()
 197 {
 198     Q_ASSERT(m_dirtyCache);
 199
 200     // Calculate the role- and line-color. No alphablending is used for
 201     // performance reasons.
 202     const QColor c1 = m_styleOption.palette.text().color();
 203     const QColor c2 = m_styleOption.palette.base().color();
 204     m_lineColor = mixedColor(c1, c2, 10);
 205     m_roleColor = mixedColor(c1, c2, 70);
 206
 207     const int padding = qMax(1, m_styleOption.padding);
 208     const int horizontalMargin = qMax(2, m_styleOption.horizontalMargin);
 209
 210     const QFontMetrics fontMetrics(m_styleOption.font);
 211     const qreal roleHeight = fontMetrics.height();
 212
 213     const int y = (m_scrollOrientation == Qt::Vertical) ? padding : horizontalMargin;
 214
 215     m_roleBounds = QRectF(horizontalMargin + padding,
 216                           y,
 217                           size().width() - 2 * padding - horizontalMargin,
 218                           roleHeight);
 219
 220     m_dirtyCache = false;
 221 }
 222
 223 QColor KItemListGroupHeader::mixedColor(const QColor& c1, const QColor& c2, int c1Percent)
 224 {
 225     Q_ASSERT(c1Percent >= 0 && c1Percent <= 100);
 226
 227     const int c2Percent = 100 - c1Percent;
 228     return QColor((c1.red()   * c1Percent + c2.red()   * c2Percent) / 100,
 229                   (c1.green() * c1Percent + c2.green() * c2Percent) / 100,
 230                   (c1.blue()  * c1Percent + c2.blue()  * c2Percent) / 100);
 231 }
 232
 233 #include "kitemlistgroupheader.moc"