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     m_movingRole()
  43 {
  44     m_movingRole.x = 0;
  45     m_movingRole.xDec = 0;
  46     m_movingRole.index = -1;
  47
  48     setAcceptHoverEvents(true);
  49
  50     QStyleOptionHeader option;
  51     const QSize headerSize = style()->sizeFromContents(QStyle::CT_HeaderSection, &option, QSize());
  52     resize(0, headerSize.height());
  53 }
  54
  55 KItemListHeader::~KItemListHeader()
  56 {
  57 }
  58
  59 void KItemListHeader::setModel(KItemModelBase* model)
  60 {
  61     if (m_model == model) {
  62         return;
  63     }
  64
  65     if (m_model) {
  66         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
  67                    this, SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
  68         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
  69                    this, SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
  70     }
  71
  72     m_model = model;
  73
  74     if (m_model) {
  75         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
  76                 this, SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
  77         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
  78                 this, SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
  79     }
  80 }
  81
  82 KItemModelBase* KItemListHeader::model() const
  83 {
  84     return m_model;
  85 }
  86
  87 void KItemListHeader::setVisibleRoles(const QList<QByteArray>& roles)
  88 {
  89     m_visibleRoles = roles;
  90     update();
  91 }
  92
  93 QList<QByteArray> KItemListHeader::visibleRoles() const
  94 {
  95     return m_visibleRoles;
  96 }
  97
  98 void KItemListHeader::setVisibleRolesWidths(const QHash<QByteArray, qreal> rolesWidths)
  99 {
 100     m_visibleRolesWidths = rolesWidths;
 101
 102     // Assure that no width is smaller than the minimum allowed width
 103     const qreal minWidth = minimumRoleWidth();
 104     QMutableHashIterator<QByteArray, qreal> it(m_visibleRolesWidths);
 105     while (it.hasNext()) {
 106         it.next();
 107         if (it.value() < minWidth) {
 108             m_visibleRolesWidths.insert(it.key(), minWidth);
 109         }
 110     }
 111
 112     update();
 113 }
 114
 115 QHash<QByteArray, qreal> KItemListHeader::visibleRolesWidths() const
 116 {
 117     return m_visibleRolesWidths;
 118 }
 119
 120 qreal KItemListHeader::minimumRoleWidth() const
 121 {
 122     QFontMetricsF fontMetrics(font());
 123     return fontMetrics.height() * 4;
 124 }
 125
 126 void KItemListHeader::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 127 {
 128     Q_UNUSED(option);
 129     Q_UNUSED(widget);
 130
 131     if (!m_model) {
 132         return;
 133     }
 134
 135     // Draw roles
 136     painter->setFont(font());
 137     painter->setPen(palette().text().color());
 138
 139     qreal x = 0;
 140     int orderIndex = 0;
 141     foreach (const QByteArray& role, m_visibleRoles) {
 142         const qreal roleWidth = m_visibleRolesWidths.value(role);
 143         const QRectF rect(x, 0, roleWidth, size().height());
 144         paintRole(painter, role, rect, orderIndex);
 145         x += roleWidth;
 146         ++orderIndex;
 147     }
 148
 149     // Draw background without roles
 150     QStyleOption opt;
 151     opt.init(widget);
 152     opt.rect = QRect(x, 0, size().width() - x, size().height());
 153     opt.state |= QStyle::State_Horizontal;
 154     style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, painter);
 155
 156     if (!m_movingRole.pixmap.isNull()) {
 157         Q_ASSERT(m_roleOperation == MoveRoleOperation);
 158         painter->drawPixmap(m_movingRole.x, 0, m_movingRole.pixmap);
 159     }
 160 }
 161
 162 void KItemListHeader::mousePressEvent(QGraphicsSceneMouseEvent* event)
 163 {
 164     if (event->button() & Qt::LeftButton) {
 165         updatePressedRoleIndex(event->pos());
 166         m_pressedMousePos = event->pos();
 167         m_roleOperation = isAboveRoleGrip(m_pressedMousePos, m_pressedRoleIndex) ?
