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 "kstandarditemlistgroupheader.h"
  24
  25 #include "kitemlistview.h"
  26
  27 #include <QGraphicsSceneResizeEvent>
  28 #include <QPainter>
  29 #include <QStyleOptionGraphicsItem>
  30
  31 KItemListGroupHeader::KItemListGroupHeader(QGraphicsWidget* parent) :
  32     QGraphicsWidget(parent, nullptr),
  33     m_dirtyCache(true),
  34     m_role(),
  35     m_data(),
  36     m_styleOption(),
  37     m_scrollOrientation(Qt::Vertical),
  38     m_itemIndex(-1),
  39     m_separatorColor(),
  40     m_roleColor(),
  41     m_roleBounds()
  42 {
  43 }
  44
  45 KItemListGroupHeader::~KItemListGroupHeader()
  46 {
  47 }
  48
  49 void KItemListGroupHeader::setRole(const QByteArray& role)
  50 {
  51     if (m_role != role) {
  52         const QByteArray previous = m_role;
  53         m_role = role;
  54         update();
  55         roleChanged(role, previous);
  56     }
  57 }
  58
  59 QByteArray KItemListGroupHeader::role() const
  60 {
  61     return m_role;
  62 }
  63
  64 void KItemListGroupHeader::setData(const QVariant& data)
  65 {
  66     if (m_data != data) {
  67         const QVariant previous = m_data;
  68         m_data = data;
  69         update();
  70         dataChanged(data, previous);
  71     }
  72 }
  73
  74 QVariant KItemListGroupHeader::data() const
  75 {
  76     return m_data;
  77 }
  78
  79 void KItemListGroupHeader::setStyleOption(const KItemListStyleOption& option)
  80 {
  81     if (m_styleOption == option) {
  82         return;
  83     }
  84
  85     const KItemListStyleOption previous = m_styleOption;
  86     m_styleOption = option;
  87     m_dirtyCache = true;
  88     styleOptionChanged(option, previous);
  89 }
  90
  91 const KItemListStyleOption& KItemListGroupHeader::styleOption() const
  92 {
  93     return m_styleOption;
  94 }
  95
  96 void KItemListGroupHeader::setScrollOrientation(Qt::Orientation orientation)
  97 {
  98     if (m_scrollOrientation != orientation) {
  99         const Qt::Orientation previous = m_scrollOrientation;
 100         m_scrollOrientation = orientation;
 101         if (orientation == Qt::Vertical) {
 102             m_dirtyCache = true;
 103         }
 104         scrollOrientationChanged(orientation, previous);
 105     }
 106 }
 107
 108 void KItemListGroupHeader::setItemIndex(int index)
 109 {
 110     if (m_itemIndex != index) {
 111         const int previous = m_itemIndex;
 112         m_itemIndex = index;
 113         m_dirtyCache = true;
 114         itemIndexChanged(m_itemIndex, previous);
 115     }
 116 }
 117
 118 int KItemListGroupHeader::itemIndex() const
 119 {
 120     return m_itemIndex;
 121 }
 122
 123 Qt::Orientation KItemListGroupHeader::scrollOrientation() const
 124 {
 125     return m_scrollOrientation;
 126 }
 127
 128 void KItemListGroupHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 129 {
 130     Q_UNUSED(painter);
 131     Q_UNUSED(option);
 132     Q_UNUSED(widget);
 133
 134     if (m_dirtyCache) {
 135         updateCache();
 136     }
 137
 138     paintSeparator(painter, m_separatorColor);
 139     paintRole(painter, m_roleBounds, m_roleColor);
 140 }
 141
 142 void KItemListGroupHeader::roleChanged(const QByteArray& current, const QByteArray& previous)
 143 {
 144     Q_UNUSED(current);
 145     Q_UNUSED(previous);
 146 }
 147
 148 void KItemListGroupHeader::dataChanged(const QVariant& current, const QVariant& previous)
 149 {
 150     Q_UNUSED(current);
 151     Q_UNUSED(previous);
 152 }
 153
 154 void KItemListGroupHeader::styleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 155 {
 156     Q_UNUSED(current);
 157     Q_UNUSED(previous);
 158 }
 159
 160 void KItemListGroupHeader::scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 161 {
 162     Q_UNUSED(current);
 163     Q_UNUSED(previous);
 164 }
 165
 166 void KItemListGroupHeader::itemIndexChanged(int current, int previous)
 167 {
 168     Q_UNUSED(current);
 169     Q_UNUSED(previous);
 170 }
 171
 172 void KItemListGroupHeader::resizeEvent(QGraphicsSceneResizeEvent* event)
 173 {
 174     QGraphicsWidget::resizeEvent(event);
 175     if (event->oldSize().height() != event->newSize().height()) {
 176         m_dirtyCache = true;
 177     }
 178 }
 179
 180 void KItemListGroupHeader::updateCache()
 181 {
 182     Q_ASSERT(m_dirtyCache);
 183
 184     // Calculate the role- and line-color. No alphablending is used for
 185     // performance reasons.
 186     const QColor c1 = textColor();
 187     const QColor c2 = baseColor();
 188     m_separatorColor = mixedColor(c1, c2, 10);
 189     m_roleColor = mixedColor(c1, c2, 60);
 190
 191     const int padding = qMax(1, m_styleOption.padding);
 192     const int horizontalMargin = qMax(2, m_styleOption.horizontalMargin);
 193
 194     const QFontMetrics fontMetrics(m_styleOption.font);
 195     const qreal roleHeight = fontMetrics.height();
 196
 197     const int y = (m_scrollOrientation == Qt::Vertical) ? padding : horizontalMargin;
 198
 199     m_roleBounds = QRectF(horizontalMargin + padding,
 200                           y,
 201                           size().width() - 2 * padding - horizontalMargin,
 202                           roleHeight);
 203
 204     m_dirtyCache = false;
 205 }
 206
 207 QColor KItemListGroupHeader::mixedColor(const QColor& c1, const QColor& c2, int c1Percent)
 208 {
 209     Q_ASSERT(c1Percent >= 0 && c1Percent <= 100);
 210
 211     const int c2Percent = 100 - c1Percent;
 212     return QColor((c1.red()   * c1Percent + c2.red()   * c2Percent) / 100,
 213                   (c1.green() * c1Percent + c2.green() * c2Percent) / 100,
 214                   (c1.blue()  * c1Percent + c2.blue()  * c2Percent) / 100);
 215 }
 216
 217 QPalette::ColorRole KItemListGroupHeader::normalTextColorRole() const
 218 {
 219     return QPalette::Text;
 220 }
 221
 222 QPalette::ColorRole KItemListGroupHeader::normalBaseColorRole() const
 223 {
 224     return QPalette::Window;
 225 }
 226
 227 QColor KItemListGroupHeader::textColor() const
 228 {
 229     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 230     return styleOption().palette.color(group, normalTextColorRole());
 231 }
 232
 233 QColor KItemListGroupHeader::baseColor() const
 234 {
 235     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 236     return styleOption().palette.color(group, normalBaseColorRole());
 237 }
 238