src/kitemviews/private/kitemlistheaderwidget.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 "kitemlistheaderwidget.h"
  21
  22 #include <KAction>
  23 #include <KMenu>
  24 #include <kitemviews/kitemmodelbase.h>
  25
  26 #include <QApplication>
  27 #include <QGraphicsSceneHoverEvent>
  28 #include <QPainter>
  29 #include <QStyleOptionHeader>
  30
  31 #include <KDebug>
  32
  33 KItemListHeaderWidget::KItemListHeaderWidget(QGraphicsWidget* parent) :
  34     QGraphicsWidget(parent),
  35     m_automaticColumnResizing(true),
  36     m_model(0),
  37     m_offset(0),
  38     m_columns(),
  39     m_columnWidths(),
  40     m_preferredColumnWidths(),
  41     m_hoveredRoleIndex(-1),
  42     m_pressedRoleIndex(-1),
  43     m_roleOperation(NoRoleOperation),
  44     m_pressedMousePos(),
  45     m_movingRole()
  46 {
  47     m_movingRole.x = 0;
  48     m_movingRole.xDec = 0;
  49     m_movingRole.index = -1;
  50
  51     setAcceptHoverEvents(true);
  52 }
  53
  54 KItemListHeaderWidget::~KItemListHeaderWidget()
  55 {
  56 }
  57
  58 void KItemListHeaderWidget::setModel(KItemModelBase* model)
  59 {
  60     if (m_model == model) {
  61         return;
  62     }
  63
  64     if (m_model) {
  65         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
  66                    this, SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
  67         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
  68                    this, SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
  69     }
  70
  71     m_model = model;
  72
  73     if (m_model) {
  74         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
  75                 this, SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
  76         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
  77                 this, SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
  78     }
  79 }
  80
  81 KItemModelBase* KItemListHeaderWidget::model() const
  82 {
  83     return m_model;
  84 }
  85
  86 void KItemListHeaderWidget::setAutomaticColumnResizing(bool automatic)
  87 {
  88     m_automaticColumnResizing = automatic;
  89 }
  90
  91 bool KItemListHeaderWidget::automaticColumnResizing() const
  92 {
  93     return m_automaticColumnResizing;
  94 }
  95
  96 void KItemListHeaderWidget::setColumns(const QList<QByteArray>& roles)
  97 {
  98     foreach (const QByteArray& role, roles) {
  99         if (!m_columnWidths.contains(role)) {
 100             m_columnWidths.remove(role);
 101             m_preferredColumnWidths.remove(role);
 102         }
 103     }
 104
 105     m_columns = roles;
 106     update();
 107 }
 108
 109 QList<QByteArray> KItemListHeaderWidget::columns() const
 110 {
 111     return m_columns;
 112 }
 113
 114 void KItemListHeaderWidget::setColumnWidth(const QByteArray& role, qreal width)
 115 {
 116     const qreal minWidth = minimumColumnWidth();
 117     if (width < minWidth) {
 118         width = minWidth;
 119     }
 120
 121     if (m_columnWidths.value(role) != width) {
 122         m_columnWidths.insert(role, width);
 123         update();
 124     }
 125 }
 126
 127 qreal KItemListHeaderWidget::columnWidth(const QByteArray& role) const
 128 {
 129     return m_columnWidths.value(role);
 130 }
 131
 132 void KItemListHeaderWidget::setPreferredColumnWidth(const QByteArray& role, qreal width)
 133 {
 134     m_preferredColumnWidths.insert(role, width);
 135 }
 136
 137 qreal KItemListHeaderWidget::preferredColumnWidth(const QByteArray& role) const
 138 {
 139     return m_preferredColumnWidths.value(role);
 140 }
 141
 142 void KItemListHeaderWidget::setOffset(qreal offset)
 143 {
 144     if (m_offset != offset) {
 145         m_offset = offset;
 146         update();
 147     }
 148 }
 149
 150 qreal KItemListHeaderWidget::offset() const
 151 {
 152     return m_offset;
 153 }
 154
 155 qreal KItemListHeaderWidget::minimumColumnWidth() const
 156 {
 157     QFontMetricsF fontMetrics(font());
 158     return fontMetrics.height() * 4;
 159 }
 160
 161 void KItemListHeaderWidget::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 162 {
 163     Q_UNUSED(option);
 164     Q_UNUSED(widget);
 165
 166     if (!m_model) {
 167         return;
 168     }
 169
 170     // Draw roles
 171     painter->setFont(font());
 172     painter->setPen(palette().text().color());
 173
 174     qreal x = -m_offset;
 175     int orderIndex = 0;
 176     foreach (const QByteArray& role, m_columns) {
 177         const qreal roleWidth = m_columnWidths.value(role);
 178         const QRectF rect(x, 0, roleWidth, size().height());
 179         paintRole(painter, role, rect, orderIndex, widget);
 180         x += roleWidth;
 181         ++orderIndex;
 182     }
 183
 184     if (!m_movingRole.pixmap.isNull()) {
 185         Q_ASSERT(m_roleOperation == MoveRoleOperation);
 186         painter->drawPixmap(m_movingRole.x, 0, m_movingRole.pixmap);
 187     }
 188 }
 189
 190 void KItemListHeaderWidget::mousePressEvent(QGraphicsSceneMouseEvent* event)
 191 {
 192     if (event->button() & Qt::LeftButton) {
 193         updatePressedRoleIndex(event->pos());
 194         m_pressedMousePos = event->pos();
 195         m_roleOperation = isAboveRoleGrip(m_pressedMousePos, m_pressedRoleIndex) ?
