Draw space controller

PdfForQtLib/sources/pdfdrawspacecontroller.h

@@ -0,0 +1,88 @@
+//    Copyright (C) 2019 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 PDFDRAWSPACECONTROLLER_H
+#define PDFDRAWSPACECONTROLLER_H
+
+#include "pdfdocument.h"
+
+#include <QRectF>
+#include <QObject>
+#include <QMarginsF>
+
+namespace pdf
+{
+
+/// This class controls draw space - page layout. Pages are divided into blocks
+/// each block can contain one or multiple pages. Units are in milimeters.
+/// Pages are layouted in zoom-independent mode.
+class PDFDrawSpaceController : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit PDFDrawSpaceController(QObject* parent);
+
+signals:
+    void drawSpaceChanged();
+
+private:
+    /// Recalculates the draw space. Preserves setted page rotation.
+    void recalculate();
+
+    /// Clears the draw space. Emits signal if desired.
+    void clear(bool emitSignal);
+
+    /// Represents layouted page. This structure contains index of the block, index of the
+    /// page and page rectangle, in which the page is contained.
+    struct LayoutItem
+    {
+        constexpr inline explicit LayoutItem() : blockIndex(-1), pageIndex(-1), pageRotation(PageRotation::None) { }
+        constexpr inline explicit LayoutItem(PDFInteger blockIndex, PDFInteger pageIndex, PageRotation rotation, const QRectF& pageRectMM) :
+            blockIndex(blockIndex), pageIndex(pageIndex), pageRotation(rotation), pageRectMM(pageRectMM) { }
+
+        PDFInteger blockIndex;
+        PDFInteger pageIndex;
+        PageRotation pageRotation;
+        QRectF pageRectMM;
+    };
+
+    using LayoutItems = std::vector<LayoutItem>;
+
+    /// Represents data for the single block. Contains block size in milimeters.
+    struct LayoutBlock
+    {
+        constexpr inline explicit LayoutBlock() = default;
+        constexpr inline explicit LayoutBlock(const QRectF& blockRectMM) : blockRectMM(blockRectMM) { }
+
+        QRectF blockRectMM;
+    };
+
+    using BlockItems = std::vector<LayoutBlock>;
+
+    const PDFDocument* m_document;
+
+    PageLayout m_pageLayoutMode;
+    LayoutItems m_layoutItems;
+    BlockItems m_blockItems;
+    PDFReal m_verticalSpacingMM;
+    PDFReal m_horizontalSpacingMM;
+};
+
+}   // namespace pdf
+
+#endif // PDFDRAWSPACECONTROLLER_H