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