src/kitemviews/private/kitemlistheaderwidget.cpp

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-or-later
   5  */
   6
   7 #include "kitemlistheaderwidget.h"
   8 #include "kitemviews/kitemmodelbase.h"
   9
  10 #include <QApplication>
  11 #include <QGraphicsSceneHoverEvent>
  12 #include <QPainter>
  13 #include <QStyleOptionHeader>
  14
  15 KItemListHeaderWidget::KItemListHeaderWidget(QGraphicsWidget *parent)
  16     : QGraphicsWidget(parent)
  17     , m_automaticColumnResizing(true)
  18     , m_model(nullptr)
  19     , m_offset(0)
  20     , m_sidePadding(0)
  21     , m_columns()
  22     , m_columnWidths()
  23     , m_preferredColumnWidths()
  24     , m_hoveredRoleIndex(-1)
  25     , m_pressedRoleIndex(-1)
  26     , m_roleOperation(NoRoleOperation)
  27     , m_pressedMousePos()
  28     , m_movingRole()
  29 {
  30     m_movingRole.x = 0;
  31     m_movingRole.xDec = 0;
  32     m_movingRole.index = -1;
  33
  34     setAcceptHoverEvents(true);
  35     // TODO update when font changes at runtime
  36     setFont(QApplication::font("QHeaderView"));
  37 }
  38
  39 KItemListHeaderWidget::~KItemListHeaderWidget()
  40 {
  41 }
  42
  43 void KItemListHeaderWidget::setModel(KItemModelBase *model)
  44 {
  45     if (m_model == model) {
  46         return;
  47     }
  48
  49     if (m_model) {
  50         disconnect(m_model, &KItemModelBase::sortRoleChanged, this, &KItemListHeaderWidget::slotSortRoleChanged);
  51         disconnect(m_model, &KItemModelBase::sortOrderChanged, this, &KItemListHeaderWidget::slotSortOrderChanged);
  52     }
  53
  54     m_model = model;
  55
  56     if (m_model) {
  57         connect(m_model, &KItemModelBase::sortRoleChanged, this, &KItemListHeaderWidget::slotSortRoleChanged);
  58         connect(m_model, &KItemModelBase::sortOrderChanged, this, &KItemListHeaderWidget::slotSortOrderChanged);
  59     }
  60 }
  61
  62 KItemModelBase *KItemListHeaderWidget::model() const
  63 {
  64     return m_model;
  65 }
  66
  67 void KItemListHeaderWidget::setAutomaticColumnResizing(bool automatic)
  68 {
  69     m_automaticColumnResizing = automatic;
  70 }
  71
  72 bool KItemListHeaderWidget::automaticColumnResizing() const
  73 {
  74     return m_automaticColumnResizing;
  75 }
  76
  77 void KItemListHeaderWidget::setColumns(const QList<QByteArray> &roles)
  78 {
  79     for (const QByteArray &role : roles) {
  80         if (!m_columnWidths.contains(role)) {
  81             m_preferredColumnWidths.remove(role);
  82         }
  83     }
  84
  85     m_columns = roles;
  86     update();
  87 }
  88
  89 QList<QByteArray> KItemListHeaderWidget::columns() const
  90 {
  91     return m_columns;
  92 }
  93
  94 void KItemListHeaderWidget::setColumnWidth(const QByteArray &role, qreal width)
  95 {
  96     const qreal minWidth = minimumColumnWidth();
  97     if (width < minWidth) {
  98         width = minWidth;
  99     }
 100
 101     if (m_columnWidths.value(role) != width) {
 102         m_columnWidths.insert(role, width);
 103         update();
 104     }
 105 }
 106
 107 qreal KItemListHeaderWidget::columnWidth(const QByteArray &role) const
 108 {
 109     return m_columnWidths.value(role);
 110 }
 111
 112 void KItemListHeaderWidget::setPreferredColumnWidth(const QByteArray &role, qreal width)
 113 {
 114     m_preferredColumnWidths.insert(role, width);
 115 }
 116
 117 qreal KItemListHeaderWidget::preferredColumnWidth(const QByteArray &role) const
 118 {
 119     return m_preferredColumnWidths.value(role);
 120 }
 121
 122 void KItemListHeaderWidget::setOffset(qreal offset)
 123 {
 124     if (m_offset != offset) {
 125         m_offset = offset;