 196                           ResizeRoleOperation : NoRoleOperation;
 197         event->accept();
 198     } else {
 199         event->ignore();
 200     }
 201 }
 202
 203 void KItemListHeaderWidget::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
 204 {
 205     QGraphicsWidget::mouseReleaseEvent(event);
 206
 207     if (m_pressedRoleIndex == -1) {
 208         return;
 209     }
 210
 211     switch (m_roleOperation) {
 212     case NoRoleOperation: {
 213         // Only a click has been done and no moving or resizing has been started
 214         const QByteArray sortRole = m_model->sortRole();
 215         const int sortRoleIndex = m_columns.indexOf(sortRole);
 216         if (m_pressedRoleIndex == sortRoleIndex) {
 217             // Toggle the sort order
 218             const Qt::SortOrder previous = m_model->sortOrder();
 219             const Qt::SortOrder current = (m_model->sortOrder() == Qt::AscendingOrder) ?
 220                                           Qt::DescendingOrder : Qt::AscendingOrder;
 221             m_model->setSortOrder(current);
 222             emit sortOrderChanged(current, previous);
 223         } else {
 224             // Change the sort role and reset to the ascending order
 225             const QByteArray previous = m_model->sortRole();
 226             const QByteArray current = m_columns[m_pressedRoleIndex];
 227             m_model->setSortRole(current);
 228             emit sortRoleChanged(current, previous);
 229
 230             if (m_model->sortOrder() == Qt::DescendingOrder) {
 231                 m_model->setSortOrder(Qt::AscendingOrder);
 232                 emit sortOrderChanged(Qt::AscendingOrder, Qt::DescendingOrder);
 233             }
 234         }
 235         break;
 236     }
 237
 238     case MoveRoleOperation:
 239         m_movingRole.pixmap = QPixmap();
 240         m_movingRole.x = 0;
 241         m_movingRole.xDec = 0;
 242         m_movingRole.index = -1;
 243         break;
 244
 245     default:
 246         break;
 247     }
 248
 249     m_pressedRoleIndex = -1;
 250     m_roleOperation = NoRoleOperation;
 251     update();
 252
 253     QApplication::restoreOverrideCursor();
 254 }
 255
 256 void KItemListHeaderWidget::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 257 {
 258     QGraphicsWidget::mouseMoveEvent(event);
 259
 260     switch (m_roleOperation) {
 261     case NoRoleOperation:
 262         if ((event->pos() - m_pressedMousePos).manhattanLength() >= QApplication::startDragDistance()) {
 263             // A role gets dragged by the user. Create a pixmap of the role that will get
 264             // synchronized on each furter mouse-move-event with the mouse-position.
 265             m_roleOperation = MoveRoleOperation;
 266             const int roleIndex = roleIndexAt(m_pressedMousePos);
 267             m_movingRole.index = roleIndex;
 268             if (roleIndex == 0) {
 269                 // TODO: It should be configurable whether moving the first role is allowed.
 270                 // In the context of Dolphin this is not required, however this should be
 271                 // changed if KItemViews are used in a more generic way.
 272                 QApplication::setOverrideCursor(QCursor(Qt::ForbiddenCursor));
 273             } else {
 274                 m_movingRole.pixmap = createRolePixmap(roleIndex);
 275
 276                 qreal roleX = -m_offset;
 277                 for (int i = 0; i < roleIndex; ++i) {
 278                     const QByteArray role = m_columns[i];
 279                     roleX += m_columnWidths.value(role);
 280                 }
 281
 282                 m_movingRole.xDec = event->pos().x() - roleX;
 283                 m_movingRole.x = roleX;
 284                 update();
 285             }
 286         }
 287         break;
 288
 289     case ResizeRoleOperation: {
 290         const QByteArray pressedRole = m_columns[m_pressedRoleIndex];
 291
 292         qreal previousWidth = m_columnWidths.value(pressedRole);
 293         qreal currentWidth = previousWidth;
 294         currentWidth += event->pos().x() - event->lastPos().x();
 295         currentWidth = qMax(minimumColumnWidth(), currentWidth);
 296
 297         m_columnWidths.insert(pressedRole, currentWidth);
 298         update();
 299
 300         emit columnWidthChanged(pressedRole, currentWidth, previousWidth);
 301         break;
 302     }
 303
 304     case MoveRoleOperation: {
 305         // TODO: It should be configurable whether moving the first role is allowed.
