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Diffstat (limited to 'examples/scroller/wheel/wheelwidget.cpp')
| -rw-r--r-- | examples/scroller/wheel/wheelwidget.cpp | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/examples/scroller/wheel/wheelwidget.cpp b/examples/scroller/wheel/wheelwidget.cpp new file mode 100644 index 0000000..64a459b --- /dev/null +++ b/examples/scroller/wheel/wheelwidget.cpp @@ -0,0 +1,276 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtGui module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QtGui> + +#include "wheelwidget.h" + +#define WHEEL_SCROLL_OFFSET 50000.0 + +AbstractWheelWidget::AbstractWheelWidget(bool touch, QWidget *parent) + : QWidget(parent) + , m_currentItem(0) + , m_itemOffset(0) +{ +// ![0] + QScroller::grabGesture(this, touch ? QScroller::TouchGesture : QScroller::LeftMouseButtonGesture); +// ![0] +} + +AbstractWheelWidget::~AbstractWheelWidget() +{ } + +int AbstractWheelWidget::currentIndex() const +{ + return m_currentItem; +} + +void AbstractWheelWidget::setCurrentIndex(int index) +{ + if (index >= 0 && index < itemCount()) { + m_currentItem = index; + m_itemOffset = 0; + update(); + } +} + +bool AbstractWheelWidget::event(QEvent *e) +{ + switch (e->type()) { +// ![1] + case QEvent::ScrollPrepare: + { + // We set the snap positions as late as possible so that we are sure + // we get the correct itemHeight + QScroller *scroller = QScroller::scroller(this); + scroller->setSnapPositionsY( WHEEL_SCROLL_OFFSET, itemHeight() ); + + QScrollPrepareEvent *se = static_cast<QScrollPrepareEvent *>(e); + se->setViewportSize(QSizeF(size())); + // we claim a huge scrolling area and a huge content position and + // hope that the user doesn't notice that the scroll area is restricted + se->setContentPosRange(QRectF(0.0, 0.0, 0.0, WHEEL_SCROLL_OFFSET * 2)); + se->setContentPos(QPointF(0.0, WHEEL_SCROLL_OFFSET + m_currentItem * itemHeight() + m_itemOffset)); + se->accept(); + return true; + } +// ![1] +// ![2] + case QEvent::Scroll: + { + QScrollEvent *se = static_cast<QScrollEvent *>(e); + + qreal y = se->contentPos().y(); + int iy = y - WHEEL_SCROLL_OFFSET; + int ih = itemHeight(); + +// ![2] + + // -- calculate the current item position and offset and redraw the widget + int ic = itemCount(); + if (ic>0) { + m_currentItem = iy / ih % ic; + m_itemOffset = iy % ih; + + // take care when scrolling backwards. Modulo returns negative numbers + if (m_itemOffset < 0) { + m_itemOffset += ih; + m_currentItem--; + } + + if (m_currentItem < 0) + m_currentItem += ic; + } + // -- repaint + update(); + + se->accept(); + return true; + } + default: + return QWidget::event(e); + } + return true; +} + +void AbstractWheelWidget::paintEvent(QPaintEvent* event) +{ + Q_UNUSED( event ); + + // -- first calculate size and position. + int w = width(); + int h = height(); + + QPainter painter(this); + QPalette palette = QApplication::palette(); + QPalette::ColorGroup colorGroup = isEnabled() ? QPalette::Active : QPalette::Disabled; + + // linear gradient brush + QLinearGradient grad(0.5, 0, 0.5, 1.0); + grad.setColorAt(0, palette.color(colorGroup, QPalette::ButtonText)); + grad.setColorAt(0.2, palette.color(colorGroup, QPalette::Button)); + grad.setColorAt(0.8, palette.color(colorGroup, QPalette::Button)); + grad.setColorAt(1.0, palette.color(colorGroup, QPalette::ButtonText)); + grad.setCoordinateMode( QGradient::ObjectBoundingMode ); + QBrush gBrush( grad ); + + // paint a border and background + painter.setPen(palette.color(colorGroup, QPalette::ButtonText)); + painter.setBrush(gBrush); + // painter.setBrushOrigin( QPointF( 0.0, 0.0 ) ); + painter.drawRect( 0, 0, w-1, h-1 ); + + // paint inner border + painter.setPen(palette.color(colorGroup, QPalette::Button)); + painter.setBrush(Qt::NoBrush); + painter.drawRect( 1, 1, w-3, h-3 ); + + // paint the items + painter.setClipRect( QRect( 3, 3, w-6, h-6 ) ); + painter.setPen(palette.color(colorGroup, QPalette::ButtonText)); + + int iH = itemHeight(); + int iC = itemCount(); + if (iC > 0) { + + m_itemOffset = m_itemOffset % iH; + + for (int i=-h/2/iH; i<=h/2/iH+1; i++) { + + int itemNum = m_currentItem + i; + while (itemNum < 0) + itemNum += iC; + while (itemNum >= iC) + itemNum -= iC; + + paintItem(&painter, itemNum, QRect(6, h/2 +i*iH - m_itemOffset - iH/2, w-6, iH )); + } + } + + // draw a transparent bar over the center + QColor highlight = palette.color(colorGroup, QPalette::Highlight); + highlight.setAlpha(150); + + QLinearGradient grad2(0.5, 0, 0.5, 1.0); + grad2.setColorAt(0, highlight); + grad2.setColorAt(1.0, highlight.lighter()); + grad2.setCoordinateMode( QGradient::ObjectBoundingMode ); + QBrush gBrush2( grad2 ); + + QLinearGradient grad3(0.5, 0, 0.5, 1.0); + grad3.setColorAt(0, highlight); + grad3.setColorAt(1.0, highlight.darker()); + grad3.setCoordinateMode( QGradient::ObjectBoundingMode ); + QBrush gBrush3( grad3 ); + + painter.fillRect( QRect( 0, h/2 - iH/2, w, iH/2 ), gBrush2 ); + painter.fillRect( QRect( 0, h/2, w, iH/2 ), gBrush3 ); +} + +/*! + Rotates the wheel widget to a given index. + You can also give an index greater than itemCount or less than zero in which + case the wheel widget will scroll in the given direction and end up with + (index % itemCount) +*/ +void AbstractWheelWidget::scrollTo(int index) +{ + QScroller *scroller = QScroller::scroller(this); + + scroller->scrollTo(QPointF(0, WHEEL_SCROLL_OFFSET + index * itemHeight()), 5000); +} + +/*! + \class StringWheelWidget + \brief The StringWheelWidget class is an implementation of the AbstractWheelWidget class that draws QStrings as items. + \sa AbstractWheelWidget +*/ + +StringWheelWidget::StringWheelWidget(bool touch) + : AbstractWheelWidget(touch) +{ } + +QStringList StringWheelWidget::items() const +{ + return m_items; +} + +void StringWheelWidget::setItems( const QStringList &items ) +{ + m_items = items; + if (m_currentItem >= items.count()) + m_currentItem = items.count()-1; + update(); +} + + +QSize StringWheelWidget::sizeHint() const +{ + // determine font size + QFontMetrics fm(font()); + + return QSize( fm.width("m") * 10 + 6, fm.height() * 7 + 6 ); +} + +QSize StringWheelWidget::minimumSizeHint() const +{ + QFontMetrics fm(font()); + + return QSize( fm.width("m") * 5 + 6, fm.height() * 3 + 6 ); +} + +void StringWheelWidget::paintItem(QPainter* painter, int index, const QRect &rect) +{ + painter->drawText(rect, Qt::AlignCenter, m_items.at(index)); +} + +int StringWheelWidget::itemHeight() const +{ + QFontMetrics fm(font()); + return fm.height(); +} + +int StringWheelWidget::itemCount() const +{ + return m_items.count(); +} + + |