qwt_polar_renderer.cpp

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/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * QwtPolar Widget Library
 * Copyright (C) 2008   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_polar_renderer.h"
#include "qwt_polar_plot.h"
#include "qwt_polar_layout.h"
#include "qwt_legend.h"
#include "qwt_dyngrid_layout.h"
#include "qwt_text_label.h"
#include "qwt_text.h"

#include <qpainter.h>
#include <qprinter.h>
#include <qprintdialog.h>
#include <qfiledialog.h>
#include <qimagewriter.h>
#include <qfileinfo.h>
#include <qmath.h>

#ifndef QWT_NO_SVG
#ifdef QT_SVG_LIB
#define QWT_FORMAT_SVG 1
#endif
#endif

#ifndef QT_NO_PRINTER
#define QWT_FORMAT_PDF 1
#endif

#ifndef QT_NO_PDF

// QPdfWriter::setResolution() has been introduced with
// Qt 5.3. Guess it is o.k. to stay with QPrinter for older
// versions.

#if QT_VERSION >= 0x050300

#ifndef QWT_FORMAT_PDF
#define QWT_FORMAT_PDF 1
#endif

#define QWT_PDF_WRITER 1

#endif
#endif

#ifndef QT_NO_PRINTER
// postscript support has been dropped in Qt5
#if QT_VERSION < 0x050000
#define QWT_FORMAT_POSTSCRIPT 1
#endif
#endif

#if QWT_FORMAT_SVG
#include <qsvggenerator.h>
#endif

#if QWT_PDF_WRITER
#include <qpdfwriter.h>
#endif

static inline double qwtDistance(
    const QPointF &p1, const QPointF &p2 )
{
    double dx = p2.x() - p1.x();
    double dy = p2.y() - p1.y();
    return qSqrt( dx * dx + dy * dy );
}

class QwtPolarRenderer::PrivateData
{
public:
    PrivateData():
        plot( NULL )
    {
    }

    QwtPolarPlot *plot;
};

QwtPolarRenderer::QwtPolarRenderer( QObject *parent ):
    QObject( parent )
{
    d_data = new PrivateData;
}

QwtPolarRenderer::~QwtPolarRenderer()
{
    delete d_data;
}

void QwtPolarRenderer::renderDocument( QwtPolarPlot *plot,
    const QString &fileName, const QSizeF &sizeMM, int resolution )
{
    renderDocument( plot, fileName,
        QFileInfo( fileName ).suffix(), sizeMM, resolution );
}

void QwtPolarRenderer::renderDocument( QwtPolarPlot *plot,
    const QString &fileName, const QString &format,
    const QSizeF &sizeMM, int resolution )
{
    if ( plot == NULL || sizeMM.isEmpty() || resolution <= 0 )
        return;

    QString title = plot->title().text();
    if ( title.isEmpty() )
        title = "Plot Document";

    const double mmToInch = 1.0 / 25.4;
    const QSizeF size = sizeMM * mmToInch * resolution;

    const QRectF documentRect( 0.0, 0.0, size.width(), size.height() );

    const QString fmt = format.toLower();
    if ( format == "pdf" )
    {
#if QWT_FORMAT_PDF
#if QWT_PDF_WRITER
        QPdfWriter pdfWriter( fileName );
        pdfWriter.setPageSize( QPageSize( sizeMM, QPageSize::Millimeter ) );
        pdfWriter.setTitle( title );
        pdfWriter.setPageMargins( QMarginsF() );
        pdfWriter.setResolution( resolution );

        QPainter painter( &pdfWriter );
        render( plot, &painter, documentRect );

#else
        QPrinter printer;
        printer.setOutputFormat( QPrinter::PdfFormat );
        printer.setColorMode( QPrinter::Color );
        printer.setFullPage( true );
        printer.setPaperSize( sizeMM, QPrinter::Millimeter );
        printer.setDocName( title );
        printer.setOutputFileName( fileName );
        printer.setResolution( resolution );

        QPainter painter( &printer );
        render( plot, &painter, documentRect );
#endif
#endif
    }
    else if ( format == "ps" )
    {
#if QWT_FORMAT_POSTSCRIPT
        QPrinter printer;
        printer.setColorMode( QPrinter::Color );
        printer.setFullPage( true );
        printer.setPaperSize( sizeMM, QPrinter::Millimeter );
        printer.setDocName( title );
        printer.setOutputFileName( fileName );
        printer.setOutputFormat( QPrinter::PostScriptFormat );
        printer.setResolution( resolution );

        QPainter painter( &printer );
        render( plot, &painter, documentRect );
#endif
    }
    else if ( format == "svg" )
    {
#ifdef QWT_FORMAT_SVG
        QSvgGenerator generator;
        generator.setTitle( title );
        generator.setFileName( fileName );
        generator.setResolution( resolution );
        generator.setViewBox( documentRect );

        QPainter painter( &generator );
        render( plot, &painter, documentRect );
#endif
    }
    else
    {
        if ( QImageWriter::supportedImageFormats().indexOf(
            format.toLatin1() ) >= 0 )
        {
            const QRect imageRect = documentRect.toRect();
            const int dotsPerMeter = qRound( resolution * mmToInch * 1000.0 );

            QImage image( imageRect.size(), QImage::Format_ARGB32 );
            image.setDotsPerMeterX( dotsPerMeter );
            image.setDotsPerMeterY( dotsPerMeter );
            image.fill( QColor( Qt::white ).rgb() );

