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     // Draw background without roles
 185     QStyleOption opt;
 186     opt.init(widget);
 187     opt.rect = QRect(x, 0, size().width() - x, size().height());
 188     opt.state |= QStyle::State_Horizontal;
 189     style()->drawControl(QStyle::CE_HeaderEmptyArea, &opt, painter);
 190
 191     if (!m_movingRole.pixmap.isNull()) {
 192         Q_ASSERT(m_roleOperation == MoveRoleOperation);
 193         painter->drawPixmap(m_movingRole.x, 0, m_movingRole.pixmap);
 194     }
 195 }
 196
 197 void KItemListHeaderWidget::mousePressEvent(QGraphicsSceneMouseEvent* event)
 198 {
 199     if (event->button() & Qt::LeftButton) {
 200         updatePressedRoleIndex(event->pos());
 201         m_pressedMousePos = event->pos();
 202         m_roleOperation = isAboveRoleGrip(m_pressedMousePos, m_pressedRoleIndex) ?
 203                           ResizeRoleOperation : NoRoleOperation;
 204         event->accept();
 205     } else {
 206         event->ignore();
 207     }
 208 }
 209
 210 void KItemListHeaderWidget::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
 211 {
 212     QGraphicsWidget::mouseReleaseEvent(event);
 213
 214     if (m_pressedRoleIndex == -1) {
 215         return;
 216     }
 217
 218     switch (m_roleOperation) {
 219     case NoRoleOperation: {
 220         // Only a click has been done and no moving or resizing has been started
 221         const QByteArray sortRole = m_model->sortRole();
 222         const int sortRoleIndex = m_columns.indexOf(sortRole);
 223         if (m_pressedRoleIndex == sortRoleIndex) {
 224             // Toggle the sort order
 225             const Qt::SortOrder previous = m_model->sortOrder();
 226             const Qt::SortOrder current = (m_model->sortOrder() == Qt::AscendingOrder) ?
 227                                           Qt::DescendingOrder : Qt::AscendingOrder;
 228             m_model->setSortOrder(current);
 229             emit sortOrderChanged(current, previous);
 230         } else {
 231             // Change the sort role and reset to the ascending order
 232             const QByteArray previous = m_model->sortRole();
 233             const QByteArray current = m_columns[m_pressedRoleIndex];
 234             m_model->setSortRole(current);
 235             emit sortRoleChanged(current, previous);
 236
 237             if (m_model->sortOrder() == Qt::DescendingOrder) {
 238                 m_model->setSortOrder(Qt::AscendingOrder);
 239                 emit sortOrderChanged(Qt::AscendingOrder, Qt::DescendingOrder);
 240             }
 241         }
 242         break;
 243     }
 244
 245     case MoveRoleOperation:
 246         m_movingRole.pixmap = QPixmap();
 247         m_movingRole.x = 0;
 248         m_movingRole.xDec = 0;
 249         m_movingRole.index = -1;
 250         break;
 251
 252     default:
 253         break;
 254     }
 255
 256     m_pressedRoleIndex = -1;
 257     m_roleOperation = NoRoleOperation;
 258     update();
 259
 260     QApplication::restoreOverrideCursor();
 261 }
 262
 263 void KItemListHeaderWidget::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 264 {
 265     QGraphicsWidget::mouseMoveEvent(event);
 266
 267     switch (m_roleOperation) {
 268     case NoRoleOperation:
 269         if ((event->pos() - m_pressedMousePos).manhattanLength() >= QApplication::startDragDistance()) {
 270             // A role gets dragged by the user. Create a pixmap of the role that will get
 271             // synchronized on each furter mouse-move-event with the mouse-position.
 272             m_roleOperation = MoveRoleOperation;
 273             const int roleIndex = roleIndexAt(m_pressedMousePos);
 274             m_movingRole.index = roleIndex;
 275             if (roleIndex == 0) {
 276                 // TODO: It should be configurable whether moving the first role is allowed.
 277                 // In the context of Dolphin this is not required, however this should be
 278                 // changed if KItemViews are used in a more generic way.
