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 qreal KItemListHeader::minimumRoleWidth() const
 116 {
 117     QFontMetricsF fontMetrics(font());
 118     return fontMetrics.height() * 4;
 119 }
 120
 121 void KItemListHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 122 {
 123     Q_UNUSED(option);
 124     Q_UNUSED(widget);
 125
 126     if (!m_model) {
 127         return;
 128     }
 129
 130     // Draw roles
 131     painter->setFont(font());
 132     painter->setPen(palette().text().color());
 133
 134     qreal x = 0;
 135     int orderIndex = 0;
 136     foreach (const QByteArray& role, m_visibleRoles) {
 137         const qreal roleWidth = m_visibleRolesWidths.value(role);
 138         const QRectF rect(x, 0, roleWidth, size().height());
 139         paintRole(painter, role, rect, orderIndex);
 140         x += roleWidth;
 141         ++orderIndex;
 142     }
 143
 144     // Draw background without roles
 145     QStyleOption opt;
 146     opt.init(widget);
 147     opt.rect = QRect(x, 0, size().width() - x, size().height());
 148     opt.state |= QStyle::State_Horizontal;
 149     style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, painter);
 150 }
 151
 152 void KItemListHeader::mousePressEvent(QGraphicsSceneMouseEvent* event)
 153 {
 154     if (event->button() & Qt::LeftButton) {
 155         updatePressedRoleIndex(event->pos());
 156         m_pressedMousePos = event->pos();
 157         m_roleOperation = isAboveRoleGrip(m_pressedMousePos, m_pressedRoleIndex) ?
 158                           ResizeRoleOperation : NoRoleOperation;
 159         event->accept();
 160     } else {
 161         event->ignore();
 162     }
 163 }
 164
 165 void KItemListHeader::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
 166 {
 167     QGraphicsWidget::mouseReleaseEvent(event);
 168
 169     if (m_pressedRoleIndex == -1) {
 170         return;
 171     }
 172
 173     if (m_roleOperation == NoRoleOperation) {
 174         // Only a click has been done and no moving or resizing has been started
 175         const QByteArray sortRole = m_model->sortRole();
 176         const int sortRoleIndex = m_visibleRoles.indexOf(sortRole);
 177         if (m_pressedRoleIndex == sortRoleIndex) {
 178             // Toggle the sort order
 179             const Qt::SortOrder toggled = (m_model->sortOrder() == Qt::AscendingOrder) ?
 180                                           Qt::DescendingOrder : Qt::AscendingOrder;
 181             m_model->setSortOrder(toggled);
 182         } else {
 183             // Change the sort role
 184             const QByteArray sortRole = m_visibleRoles.at(m_pressedRoleIndex);
 185             m_model->setSortRole(sortRole);
 186         }
 187     }
 188
 189     m_pressedRoleIndex = -1;
 190     m_roleOperation = NoRoleOperation;
 191     update();
 192 }
 193
 194 void KItemListHeader::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 195 {
 196     QGraphicsWidget::mouseMoveEvent(event);
 197
 198     if (m_roleOperation == ResizeRoleOperation) {
 199         const QByteArray pressedRole = m_visibleRoles.at(m_pressedRoleIndex);
 200
 201         qreal previousWidth = m_visibleRolesWidths.value(pressedRole);
 202         qreal currentWidth = previousWidth;
 203         currentWidth += event->pos().x() - event->lastPos().x();
 204         currentWidth = qMax(minimumRoleWidth(), currentWidth);
 205
 206         m_visibleRolesWidths.insert(pressedRole, currentWidth);
 207         update();
 208
 209         emit visibleRoleWidthChanged(pressedRole, currentWidth, previousWidth);
 210     } else if ((event->pos() - m_pressedMousePos).manhattanLength() >= QApplication::startDragDistance()) {
 211         kDebug() << "Moving of role not supported yet";
 212         m_roleOperation = MoveRoleOperation;
 213     }
 214 }
 215
 216 void KItemListHeader::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
 217 {
 218     QGraphicsWidget::hoverEnterEvent(event);
 219     updateHoveredRoleIndex(event->pos());
 220 }
 221
 222 void KItemListHeader::hoverLeaveEvent(QGraphicsSceneHoverEvent* event)
 223 {
 224     QGraphicsWidget::hoverLeaveEvent(event);
 225     if (m_hoveredRoleIndex != -1) {
 226         m_hoveredRoleIndex = -1;
 227         update();
 228     }
 229 }
 230
 231 void KItemListHeader::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
 232 {
 233     QGraphicsWidget::hoverMoveEvent(event);
 234
 235     const QPointF& pos = event->pos();
 236     updateHoveredRoleIndex(pos);
 237     if (m_hoveredRoleIndex >= 0 && isAboveRoleGrip(pos, m_hoveredRoleIndex)) {
 238         setCursor(Qt::SplitHCursor);
 239     } else {
 240         unsetCursor();
 241     }
 242 }
 243
 244 void KItemListHeader::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 245 {
 246     Q_UNUSED(current);
 247     Q_UNUSED(previous);
 248     update();
 249 }
 250
 251 void KItemListHeader::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 252 {
 253     Q_UNUSED(current);
 254     Q_UNUSED(previous);
 255     update();
 256 }
 257
 258 void KItemListHeader::paintRole(QPainter* painter,
 259                                 const QByteArray& role,
 260                                 const QRectF& rect,
 261                                 int orderIndex)
 262 {
 263     // The following code is based on the code from QHeaderView::paintSection().
