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Diffstat (limited to 'src/pdf/quick/qquickpdfnavigationstack.cpp')
| -rw-r--r-- | src/pdf/quick/qquickpdfnavigationstack.cpp | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/pdf/quick/qquickpdfnavigationstack.cpp b/src/pdf/quick/qquickpdfnavigationstack.cpp new file mode 100644 index 000000000..7ba317557 --- /dev/null +++ b/src/pdf/quick/qquickpdfnavigationstack.cpp @@ -0,0 +1,266 @@ +/**************************************************************************** +** +** Copyright (C) 2020 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 "qquickpdfnavigationstack_p.h" +#include <QLoggingCategory> + +QT_BEGIN_NAMESPACE + +Q_LOGGING_CATEGORY(qLcNav, "qt.pdf.navigationstack") + +/*! + \qmltype PdfNavigationStack + \instantiates QQuickPdfNavigationStack + \inqmlmodule QtQuick.Pdf + \ingroup pdf + \brief History of the destinations visited within a PDF Document. + \since 5.15 + + PdfNavigationStack remembers which destinations the user has visited in a PDF + document, and provides the ability to traverse backward and forward. +*/ + +QQuickPdfNavigationStack::QQuickPdfNavigationStack(QObject *parent) + : QObject(parent) +{ + push(0, QPointF(), 1); +} + +/*! + \qmlmethod void PdfNavigationStack::forward() + + Goes back to the page, location and zoom level that was being viewed before + back() was called, and then emits the \l jumped() signal. + + If a new destination was pushed since the last time \l back() was called, + the forward() function does nothing, because there is a branch in the + timeline which causes the "future" to be lost. +*/ +void QQuickPdfNavigationStack::forward() +{ + if (m_currentHistoryIndex >= m_pageHistory.count() - 1) + return; + bool backAvailableWas = backAvailable(); + bool forwardAvailableWas = forwardAvailable(); + QPointF currentLocationWas = currentLocation(); + qreal currentZoomWas = currentZoom(); + ++m_currentHistoryIndex; + m_changing = true; + emit jumped(currentPage(), currentLocation(), currentZoom()); + if (currentZoomWas != currentZoom()) + emit currentZoomChanged(); + emit currentPageChanged(); + if (currentLocationWas != currentLocation()) + emit currentLocationChanged(); + if (!backAvailableWas) + emit backAvailableChanged(); + if (forwardAvailableWas != forwardAvailable()) + emit forwardAvailableChanged(); + m_changing = false; +} + +/*! + \qmlmethod void PdfNavigationStack::back() + + Pops the stack, updates the \l currentPage, \l currentLocation and + \l currentZoom properties to the most-recently-viewed destination, and then + emits the \l jumped() signal. +*/ +void QQuickPdfNavigationStack::back() +{ + if (m_currentHistoryIndex <= 0) + return; + bool backAvailableWas = backAvailable(); + bool forwardAvailableWas = forwardAvailable(); + QPointF currentLocationWas = currentLocation(); + qreal currentZoomWas = currentZoom(); + --m_currentHistoryIndex; + m_changing = true; + emit jumped(currentPage(), currentLocation(), currentZoom()); + if (currentZoomWas != currentZoom()) + emit currentZoomChanged(); + emit currentPageChanged(); + if (currentLocationWas != currentLocation()) + emit currentLocationChanged(); + if (backAvailableWas != backAvailable()) + emit backAvailableChanged(); + if (!forwardAvailableWas) + emit forwardAvailableChanged(); + m_changing = false; +} + +/*! + \qmlproperty int PdfNavigationStack::currentPage + + This property holds the current page that is being viewed. + If there is no current page, it holds \c -1. +*/ +int QQuickPdfNavigationStack::currentPage() const +{ + if (m_currentHistoryIndex < 0 || m_currentHistoryIndex >= m_pageHistory.count()) + return -1; + return m_pageHistory.at(m_currentHistoryIndex)->page; +} + +/*! + \qmlproperty point PdfNavigationStack::currentLocation + + This property holds the current location on the page that is being viewed. +*/ +QPointF QQuickPdfNavigationStack::currentLocation() const +{ + if (m_currentHistoryIndex < 0 || m_currentHistoryIndex >= m_pageHistory.count()) + return QPointF(); + return m_pageHistory.at(m_currentHistoryIndex)->location; +} + +/*! + \qmlproperty real PdfNavigationStack::currentZoom + + This property holds the magnification scale on the page that is being viewed. +*/ +qreal QQuickPdfNavigationStack::currentZoom() const +{ + if (m_currentHistoryIndex < 0 || m_currentHistoryIndex >= m_pageHistory.count()) + return 1; + return m_pageHistory.at(m_currentHistoryIndex)->zoom; +} + +/*! + \qmlmethod void PdfNavigationStack::push(int page, point location, qreal zoom) + + Adds the given destination, consisting of \a page, \a location and \a zoom, + to the history of visited locations. + + If forwardAvailable is \c true, calling this function represents a branch + in the timeline which causes the "future" to be lost, and therefore + forwardAvailable will change to \c false. +*/ +void QQuickPdfNavigationStack::push(int page, QPointF location, qreal zoom) +{ + if (page == currentPage() && location == currentLocation() && zoom == currentZoom()) + return; + if (qFuzzyIsNull(zoom)) + zoom = currentZoom(); + bool backAvailableWas = backAvailable(); + bool forwardAvailableWas = forwardAvailable(); + if (!m_changing) { + if (m_currentHistoryIndex >= 0 && forwardAvailableWas) + m_pageHistory.remove(m_currentHistoryIndex + 1, m_pageHistory.count() - m_currentHistoryIndex - 1); + m_pageHistory.append(QExplicitlySharedDataPointer<QPdfDestinationPrivate>(new QPdfDestinationPrivate(page, location, zoom))); + m_currentHistoryIndex = m_pageHistory.count() - 1; + } + emit currentZoomChanged(); + emit currentPageChanged(); + emit currentLocationChanged(); + if (m_changing) + return; + if (!backAvailableWas) + emit backAvailableChanged(); + if (forwardAvailableWas) + emit forwardAvailableChanged(); + emit jumped(page, location, zoom); + qCDebug(qLcNav) << "push: index" << m_currentHistoryIndex << "page" << page + << "@" << location << "zoom" << zoom << "-> history" << + [this]() { + QStringList ret; + for (auto d : m_pageHistory) + ret << QString::number(d->page); + return ret.join(','); + }(); +} + +/*! + \qmlmethod void PdfNavigationStack::update(int page, point location, qreal zoom) + + Modifies the current destination, consisting of \a page, \a location and \a zoom. + + This can be called periodically while the user is manually moving around + the document, so that after back() is called, forward() will jump back to + the most-recently-viewed destination rather than the destination that was + last specified by push(). + + The \c currentZoomChanged, \c currentPageChanged and \c currentLocationChanged + signals will be emitted if the respective properties are actually changed. + The \l jumped signal is not emitted, because this operation + represents smooth movement rather than a navigational jump. +*/ +void QQuickPdfNavigationStack::update(int page, QPointF location, qreal zoom) +{ + if (m_currentHistoryIndex < 0 || m_currentHistoryIndex >= m_pageHistory.count()) + return; + int currentPageWas = currentPage(); + QPointF currentLocationWas = currentLocation(); + qreal currentZoomWas = currentZoom(); + if (page == currentPageWas && location == currentLocationWas && zoom == currentZoomWas) + return; + m_pageHistory[m_currentHistoryIndex]->page = page; + m_pageHistory[m_currentHistoryIndex]->location = location; + m_pageHistory[m_currentHistoryIndex]->zoom = zoom; + if (currentZoomWas != zoom) + emit currentZoomChanged(); + if (currentPageWas != page) + emit currentPageChanged(); + if (currentLocationWas != location) + emit currentLocationChanged(); + qCDebug(qLcNav) << "update: index" << m_currentHistoryIndex << "page" << page + << "@" << location << "zoom" << zoom << "-> history" << + [this]() { + QStringList ret; + for (auto d : m_pageHistory) + ret << QString::number(d->page); + return ret.join(','); + }(); +} + +bool QQuickPdfNavigationStack::backAvailable() const +{ + return m_currentHistoryIndex > 0; +} + +bool QQuickPdfNavigationStack::forwardAvailable() const +{ + return m_currentHistoryIndex < m_pageHistory.count() - 1; +} + +/*! + \qmlsignal PdfNavigationStack::jumped(int page, point location, qreal zoom) + + This signal is emitted when forward(), back() or push() is called, but not + when update() is called. +*/ + +QT_END_NAMESPACE |