 126         update();
 127     }
 128 }
 129
 130 qreal KItemListHeaderWidget::offset() const
 131 {
 132     return m_offset;
 133 }
 134
 135 void KItemListHeaderWidget::setSidePadding(qreal width)
 136 {
 137     if (m_sidePadding != width) {
 138         m_sidePadding = width;
 139         sidePaddingChanged(width);
 140         update();
 141     }
 142 }
 143
 144 qreal KItemListHeaderWidget::sidePadding() const
 145 {
 146     return m_sidePadding;
 147 }
 148
 149 qreal KItemListHeaderWidget::minimumColumnWidth() const
 150 {
 151     QFontMetricsF fontMetrics(font());
 152     return fontMetrics.height() * 4;
 153 }
 154
 155 void KItemListHeaderWidget::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
 156 {
 157     Q_UNUSED(option)
 158     Q_UNUSED(widget)
 159
 160     if (!m_model) {
 161         return;
 162     }
 163
 164     // Draw roles
 165     painter->setFont(font());
 166     painter->setPen(palette().text().color());
 167
 168     qreal x = -m_offset + m_sidePadding;
 169     int orderIndex = 0;
 170     for (const QByteArray &role : qAsConst(m_columns)) {
 171         const qreal roleWidth = m_columnWidths.value(role);
 172         const QRectF rect(x, 0, roleWidth, size().height());
 173         paintRole(painter, role, rect, orderIndex, widget);
 174         x += roleWidth;
 175         ++orderIndex;
 176     }
 177
 178     if (!m_movingRole.pixmap.isNull()) {
 179         Q_ASSERT(m_roleOperation == MoveRoleOperation);
 180         painter->drawPixmap(m_movingRole.x, 0, m_movingRole.pixmap);
 181     }
 182 }
 183
 184 void KItemListHeaderWidget::mousePressEvent(QGraphicsSceneMouseEvent *event)
 185 {
 186     if (event->button() & Qt::LeftButton) {
 187         m_pressedMousePos = event->pos();
 188         if (isAbovePaddingGrip(m_pressedMousePos, PaddingGrip::Leading)) {
 189             m_roleOperation = ResizePaddingColumnOperation;
 190         } else {
 191             updatePressedRoleIndex(event->pos());
 192             m_roleOperation = isAboveRoleGrip(m_pressedMousePos, m_pressedRoleIndex) ? ResizeRoleOperation : NoRoleOperation;
 193         }
 194         event->accept();
 195     } else {
 196         event->ignore();
 197     }
 198 }
 199
 200 void KItemListHeaderWidget::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 201 {
 202     QGraphicsWidget::mouseReleaseEvent(event);
 203
 204     if (m_pressedRoleIndex == -1) {
 205         return;
 206     }
 207
 208     switch (m_roleOperation) {
 209     case NoRoleOperation: {
 210         // Only a click has been done and no moving or resizing has been started
 211         const QByteArray sortRole = m_model->sortRole();
 212         const int sortRoleIndex = m_columns.indexOf(sortRole);
 213         if (m_pressedRoleIndex == sortRoleIndex) {
 214             // Toggle the sort order
 215             const Qt::SortOrder previous = m_model->sortOrder();
 216             const Qt::SortOrder current = (m_model->sortOrder() == Qt::AscendingOrder) ? Qt::DescendingOrder : Qt::AscendingOrder;
 217             m_model->setSortOrder(current);
 218             Q_EMIT sortOrderChanged(current, previous);
 219         } else {
 220             // Change the sort role and reset to the ascending order
 221             const QByteArray previous = m_model->sortRole();
 222             const QByteArray current = m_columns[m_pressedRoleIndex];
 223             const bool resetSortOrder = m_model->sortOrder() == Qt::DescendingOrder;
 224             m_model->setSortRole(current, !resetSortOrder);
 225             Q_EMIT sortRoleChanged(current, previous);
 226
 227             if (resetSortOrder) {