 306         // In the context of Dolphin this is not required, however this should be
 307         // changed if KItemViews are used in a more generic way.
 308         if (m_movingRole.index > 0) {
 309             m_movingRole.x = event->pos().x() - m_movingRole.xDec;
 310             update();
 311
 312             const int targetIndex = targetOfMovingRole();
 313             if (targetIndex > 0 && targetIndex != m_movingRole.index) {
 314                 const QByteArray role = m_columns[m_movingRole.index];
 315                 const int previousIndex = m_movingRole.index;
 316                 m_movingRole.index = targetIndex;
 317                 emit columnMoved(role, targetIndex, previousIndex);
 318
 319                 m_movingRole.xDec = event->pos().x() - roleXPosition(role);
 320             }
 321         }
 322         break;
 323     }
 324
 325     default:
 326         break;
 327     }
 328 }
 329
 330 void KItemListHeaderWidget::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
 331 {
 332     QGraphicsWidget::hoverEnterEvent(event);
 333     updateHoveredRoleIndex(event->pos());
 334 }
 335
 336 void KItemListHeaderWidget::hoverLeaveEvent(QGraphicsSceneHoverEvent* event)
 337 {
 338     QGraphicsWidget::hoverLeaveEvent(event);
 339     if (m_hoveredRoleIndex != -1) {
 340         m_hoveredRoleIndex = -1;
 341         update();
 342     }
 343 }
 344
 345 void KItemListHeaderWidget::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
 346 {
 347     QGraphicsWidget::hoverMoveEvent(event);
 348
 349     const QPointF& pos = event->pos();
 350     updateHoveredRoleIndex(pos);
 351     if (m_hoveredRoleIndex >= 0 && isAboveRoleGrip(pos, m_hoveredRoleIndex)) {
 352         setCursor(Qt::SplitHCursor);
 353     } else {
 354         unsetCursor();
 355     }
 356 }
 357
 358 void KItemListHeaderWidget::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 359 {
 360     Q_UNUSED(current);
 361     Q_UNUSED(previous);
 362     update();
 363 }
 364
 365 void KItemListHeaderWidget::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 366 {
 367     Q_UNUSED(current);
 368     Q_UNUSED(previous);
 369     update();
 370 }
 371
 372 void KItemListHeaderWidget::paintRole(QPainter* painter,
 373                                       const QByteArray& role,
 374                                       const QRectF& rect,
 375                                       int orderIndex,
 376                                       QWidget* widget) const
 377 {
 378     // The following code is based on the code from QHeaderView::paintSection().
 379     // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 380     QStyleOptionHeader option;
 381     option.section = orderIndex;
 382     option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 383     if (isEnabled()) {
 384         option.state |= QStyle::State_Enabled;
 385     }
 386     if (window() && window()->isActiveWindow()) {
 387         option.state |= QStyle::State_Active;
 388     }
 389     if (m_hoveredRoleIndex == orderIndex) {
 390         option.state |= QStyle::State_MouseOver;
 391     }
 392     if (m_pressedRoleIndex == orderIndex) {
 393         option.state |= QStyle::State_Sunken;
 394     }
 395     if (m_model->sortRole() == role) {
 396         option.sortIndicator = (m_model->sortOrder() == Qt::AscendingOrder) ?
 397                                 QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;
 398     }
 399     option.rect = rect.toRect();
 400
 401     bool paintBackgroundForEmptyArea = false;
 402
 403     if (m_columns.count() == 1) {
 404         option.position = QStyleOptionHeader::OnlyOneSection;
 405     } else if (orderIndex == 0) {
 406         option.position = QStyleOptionHeader::Beginning;
 407     } else if (orderIndex == m_columns.count() - 1) {
 408         // We are just painting the header for the last column. Check if there
 409         // is some empty space to the right which needs to be filled.
