Add support for render rotation and flags

Extend the QPdfDocument::render() method with a parameter of new
type QPdfDocumentRenderOptions to specify the rotation and
additional render flags.

Change-Id: I354acc7fad4d094a96cefcea4dfa3513f4955c47
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

8 files changed, 390 insertions, 7 deletions

diff --git a/examples/pdf/pdfviewer/pagerenderer.cpp b/examples/pdf/pdfviewer/pagerenderer.cpp
index c8f2456..8cb1ed6 100644
--- a/examples/pdf/pdfviewer/pagerenderer.cpp
+++ b/examples/pdf/pdfviewer/pagerenderer.cpp
@@ -84,7 +84,7 @@ void PageRenderer::renderPage(int page, qreal zoom)
     QElapsedTimer timer;
     timer.start();
 
-    const QImage &img = m_document->render(page, size);
+    const QImage &img = m_document->render(page, size.toSize());
 
     const qreal secs = timer.nsecsElapsed() / 1000000000.0;
     if (secs < m_minRenderTime)
diff --git a/src/pdf/pdf.pro b/src/pdf/pdf.pro
index 9d0e1cb..606a2cb 100644
--- a/src/pdf/pdf.pro
+++ b/src/pdf/pdf.pro
@@ -29,4 +29,6 @@ HEADERS += \
     qpdfbookmarkmodel.h \
     qpdfdocument.h \
     qpdfdocument_p.h \
+    qpdfdocumentrenderoptions.h \
+    qpdfnamespace.h \
     qtpdfglobal.h
diff --git a/src/pdf/qpdfdocument.cpp b/src/pdf/qpdfdocument.cpp
index c737ca0..1dd6f40 100644
--- a/src/pdf/qpdfdocument.cpp
+++ b/src/pdf/qpdfdocument.cpp
@@ -546,7 +546,17 @@ QSizeF QPdfDocument::pageSize(int page) const
     return result;
 }
 
-QImage QPdfDocument::render(int page, const QSizeF &pageSize)
+/*!
+    Renders the \a page into a QImage of size \a imageSize according to the
+    provided \a renderOptions.
+
+    Returns the rendered page or an empty image in case of an error.
+
+    Note: If the \a imageSize does not match the aspect ratio of the page in the
+    PDF document, the page is rendered scaled, so that it covers the
+    complete \a imageSize.
+*/
+QImage QPdfDocument::render(int page, QSize imageSize, QPdfDocumentRenderOptions renderOptions)
 {
     if (!d->doc)
         return QImage();
@@ -557,11 +567,44 @@ QImage QPdfDocument::render(int page, const QSizeF &pageSize)
     if (!pdfPage)
         return QImage();
 
-    QImage result(pageSize.toSize(), QImage::Format_ARGB32);
+    QImage result(imageSize, QImage::Format_ARGB32);
     result.fill(Qt::transparent);
     FPDF_BITMAP bitmap = FPDFBitmap_CreateEx(result.width(), result.height(), FPDFBitmap_BGRA, result.bits(), result.bytesPerLine());
 
-    FPDF_RenderPageBitmap(bitmap, pdfPage, 0, 0, result.width(), result.height(), 0, 0);
+    int rotation = 0;
+    switch (renderOptions.rotation()) {
+    case QPdf::Rotate0:
+        rotation = 0;
+        break;
+    case QPdf::Rotate90:
+        rotation = 1;
+        break;
+    case QPdf::Rotate180:
+        rotation = 2;
+        break;
+    case QPdf::Rotate270:
+        rotation = 3;
+        break;
+    }
+
+    const QPdf::RenderFlags renderFlags = renderOptions.renderFlags();
+    int flags = 0;
+    if (renderFlags & QPdf::RenderAnnotations)
+        flags |= FPDF_ANNOT;
+    if (renderFlags & QPdf::RenderOptimizedForLcd)
+        flags |= FPDF_LCD_TEXT;
+    if (renderFlags & QPdf::RenderGrayscale)
+        flags |= FPDF_GRAYSCALE;
+    if (renderFlags & QPdf::RenderForceHalftone)
+        flags |= FPDF_RENDER_FORCEHALFTONE;
+    if (renderFlags & QPdf::RenderTextAliased)
+        flags |= FPDF_RENDER_NO_SMOOTHTEXT;
+    if (renderFlags & QPdf::RenderImageAliased)
+        flags |= FPDF_RENDER_NO_SMOOTHIMAGE;
+    if (renderFlags & QPdf::RenderPathAliased)
+        flags |= FPDF_RENDER_NO_SMOOTHPATH;
+
+    FPDF_RenderPageBitmap(bitmap, pdfPage, 0, 0, result.width(), result.height(), rotation, flags);
 
