sd/source/ui/slidesorter/cache/SlsCacheCompactor.hxx

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  19
  20 #ifndef INCLUDED_SD_SOURCE_UI_SLIDESORTER_CACHE_SLSCACHECOMPACTOR_HXX
  21 #define INCLUDED_SD_SOURCE_UI_SLIDESORTER_CACHE_SLSCACHECOMPACTOR_HXX
  22
  23 #include <sal/types.h>
  24 #include <vcl/timer.hxx>
  25 #include <memory>
  26
  27 namespace sd { namespace slidesorter { namespace cache {
  28
  29 class BitmapCache;
  30
  31 /** This is an interface class whose implementations are created via the
  32     Create() factory method.
  33 */
  34 class CacheCompactor
  35 {
  36 public:
  37     virtual ~CacheCompactor() {};
  38
  39     /** Create a new instance of the CacheCompactor interface class.  The
  40         type of compaction algorithm used depends on values from the
  41         configuration: the SlideSorter/PreviewCache/CompactionPolicy
  42         property of the Impress.xcs file currently supports the values
  43         "None" and "Compress".  With the later the CompressionPolicy
  44         property is evaluated which implementation of the BitmapCompress
  45         interface class to use as bitmap compressor.
  46         @param rCache
  47             The bitmap cache on which to operate.
  48         @param nMaximalCacheSize
  49             The total number of bytes the off-screen bitmaps in the cache
  50             may have.  When the Run() method is (indirectly) called the
  51             compactor tries to reduce that summed size of off-screen bitmaps
  52             under this number.  However, it is not guaranteed that this
  53             works in all cases.
  54     */
  55     static ::std::unique_ptr<CacheCompactor> Create (
  56         BitmapCache& rCache,
  57         sal_Int32 nMaximalCacheSize);
  58
  59     /** Request a compaction of the off-screen previews in the bitmap
  60         cache.  This calls via a timer the Run() method.
  61     */
  62     virtual void RequestCompaction();
  63
  64 protected:
  65     BitmapCache& mrCache;
  66     sal_Int32 mnMaximalCacheSize;
  67
  68     CacheCompactor(
  69         BitmapCache& rCache,
  70         sal_Int32 nMaximalCacheSize);
  71
  72     /** This method actually tries to reduce the total number of bytes used
  73         by the off-screen preview bitmaps.
  74     */
  75     virtual void Run() = 0;
  76
  77 private:
  78     /** This timer is used to collect calles to RequestCompaction() and
  79         eventually call Run().
  80     */
  81     Timer maCompactionTimer;
  82     bool mbIsCompactionRunning;
  83     DECL_LINK_TYPED(CompactionCallback, Timer *, void);
  84 };
  85
  86 } } } // end of namespace ::sd::slidesorter::cache
  87
  88 #endif
  89
  90 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */