Add PdfNavigationStack for forward/back navigation

Works well enough to use, but needs autotests and at least one fix.

Change-Id: I2114b9fb3b5ddf7cfe2106d4a4fbc7d74852c61d
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 95 insertions, 0 deletions

diff --git a/src/pdf/quick/qquickpdfnavigationstack_p.h b/src/pdf/quick/qquickpdfnavigationstack_p.h
new file mode 100644
index 000000000..54713fabb
--- /dev/null
+++ b/src/pdf/quick/qquickpdfnavigationstack_p.h
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKPDFNAVIGATIONSTACK_P_H
+#define QQUICKPDFNAVIGATIONSTACK_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qquickpdfdocument_p.h"
+
+#include <QtQml/qqml.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickPdfNavigationStack : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(int currentPage READ currentPage WRITE setCurrentPage NOTIFY currentPageChanged)
+    Q_PROPERTY(bool backAvailable READ backAvailable NOTIFY backAvailableChanged)
+    Q_PROPERTY(bool forwardAvailable READ forwardAvailable NOTIFY forwardAvailableChanged)
+
+public:
+    explicit QQuickPdfNavigationStack(QObject *parent = nullptr);
+
+    Q_INVOKABLE void forward();
+    Q_INVOKABLE void back();
+
+    int currentPage() const { return m_currentPage; }
+    void setCurrentPage(int currentPage);
+
+    bool backAvailable() const;
+    bool forwardAvailable() const;
+
+Q_SIGNALS:
+    void currentPageChanged();
+    void currentPageJumped(int page);
+    void backAvailableChanged();
+    void forwardAvailableChanged();
+
+private:
+    QVector<int> m_pageHistory;
+    int m_nextHistoryIndex = 0;
+    int m_currentPage = 0;
+    bool m_changing = false;
+
+    Q_DISABLE_COPY(QQuickPdfNavigationStack)
+};
+
+QT_END_NAMESPACE
+
+QML_DECLARE_TYPE(QQuickPdfNavigationStack)
+
+#endif // QQUICKPDFNAVIGATIONSTACK_P_H