     FPDFBitmap_Destroy(bitmap);
 
diff --git a/src/pdf/qpdfdocument.h b/src/pdf/qpdfdocument.h
index 751c1b3..63532b3 100644
--- a/src/pdf/qpdfdocument.h
+++ b/src/pdf/qpdfdocument.h
@@ -37,10 +37,12 @@
 #ifndef QPDFDOCUMENT_H
 #define QPDFDOCUMENT_H
 
-#include <QObject>
-#include <QImage>
 #include "qtpdfglobal.h"
 
+#include <QImage>
+#include <QObject>
+#include <QPdfDocumentRenderOptions>
+
 QT_BEGIN_NAMESPACE
 
 class QPdfDocumentPrivate;
@@ -107,7 +109,7 @@ public:
 
     QSizeF pageSize(int page) const;
 
-    QImage render(int page, const QSizeF &pageSize);
+    QImage render(int page, QSize imageSize, QPdfDocumentRenderOptions options = QPdfDocumentRenderOptions());
 
 Q_SIGNALS:
     void passwordChanged();
diff --git a/src/pdf/qpdfdocumentrenderoptions.h b/src/pdf/qpdfdocumentrenderoptions.h
new file mode 100644
index 0000000..b602bb0
--- /dev/null
+++ b/src/pdf/qpdfdocumentrenderoptions.h
@@ -0,0 +1,88 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Tobias König <tobias.koenig@kdab.com>
+** 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 QPDFDOCUMENTRENDEROPTIONS_H
+#define QPDFDOCUMENTRENDEROPTIONS_H
+
+#include "qpdfnamespace.h"
+
+#include <QtCore/QObject>
+
+QT_BEGIN_NAMESPACE
+
+class QPdfDocumentRenderOptions
+{
+public:
+    Q_DECL_CONSTEXPR QPdfDocumentRenderOptions() Q_DECL_NOTHROW : data(0) {}
+
+    Q_DECL_CONSTEXPR QPdf::Rotation rotation() const Q_DECL_NOTHROW { return static_cast<QPdf::Rotation>(bits.rotation); }
+    Q_DECL_RELAXED_CONSTEXPR void setRotation(QPdf::Rotation _rotation) Q_DECL_NOTHROW { bits.rotation = _rotation; }
+
+    Q_DECL_CONSTEXPR QPdf::RenderFlags renderFlags() const Q_DECL_NOTHROW { return static_cast<QPdf::RenderFlags>(bits.renderFlags); }
+    Q_DECL_RELAXED_CONSTEXPR void setRenderFlags(QPdf::RenderFlags _renderFlags) Q_DECL_NOTHROW { bits.renderFlags = _renderFlags; }
+
+private:
+    friend Q_DECL_CONSTEXPR inline bool operator==(QPdfDocumentRenderOptions lhs, QPdfDocumentRenderOptions rhs) Q_DECL_NOTHROW;
+
+
+    struct Bits {
+        quint32 renderFlags : 8;
+        quint32 rotation    : 3;
+        quint32 reserved    : 21;
+        quint32 reserved2   : 32;
+    };
+
+    union {
+        Bits bits;
+        quint64 data;
+    };
+};
+
+Q_DECLARE_TYPEINFO(QPdfDocumentRenderOptions, Q_PRIMITIVE_TYPE);
+
+Q_DECL_CONSTEXPR inline bool operator==(QPdfDocumentRenderOptions lhs, QPdfDocumentRenderOptions rhs) Q_DECL_NOTHROW
+{
+    return lhs.data == rhs.data;
+}
+
+Q_DECL_CONSTEXPR inline bool operator!=(QPdfDocumentRenderOptions lhs, QPdfDocumentRenderOptions rhs) Q_DECL_NOTHROW
+{
+    return !operator==(lhs, rhs);
+}
+
+QT_END_NAMESPACE
+
+#endif // QPDFDOCUMENTRENDEROPTIONS_H
diff --git a/src/pdf/qpdfdocumentrenderoptions.qdoc b/src/pdf/qpdfdocumentrenderoptions.qdoc
new file mode 100644
index 0000000..cafb0af
--- /dev/null
+++ b/src/pdf/qpdfdocumentrenderoptions.qdoc
@@ -0,0 +1,105 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Tobias König <tobias.koenig@kdab.com>
+** 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 "qpdfdocumentrenderoptions.h"
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QPdfDocumentRenderOptions
+    \since 5.10
+    \inmodule QtPdf
+
+    \brief The QPdfDocumentRenderOptions class holds the options to render a page from a PDF document.
+
+    \sa QPdfDocument
+*/
+
+/*!
+    \fn QPdfDocumentRenderOptions::QPdfDocumentRenderOptions()
+
+    Constructs a QPdfDocumentRenderOptions object.
+*/
+
+/*!
+    \fn  QPdf::Rotation QPdfDocumentRenderOptions::rotation() const
+
+    Returns the rotation used for rendering a page from a PDF document.
+
+    \sa setRotation()
+*/
+
+/*!
+    \fn void QPdfDocumentRenderOptions::setRotation(QPdf::Rotation rotation)
+
+    Sets the \a rotation used for rendering a page from a PDF document.
+
+    \sa rotation()
+*/
+
+/*!
+    \fn QPdf::RenderFlags QPdfDocumentRenderOptions::renderFlags() const
+
+    Returns the special flags used for rendering a page from a PDF document.
+
+    \sa setRenderFlags()
+*/
+
+/*!
+    \fn void QPdfDocumentRenderOptions::setRenderFlags(QPdf::RenderFlags flags)
+
+    Sets the special \a flags used for rendering a page from a PDF document.
+
+    \sa renderFlags()
+*/
+
+/*!
+    \fn bool operator!=(QPdfDocumentRenderOptions lhs, QPdfDocumentRenderOptions rhs)
+    \relates QPdfDocumentRenderOptions
+
+    Returns \c true if the options \a lhs and \a rhs are different, otherwise
+    returns \c false.
+*/
+
+/*!
+    \fn bool operator==(QPdfDocumentRenderOptions lhs, QPdfDocumentRenderOptions rhs)
+    \relates QPdfDocumentRenderOptions
+
+    Returns \c true if the options \a lhs and \a rhs are equal,
+    otherwise returns \c false.
+*/
+
+QT_END_NAMESPACE
diff --git a/src/pdf/qpdfnamespace.h b/src/pdf/qpdfnamespace.h
new file mode 100644
index 0000000..a8e7dc0
--- /dev/null
+++ b/src/pdf/qpdfnamespace.h
@@ -0,0 +1,69 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Tobias König <tobias.koenig@kdab.com>
+** 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 QPDFNAMESPACE_H
+#define QPDFNAMESPACE_H
+
+#include <QObject>
+
+namespace QPdf {
+    Q_NAMESPACE
+
+    enum Rotation {
+        Rotate0,
+        Rotate90,
+        Rotate180,
+        Rotate270
+    };
+    Q_ENUM_NS(Rotation)
+
+    enum RenderFlag {
+        NoRenderFlags = 0x000,
+        RenderAnnotations = 0x001,
+        RenderOptimizedForLcd = 0x002,
+        RenderGrayscale = 0x004,
+        RenderForceHalftone = 0x008,
+        RenderTextAliased = 0x010,
+        RenderImageAliased = 0x020,
+        RenderPathAliased = 0x040
+    };
+    Q_FLAG_NS(RenderFlag)
+    Q_DECLARE_FLAGS(RenderFlags, RenderFlag)
+}
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(QPdf::RenderFlags)
+
+#endif
diff --git a/src/pdf/qpdfnamespace.qdoc b/src/pdf/qpdfnamespace.qdoc
new file mode 100644
index 0000000..96bb090
--- /dev/null
+++ b/src/pdf/qpdfnamespace.qdoc
@@ -0,0 +1,74 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Tobias König <tobias.koenig@kdab.com>
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \namespace QPdf
+    \inmodule QtPdf
+    \keyword QPdf Namespace
+
+    \brief The QPdf namespace contains miscellaneous identifiers
+           used throughout the QtPdf module.
+*/
+
+/*!
+    \enum QPdf::Rotation
+
+    This enum describes the rotation of the page for rendering.
+
+    \value Rotate0 Do not rotate (the default)
+    \value Rotate90 Rotate 90 degrees clockwise
+    \value Rotate180 Rotate 180 degrees
+    \value Rotate270 Rotate 270 degrees clockwise
+
+    \sa QPdfDocument::render()
+*/
+/*!
+    \enum QPdf::RenderFlag
+
+    This enum is used to describe how a page should be rendered.
+
+    \value NoRenderFlags The default value, representing no flags.
+    \value RenderAnnotations The page is rendered with annotations.
+    \value RenderOptimizedForLcd The text of the page is rendered optimized for LCD display.
+    \value RenderGrayscale The page is rendered grayscale.
+    \value RenderForceHalftone Always use halftones for rendering if the output image is stretched.
+    \value RenderTextAliased Anti-aliasing is disabled for rendering text.
+    \value RenderImageAliased Anti-aliasing is disabled for rendering images.
+    \value RenderPathAliased Anti-aliasing is disabled for rendering paths.
+
+    \sa QPdfDocument::render()
+*/
+