1 files changed, 87 insertions, 0 deletions
diff --git a/sd/source/ui/slidesorter/cache/SlsCacheCompactor.hxx b/sd/source/ui/slidesorter/cache/SlsCacheCompactor.hxx
new file mode 100644
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+++ b/sd/source/ui/slidesorter/cache/SlsCacheCompactor.hxx
@@ -0,0 +1,87 @@
+/* -*- 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 .
+ */
+
+#pragma once
+
+#include <sal/types.h>
+#include <vcl/timer.hxx>
+#include <memory>
+
+namespace sd::slidesorter::cache {
+
+class BitmapCache;
+
+/** This is an interface class whose implementations are created via the
+    Create() factory method.
+*/
+class CacheCompactor
+{
+public:
+    virtual ~CacheCompactor() {};
+
+    /** Create a new instance of the CacheCompactor interface class.  The
+        type of compaction algorithm used depends on values from the
+        configuration: the SlideSorter/PreviewCache/CompactionPolicy
+        property of the Impress.xcs file currently supports the values
+        "None" and "Compress".  With the later the CompressionPolicy
+        property is evaluated which implementation of the BitmapCompress
+        interface class to use as bitmap compressor.
+        @param rCache
+            The bitmap cache on which to operate.
+        @param nMaximalCacheSize
+            The total number of bytes the off-screen bitmaps in the cache
+            may have.  When the Run() method is (indirectly) called the
+            compactor tries to reduce that summed size of off-screen bitmaps
+            under this number.  However, it is not guaranteed that this
+            works in all cases.
+    */
+    static ::std::unique_ptr<CacheCompactor> Create (
+        BitmapCache& rCache,
+        sal_Int32 nMaximalCacheSize);
+
+    /** Request a compaction of the off-screen previews in the bitmap
+        cache.  This calls via a timer the Run() method.
+    */
+    virtual void RequestCompaction();
+
+protected:
+    BitmapCache& mrCache;
+    sal_Int32 mnMaximalCacheSize;
+
+    CacheCompactor(
+        BitmapCache& rCache,
+        sal_Int32 nMaximalCacheSize);
+
+    /** This method actually tries to reduce the total number of bytes used
+        by the off-screen preview bitmaps.
+    */
+    virtual void Run() = 0;
+
+private:
+    /** This timer is used to collect calls to RequestCompaction() and
+        eventually call Run().
+    */
+    Timer maCompactionTimer;
+    bool mbIsCompactionRunning;
+    DECL_LINK(CompactionCallback, Timer *, void);
+};
+
+} // end of namespace ::sd::slidesorter::cache
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */