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Diffstat (limited to 'examples/pdf/pdfviewer/sequentialpagewidget.cpp')
| -rw-r--r-- | examples/pdf/pdfviewer/sequentialpagewidget.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/examples/pdf/pdfviewer/sequentialpagewidget.cpp b/examples/pdf/pdfviewer/sequentialpagewidget.cpp new file mode 100644 index 0000000..904bc17 --- /dev/null +++ b/examples/pdf/pdfviewer/sequentialpagewidget.cpp @@ -0,0 +1,192 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** 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 "sequentialpagewidget.h" +#include "pagerenderer.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_pageCacheLimit(20) + , m_pageRenderer(new PageRenderer()) + , m_background(Qt::darkGray) + , m_placeholderIcon(":icons/images/busy.png") + , m_placeholderBackground(Qt::white) + , m_pageSpacing(3) + , m_topPageShowing(0) + , m_zoom(1.) + , m_screenResolution(QGuiApplication::primaryScreen()->logicalDotsPerInch() / 72.0) + , m_document(nullptr) +{ + connect(m_pageRenderer, SIGNAL(pageReady(int, qreal, QImage)), this, SLOT(pageLoaded(int, qreal, QImage)), Qt::QueuedConnection); + grabGesture(Qt::SwipeGesture); +} + +SequentialPageWidget::~SequentialPageWidget() +{ + delete m_pageRenderer; +} + +void SequentialPageWidget::setDocument(QPdfDocument *document) +{ + m_pageRenderer->setDocument(document); + + m_document = document; + connect(m_document, &QPdfDocument::statusChanged, this, &SequentialPageWidget::documentStatusChanged); + + documentStatusChanged(); +} + +void SequentialPageWidget::setZoom(qreal factor) +{ + m_zoom = factor; + emit zoomChanged(factor); + invalidate(); +} + +QSizeF SequentialPageWidget::pageSize(int page) +{ +// if (!m_pageSizes.length() <= page) +// return QSizeF(); + return m_pageSizes[page] * m_screenResolution * m_zoom; +} + +void SequentialPageWidget::invalidate() +{ + QSizeF totalSize(0, m_pageSpacing); + for (int page = 0; page < pageCount(); ++page) { + QSizeF size = pageSize(page); + 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; + m_pageCache.clear(); + update(); +} + +void SequentialPageWidget::documentStatusChanged() +{ + m_pageSizes.clear(); + m_topPageShowing = 0; + + if (m_document->status() == QPdfDocument::Ready) { + for (int page = 0; page < m_document->pageCount(); ++page) + m_pageSizes.append(m_document->pageSize(page)); + } + + invalidate(); +} + +void SequentialPageWidget::pageLoaded(int page, qreal zoom, QImage image) +{ + Q_UNUSED(zoom) + if (m_cachedPagesLRU.length() > m_pageCacheLimit) + m_pageCache.remove(m_cachedPagesLRU.takeFirst()); + m_pageCache.insert(page, image); + m_cachedPagesLRU.append(page); + update(); +} + +int SequentialPageWidget::pageCount() +{ + return m_pageSizes.count(); +} + +void SequentialPageWidget::paintEvent(QPaintEvent * event) +{ + QPainter painter(this); + painter.fillRect(event->rect(), m_background); + + if (m_pageSizes.isEmpty()) + return; + + // Find the first page that needs to be rendered + int page = 0; + int y = 0; + while (page < 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; + + // Actually render pages + while (y < event->rect().bottom() && page < pageCount()) { + QSizeF size = pageSize(page); + if (m_pageCache.contains(page)) { + const QImage &img = m_pageCache[page]; + painter.fillRect((width() - img.width()) / 2, y, size.width(), size.height(), Qt::white); + painter.drawImage((width() - img.width()) / 2, y, img); + } else { + painter.fillRect((width() - size.width()) / 2, y, size.width(), size.height(), m_placeholderBackground); + painter.drawPixmap((size.width() - m_placeholderIcon.width()) / 2, + (size.height() - m_placeholderIcon.height()) / 2, m_placeholderIcon); + m_pageRenderer->requestPage(page, m_screenResolution * m_zoom); + } + y += size.height() + m_pageSpacing; + ++page; + } + m_bottomPageShowing = page - 1; + emit showingPageRange(m_topPageShowing, m_bottomPageShowing); +} + +qreal SequentialPageWidget::yForPage(int endPage) +{ + // TODO maybe put this loop into a page iterator class + int y = m_pageSpacing; + for (int page = 0; page < pageCount() && page < endPage; ++page) { + QSizeF size = pageSize(page); + int height = size.toSize().height(); + y += height + m_pageSpacing; + } + return y; +} |