/************************************************************************
**
**  Copyright (C) 2009, 2010, 2011  Strahinja Markovic  <strahinja.markovic@gmail.com>
**
**  This file is part of Sigil.
**
**  Sigil is free software: you can redistribute it and/or modify
**  it under the terms of the GNU General Public License as published by
**  the Free Software Foundation, either version 3 of the License, or
**  (at your option) any later version.
**
**  Sigil is distributed in the hope that it will be useful,
**  but WITHOUT ANY WARRANTY; without even the implied warranty of
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**  GNU General Public License for more details.
**
**  You should have received a copy of the GNU General Public License
**  along with Sigil.  If not, see <http://www.gnu.org/licenses/>.
**
*************************************************************************/

#include <QtCore>
#include <QtGui/QPainter>
#include <QtGui/QPixmap>
#include <QtWebKitWidgets/QWebPage>
#include <QtWebKitWidgets/QWebFrame>

#include "Misc/RasterizeImageResource.h"
#include "Misc/SleepFunctions.h"
#include "Misc/Utility.h"
#include "ResourceObjects/ImageResource.h"

static const QString PAGE_SOURCE =  "<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\">"
                                    "<head>"
                                    "<meta content=\"text/html; charset=UTF-8\"/>"
                                    "</head>"
                                    "<body style=\"margin: 0;\" >"
                                    "<img src=\"REPLACEME\" />"
                                    "</body>"
                                    "</html>";


RasterizeImageResource::RasterizeImageResource(QWidget *parent)
    :
    QObject(parent),
    m_WebPage(*new QWebPage(this)),
    m_LoadFinishedFlag(false)
{
    connect(m_WebPage.mainFrame(), SIGNAL(loadFinished(bool)), this, SLOT(SetLoadFinishedFlag()));
}


// We could use the native QPixmap loading process for JPG, PNG and GIF images.
// But we have to use webkit to rasterize SVG's since QSvgRenderer supports
// only SVG Tiny. And if we're going to use webkit, then let's use it for all
// image types to reduce complexity. It also makes zooming/scaling much simpler.
QPixmap RasterizeImageResource::operator()(const ImageResource &resource, float zoom_factor)
{
    QString source(PAGE_SOURCE);
    source.replace("REPLACEME", Utility::URLEncodePath(resource.Filename()));
    m_WebPage.mainFrame()->setHtml(source, resource.GetBaseUrl());
    m_WebPage.mainFrame()->setZoomFactor(zoom_factor);

    while (!m_LoadFinishedFlag) {
        // Make sure Qt processes events, signals and calls slots
        qApp->processEvents();
        SleepFunctions::msleep(10);
    }

    // The flag needs to be reset so the caller
    // can call this func multiple times on the same object
    m_LoadFinishedFlag = false;
    // Now we render the frame onto an image
    m_WebPage.setViewportSize(m_WebPage.mainFrame()->contentsSize());
    QImage image(m_WebPage.viewportSize(), QImage::Format_ARGB32);
    QPainter painter(&image);
    m_WebPage.mainFrame()->render(&painter);
    painter.end();
    return QPixmap::fromImage(image);
}


void RasterizeImageResource::SetLoadFinishedFlag()
{
    m_LoadFinishedFlag = true;
}
