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Diffstat (limited to 'src/pdfwidgets/qpdfview.cpp')
| -rw-r--r-- | src/pdfwidgets/qpdfview.cpp | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/src/pdfwidgets/qpdfview.cpp b/src/pdfwidgets/qpdfview.cpp new file mode 100644 index 000000000..19e5b719a --- /dev/null +++ b/src/pdfwidgets/qpdfview.cpp @@ -0,0 +1,493 @@ +/**************************************************************************** +** +** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Tobias König <tobias.koenig@kdab.com> +** Contact: http://www.qt.io/licensing/ +** +** This file is part of the QtPDF module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL3$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see http://www.qt.io/terms-conditions. For further +** information use the contact form at http://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPLv3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or later 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 2.0 requirements will be +** met: http://www.gnu.org/licenses/gpl-2.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qpdfview.h" +#include "qpdfview_p.h" + +#include "qpdfpagerenderer.h" + +#include <QGuiApplication> +#include <QPdfDocument> +#include <QPdfPageNavigation> +#include <QScreen> +#include <QScrollBar> +#include <QScroller> + +QT_BEGIN_NAMESPACE + +QPdfViewPrivate::QPdfViewPrivate() + : QAbstractScrollAreaPrivate() + , m_document(nullptr) + , m_pageNavigation(nullptr) + , m_pageRenderer(nullptr) + , m_pageMode(QPdfView::SinglePage) + , m_zoomMode(QPdfView::CustomZoom) + , m_zoomFactor(1.0) + , m_pageSpacing(3) + , m_documentMargins(6, 6, 6, 6) + , m_blockPageScrolling(false) + , m_pageCacheLimit(20) + , m_screenResolution(QGuiApplication::primaryScreen()->logicalDotsPerInch() / 72.0) +{ +} + +void QPdfViewPrivate::init() +{ + Q_Q(QPdfView); + + m_pageNavigation = new QPdfPageNavigation(q); + m_pageRenderer = new QPdfPageRenderer(q); + m_pageRenderer->setRenderMode(QPdfPageRenderer::MultiThreadedRenderMode); +} + +void QPdfViewPrivate::documentStatusChanged() +{ + updateDocumentLayout(); + invalidatePageCache(); +} + +void QPdfViewPrivate::currentPageChanged(int currentPage) +{ + Q_Q(QPdfView); + + if (m_blockPageScrolling) + return; + + q->verticalScrollBar()->setValue(yPositionForPage(currentPage)); + + if (m_pageMode == QPdfView::SinglePage) + invalidateDocumentLayout(); +} + +void QPdfViewPrivate::calculateViewport() +{ + Q_Q(QPdfView); + + const int x = q->horizontalScrollBar()->value(); + const int y = q->verticalScrollBar()->value(); + const int width = q->viewport()->width(); + const int height = q->viewport()->height(); + + setViewport(QRect(x, y, width, height)); +} + +void QPdfViewPrivate::setViewport(QRect viewport) +{ + if (m_viewport == viewport) + return; + + const QSize oldSize = m_viewport.size(); + + m_viewport = viewport; + + if (oldSize != m_viewport.size()) { + updateDocumentLayout(); + + if (m_zoomMode != QPdfView::CustomZoom) { + invalidatePageCache(); + } + } + + if (m_pageMode == QPdfView::MultiPage) { + // An imaginary, 2px height line at the upper half of the viewport, which is used to + // determine which page is currently located there -> we propagate that as 'current' page + // to the QPdfPageNavigation object + const QRect currentPageLine(m_viewport.x(), m_viewport.y() + m_viewport.height() * 0.4, m_viewport.width(), 2); + + int currentPage = 0; + for (auto it = m_documentLayout.pageGeometries.cbegin(); it != m_documentLayout.pageGeometries.cend(); ++it) { + const QRect pageGeometry = it.value(); + if (pageGeometry.intersects(currentPageLine)) { + currentPage = it.key(); + break; + } + } + + if (currentPage != m_pageNavigation->currentPage()) { + m_blockPageScrolling = true; + m_pageNavigation->setCurrentPage(currentPage); + m_blockPageScrolling = false; + } + } +} + +void QPdfViewPrivate::updateScrollBars() +{ + Q_Q(QPdfView); + + const QSize p = q->viewport()->size(); + const QSize v = m_documentLayout.documentSize; + + q->horizontalScrollBar()->setRange(0, v.width() - p.width()); + q->horizontalScrollBar()->setPageStep(p.width()); + q->verticalScrollBar()->setRange(0, v.height() - p.height()); + q->verticalScrollBar()->setPageStep(p.height()); +} + +void QPdfViewPrivate::pageRendered(int pageNumber, QSize imageSize, const QImage &image, quint64 requestId) +{ + Q_Q(QPdfView); + + Q_UNUSED(imageSize) + Q_UNUSED(requestId) + + if (!m_cachedPagesLRU.contains(pageNumber)) { + if (m_cachedPagesLRU.length() > m_pageCacheLimit) + m_pageCache.remove(m_cachedPagesLRU.takeFirst()); + + m_cachedPagesLRU.append(pageNumber); + } + + m_pageCache.insert(pageNumber, image); + + q->viewport()->update(); +} + +void QPdfViewPrivate::invalidateDocumentLayout() +{ + updateDocumentLayout(); + invalidatePageCache(); +} + +void QPdfViewPrivate::invalidatePageCache() +{ + Q_Q(QPdfView); + + m_pageCache.clear(); + q->viewport()->update(); +} + +QPdfViewPrivate::DocumentLayout QPdfViewPrivate::calculateDocumentLayout() const +{ + // The DocumentLayout describes a virtual layout where all pages are positioned inside + // - For SinglePage mode, this is just an area as large as the current page surrounded + // by the m_documentMargins. + // - For MultiPage mode, this is the area that is covered by all pages which are placed + // below each other, with m_pageSpacing inbetween and surrounded by m_documentMargins + + DocumentLayout documentLayout; + + if (!m_document || m_document->status() != QPdfDocument::Ready) + return documentLayout; + + QHash<int, QRect> pageGeometries; + + const int pageCount = m_document->pageCount(); + + int totalWidth = 0; + + const int startPage = (m_pageMode == QPdfView::SinglePage ? m_pageNavigation->currentPage() : 0); + const int endPage = (m_pageMode == QPdfView::SinglePage ? m_pageNavigation->currentPage() + 1 : pageCount); + + // calculate page sizes + for (int page = startPage; page < endPage; ++page) { + QSize pageSize; + if (m_zoomMode == QPdfView::CustomZoom) { + pageSize = QSizeF(m_document->pageSize(page) * m_screenResolution * m_zoomFactor).toSize(); + } else if (m_zoomMode == QPdfView::FitToWidth) { + pageSize = QSizeF(m_document->pageSize(page) * m_screenResolution).toSize(); + const qreal factor = (qreal(m_viewport.width() - m_documentMargins.left() - m_documentMargins.right()) / qreal(pageSize.width())); + pageSize *= factor; + } else if (m_zoomMode == QPdfView::FitInView) { + const QSize viewportSize(m_viewport.size() + QSize(-m_documentMargins.left() - m_documentMargins.right(), -m_pageSpacing)); + + pageSize = QSizeF(m_document->pageSize(page) * m_screenResolution).toSize(); + pageSize = pageSize.scaled(viewportSize, Qt::KeepAspectRatio); + } + + totalWidth = qMax(totalWidth, pageSize.width()); + + pageGeometries[page] = QRect(QPoint(0, 0), pageSize); + } + + totalWidth += m_documentMargins.left() + m_documentMargins.right(); + + int pageY = m_documentMargins.top(); + + // calculate page positions + for (int page = startPage; page < endPage; ++page) { + const QSize pageSize = pageGeometries[page].size(); + + // center horizontal inside the viewport + const int pageX = (qMax(totalWidth, m_viewport.width()) - pageSize.width()) / 2; + + pageGeometries[page].moveTopLeft(QPoint(pageX, pageY)); + + pageY += pageSize.height() + m_pageSpacing; + } + + pageY += m_documentMargins.bottom(); + + documentLayout.pageGeometries = pageGeometries; + + // calculate overall document size + documentLayout.documentSize = QSize(totalWidth, pageY); + + return documentLayout; +} + +qreal QPdfViewPrivate::yPositionForPage(int pageNumber) const +{ + const auto it = m_documentLayout.pageGeometries.constFind(pageNumber); + if (it == m_documentLayout.pageGeometries.cend()) + return 0.0; + + return (*it).y(); +} + +void QPdfViewPrivate::updateDocumentLayout() +{ + m_documentLayout = calculateDocumentLayout(); + + updateScrollBars(); +} + + +QPdfView::QPdfView(QWidget *parent) + : QAbstractScrollArea(*new QPdfViewPrivate(), parent) +{ + Q_D(QPdfView); + + d->init(); + + connect(d->m_pageNavigation, &QPdfPageNavigation::currentPageChanged, this, [d](int page){ d->currentPageChanged(page); }); + + connect(d->m_pageRenderer, &QPdfPageRenderer::pageRendered, + this, [d](int pageNumber, QSize imageSize, const QImage &image, QPdfDocumentRenderOptions, quint64 requestId){ d->pageRendered(pageNumber, imageSize, image, requestId); }); + + verticalScrollBar()->setSingleStep(20); + horizontalScrollBar()->setSingleStep(20); + + QScroller::grabGesture(this); + + d->calculateViewport(); +} + +/*! + \internal +*/ +QPdfView::QPdfView(QPdfViewPrivate &dd, QWidget *parent) + : QAbstractScrollArea(dd, parent) +{ +} + +QPdfView::~QPdfView() +{ +} + +void QPdfView::setDocument(QPdfDocument *document) +{ + Q_D(QPdfView); + + if (d->m_document == document) + return; + + if (d->m_document) + disconnect(d->m_documentStatusChangedConnection); + + d->m_document = document; + emit documentChanged(d->m_document); + + if (d->m_document) + d->m_documentStatusChangedConnection = connect(d->m_document.data(), &QPdfDocument::statusChanged, this, [d](){ d->documentStatusChanged(); }); + + d->m_pageNavigation->setDocument(d->m_document); + d->m_pageRenderer->setDocument(d->m_document); + + d->documentStatusChanged(); +} + +QPdfDocument *QPdfView::document() const +{ + Q_D(const QPdfView); + + return d->m_document; +} + +QPdfPageNavigation *QPdfView::pageNavigation() const +{ + Q_D(const QPdfView); + + return d->m_pageNavigation; +} + +QPdfView::PageMode QPdfView::pageMode() const +{ + Q_D(const QPdfView); + + return d->m_pageMode; +} + +void QPdfView::setPageMode(PageMode mode) +{ + Q_D(QPdfView); + + if (d->m_pageMode == mode) + return; + + d->m_pageMode = mode; + d->invalidateDocumentLayout(); + + emit pageModeChanged(d->m_pageMode); +} + +QPdfView::ZoomMode QPdfView::zoomMode() const +{ + Q_D(const QPdfView); + + return d->m_zoomMode; +} + +void QPdfView::setZoomMode(ZoomMode mode) +{ + Q_D(QPdfView); + + if (d->m_zoomMode == mode) + return; + + d->m_zoomMode = mode; + d->invalidateDocumentLayout(); + + emit zoomModeChanged(d->m_zoomMode); +} + +qreal QPdfView::zoomFactor() const +{ + Q_D(const QPdfView); + + return d->m_zoomFactor; +} + +void QPdfView::setZoomFactor(qreal factor) +{ + Q_D(QPdfView); + + if (d->m_zoomFactor == factor) + return; + + d->m_zoomFactor = factor; + d->invalidateDocumentLayout(); + + emit zoomFactorChanged(d->m_zoomFactor); +} + +int QPdfView::pageSpacing() const +{ + Q_D(const QPdfView); + + return d->m_pageSpacing; +} + +void QPdfView::setPageSpacing(int spacing) +{ + Q_D(QPdfView); + + if (d->m_pageSpacing == spacing) + return; + + d->m_pageSpacing = spacing; + d->invalidateDocumentLayout(); + + emit pageSpacingChanged(d->m_pageSpacing); +} + +QMargins QPdfView::documentMargins() const +{ + Q_D(const QPdfView); + + return d->m_documentMargins; +} + +void QPdfView::setDocumentMargins(QMargins margins) +{ + Q_D(QPdfView); + + if (d->m_documentMargins == margins) + return; + + d->m_documentMargins = margins; + d->invalidateDocumentLayout(); + + emit documentMarginsChanged(d->m_documentMargins); +} + +void QPdfView::paintEvent(QPaintEvent *event) +{ + Q_D(QPdfView); + + QPainter painter(viewport()); + painter.fillRect(event->rect(), palette().brush(QPalette::Dark)); + painter.translate(-d->m_viewport.x(), -d->m_viewport.y()); + + for (auto it = d->m_documentLayout.pageGeometries.cbegin(); it != d->m_documentLayout.pageGeometries.cend(); ++it) { + const QRect pageGeometry = it.value(); + if (pageGeometry.intersects(d->m_viewport)) { // page needs to be painted + painter.fillRect(pageGeometry, Qt::white); + + const int page = it.key(); + const auto pageIt = d->m_pageCache.constFind(page); + if (pageIt != d->m_pageCache.cend()) { + const QImage &img = pageIt.value(); + painter.drawImage(pageGeometry.topLeft(), img); + } else { + d->m_pageRenderer->requestPage(page, pageGeometry.size()); + } + } + } +} + +void QPdfView::resizeEvent(QResizeEvent *event) +{ + Q_D(QPdfView); + + QAbstractScrollArea::resizeEvent(event); + + d->updateScrollBars(); + d->calculateViewport(); +} + +void QPdfView::scrollContentsBy(int dx, int dy) +{ + Q_D(QPdfView); + + QAbstractScrollArea::scrollContentsBy(dx, dy); + + d->calculateViewport(); +} + +QT_END_NAMESPACE + +#include "moc_qpdfview.cpp" |