1 files changed, 197 insertions, 0 deletions
diff --git a/sd/source/ui/slidesorter/cache/SlsBitmapCompressor.cxx b/sd/source/ui/slidesorter/cache/SlsBitmapCompressor.cxx
new file mode 100644
index 000000000..d4da935dd
--- /dev/null
+++ b/sd/source/ui/slidesorter/cache/SlsBitmapCompressor.cxx
@@ -0,0 +1,197 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include "SlsBitmapCompressor.hxx"
+
+#include <tools/stream.hxx>
+#include <vcl/bitmapex.hxx>
+#include <vcl/filter/PngImageReader.hxx>
+#include <vcl/pngwrite.hxx>
+
+namespace sd::slidesorter::cache {
+
+//===== NoBitmapCompression ===================================================
+
+/** This dummy replacement simply stores a shared pointer to the original
+    preview bitmap.
+*/
+class NoBitmapCompression::DummyReplacement
+    : public BitmapReplacement
+{
+public:
+    BitmapEx maPreview;
+
+    explicit DummyReplacement (const BitmapEx& rPreview) : maPreview(rPreview)  { }
+    virtual ~DummyReplacement() {}
+    virtual sal_Int32 GetMemorySize() const override { return maPreview.GetSizeBytes(); }
+};
+
+std::shared_ptr<BitmapReplacement> NoBitmapCompression::Compress (const BitmapEx& rBitmap) const
+{
+    return std::make_shared<DummyReplacement>(rBitmap);
+}
+
+BitmapEx NoBitmapCompression::Decompress (const BitmapReplacement& rBitmapData) const
+{
+    return dynamic_cast<const DummyReplacement&>(rBitmapData).maPreview;
+}
+
+bool NoBitmapCompression::IsLossless() const
+{
+    return true;
+}
+
+//===== CompressionByDeletion =================================================
+
+std::shared_ptr<BitmapReplacement> CompressionByDeletion::Compress (const BitmapEx& ) const
+{
+    return std::shared_ptr<BitmapReplacement>();
+}
+
+BitmapEx CompressionByDeletion::Decompress (const BitmapReplacement& ) const
+{
+    // Return a NULL pointer.  This will eventually lead to a request for
+    // the creation of a new one.
+    return BitmapEx();
+}
+
+bool CompressionByDeletion::IsLossless() const
+{
+    return false;
+}
+
+//===== ResolutionReduction ===================================================
+
+/** Store a scaled down bitmap together with the original size.
+*/
+class ResolutionReduction::ResolutionReducedReplacement : public BitmapReplacement
+{
+public:
+    BitmapEx maPreview;
+    Size maOriginalSize;
+
+    virtual ~ResolutionReducedReplacement();
+    virtual sal_Int32 GetMemorySize() const override;
+};
+
+ResolutionReduction::ResolutionReducedReplacement::~ResolutionReducedReplacement()
+{
+}
+
+sal_Int32 ResolutionReduction::ResolutionReducedReplacement::GetMemorySize() const
+{
+    return maPreview.GetSizeBytes();
+}
+
+std::shared_ptr<BitmapReplacement> ResolutionReduction::Compress (
+    const BitmapEx& rBitmap) const
+{
+    auto pResult = std::make_shared<ResolutionReducedReplacement>();
+    pResult->maPreview = rBitmap;
+    Size aSize (rBitmap.GetSizePixel());
+    pResult->maOriginalSize = aSize;
+    if (aSize.Width()>0 && aSize.Width()<mnWidth)
+    {
+        int nHeight = aSize.Height() * mnWidth / aSize.Width() ;
+        pResult->maPreview.Scale(Size(mnWidth,nHeight));
+    }
+
+    return pResult;
+}
+
+BitmapEx ResolutionReduction::Decompress (const BitmapReplacement& rBitmapData) const
+{
+    BitmapEx aResult;
+
+    const ResolutionReducedReplacement* pData (
+        dynamic_cast<const ResolutionReducedReplacement*>(&rBitmapData));
+
+    if ( pData && ! pData->maPreview.IsEmpty())
+    {
+        aResult = pData->maPreview;
+        if (pData->maOriginalSize.Width() > mnWidth)
+            aResult.Scale(pData->maOriginalSize);
+    }
+
+    return aResult;
+}
+
+bool ResolutionReduction::IsLossless() const
+{
+    return false;
+}
+
+//===== PNGCompression ========================================================
+
+class PngCompression::PngReplacement : public BitmapReplacement
+{
+public:
+    void* mpData;
+    sal_Int32 mnDataSize;
+    PngReplacement()
+        : mpData(nullptr),
+          mnDataSize(0)
+    {}
+    virtual ~PngReplacement()
+    {
+        delete [] static_cast<char*>(mpData);
+    }
+    virtual sal_Int32 GetMemorySize() const override
+    {
+        return mnDataSize;
+    }
+};
+
+std::shared_ptr<BitmapReplacement> PngCompression::Compress (const BitmapEx& rBitmap) const
+{
+    vcl::PNGWriter aWriter(rBitmap);
+    SvMemoryStream aStream (32768, 32768);
+    aWriter.Write(aStream);
+
+    auto pResult = std::make_shared<PngReplacement>();
+    pResult->mnDataSize = aStream.Tell();
+    pResult->mpData = new char[pResult->mnDataSize];
+    memcpy(pResult->mpData, aStream.GetData(), pResult->mnDataSize);
+
+    return pResult;
+}
+
+BitmapEx PngCompression::Decompress (
+    const BitmapReplacement& rBitmapData) const
+{
+    BitmapEx aResult;
+    const PngReplacement* pData (dynamic_cast<const PngReplacement*>(&rBitmapData));
+    if (pData != nullptr)
+    {
+        SvMemoryStream aStream (pData->mpData, pData->mnDataSize, StreamMode::READ);
+        vcl::PngImageReader aReader (aStream);
+        aResult = aReader.read().GetBitmap();
+    }
+
+    return aResult;
+}
+
+bool PngCompression::IsLossless() const
+{
+    return true;
+}
+
+} // end of namespace ::sd::slidesorter::cache
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */