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, 0),
  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     const KItemListStyleOption previous = m_styleOption;
  82     m_styleOption = option;
  83     m_dirtyCache = true;
  84     styleOptionChanged(option, previous);
  85 }
  86
  87 const KItemListStyleOption& KItemListGroupHeader::styleOption() const
  88 {
  89     return m_styleOption;
  90 }
  91
  92 void KItemListGroupHeader::setScrollOrientation(Qt::Orientation orientation)
  93 {
  94     if (m_scrollOrientation != orientation) {
  95         const Qt::Orientation previous = m_scrollOrientation;
  96         m_scrollOrientation = orientation;
  97         if (orientation == Qt::Vertical) {
  98             m_dirtyCache = true;
  99         }
 100         scrollOrientationChanged(orientation, previous);
 101     }
 102 }
 103
 104 void KItemListGroupHeader::setItemIndex(int index)
 105 {
 106     if (m_itemIndex != index) {
 107         const int previous = m_itemIndex;
 108         m_itemIndex = index;
 109         m_dirtyCache = true;
 110         itemIndexChanged(m_itemIndex, previous);
 111     }
 112 }
 113
 114 int KItemListGroupHeader::itemIndex() const
 115 {
 116     return m_itemIndex;
 117 }
 118
 119 Qt::Orientation KItemListGroupHeader::scrollOrientation() const
 120 {
 121     return m_scrollOrientation;
 122 }
 123
 124 void KItemListGroupHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 125 {
 126     Q_UNUSED(painter);
 127     Q_UNUSED(option);
 128     Q_UNUSED(widget);
 129
 130     if (m_dirtyCache) {
 131         updateCache();
 132     }
 133
 134     paintSeparator(painter, m_separatorColor);
 135     paintRole(painter, m_roleBounds, m_roleColor);
 136 }
 137
 138 void KItemListGroupHeader::roleChanged(const QByteArray& current, const QByteArray& previous)
 139 {
 140     Q_UNUSED(current);
 141     Q_UNUSED(previous);
 142 }
 143
 144 void KItemListGroupHeader::dataChanged(const QVariant& current, const QVariant& previous)
 145 {
 146     Q_UNUSED(current);
 147     Q_UNUSED(previous);
 148 }
 149
 150 void KItemListGroupHeader::styleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 151 {
 152     Q_UNUSED(current);
 153     Q_UNUSED(previous);
 154 }
 155
 156 void KItemListGroupHeader::scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 157 {
 158     Q_UNUSED(current);
 159     Q_UNUSED(previous);
 160 }
 161
 162 void KItemListGroupHeader::itemIndexChanged(int current, int previous)
 163 {
 164     Q_UNUSED(current);
 165     Q_UNUSED(previous);
 166 }
 167
 168 void KItemListGroupHeader::resizeEvent(QGraphicsSceneResizeEvent* event)
 169 {
 170     QGraphicsWidget::resizeEvent(event);
 171     if (event->oldSize().height() != event->newSize().height()) {
 172         m_dirtyCache = true;
 173     }
 174 }
 175
 176 void KItemListGroupHeader::updateCache()
 177 {
 178     Q_ASSERT(m_dirtyCache);
 179
 180     // Calculate the role- and line-color. No alphablending is used for
 181     // performance reasons.
 182     const QColor c1 = textColor();
 183     const QColor c2 = baseColor();
 184     m_separatorColor = mixedColor(c1, c2, 10);
 185     m_roleColor = mixedColor(c1, c2, 60);
 186
 187     const int padding = qMax(1, m_styleOption.padding);
 188     const int horizontalMargin = qMax(2, m_styleOption.horizontalMargin);
 189
 190     const QFontMetrics fontMetrics(m_styleOption.font);
 191     const qreal roleHeight = fontMetrics.height();
 192
 193     const int y = (m_scrollOrientation == Qt::Vertical) ? padding : horizontalMargin;
 194
 195     m_roleBounds = QRectF(horizontalMargin + padding,
 196                           y,
 197                           size().width() - 2 * padding - horizontalMargin,
 198                           roleHeight);
 199
 200     m_dirtyCache = false;
 201 }
 202
 203 QColor KItemListGroupHeader::mixedColor(const QColor& c1, const QColor& c2, int c1Percent)
 204 {
 205     Q_ASSERT(c1Percent >= 0 && c1Percent <= 100);
 206
 207     const int c2Percent = 100 - c1Percent;
 208     return QColor((c1.red()   * c1Percent + c2.red()   * c2Percent) / 100,
 209                   (c1.green() * c1Percent + c2.green() * c2Percent) / 100,
 210                   (c1.blue()  * c1Percent + c2.blue()  * c2Percent) / 100);
 211 }
 212
 213 QPalette::ColorRole KItemListGroupHeader::normalTextColorRole() const
 214 {
 215     return QPalette::Text;
 216 }
 217
 218 QPalette::ColorRole KItemListGroupHeader::normalBaseColorRole() const
 219 {
 220     return QPalette::Window;
 221 }
 222
 223 QColor KItemListGroupHeader::textColor() const
 224 {
 225     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 226     return styleOption().palette.color(group, normalTextColorRole());
 227 }
 228
 229 QColor KItemListGroupHeader::baseColor() const
 230 {
 231     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 232     return styleOption().palette.color(group, normalBaseColorRole());
 233 }
 234