 168                           ResizeRoleOperation : NoRoleOperation;
 169         event->accept();
 170     } else {
 171         event->ignore();
 172     }
 173 }
 174
 175 void KItemListHeader::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
 176 {
 177     QGraphicsWidget::mouseReleaseEvent(event);
 178
 179     if (m_pressedRoleIndex == -1) {
 180         return;
 181     }
 182
 183     switch (m_roleOperation) {
 184     case NoRoleOperation: {
 185         // Only a click has been done and no moving or resizing has been started
 186         const QByteArray sortRole = m_model->sortRole();
 187         const int sortRoleIndex = m_visibleRoles.indexOf(sortRole);
 188         if (m_pressedRoleIndex == sortRoleIndex) {
 189             // Toggle the sort order
 190             const Qt::SortOrder previous = m_model->sortOrder();
 191             const Qt::SortOrder current = (m_model->sortOrder() == Qt::AscendingOrder) ?
 192                                           Qt::DescendingOrder : Qt::AscendingOrder;
 193             m_model->setSortOrder(current);
 194             emit sortOrderChanged(current, previous);
 195         } else {
 196             // Change the sort role
 197             const QByteArray previous = m_model->sortRole();
 198             const QByteArray current = m_visibleRoles[m_pressedRoleIndex];
 199             m_model->setSortRole(current);
 200             emit sortRoleChanged(current, previous);
 201         }
 202         break;
 203     }
 204
 205     case MoveRoleOperation:
 206         m_movingRole.pixmap = QPixmap();
 207         m_movingRole.x = 0;
 208         m_movingRole.xDec = 0;
 209         m_movingRole.index = -1;
 210         break;
 211
 212     default:
 213         break;
 214     }
 215
 216     m_pressedRoleIndex = -1;
 217     m_roleOperation = NoRoleOperation;
 218     update();
 219
 220     QApplication::restoreOverrideCursor();
 221 }
 222
 223 void KItemListHeader::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 224 {
 225     QGraphicsWidget::mouseMoveEvent(event);
 226
 227     switch (m_roleOperation) {
 228     case NoRoleOperation:
 229         if ((event->pos() - m_pressedMousePos).manhattanLength() >= QApplication::startDragDistance()) {
 230             // A role gets dragged by the user. Create a pixmap of the role that will get
 231             // synchronized on each furter mouse-move-event with the mouse-position.
 232             m_roleOperation = MoveRoleOperation;
 233             const int roleIndex = roleIndexAt(m_pressedMousePos);
 234             m_movingRole.index = roleIndex;
 235             if (roleIndex == 0) {
 236                 // TODO: It should be configurable whether moving the first role is allowed.
 237                 // In the context of Dolphin this is not required, however this should be
 238                 // changed if KItemViews are used in a more generic way.
 239                 QApplication::setOverrideCursor(QCursor(Qt::ForbiddenCursor));
 240             } else {
 241                 m_movingRole.pixmap = createRolePixmap(roleIndex);
 242
 243                 qreal roleX = 0;
 244                 for (int i = 0; i < roleIndex; ++i) {
 245                     const QByteArray role = m_visibleRoles[i];
 246                     roleX += m_visibleRolesWidths.value(role);
 247                 }
 248
 249                 m_movingRole.xDec = event->pos().x() - roleX;
 250                 m_movingRole.x = roleX;
 251                 update();
 252             }
 253         }
 254         break;
 255
 256     case ResizeRoleOperation: {
 257         const QByteArray pressedRole = m_visibleRoles[m_pressedRoleIndex];
 258
 259         qreal previousWidth = m_visibleRolesWidths.value(pressedRole);
 260         qreal currentWidth = previousWidth;
 261         currentWidth += event->pos().x() - event->lastPos().x();
 262         currentWidth = qMax(minimumRoleWidth(), currentWidth);
 263
 264         m_visibleRolesWidths.insert(pressedRole, currentWidth);
 265         update();
 266
 267         emit visibleRoleWidthChanged(pressedRole, currentWidth, previousWidth);
 268         break;
 269     }
 270
 271     case MoveRoleOperation: {
 272         // TODO: It should be configurable whether moving the first role is allowed.
