src/kitemviews/kitemlistheader.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  18  ***************************************************************************/
  19
  20 #include "kitemlistheader_p.h"
  21
  22 #include <KAction>
  23 #include <KMenu>
  24 #include "kitemmodelbase.h"
  25
  26 #include <QApplication>
  27 #include <QGraphicsSceneHoverEvent>
  28 #include <QPainter>
  29 #include <QStyleOptionHeader>
  30
  31 #include <KDebug>
  32
  33 KItemListHeader::KItemListHeader(QGraphicsWidget* parent) :
  34     QGraphicsWidget(parent),
  35     m_model(0),
  36     m_visibleRoles(),
  37     m_visibleRolesWidths(),
  38     m_hoveredRoleIndex(-1),
  39     m_pressedRoleIndex(-1),
  40     m_roleOperation(NoRoleOperation),
  41     m_pressedMousePos()
  42 {
  43     setAcceptHoverEvents(true);
  44
  45     QStyleOptionHeader option;
  46     const QSize headerSize = style()->sizeFromContents(QStyle::CT_HeaderSection, &option, QSize());
  47     resize(0, headerSize.height());
  48 }
  49
  50 KItemListHeader::~KItemListHeader()
  51 {
  52 }
  53
  54 void KItemListHeader::setModel(KItemModelBase* model)
  55 {
  56     if (m_model == model) {
  57         return;
  58     }
  59
  60     if (m_model) {
  61         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
  62                    this, SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
  63         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
  64                    this, SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
  65     }
  66
  67     m_model = model;
  68
  69     if (m_model) {
  70         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
  71                 this, SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
  72         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
  73                 this, SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
  74     }
  75 }
  76
  77 KItemModelBase* KItemListHeader::model() const
  78 {
  79     return m_model;
  80 }
  81
  82 void KItemListHeader::setVisibleRoles(const QList<QByteArray>& roles)
  83 {
  84     m_visibleRoles = roles;
  85     update();
  86 }
  87
  88 QList<QByteArray> KItemListHeader::visibleRoles() const
  89 {
  90     return m_visibleRoles;
  91 }
  92
  93 void KItemListHeader::setVisibleRolesWidths(const QHash<QByteArray, qreal> rolesWidths)
  94 {
  95     m_visibleRolesWidths = rolesWidths;
  96
  97     // Assure that no width is smaller than the minimum allowed width
  98     const qreal minWidth = minimumRoleWidth();
  99     QMutableHashIterator<QByteArray, qreal> it(m_visibleRolesWidths);
 100     while (it.hasNext()) {
 101         it.next();
 102         if (it.value() < minWidth) {
 103             m_visibleRolesWidths.insert(it.key(), minWidth);
 104         }
 105     }
 106
 107     update();
 108 }
 109
 110 QHash<QByteArray, qreal> KItemListHeader::visibleRolesWidths() const
 111 {
 112     return m_visibleRolesWidths;
 113 }
 114
 115 void KItemListHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 116 {
 117     Q_UNUSED(option);
 118     Q_UNUSED(widget);
 119
 120     if (!m_model) {
 121         return;
 122     }
 123
 124     // Draw roles
 125     painter->setFont(font());
 126     painter->setPen(palette().text().color());
 127
 128     qreal x = 0;
 129     int orderIndex = 0;
 130     foreach (const QByteArray& role, m_visibleRoles) {
 131         const qreal roleWidth = m_visibleRolesWidths.value(role);
 132         const QRectF rect(x, 0, roleWidth, size().height());
 133         paintRole(painter, role, rect, orderIndex);
 134         x += roleWidth;
 135         ++orderIndex;
 136     }
 137
 138     // Draw background without roles
 139     QStyleOption opt;
 140     opt.init(widget);
 141     opt.rect = QRect(x, 0, size().width() - x, size().height());
 142     opt.state |= QStyle::State_Horizontal;
 143     style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, painter);
 144 }
 145
 146 void KItemListHeader::mousePressEvent(QGraphicsSceneMouseEvent* event)
 147 {
 148     if (event->button() & Qt::LeftButton) {
 149         updatePressedRoleIndex(event->pos());
 150         m_pressedMousePos = event->pos();
 151         m_roleOperation = isAboveRoleGrip(m_pressedMousePos, m_pressedRoleIndex) ?
 152                           ResizeRoleOperation : NoRoleOperation;
 153         event->accept();
 154     } else {
 155         event->ignore();
 156     }
 157 }
 158
 159 void KItemListHeader::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
 160 {
 161     QGraphicsWidget::mouseReleaseEvent(event);
 162
 163     if (m_pressedRoleIndex == -1) {
 164         return;
 165     }
 166
 167     if (m_roleOperation == NoRoleOperation) {
 168         // Only a click has been done and no moving or resizing has been started
 169         const QByteArray sortRole = m_model->sortRole();
 170         const int sortRoleIndex = m_visibleRoles.indexOf(sortRole);
 171         if (m_pressedRoleIndex == sortRoleIndex) {
 172             // Toggle the sort order
 173             const Qt::SortOrder toggled = (m_model->sortOrder() == Qt::AscendingOrder) ?