            QPainter painter( &image );
            render( plot, &painter, imageRect );
            painter.end();

            image.save( fileName, format.toLatin1() );
        }
    }
}

void QwtPolarRenderer::renderTo(
    QwtPolarPlot *plot, QPaintDevice &paintDevice ) const
{
    int w = paintDevice.width();
    int h = paintDevice.height();

    QPainter p( &paintDevice );
    render( plot, &p, QRectF( 0, 0, w, h ) );
}


#ifndef QT_NO_PRINTER

void QwtPolarRenderer::renderTo(
    QwtPolarPlot *plot, QPrinter &printer ) const
{
    int w = printer.width();
    int h = printer.height();

    QRectF rect( 0, 0, w, h );
    double aspect = rect.width() / rect.height();
    if ( ( aspect < 1.0 ) )
        rect.setHeight( aspect * rect.width() );

    QPainter p( &printer );
    render( plot, &p, rect );
}

#endif

#ifdef QWT_FORMAT_SVG

void QwtPolarRenderer::renderTo(
    QwtPolarPlot *plot, QSvgGenerator &generator ) const
{
    QRectF rect = generator.viewBoxF();
    if ( rect.isEmpty() )
        rect.setRect( 0, 0, generator.width(), generator.height() );

    if ( rect.isEmpty() )
        rect.setRect( 0, 0, 800, 600 ); // something

    QPainter p( &generator );
    render( plot, &p, rect );
}

#endif

void QwtPolarRenderer::render( QwtPolarPlot *plot,
    QPainter *painter, const QRectF &plotRect ) const
{
    if ( plot == NULL || painter == NULL || !painter->isActive() ||
        !plotRect.isValid() || plot->size().isNull() )
    {
        return;
    }

    d_data->plot = plot;

    /*
      The layout engine uses the same methods as they are used
      by the Qt layout system. Therefore we need to calculate the
      layout in screen coordinates and paint with a scaled painter.
     */
    QTransform transform;
    transform.scale(
        double( painter->device()->logicalDpiX() ) / plot->logicalDpiX(),
        double( painter->device()->logicalDpiY() ) / plot->logicalDpiY() );

    const QRectF layoutRect = transform.inverted().mapRect( plotRect );

    QwtPolarLayout *layout = plot->plotLayout();

    // All paint operations need to be scaled according to
    // the paint device metrics.

    QwtPolarLayout::Options layoutOptions =
        QwtPolarLayout::IgnoreScrollbars | QwtPolarLayout::IgnoreFrames;

    layout->activate( plot, layoutRect, layoutOptions );

    painter->save();
    painter->setWorldTransform( transform, true );

    painter->save();
    renderTitle( painter, layout->titleRect() );
    painter->restore();

    painter->save();
    renderLegend( plot, painter, layout->legendRect() );
    painter->restore();

    const QRectF canvasRect = layout->canvasRect();

    painter->save();
    painter->setClipRect( canvasRect );
    plot->drawCanvas( painter, canvasRect );
    painter->restore();

    painter->restore();

    layout->invalidate();

    d_data->plot = NULL;
}

void QwtPolarRenderer::renderTitle( QPainter *painter, const QRectF &rect ) const
{
    QwtTextLabel *title = d_data->plot->titleLabel();

    painter->setFont( title->font() );

    const QColor color = title->palette().color(
        QPalette::Active, QPalette::Text );

    painter->setPen( color );
    title->text().draw( painter, rect );
}

void QwtPolarRenderer::renderLegend( const QwtPolarPlot *plot,
    QPainter *painter, const QRectF &rect ) const
{
    if ( plot->legend() )
        plot->legend()->renderLegend( painter, rect, true );
}

bool QwtPolarRenderer::exportTo( QwtPolarPlot *plot, 
    const QString &documentName, const QSizeF &sizeMM, int resolution )
{
    if ( plot == NULL )
        return false;

    QString fileName = documentName;

    // What about translation 

#ifndef QT_NO_FILEDIALOG
    const QList<QByteArray> imageFormats =
        QImageWriter::supportedImageFormats();

    QStringList filter;
#ifndef QT_NO_PRINTER
    filter += QString( "PDF " ) + tr( "Documents" ) + " (*.pdf)";
#endif
#ifndef QWT_NO_SVG
    filter += QString( "SVG " ) + tr( "Documents" ) + " (*.svg)";
#endif
#ifndef QT_NO_PRINTER
    filter += QString( "Postscript " ) + tr( "Documents" ) + " (*.ps)";
#endif

    if ( imageFormats.size() > 0 )
    {
        QString imageFilter( tr( "Images" ) );
        imageFilter += " (";
        for ( int i = 0; i < imageFormats.size(); i++ )
        {
            if ( i > 0 )
                imageFilter += " ";
            imageFilter += "*.";
            imageFilter += imageFormats[i];
        }
        imageFilter += ")";

        filter += imageFilter;
    }

    fileName = QFileDialog::getSaveFileName(
        NULL, tr( "Export File Name" ), fileName,
        filter.join( ";;" ), NULL, QFileDialog::DontConfirmOverwrite );
#endif
    if ( fileName.isEmpty() )
        return false;

    renderDocument( plot, fileName, sizeMM, resolution );

    return true;
}

#if QWT_MOC_INCLUDE
#include "moc_qwt_polar_renderer.cpp"
#endif