 273         // In the context of Dolphin this is not required, however this should be
 274         // changed if KItemViews are used in a more generic way.
 275         if (m_movingRole.index > 0) {
 276             m_movingRole.x = event->pos().x() - m_movingRole.xDec;
 277             update();
 278
 279             const int targetIndex = targetOfMovingRole();
 280             if (targetIndex > 0 && targetIndex != m_movingRole.index) {
 281                 const QByteArray role = m_visibleRoles[m_movingRole.index];
 282                 const int previousIndex = m_movingRole.index;
 283                 m_movingRole.index = targetIndex;
 284                 emit visibleRoleMoved(role, targetIndex, previousIndex);
 285
 286                 m_movingRole.xDec = event->pos().x() - roleXPosition(role);
 287             }
 288         }
 289         break;
 290     }
 291
 292     default:
 293         break;
 294     }
 295 }
 296
 297 void KItemListHeader::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
 298 {
 299     QGraphicsWidget::hoverEnterEvent(event);
 300     updateHoveredRoleIndex(event->pos());
 301 }
 302
 303 void KItemListHeader::hoverLeaveEvent(QGraphicsSceneHoverEvent* event)
 304 {
 305     QGraphicsWidget::hoverLeaveEvent(event);
 306     if (m_hoveredRoleIndex != -1) {
 307         m_hoveredRoleIndex = -1;
 308         update();
 309     }
 310 }
 311
 312 void KItemListHeader::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
 313 {
 314     QGraphicsWidget::hoverMoveEvent(event);
 315
 316     const QPointF& pos = event->pos();
 317     updateHoveredRoleIndex(pos);
 318     if (m_hoveredRoleIndex >= 0 && isAboveRoleGrip(pos, m_hoveredRoleIndex)) {
 319         setCursor(Qt::SplitHCursor);
 320     } else {
 321         unsetCursor();
 322     }
 323 }
 324
 325 void KItemListHeader::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 326 {
 327     Q_UNUSED(current);
 328     Q_UNUSED(previous);
 329     update();
 330 }
 331
 332 void KItemListHeader::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 333 {
 334     Q_UNUSED(current);
 335     Q_UNUSED(previous);
 336     update();
 337 }
 338
 339 void KItemListHeader::paintRole(QPainter* painter,
 340                                 const QByteArray& role,
 341                                 const QRectF& rect,
 342                                 int orderIndex) const
 343 {
 344     // The following code is based on the code from QHeaderView::paintSection().
 345     // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 346     QStyleOptionHeader option;
 347     option.section = orderIndex;
 348     option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 349     if (isEnabled()) {
 350         option.state |= QStyle::State_Enabled;
 351     }
 352     if (window() && window()->isActiveWindow()) {
 353         option.state |= QStyle::State_Active;
 354     }
 355     if (m_hoveredRoleIndex == orderIndex) {
 356         option.state |= QStyle::State_MouseOver;
 357     }
 358     if (m_pressedRoleIndex == orderIndex) {
 359         option.state |= QStyle::State_Sunken;
 360     }
 361     if (m_model->sortRole() == role) {
 362         option.sortIndicator = (m_model->sortOrder() == Qt::AscendingOrder) ?
