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