sd/source/ui/slidesorter/inc/cache/SlsCacheContext.hxx

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  31
  32 #ifndef SD_SLIDESORTER_CACHE_CONTEXT_HXX
  33 #define SD_SLIDESORTER_CACHE_CONTEXT_HXX
  34
  35 #include <sal/types.h>
  36 #include <com/sun/star/uno/XInterface.hpp>
  37 #include <boost/shared_ptr.hpp>
  38 #include <vector>
  39
  40 class BitmapEx;
  41 class SdrPage;
  42
  43 namespace sd { namespace slidesorter { namespace cache {
  44
  45 typedef const SdrPage* CacheKey;
  46
  47 /** This interface allows the individualisation of different instances of
  48     the PreviewCache.
  49 */
  50 class CacheContext
  51 {
  52 public:
  53     /** This method is called when the asynchronous creation of a preview
  54         has been finished.
  55         @param aKey
  56             The key of the page for which the preview has been created.
  57         @param aPreview
  58             The newly created preview.
  59     */
  60     virtual void NotifyPreviewCreation (
  61         CacheKey aKey,
  62         const ::boost::shared_ptr<BitmapEx>& rPreview) = 0;
  63
  64     /** Called to determine whether the system is idle and a preview can be
  65         created without annoying the user.
  66     */
  67     virtual bool IsIdle (void) = 0;
  68
  69     /** This method is used to determine whether a page is currently visible
  70         or not.  It is called when the cache becomes to large and some
  71         previews have to be released or scaled down.
  72     */
  73     virtual bool IsVisible (CacheKey aKey) = 0;
  74
  75     /** Return the page associdated with the given key.  Note that different
  76         keys may map to a single page (this may be the case with custom
  77         slide shows.)
  78     */
  79     virtual const SdrPage* GetPage (CacheKey aKey) = 0;
  80
  81     /** This method is used when the request queue is filled.  It asks for
  82         the list of visible entries and maybe for the list of not visible
  83         entries and creates preview creation requests for them.
  84         @param bVisible
  85             When this is <FALSE/> then the implementation can decide whether
  86             to allow rendering of previews that are not visible (ahead of
  87             time). When not then return an empty pointer or an empty vector.
  88     */
  89     virtual ::boost::shared_ptr<std::vector<CacheKey> > GetEntryList (bool bVisible) = 0;
  90
  91     /** Return the priority that defines the order in which previews are
  92         created for different keys/pages.  Typically the visible pages come
  93         first, then top-down, left-to-right.
  94     */
  95     virtual sal_Int32 GetPriority (CacheKey aKey) = 0;
  96
  97     /** Return the model to which the pages belong for which the called
  98         cache manages the previews.  Different caches that belong to the
  99         same model but have different preview sizes may acces previews of
 100         each other in order to create fast previews of the previews.
 101     */
 102     virtual ::com::sun::star::uno::Reference<com::sun::star::uno::XInterface> GetModel (void) = 0;
 103 };
 104
 105 typedef ::boost::shared_ptr<CacheContext> SharedCacheContext;
 106
 107 } } } // end of namespace ::sd::slidesorter::cache
 108
 109 #endif
 110