 228                 m_model->setSortOrder(Qt::AscendingOrder);
 229                 Q_EMIT sortOrderChanged(Qt::AscendingOrder, Qt::DescendingOrder);
 230             }
 231         }
 232         break;
 233     }
 234
 235     case ResizeRoleOperation: {
 236         const QByteArray pressedRole = m_columns[m_pressedRoleIndex];
 237         const qreal currentWidth = m_columnWidths.value(pressedRole);
 238         Q_EMIT columnWidthChangeFinished(pressedRole, currentWidth);
 239         break;
 240     }
 241
 242     case MoveRoleOperation:
 243         m_movingRole.pixmap = QPixmap();
 244         m_movingRole.x = 0;
 245         m_movingRole.xDec = 0;
 246         m_movingRole.index = -1;
 247         break;
 248
 249     default:
 250         break;
 251     }
 252
 253     m_pressedRoleIndex = -1;
 254     m_roleOperation = NoRoleOperation;
 255     update();
 256
 257     QApplication::restoreOverrideCursor();
 258 }
 259
 260 void KItemListHeaderWidget::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 261 {
 262     QGraphicsWidget::mouseMoveEvent(event);
 263
 264     switch (m_roleOperation) {
 265     case NoRoleOperation:
 266         if ((event->pos() - m_pressedMousePos).manhattanLength() >= QApplication::startDragDistance()) {
 267             // A role gets dragged by the user. Create a pixmap of the role that will get
 268             // synchronized on each further mouse-move-event with the mouse-position.
 269             m_roleOperation = MoveRoleOperation;
 270             const int roleIndex = roleIndexAt(m_pressedMousePos);
 271             m_movingRole.index = roleIndex;
 272             if (roleIndex == 0) {
 273                 // TODO: It should be configurable whether moving the first role is allowed.
 274                 // In the context of Dolphin this is not required, however this should be
 275                 // changed if KItemViews are used in a more generic way.
 276                 QApplication::setOverrideCursor(QCursor(Qt::ForbiddenCursor));
 277             } else {
 278                 m_movingRole.pixmap = createRolePixmap(roleIndex);
 279
 280                 qreal roleX = -m_offset + m_sidePadding;
 281                 for (int i = 0; i < roleIndex; ++i) {
 282                     const QByteArray role = m_columns[i];
 283                     roleX += m_columnWidths.value(role);
 284                 }
 285
 286                 m_movingRole.xDec = event->pos().x() - roleX;
 287                 m_movingRole.x = roleX;
 288                 update();
 289             }
 290         }
 291         break;
 292
 293     case ResizeRoleOperation: {
 294         const QByteArray pressedRole = m_columns[m_pressedRoleIndex];
 295
 296         qreal previousWidth = m_columnWidths.value(pressedRole);
 297         qreal currentWidth = previousWidth;
 298         currentWidth += event->pos().x() - event->lastPos().x();
 299         currentWidth = qMax(minimumColumnWidth(), currentWidth);
 300
 301         m_columnWidths.insert(pressedRole, currentWidth);
 302         update();
 303
 304         Q_EMIT columnWidthChanged(pressedRole, currentWidth, previousWidth);
 305         break;
 306     }
 307
 308     case ResizePaddingColumnOperation: {
 309         qreal currentWidth = m_sidePadding;
 310         currentWidth += event->pos().x() - event->lastPos().x();
 311         currentWidth = qMax(0.0, currentWidth);
 312
 313         m_sidePadding = currentWidth;
 314
 315         update();
 316
 317         Q_EMIT sidePaddingChanged(currentWidth);
 318
 319         break;
 320     }
 321
 322     case MoveRoleOperation: {
 323         // TODO: It should be configurable whether moving the first role is allowed.