 174                                           Qt::DescendingOrder : Qt::AscendingOrder;
 175             m_model->setSortOrder(toggled);
 176         } else {
 177             // Change the sort role
 178             const QByteArray sortRole = m_visibleRoles.at(m_pressedRoleIndex);
 179             m_model->setSortRole(sortRole);
 180         }
 181     }
 182
 183     m_pressedRoleIndex = -1;
 184     m_roleOperation = NoRoleOperation;
 185     update();
 186 }
 187
 188 void KItemListHeader::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 189 {
 190     QGraphicsWidget::mouseMoveEvent(event);
 191
 192     if (m_roleOperation == ResizeRoleOperation) {
 193         const QByteArray pressedRole = m_visibleRoles.at(m_pressedRoleIndex);
 194
 195         qreal previousWidth = m_visibleRolesWidths.value(pressedRole);
 196         qreal currentWidth = previousWidth;
 197         currentWidth += event->pos().x() - event->lastPos().x();
 198         currentWidth = qMax(minimumRoleWidth(), currentWidth);
 199
 200         m_visibleRolesWidths.insert(pressedRole, currentWidth);
 201         update();
 202
 203         emit visibleRoleWidthChanged(pressedRole, currentWidth, previousWidth);
 204     } else if ((event->pos() - m_pressedMousePos).manhattanLength() >= QApplication::startDragDistance()) {
 205         kDebug() << "Moving of role not supported yet";
 206         m_roleOperation = MoveRoleOperation;
 207     }
 208 }
 209
 210 void KItemListHeader::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
 211 {
 212     QGraphicsWidget::hoverEnterEvent(event);
 213     updateHoveredRoleIndex(event->pos());
 214 }
 215
 216 void KItemListHeader::hoverLeaveEvent(QGraphicsSceneHoverEvent* event)
 217 {
 218     QGraphicsWidget::hoverLeaveEvent(event);
 219     if (m_hoveredRoleIndex != -1) {
 220         m_hoveredRoleIndex = -1;
 221         update();
 222     }
 223 }
 224
 225 void KItemListHeader::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
 226 {
 227     QGraphicsWidget::hoverMoveEvent(event);
 228
 229     const QPointF& pos = event->pos();
 230     updateHoveredRoleIndex(pos);
 231     if (m_hoveredRoleIndex >= 0 && isAboveRoleGrip(pos, m_hoveredRoleIndex)) {
 232         setCursor(Qt::SplitHCursor);
 233     } else {
 234         unsetCursor();
 235     }
 236 }
 237
 238 void KItemListHeader::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 239 {
 240     Q_UNUSED(current);
 241     Q_UNUSED(previous);
 242     update();
 243 }
 244
 245 void KItemListHeader::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 246 {
 247     Q_UNUSED(current);
 248     Q_UNUSED(previous);
 249     update();
 250 }
 251
 252 void KItemListHeader::paintRole(QPainter* painter,
 253                                 const QByteArray& role,
 254                                 const QRectF& rect,
 255                                 int orderIndex)
 256 {
 257     // The following code is based on the code from QHeaderView::paintSection().
 258     // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 259     QStyleOptionHeader option;
 260     option.section = orderIndex;
 261     option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 262     if (isEnabled()) {
 263         option.state |= QStyle::State_Enabled;
 264     }
 265     if (window() && window()->isActiveWindow()) {
 266         option.state |= QStyle::State_Active;
 267     }
 268     if (m_hoveredRoleIndex == orderIndex) {
 269         option.state |= QStyle::State_MouseOver;
 270     }
 271     if (m_pressedRoleIndex == orderIndex) {
 272         option.state |= QStyle::State_Sunken;
 273     }
 274     if (m_model->sortRole() == role) {
 275         option.sortIndicator = (m_model->sortOrder() == Qt::AscendingOrder) ?
 276                                 QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;
 277     }
 278     option.rect = rect.toRect();
 279
 280     if (m_visibleRoles.count() == 1) {
 281         option.position = QStyleOptionHeader::OnlyOneSection;
 282     } else if (orderIndex == 0) {
 283         option.position = QStyleOptionHeader::Beginning;
 284     } else if (orderIndex == m_visibleRoles.count() - 1) {
 285         option.position = QStyleOptionHeader::End;
 286     } else {
 287         option.position = QStyleOptionHeader::Middle;
 288     }
 289
 290     option.orientation = Qt::Horizontal;
 291     option.selectedPosition = QStyleOptionHeader::NotAdjacent;
 292     option.text = m_model->roleDescription(role);
 293
 294     style()->drawControl(QStyle::CE_Header, &option, painter);
 295 }
 296
 297 void KItemListHeader::updatePressedRoleIndex(const QPointF& pos)
 298 {
 299     const int pressedIndex = roleIndexAt(pos);
 300     if (m_pressedRoleIndex != pressedIndex) {
 301         m_pressedRoleIndex = pressedIndex;
 302         update();
 303     }
 304 }
 305
 306 void KItemListHeader::updateHoveredRoleIndex(const QPointF& pos)
 307 {
 308     const int hoverIndex = roleIndexAt(pos);
 309     if (m_hoveredRoleIndex != hoverIndex) {
 310         m_hoveredRoleIndex = hoverIndex;
 311         update();
 312     }
 313 }
 314
 315 int KItemListHeader::roleIndexAt(const QPointF& pos) const
 316 {
 317     int index = -1;
 318
 319     qreal x = 0;
 320     foreach (const QByteArray& role, m_visibleRoles) {
 321         ++index;
 322         x += m_visibleRolesWidths.value(role);
 323         if (pos.x() <= x) {
 324             break;
 325         }
 326     }
 327
 328     return index;
 329 }
 330
 331 bool KItemListHeader::isAboveRoleGrip(const QPointF& pos, int roleIndex) const
 332 {
 333     qreal x = 0;
 334     for (int i = 0; i <= roleIndex; ++i) {
 335         const QByteArray role = m_visibleRoles.at(i);
 336         x += m_visibleRolesWidths.value(role);
 337     }
 338
 339     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 340     return pos.x() >= (x - grip) && pos.x() <= x;
 341 }
 342
 343 qreal KItemListHeader::minimumRoleWidth() const
 344 {
 345     QFontMetricsF fontMetrics(font());
 346     return fontMetrics.height() * 4;
 347 }
 348
 349 #include "kitemlistheader_p.moc"