qt-all-opensource-src-4.5.3/examples/painting/svgviewer/svgview.cpp

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** 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.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#include "svgview.h"

#include <QFile>
#include <QWheelEvent>
#include <QMouseEvent>
#include <QGraphicsRectItem>
#include <QGraphicsSvgItem>
#include <QPaintEvent>
#include <qmath.h>

#ifndef QT_NO_OPENGL
#include <QGLWidget>
#endif

SvgView::SvgView(QWidget *parent)
    : QGraphicsView(parent)
    , m_renderer(Native)
    , m_svgItem(0)
    , m_backgroundItem(0)
    , m_outlineItem(0)
{
    setScene(new QGraphicsScene(this));
    setTransformationAnchor(AnchorUnderMouse);
    setDragMode(ScrollHandDrag);

    // Prepare background check-board pattern
    QPixmap tilePixmap(64, 64);
    tilePixmap.fill(Qt::white);
    QPainter tilePainter(&tilePixmap);
    QColor color(220, 220, 220);
    tilePainter.fillRect(0, 0, 32, 32, color);
    tilePainter.fillRect(32, 32, 32, 32, color);
    tilePainter.end();

    setBackgroundBrush(tilePixmap);
}

void SvgView::drawBackground(QPainter *p, const QRectF &)
{
    p->save();
    p->resetTransform();
    p->drawTiledPixmap(viewport()->rect(), backgroundBrush().texture());
    p->restore();
}

void SvgView::openFile(const QFile &file)
{
    if (!file.exists())
        return;

    QGraphicsScene *s = scene();

    bool drawBackground = (m_backgroundItem ? m_backgroundItem->isVisible() : false);
    bool drawOutline = (m_outlineItem ? m_outlineItem->isVisible() : true);

    s->clear();
    resetTransform();

    m_svgItem = new QGraphicsSvgItem(file.fileName());
    m_svgItem->setFlags(QGraphicsItem::ItemClipsToShape);
    m_svgItem->setCacheMode(QGraphicsItem::NoCache);
    m_svgItem->setZValue(0);

    m_backgroundItem = new QGraphicsRectItem(m_svgItem->boundingRect());
    m_backgroundItem->setBrush(Qt::white);
    m_backgroundItem->setPen(Qt::NoPen);
    m_backgroundItem->setVisible(drawBackground);
    m_backgroundItem->setZValue(-1);

    m_outlineItem = new QGraphicsRectItem(m_svgItem->boundingRect());
    QPen outline(Qt::black, 2, Qt::DashLine);
    outline.setCosmetic(true);
    m_outlineItem->setPen(outline);
    m_outlineItem->setBrush(Qt::NoBrush);
    m_outlineItem->setVisible(drawOutline);
    m_outlineItem->setZValue(1);

    s->addItem(m_backgroundItem);
    s->addItem(m_svgItem);
    s->addItem(m_outlineItem);

    s->setSceneRect(m_outlineItem->boundingRect().adjusted(-10, -10, 10, 10));
}

void SvgView::setRenderer(RendererType type)
{
    m_renderer = type;

    if (m_renderer == OpenGL) {
#ifndef QT_NO_OPENGL
        setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers)));
#endif
    } else {
        setViewport(new QWidget);
    }
}

void SvgView::setHighQualityAntialiasing(bool highQualityAntialiasing)
{
#ifndef QT_NO_OPENGL
    setRenderHint(QPainter::HighQualityAntialiasing, highQualityAntialiasing);
#else
    Q_UNUSED(highQualityAntialiasing);
#endif
}

void SvgView::setViewBackground(bool enable)
{
    if (!m_backgroundItem)
          return;

    m_backgroundItem->setVisible(enable);
}

void SvgView::setViewOutline(bool enable)
{
    if (!m_outlineItem)
        return;

    m_outlineItem->setVisible(enable);
}

void SvgView::paintEvent(QPaintEvent *event)
{
    if (m_renderer == Image) {
        if (m_image.size() != viewport()->size()) {
            m_image = QImage(viewport()->size(), QImage::Format_ARGB32_Premultiplied);
        }

        QPainter imagePainter(&m_image);
        QGraphicsView::render(&imagePainter);
        imagePainter.end();

        QPainter p(viewport());
        p.drawImage(0, 0, m_image);

    } else {
        QGraphicsView::paintEvent(event);
    }
}

void SvgView::wheelEvent(QWheelEvent *event)
{
    qreal factor = qPow(1.2, event->delta() / 240.0);
    scale(factor, factor);
    event->accept();
}