 324         // In the context of Dolphin this is not required, however this should be
 325         // changed if KItemViews are used in a more generic way.
 326         if (m_movingRole.index > 0) {
 327             m_movingRole.x = event->pos().x() - m_movingRole.xDec;
 328             update();
 329
 330             const int targetIndex = targetOfMovingRole();
 331             if (targetIndex > 0 && targetIndex != m_movingRole.index) {
 332                 const QByteArray role = m_columns[m_movingRole.index];
 333                 const int previousIndex = m_movingRole.index;
 334                 m_movingRole.index = targetIndex;
 335                 Q_EMIT columnMoved(role, targetIndex, previousIndex);
 336
 337                 m_movingRole.xDec = event->pos().x() - roleXPosition(role);
 338             }
 339         }
 340         break;
 341     }
 342
 343     default:
 344         break;
 345     }
 346 }
 347
 348 void KItemListHeaderWidget::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
 349 {
 350     QGraphicsItem::mouseDoubleClickEvent(event);
 351
 352     const int roleIndex = roleIndexAt(event->pos());
 353     if (roleIndex >= 0 && isAboveRoleGrip(event->pos(), roleIndex)) {
 354         const QByteArray role = m_columns.at(roleIndex);
 355
 356         qreal previousWidth = columnWidth(role);
 357         setColumnWidth(role, preferredColumnWidth(role));
 358         qreal currentWidth = columnWidth(role);
 359
 360         Q_EMIT columnWidthChanged(role, currentWidth, previousWidth);
 361         Q_EMIT columnWidthChangeFinished(role, currentWidth);
 362     }
 363 }
 364
 365 void KItemListHeaderWidget::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
 366 {
 367     QGraphicsWidget::hoverEnterEvent(event);
 368     updateHoveredRoleIndex(event->pos());
 369 }
 370
 371 void KItemListHeaderWidget::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
 372 {
 373     QGraphicsWidget::hoverLeaveEvent(event);
 374     if (m_hoveredRoleIndex != -1) {
 375         m_hoveredRoleIndex = -1;
 376         update();
 377     }
 378 }
 379
 380 void KItemListHeaderWidget::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
 381 {
 382     QGraphicsWidget::hoverMoveEvent(event);
 383
 384     const QPointF &pos = event->pos();
 385     updateHoveredRoleIndex(pos);
 386     if ((m_hoveredRoleIndex >= 0 && isAboveRoleGrip(pos, m_hoveredRoleIndex)) || isAbovePaddingGrip(pos, PaddingGrip::Leading)
 387         || isAbovePaddingGrip(pos, PaddingGrip::Trailing)) {
 388         setCursor(Qt::SplitHCursor);
 389     } else {
 390         unsetCursor();
 391     }
 392 }
 393
 394 void KItemListHeaderWidget::slotSortRoleChanged(const QByteArray &current, const QByteArray &previous)
 395 {
 396     Q_UNUSED(current)
 397     Q_UNUSED(previous)
 398     update();
 399 }
 400
 401 void KItemListHeaderWidget::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 402 {
 403     Q_UNUSED(current)
 404     Q_UNUSED(previous)
 405     update();
 406 }
 407
 408 void KItemListHeaderWidget::paintRole(QPainter *painter, const QByteArray &role, const QRectF &rect, int orderIndex, QWidget *widget) const
 409 {
 410     const auto direction = widget ? widget->layoutDirection() : qApp->layoutDirection();
 411
 412     // The following code is based on the code from QHeaderView::paintSection().
 413     // SPDX-FileCopyrightText: 2011 Nokia Corporation and/or its subsidiary(-ies).
