pdfviewer.cpp

用QT设计的手持设备PDF阅读器。实现了阅读

#include "pdfviewer.h"

Pdfviewer::Pdfviewer( QWidget * parent, Qt::WindowFlags f)
	: QLabel(parent, f)
{	
	setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
	setScaledContents(true);
	m_document = NULL;
	m_currentPage = 0;
}

Pdfviewer::~Pdfviewer()
{
	if(m_document)
		delete m_document;
}

bool Pdfviewer::OpenDocument(QString filename)
{
	if(m_document)
		delete m_document;

	m_document = Poppler::Document::load(filename);
	if (!m_document || m_document->isLocked()) {
		// ... error message ....
		qDebug()<<"Cannot open file"<<filename;
		if(m_document){
			delete m_document;
			m_document = NULL;
		}
		return false;
	}

	m_currentPage = 0;

	// Paranoid safety check
	if(!m_document)
		return false;

	// Access page of the PDF file
	pdfPage = m_document->page(m_currentPage);  // Document starts at page 0
	if (!pdfPage) {
		return false;
	}
	
	// Generate a QImage of the rendered page
	image = pdfPage->renderToImage();
	if (image.isNull()) {
		qDebug()<<"pdf file renderToImage error";
		return false;
	}
	
	resize(pdfPage->pageSize());

	showpage(0);

	return true;
}

void Pdfviewer::showpage(int npage)
{
	// Paranoid safety check
	if (m_document == NULL)
		return;
	
	// Access page of the PDF file
	pdfPage = m_document->page(npage);  // Document starts at page 0
	if (!pdfPage) {
		return;
	}
	
	// Generate a QImage of the rendered page
	image = pdfPage->renderToImage();
	if (image.isNull()) {
		qDebug()<<"pdf file renderToImage error";
		return;
	}
	
	if(m_currentPage != npage){
		m_currentPage = npage;
		update();
	}
}

int Pdfviewer::allPageNum()
{
	return m_document->numPages();	
}

void Pdfviewer::paintEvent(QPaintEvent *)
{
	QPainter painter(this);

	if (image.isNull()) {
		qDebug()<<"No image";
		return;
	}
	else
		pixmap1 = QPixmap::fromImage(image);

	// ... use image ...
	painter.drawPixmap(0,0,pixmap1);

	// after the usage, the page must be deleted
	//delete pdfPage;
}

void Mainframe::scaleImage(double factor_x,double factor_y)
{
	
	// Generate a QImage of the rendered page
	image = pdfPage->renderToImage(factor_x,factor_y);
	if (image.isNull()) {
		qDebug()<<"pdf file renderToImage error";
		return;
	}

	adjustScrollBar(scrollArea->horizontalScrollBar(), factor);
    adjustScrollBar(scrollArea->verticalScrollBar(), factor);

	actionBig->setEnabled(scaleFactor < 3.0);
    actionSmall->setEnabled(scaleFactor > 0.333);
}