 410         if (rect.right() < size().width()) {
 411             option.position = QStyleOptionHeader::Middle;
 412             paintBackgroundForEmptyArea = true;
 413         } else {
 414             option.position = QStyleOptionHeader::End;
 415         }
 416     } else {
 417         option.position = QStyleOptionHeader::Middle;
 418     }
 419
 420     option.orientation = Qt::Horizontal;
 421     option.selectedPosition = QStyleOptionHeader::NotAdjacent;
 422     option.text = m_model->roleDescription(role);
 423
 424     style()->drawControl(QStyle::CE_Header, &option, painter, widget);
 425
 426     if (paintBackgroundForEmptyArea) {
 427         option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 428         option.section = m_columns.count();
 429         option.sortIndicator = QStyleOptionHeader::None;
 430
 431         qreal backgroundRectX = rect.x() + rect.width();
 432         QRectF backgroundRect(backgroundRectX, 0.0, size().width() - backgroundRectX, rect.height());
 433         option.rect = backgroundRect.toRect();
 434         option.position = QStyleOptionHeader::End;
 435         option.text = QString();
 436
 437         style()->drawControl(QStyle::CE_Header, &option, painter, widget);
 438     }
 439 }
 440
 441 void KItemListHeaderWidget::updatePressedRoleIndex(const QPointF& pos)
 442 {
 443     const int pressedIndex = roleIndexAt(pos);
 444     if (m_pressedRoleIndex != pressedIndex) {
 445         m_pressedRoleIndex = pressedIndex;
 446         update();
 447     }
 448 }
 449
 450 void KItemListHeaderWidget::updateHoveredRoleIndex(const QPointF& pos)
 451 {
 452     const int hoverIndex = roleIndexAt(pos);
 453     if (m_hoveredRoleIndex != hoverIndex) {
 454         m_hoveredRoleIndex = hoverIndex;
 455         update();
 456     }
 457 }
 458
 459 int KItemListHeaderWidget::roleIndexAt(const QPointF& pos) const
 460 {
 461     int index = -1;
 462
 463     qreal x = -m_offset;
 464     foreach (const QByteArray& role, m_columns) {
 465         ++index;
 466         x += m_columnWidths.value(role);
 467         if (pos.x() <= x) {
 468             break;
 469         }
 470     }
 471
 472     return index;
 473 }
 474
 475 bool KItemListHeaderWidget::isAboveRoleGrip(const QPointF& pos, int roleIndex) const
 476 {
 477     qreal x = -m_offset;
 478     for (int i = 0; i <= roleIndex; ++i) {
 479         const QByteArray role = m_columns[i];
 480         x += m_columnWidths.value(role);
 481     }
 482
 483     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 484     return pos.x() >= (x - grip) && pos.x() <= x;
 485 }
 486
 487 QPixmap KItemListHeaderWidget::createRolePixmap(int roleIndex) const
 488 {
 489     const QByteArray role = m_columns[roleIndex];
 490     const qreal roleWidth = m_columnWidths.value(role);
 491     const QRect rect(0, 0, roleWidth, size().height());
 492
 493     QImage image(rect.size(), QImage::Format_ARGB32_Premultiplied);
 494
 495     QPainter painter(&image);
 496     paintRole(&painter, role, rect, roleIndex);
 497
 498     // Apply a highlighting-color
 499     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 500     QColor highlightColor = palette().color(group, QPalette::Highlight);
 501     highlightColor.setAlpha(64);
 502     painter.fillRect(rect, highlightColor);
 503
 504     // Make the image transparent
 505     painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
 506     painter.fillRect(0, 0, image.width(), image.height(), QColor(0, 0, 0, 192));
 507
 508     return QPixmap::fromImage(image);
 509 }
 510
 511 int KItemListHeaderWidget::targetOfMovingRole() const
 512 {
 513     const int movingWidth = m_movingRole.pixmap.width();
 514     const int movingLeft = m_movingRole.x;
 515     const int movingRight = movingLeft + movingWidth - 1;
 516
 517     int targetIndex = 0;
 518     qreal targetLeft = -m_offset;
 519     while (targetIndex < m_columns.count()) {
 520         const QByteArray role = m_columns[targetIndex];
 521         const qreal targetWidth = m_columnWidths.value(role);
 522         const qreal targetRight = targetLeft + targetWidth - 1;
 523
 524         const bool isInTarget = (targetWidth >= movingWidth &&
 525                                  movingLeft  >= targetLeft  &&
 526                                  movingRight <= targetRight) ||
 527                                 (targetWidth <  movingWidth &&
 528                                  movingLeft  <= targetLeft  &&
 529                                  movingRight >= targetRight);
 530
 531         if (isInTarget) {
 532             return targetIndex;
 533         }
 534
 535         targetLeft += targetWidth;
 536         ++targetIndex;
 537     }
 538
 539     return m_movingRole.index;
 540 }
 541
 542 qreal KItemListHeaderWidget::roleXPosition(const QByteArray& role) const
 543 {
 544     qreal x = -m_offset;
 545     foreach (const QByteArray& visibleRole, m_columns) {
 546         if (visibleRole == role) {
 547             return x;
 548         }
 549
 550         x += m_columnWidths.value(visibleRole);
 551     }
 552
 553     return -1;
 554 }
 555
 556 #include "kitemlistheaderwidget.moc"