 414     QStyleOptionHeader option;
 415     option.direction = direction;
 416     option.textAlignment = direction == Qt::LeftToRight ? Qt::AlignLeft : Qt::AlignRight;
 417
 418     option.section = orderIndex;
 419     option.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 420     if (isEnabled()) {
 421         option.state |= QStyle::State_Enabled;
 422     }
 423     if (window() && window()->isActiveWindow()) {
 424         option.state |= QStyle::State_Active;
 425     }
 426     if (m_hoveredRoleIndex == orderIndex) {
 427         option.state |= QStyle::State_MouseOver;
 428     }
 429     if (m_pressedRoleIndex == orderIndex) {
 430         option.state |= QStyle::State_Sunken;
 431     }
 432     if (m_model->sortRole() == role) {
 433         option.sortIndicator = (m_model->sortOrder() == Qt::AscendingOrder) ? QStyleOptionHeader::SortDown : QStyleOptionHeader::SortUp;
 434     }
 435     option.rect = rect.toRect();
 436     option.orientation = Qt::Horizontal;
 437     option.selectedPosition = QStyleOptionHeader::NotAdjacent;
 438     option.text = m_model->roleDescription(role);
 439
 440     // First we paint any potential empty (padding) space on left and/or right of this role's column.
 441     const auto paintPadding = [&](int section, const QRectF &rect, const QStyleOptionHeader::SectionPosition &pos) {
 442         QStyleOptionHeader padding;
 443         padding.state = QStyle::State_None | QStyle::State_Raised | QStyle::State_Horizontal;
 444         padding.section = section;
 445         padding.sortIndicator = QStyleOptionHeader::None;
 446         padding.rect = rect.toRect();
 447         padding.position = pos;
 448         padding.text = QString();
 449         style()->drawControl(QStyle::CE_Header, &padding, painter, widget);
 450     };
 451
 452     if (m_columns.count() == 1) {
 453         option.position = QStyleOptionHeader::Middle;
 454         paintPadding(0, QRectF(0.0, 0.0, rect.left(), rect.height()), QStyleOptionHeader::Beginning);
 455         paintPadding(1, QRectF(rect.left(), 0.0, size().width() - rect.left(), rect.height()), QStyleOptionHeader::End);
 456     } else if (orderIndex == 0) {
 457         // Paint the header for the first column; check if there is some empty space to the left which needs to be filled.
 458         if (rect.left() > 0) {
 459             option.position = QStyleOptionHeader::Middle;
 460             paintPadding(0, QRectF(0.0, 0.0, rect.left(), rect.height()), QStyleOptionHeader::Beginning);
 461         } else {
 462             option.position = QStyleOptionHeader::Beginning;
 463         }
 464     } else if (orderIndex == m_columns.count() - 1) {
 465         // Paint the header for the last column; check if there is some empty space to the right which needs to be filled.
 466         if (rect.right() < size().width()) {
 467             option.position = QStyleOptionHeader::Middle;
 468             paintPadding(m_columns.count(), QRectF(rect.left(), 0.0, size().width() - rect.left(), rect.height()), QStyleOptionHeader::End);
 469         } else {
 470             option.position = QStyleOptionHeader::End;
 471         }
 472     } else {
 473         option.position = QStyleOptionHeader::Middle;
 474     }
 475
 476     style()->drawControl(QStyle::CE_Header, &option, painter, widget);
 477 }
 478
 479 void KItemListHeaderWidget::updatePressedRoleIndex(const QPointF &pos)
 480 {
 481     const int pressedIndex = roleIndexAt(pos);
 482     if (m_pressedRoleIndex != pressedIndex) {
 483         m_pressedRoleIndex = pressedIndex;
 484         update();
 485     }
 486 }
 487
 488 void KItemListHeaderWidget::updateHoveredRoleIndex(const QPointF &pos)
 489 {
 490     const int hoverIndex = roleIndexAt(pos);
 491     if (m_hoveredRoleIndex != hoverIndex) {
 492         m_hoveredRoleIndex = hoverIndex;
 493         update();
 494     }
 495 }
 496