 363                                 QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;
 364     }
 365     option.rect = rect.toRect();
 366
 367     if (m_visibleRoles.count() == 1) {
 368         option.position = QStyleOptionHeader::OnlyOneSection;
 369     } else if (orderIndex == 0) {
 370         option.position = QStyleOptionHeader::Beginning;
 371     } else if (orderIndex == m_visibleRoles.count() - 1) {
 372         option.position = QStyleOptionHeader::End;
 373     } else {
 374         option.position = QStyleOptionHeader::Middle;
 375     }
 376
 377     option.orientation = Qt::Horizontal;
 378     option.selectedPosition = QStyleOptionHeader::NotAdjacent;
 379     option.text = m_model->roleDescription(role);
 380
 381     style()->drawControl(QStyle::CE_Header, &option, painter);
 382 }
 383
 384 void KItemListHeader::updatePressedRoleIndex(const QPointF& pos)
 385 {
 386     const int pressedIndex = roleIndexAt(pos);
 387     if (m_pressedRoleIndex != pressedIndex) {
 388         m_pressedRoleIndex = pressedIndex;
 389         update();
 390     }
 391 }
 392
 393 void KItemListHeader::updateHoveredRoleIndex(const QPointF& pos)
 394 {
 395     const int hoverIndex = roleIndexAt(pos);
 396     if (m_hoveredRoleIndex != hoverIndex) {
 397         m_hoveredRoleIndex = hoverIndex;
 398         update();
 399     }
 400 }
 401
 402 int KItemListHeader::roleIndexAt(const QPointF& pos) const
 403 {
 404     int index = -1;
 405
 406     qreal x = 0;
 407     foreach (const QByteArray& role, m_visibleRoles) {
 408         ++index;
 409         x += m_visibleRolesWidths.value(role);
 410         if (pos.x() <= x) {
 411             break;
 412         }
 413     }
 414
 415     return index;
 416 }
 417
 418 bool KItemListHeader::isAboveRoleGrip(const QPointF& pos, int roleIndex) const
 419 {
 420     qreal x = 0;
 421     for (int i = 0; i <= roleIndex; ++i) {
 422         const QByteArray role = m_visibleRoles[i];
 423         x += m_visibleRolesWidths.value(role);
 424     }
 425
 426     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 427     return pos.x() >= (x - grip) && pos.x() <= x;
 428 }
 429
 430 QPixmap KItemListHeader::createRolePixmap(int roleIndex) const
 431 {
 432     const QByteArray role = m_visibleRoles[roleIndex];
 433     const qreal roleWidth = m_visibleRolesWidths.value(role);
 434     const QRect rect(0, 0, roleWidth, size().height());
 435
 436     QImage image(rect.size(), QImage::Format_ARGB32_Premultiplied);
 437
 438     QPainter painter(&image);
 439     paintRole(&painter, role, rect, roleIndex);
 440
 441     // Apply a highlighting-color
 442     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 443     QColor highlightColor = palette().color(group, QPalette::Highlight);
 444     highlightColor.setAlpha(64);
 445     painter.fillRect(rect, highlightColor);
 446
 447     // Make the image transparent
 448     painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
 449     painter.fillRect(0, 0, image.width(), image.height(), QColor(0, 0, 0, 192));
 450
 451     return QPixmap::fromImage(image);
 452 }
 453
 454 int KItemListHeader::targetOfMovingRole() const
 455 {
 456     const int movingWidth = m_movingRole.pixmap.width();
 457     const int movingLeft = m_movingRole.x;
 458     const int movingRight = movingLeft + movingWidth - 1;
 459
 460     int targetIndex = 0;
 461     qreal targetLeft = 0;
 462     while (targetIndex < m_visibleRoles.count()) {
 463         const QByteArray role = m_visibleRoles[targetIndex];
 464         const qreal targetWidth = m_visibleRolesWidths.value(role);
 465         const qreal targetRight = targetLeft + targetWidth - 1;
 466
 467         const bool isInTarget = (targetWidth >= movingWidth &&
 468                                  movingLeft  >= targetLeft  &&
 469                                  movingRight <= targetRight) ||
 470                                 (targetWidth <  movingWidth &&
 471                                  movingLeft  <= targetLeft  &&
 472                                  movingRight >= targetRight);
 473
 474         if (isInTarget) {
 475             return targetIndex;
 476         }
 477
 478         targetLeft += targetWidth;
 479         ++targetIndex;
 480     }
 481
 482     return m_movingRole.index;
 483 }
 484
 485 qreal KItemListHeader::roleXPosition(const QByteArray& role) const
 486 {
 487     qreal x = 0;
 488     foreach (const QByteArray& visibleRole, m_visibleRoles) {
 489         if (visibleRole == role) {
 490             return x;
 491         }
 492
 493         x += m_visibleRolesWidths.value(visibleRole);
 494     }
 495
 496     return -1;
 497 }
 498
 499 #include "kitemlistheader_p.moc"