 279                 QApplication::setOverrideCursor(QCursor(Qt::ForbiddenCursor));
 280             } else {
 281                 m_movingRole.pixmap = createRolePixmap(roleIndex);
 282
 283                 qreal roleX = -m_offset;
 284                 for (int i = 0; i < roleIndex; ++i) {
 285                     const QByteArray role = m_columns[i];
 286                     roleX += m_columnWidths.value(role);
 287                 }
 288
 289                 m_movingRole.xDec = event->pos().x() - roleX;
 290                 m_movingRole.x = roleX;
 291                 update();
 292             }
 293         }
 294         break;
 295
 296     case ResizeRoleOperation: {
 297         const QByteArray pressedRole = m_columns[m_pressedRoleIndex];
 298
 299         qreal previousWidth = m_columnWidths.value(pressedRole);
 300         qreal currentWidth = previousWidth;
 301         currentWidth += event->pos().x() - event->lastPos().x();
 302         currentWidth = qMax(minimumColumnWidth(), currentWidth);
 303
 304         m_columnWidths.insert(pressedRole, currentWidth);
 305         update();
 306
 307         emit columnWidthChanged(pressedRole, currentWidth, previousWidth);
 308         break;
 309     }
 310
 311     case MoveRoleOperation: {
 312         // TODO: It should be configurable whether moving the first role is allowed.
 313         // In the context of Dolphin this is not required, however this should be
 314         // changed if KItemViews are used in a more generic way.
 315         if (m_movingRole.index > 0) {
 316             m_movingRole.x = event->pos().x() - m_movingRole.xDec;
 317             update();
 318
 319             const int targetIndex = targetOfMovingRole();
 320             if (targetIndex > 0 && targetIndex != m_movingRole.index) {
 321                 const QByteArray role = m_columns[m_movingRole.index];
 322                 const int previousIndex = m_movingRole.index;
 323                 m_movingRole.index = targetIndex;
 324                 emit columnMoved(role, targetIndex, previousIndex);
 325
 326                 m_movingRole.xDec = event->pos().x() - roleXPosition(role);
 327             }
 328         }
 329         break;
 330     }
 331
 332     default:
 333         break;
 334     }
 335 }
 336
 337 void KItemListHeaderWidget::hoverEnterEvent(QGraphicsSceneHoverEvent* event)
 338 {
 339     QGraphicsWidget::hoverEnterEvent(event);
 340     updateHoveredRoleIndex(event->pos());
 341 }
 342
 343 void KItemListHeaderWidget::hoverLeaveEvent(QGraphicsSceneHoverEvent* event)
 344 {
 345     QGraphicsWidget::hoverLeaveEvent(event);
 346     if (m_hoveredRoleIndex != -1) {
 347         m_hoveredRoleIndex = -1;
 348         update();
 349     }
 350 }
 351
 352 void KItemListHeaderWidget::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
 353 {
 354     QGraphicsWidget::hoverMoveEvent(event);
 355
 356     const QPointF& pos = event->pos();
 357     updateHoveredRoleIndex(pos);
 358     if (m_hoveredRoleIndex >= 0 && isAboveRoleGrip(pos, m_hoveredRoleIndex)) {
 359         setCursor(Qt::SplitHCursor);
 360     } else {
 361         unsetCursor();
 362     }
 363 }
 364
 365 void KItemListHeaderWidget::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 366 {
 367     Q_UNUSED(current);
 368     Q_UNUSED(previous);
 369     update();
 370 }
 371
 372 void KItemListHeaderWidget::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 373 {
 374     Q_UNUSED(current);
 375     Q_UNUSED(previous);
 376     update();
 377 }
 378
 379 void KItemListHeaderWidget::paintRole(QPainter* painter,
 380                                       const QByteArray& role,
 381                                       const QRectF& rect,
 382                                       int orderIndex,
 383                                       QWidget* widget) const
 384 {
 385     // The following code is based on the code from QHeaderView::paintSection().
 386     // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 387     QStyleOptionHeader option;
 388     option.section = orderIndex;
 389     option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 390     if (isEnabled()) {
 391         option.state |= QStyle::State_Enabled;
 392     }
 393     if (window() && window()->isActiveWindow()) {
 394         option.state |= QStyle::State_Active;
 395     }
 396     if (m_hoveredRoleIndex == orderIndex) {
 397         option.state |= QStyle::State_MouseOver;
 398     }
 399     if (m_pressedRoleIndex == orderIndex) {
 400         option.state |= QStyle::State_Sunken;
 401     }
 402     if (m_model->sortRole() == role) {
 403         option.sortIndicator = (m_model->sortOrder() == Qt::AscendingOrder) ?