 264     // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 265     QStyleOptionHeader option;
 266     option.section = orderIndex;
 267     option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 268     if (isEnabled()) {
 269         option.state |= QStyle::State_Enabled;
 270     }
 271     if (window() && window()->isActiveWindow()) {
 272         option.state |= QStyle::State_Active;
 273     }
 274     if (m_hoveredRoleIndex == orderIndex) {
 275         option.state |= QStyle::State_MouseOver;
 276     }
 277     if (m_pressedRoleIndex == orderIndex) {
 278         option.state |= QStyle::State_Sunken;
 279     }
 280     if (m_model->sortRole() == role) {
 281         option.sortIndicator = (m_model->sortOrder() == Qt::AscendingOrder) ?
 282                                 QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;
 283     }
 284     option.rect = rect.toRect();
 285
 286     if (m_visibleRoles.count() == 1) {
 287         option.position = QStyleOptionHeader::OnlyOneSection;
 288     } else if (orderIndex == 0) {
 289         option.position = QStyleOptionHeader::Beginning;
 290     } else if (orderIndex == m_visibleRoles.count() - 1) {
 291         option.position = QStyleOptionHeader::End;
 292     } else {
 293         option.position = QStyleOptionHeader::Middle;
 294     }
 295
 296     option.orientation = Qt::Horizontal;
 297     option.selectedPosition = QStyleOptionHeader::NotAdjacent;
 298     option.text = m_model->roleDescription(role);
 299
 300     style()->drawControl(QStyle::CE_Header, &option, painter);
 301 }
 302
 303 void KItemListHeader::updatePressedRoleIndex(const QPointF& pos)
 304 {
 305     const int pressedIndex = roleIndexAt(pos);
 306     if (m_pressedRoleIndex != pressedIndex) {
 307         m_pressedRoleIndex = pressedIndex;
 308         update();
 309     }
 310 }
 311
 312 void KItemListHeader::updateHoveredRoleIndex(const QPointF& pos)
 313 {
 314     const int hoverIndex = roleIndexAt(pos);
 315     if (m_hoveredRoleIndex != hoverIndex) {
 316         m_hoveredRoleIndex = hoverIndex;
 317         update();
 318     }
 319 }
 320
 321 int KItemListHeader::roleIndexAt(const QPointF& pos) const
 322 {
 323     int index = -1;
 324
 325     qreal x = 0;
 326     foreach (const QByteArray& role, m_visibleRoles) {
 327         ++index;
 328         x += m_visibleRolesWidths.value(role);
 329         if (pos.x() <= x) {
 330             break;
 331         }
 332     }
 333
 334     return index;
 335 }
 336
 337 bool KItemListHeader::isAboveRoleGrip(const QPointF& pos, int roleIndex) const
 338 {
 339     qreal x = 0;
 340     for (int i = 0; i <= roleIndex; ++i) {
 341         const QByteArray role = m_visibleRoles.at(i);
 342         x += m_visibleRolesWidths.value(role);
 343     }
 344
 345     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 346     return pos.x() >= (x - grip) && pos.x() <= x;
 347 }
 348
 349 #include "kitemlistheader_p.moc"