 497 int KItemListHeaderWidget::roleIndexAt(const QPointF &pos) const
 498 {
 499     int index = -1;
 500
 501     qreal x = -m_offset + m_sidePadding;
 502     for (const QByteArray &role : qAsConst(m_columns)) {
 503         ++index;
 504         x += m_columnWidths.value(role);
 505         if (pos.x() <= x) {
 506             break;
 507         }
 508     }
 509
 510     return index;
 511 }
 512
 513 bool KItemListHeaderWidget::isAboveRoleGrip(const QPointF &pos, int roleIndex) const
 514 {
 515     qreal x = -m_offset + m_sidePadding;
 516     for (int i = 0; i <= roleIndex; ++i) {
 517         const QByteArray role = m_columns[i];
 518         x += m_columnWidths.value(role);
 519     }
 520
 521     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 522     return pos.x() >= (x - grip) && pos.x() <= x;
 523 }
 524
 525 bool KItemListHeaderWidget::isAbovePaddingGrip(const QPointF &pos, PaddingGrip paddingGrip) const
 526 {
 527     const qreal lx = -m_offset + m_sidePadding;
 528     const int grip = style()->pixelMetric(QStyle::PM_HeaderGripMargin);
 529
 530     switch (paddingGrip) {
 531     case Leading:
 532         return pos.x() >= (lx - grip) && pos.x() <= lx;
 533     case Trailing: {
 534         qreal rx = lx;
 535         for (const QByteArray &role : qAsConst(m_columns)) {
 536             rx += m_columnWidths.value(role);
 537         }
 538         return pos.x() >= (rx - grip) && pos.x() <= rx;
 539     }
 540     default:
 541         return false;
 542     }
 543 }
 544
 545 QPixmap KItemListHeaderWidget::createRolePixmap(int roleIndex) const
 546 {
 547     const QByteArray role = m_columns[roleIndex];
 548     const qreal roleWidth = m_columnWidths.value(role);
 549     const QRect rect(0, 0, roleWidth, size().height());
 550
 551     QImage image(rect.size(), QImage::Format_ARGB32_Premultiplied);
 552
 553     QPainter painter(&image);
 554     paintRole(&painter, role, rect, roleIndex);
 555
 556     // Apply a highlighting-color
 557     const QPalette::ColorGroup group = isActiveWindow() ? QPalette::Active : QPalette::Inactive;
 558     QColor highlightColor = palette().color(group, QPalette::Highlight);
 559     highlightColor.setAlpha(64);
 560     painter.fillRect(rect, highlightColor);
 561
 562     // Make the image transparent
 563     painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
 564     painter.fillRect(0, 0, image.width(), image.height(), QColor(0, 0, 0, 192));
 565
 566     return QPixmap::fromImage(image);
 567 }
 568
 569 int KItemListHeaderWidget::targetOfMovingRole() const
 570 {
 571     const int movingWidth = m_movingRole.pixmap.width();
 572     const int movingLeft = m_movingRole.x;
 573     const int movingRight = movingLeft + movingWidth - 1;
 574
 575     int targetIndex = 0;
 576     qreal targetLeft = -m_offset + m_sidePadding;
 577     while (targetIndex < m_columns.count()) {
 578         const QByteArray role = m_columns[targetIndex];
 579         const qreal targetWidth = m_columnWidths.value(role);
 580         const qreal targetRight = targetLeft + targetWidth - 1;
 581
 582         const bool isInTarget = (targetWidth >= movingWidth && movingLeft >= targetLeft && movingRight <= targetRight)
 583             || (targetWidth < movingWidth && movingLeft <= targetLeft && movingRight >= targetRight);
 584
 585         if (isInTarget) {
 586             return targetIndex;
 587         }
 588
 589         targetLeft += targetWidth;
 590         ++targetIndex;
 591     }
 592
 593     return m_movingRole.index;
 594 }
 595
 596 qreal KItemListHeaderWidget::roleXPosition(const QByteArray &role) const
 597 {
 598     qreal x = -m_offset + m_sidePadding;
 599     for (const QByteArray &visibleRole : qAsConst(m_columns)) {
 600         if (visibleRole == role) {
 601             return x;
 602         }
 603
 604         x += m_columnWidths.value(visibleRole);
 605     }
 606
 607     return -1;
 608 }