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#include "sequentialpagewidget.h"
#include <QPaintEvent>
#include <QPainter>
#include <QPdfDocument>
#include <QGuiApplication>
#include <QScreen>
#include <QLoggingCategory>
#include <QElapsedTimer>
Q_DECLARE_LOGGING_CATEGORY(lcExample)
SequentialPageWidget::SequentialPageWidget(QWidget *parent)
: QWidget(parent)
, m_doc(Q_NULLPTR)
, m_background(Qt::darkGray)
, m_pageSpacing(3)
, m_topPageShowing(0)
, m_zoom(1.)
, m_screenResolution(QGuiApplication::primaryScreen()->logicalDotsPerInch() / 72.0)
, m_minRenderTime(1000000000.)
, m_maxRenderTime(0.)
, m_totalRenderTime(0.)
, m_totalPagesRendered(0)
{
}
SequentialPageWidget::~SequentialPageWidget()
{
}
void SequentialPageWidget::setDocument(QPdfDocument *doc)
{
m_doc = doc;
m_topPageShowing = 0;
invalidate();
}
void SequentialPageWidget::setZoom(qreal factor)
{
m_zoom = factor;
emit zoomChanged(factor);
invalidate();
}
QSizeF SequentialPageWidget::pageSize(int page)
{
return m_doc->pageSize(page) * m_screenResolution * m_zoom;
}
void SequentialPageWidget::invalidate()
{
m_pageCache.clear();
QSizeF totalSize(0, m_pageSpacing);
for (int page = 0; page < m_doc->pageCount(); ++page) {
QSizeF size = pageSize(page);
qDebug() << "page" << page << "size" << size;
totalSize.setHeight(totalSize.height() + size.height());
if (size.width() > totalSize.width())
totalSize.setWidth(size.width());
}
m_totalSize = totalSize.toSize();
setMinimumSize(m_totalSize);
emit zoomChanged(m_zoom);
qCDebug(lcExample) << "total size" << m_totalSize;
update();
}
void SequentialPageWidget::paintEvent(QPaintEvent * event)
{
QPainter painter(this);
if (!m_doc) {
painter.drawText(rect(), Qt::AlignCenter, tr("no document loaded"));
return;
}
painter.fillRect(event->rect(), m_background);
// Find the first page that needs to be rendered
int page = 0;
int y = 0;
while (page < m_doc->pageCount()) {
QSizeF size = pageSize(page);
int height = size.toSize().height();
if (y + height >= event->rect().top())
break;
y += height + m_pageSpacing;
++page;
}
y += m_pageSpacing;
m_topPageShowing = page;
int previousRendered = m_totalPagesRendered;
// Actually render pages
while (y < event->rect().bottom() && page < m_doc->pageCount()) {
if (!m_pageCache.contains(page)) {
QSizeF size = pageSize(page);
qCDebug(lcExample) << "rendering page" << page << "to size" << size;
QElapsedTimer timer; timer.start();
const QImage &img = m_doc->render(page, size);
qreal secs = timer.nsecsElapsed() / 1000000000.0;
if (secs < m_minRenderTime)
m_minRenderTime = secs;
if (secs > m_maxRenderTime)
m_maxRenderTime = secs;
m_totalRenderTime += secs;
++m_totalPagesRendered;
m_pageCache.insert(page, QPixmap::fromImage(img));
}
const QPixmap &pm = m_pageCache[page];
painter.drawPixmap((width() - pm.width()) / 2, y, pm);
y += pm.height() + m_pageSpacing;
++page;
}
m_bottomPageShowing = page - 1;
emit showingPageRange(m_topPageShowing, m_bottomPageShowing);
if (m_totalPagesRendered != previousRendered)
qCDebug(lcExample) << "rendering time: min" << m_minRenderTime <<
"avg" << m_totalRenderTime / m_totalPagesRendered <<
"max" << m_maxRenderTime;
}
qreal SequentialPageWidget::yForPage(int endPage)
{
// TODO maybe put this loop into a page iterator class
int y = m_pageSpacing;
for (int page = 0; page < m_doc->pageCount() && page < endPage; ++page) {
QSizeF size = pageSize(page);
int height = size.toSize().height();
y += height + m_pageSpacing;
}
return y;
}
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