 404                                 QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;
 405     }
 406     option.rect = rect.toRect();
 407
 408     if (m_columns.count() == 1) {
 409         option.position = QStyleOptionHeader::OnlyOneSection;
 410     } else if (orderIndex == 0) {
 411         option.position = QStyleOptionHeader::Beginning;
 412     } else if (orderIndex == m_columns.count() - 1) {
 413         option.position = QStyleOptionHeader::End;
 414     } else {
 415         option.position = QStyleOptionHeader::Middle;
 416     }
 417
 418     option.orientation = Qt::Horizontal;
 419     option.selectedPosition = QStyleOptionHeader::NotAdjacent;
 420     option.text = m_model->roleDescription(role);
 421
 422     style()->drawControl(QStyle::CE_Header, &option, painter, widget);
 423 }
 424
 425 void KItemListHeaderWidget::updatePressedRoleIndex(const QPointF& pos)
 426 {
 427     const int pressedIndex = roleIndexAt(pos);
 428     if (m_pressedRoleIndex != pressedIndex) {
 429         m_pressedRoleIndex = pressedIndex;
 430         update();
 431     }
 432 }
 433
 434 void KItemListHeaderWidget::updateHoveredRoleIndex(const QPointF& pos)
 435 {
 436     const int hoverIndex = roleIndexAt(pos);
 437     if (m_hoveredRoleIndex != hoverIndex) {
 438         m_hoveredRoleIndex = hoverIndex;
 439         update();
 440     }
 441 }
 442
 443 int KItemListHeaderWidget::roleIndexAt(const QPointF& pos) const
 444 {
 445     int index = -1;
 446
 447     qreal x = -m_offset;
 448     foreach (const QByteArray& role, m_columns) {
 449         ++index;
 450         x += m_columnWidths.value(role);
 451         if (pos.x() <= x) {
 452             break;
 453         }
 454     }
 455
 456     return index;
 457 }
 458
 459 bool KItemListHeaderWidget::isAboveRoleGrip(const QPointF& pos, int roleIndex) const
 460 {
 461     qreal x = -m_offset;
 462     for (int i = 0; i <= roleIndex; ++i) {
 463         const QByteArray role = m_columns[i];
 464         x += m_columnWidths.value(role);
 465     }
 466
 467     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 468     return pos.x() >= (x - grip) && pos.x() <= x;
 469 }
 470
 471 QPixmap KItemListHeaderWidget::createRolePixmap(int roleIndex) const
 472 {
 473     const QByteArray role = m_columns[roleIndex];
 474     const qreal roleWidth = m_columnWidths.value(role);
 475     const QRect rect(0, 0, roleWidth, size().height());
 476
 477     QImage image(rect.size(), QImage::Format_ARGB32_Premultiplied);
 478
 479     QPainter painter(&image);
 480     paintRole(&painter, role, rect, roleIndex);
 481
 482     // Apply a highlighting-color
 483     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 484     QColor highlightColor = palette().color(group, QPalette::Highlight);
 485     highlightColor.setAlpha(64);
 486     painter.fillRect(rect, highlightColor);
 487
 488     // Make the image transparent
 489     painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
 490     painter.fillRect(0, 0, image.width(), image.height(), QColor(0, 0, 0, 192));
 491
 492     return QPixmap::fromImage(image);
 493 }
 494
 495 int KItemListHeaderWidget::targetOfMovingRole() const
 496 {
 497     const int movingWidth = m_movingRole.pixmap.width();
 498     const int movingLeft = m_movingRole.x;
 499     const int movingRight = movingLeft + movingWidth - 1;
 500
 501     int targetIndex = 0;
 502     qreal targetLeft = -m_offset;
 503     while (targetIndex < m_columns.count()) {
 504         const QByteArray role = m_columns[targetIndex];
 505         const qreal targetWidth = m_columnWidths.value(role);
 506         const qreal targetRight = targetLeft + targetWidth - 1;
 507
 508         const bool isInTarget = (targetWidth >= movingWidth &&
 509                                  movingLeft  >= targetLeft  &&
 510                                  movingRight <= targetRight) ||
 511                                 (targetWidth <  movingWidth &&
 512                                  movingLeft  <= targetLeft  &&
 513                                  movingRight >= targetRight);
 514
 515         if (isInTarget) {
 516             return targetIndex;
 517         }
 518
 519         targetLeft += targetWidth;
 520         ++targetIndex;
 521     }
 522
 523     return m_movingRole.index;
 524 }
 525
 526 qreal KItemListHeaderWidget::roleXPosition(const QByteArray& role) const
 527 {
 528     qreal x = -m_offset;
 529     foreach (const QByteArray& visibleRole, m_columns) {
 530         if (visibleRole == role) {
 531             return x;
 532         }
 533
 534         x += m_columnWidths.value(visibleRole);
 535     }
 536
 537     return -1;
 538 }
 539
 540 #include "kitemlistheaderwidget.moc"