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