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PdfForQtLib/sources/pdfpage.h

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+//    Copyright (C) 2018 Jakub Melka
+//
+//    This file is part of PdfForQt.
+//
+//    PdfForQt is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    (at your option) any later version.
+//
+//    PdfForQt is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDFForQt.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef PDFPAGE_H
+#define PDFPAGE_H
+
+#include "pdfobject.h"
+
+#include <QRectF>
+
+#include <set>
+#include <optional>
+
+namespace pdf
+{
+class PDFDocument;
+
+/// This enum represents number of degree, which should be page rotated CLOCKWISE,
+/// when being displayed or printed.
+enum class PageRotation
+{
+    None,
+    Rotate90,
+    Rotate180,
+    Rotate270
+};
+
+/// This class represents attributes, which are inheritable. Also allows merging from
+/// parents.
+class PDFPageInheritableAttributes
+{
+public:
+    explicit inline PDFPageInheritableAttributes() = default;
+
+    /// Parses inheritable attributes from the page tree node
+    /// \param templateAttributes Template attributes
+    /// \param dictionary Dictionary, from which the data will be read
+    /// \param document Document owning this data
+    static PDFPageInheritableAttributes parse(const PDFPageInheritableAttributes& templateAttributes, const PDFObject& dictionary, const PDFDocument* document);
+
+    const QRectF& getMediaBox() const { return m_mediaBox; }
+    const QRectF& getCropBox() const { return m_cropBox; }
+    PageRotation getPageRotation() const;
+    const PDFObject& getResources() const { return m_resources; }
+
+private:
+    QRectF m_mediaBox;
+    QRectF m_cropBox;
+    std::optional<PageRotation> m_pageRotation;
+    PDFObject m_resources;
+};
+
+/// Object representing page in PDF document. Contains different page properties, such as
+/// media box, crop box, rotation, etc. and also page content, resources.
+class PDFPage
+{
+public:
+    explicit PDFPage() = default;
+
+    /// Parses the page tree. If error occurs, then exception is thrown.
+    /// \param document Document owning this tree
+    /// \param root Root object of page tree
+    static std::vector<PDFPage> parse(const PDFDocument* document, const PDFObject& root);
+
+    const QRectF& getMediaBox() const { return m_mediaBox; }
+    const QRectF& getCropBox() const { return m_cropBox; }
+    const QRectF& getBleedBox() const { return m_bleedBox; }
+    const QRectF& getTrimBox() const { return m_trimBox; }
+    const QRectF& getArtBox() const { return m_artBox; }
+    PageRotation getPageRotation() const { return m_pageRotation; }
+    const PDFObject& getResources() const { return m_resources; }
+    const PDFObject& getContents() const { return m_contents; }
+
+private:
+    /// Parses the page tree (implementation). If error occurs, then exception is thrown.
+    /// \param pages Page array. Pages are inserted into this array
+    /// \param visitedReferences Visited references (to check cycles in page tree and avoid hangup)
+    /// \param templateAttributes Template attributes (inheritable attributes defined in parent)
+    /// \param root Root object of page tree
+    /// \param document Document owning this tree
+    static void parseImpl(std::vector<PDFPage>& pages,
+                          std::set<PDFObjectReference>& visitedReferences,
+                          const PDFPageInheritableAttributes& templateAttributes,
+                          const PDFObject& root,
+                          const PDFDocument* document);
+
+    QRectF m_mediaBox;
+    QRectF m_cropBox;
+    QRectF m_bleedBox;
+    QRectF m_trimBox;
+    QRectF m_artBox;
+    PageRotation m_pageRotation = PageRotation::None;
+    PDFObject m_resources;
+    PDFObject m_contents;
+};
+
+}   // namespace pdf
+
+#endif // PDFPAGE_H