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

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   2 /*
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   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
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  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
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  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef INCLUDED_SD_SOURCE_UI_SLIDESORTER_INC_CACHE_SLSCACHECONTEXT_HXX
  21 #define INCLUDED_SD_SOURCE_UI_SLIDESORTER_INC_CACHE_SLSCACHECONTEXT_HXX
  22
  23 #include <sal/types.h>
  24 #include <com/sun/star/uno/Reference.hxx>
  25 #include <memory>
  26 #include <vector>
  27
  28 namespace com { namespace sun { namespace star { namespace uno { class XInterface; } } } }
  29
  30 class SdrPage;
  31
  32 namespace sd { namespace slidesorter { namespace cache {
  33
  34 typedef const SdrPage* CacheKey;
  35
  36 /** This interface allows the individualisation of different instances of
  37     the PreviewCache.
  38 */
  39 class CacheContext
  40 {
  41 public:
  42     virtual ~CacheContext() {}
  43
  44     /** This method is called when the asynchronous creation of a preview
  45         has been finished.
  46         @param aKey
  47             The key of the page for which the preview has been created.
  48     */
  49     virtual void NotifyPreviewCreation (CacheKey aKey) = 0;
  50
  51     /** Called to determine whether the system is idle and a preview can be
  52         created without annoying the user.
  53     */
  54     virtual bool IsIdle() = 0;
  55
  56     /** This method is used to determine whether a page is currently visible
  57         or not.  It is called when the cache becomes to large and some
  58         previews have to be released or scaled down.
  59     */
  60     virtual bool IsVisible (CacheKey aKey) = 0;
  61
  62     /** Return the page associated with the given key.  Note that different
  63         keys may map to a single page (this may be the case with custom
  64         slide shows.)
  65     */
  66     virtual const SdrPage* GetPage (CacheKey aKey) = 0;
  67
  68     /** This method is used when the request queue is filled.  It asks for
  69         the list of visible entries and maybe for the list of not visible
  70         entries and creates preview creation requests for them.
  71         @param bVisible
  72             When this is <FALSE/> then the implementation can decide whether
  73             to allow rendering of previews that are not visible (ahead of
  74             time). When not then return an empty pointer or an empty vector.
  75     */
  76     virtual std::shared_ptr<std::vector<CacheKey> > GetEntryList (bool bVisible) = 0;
  77
  78     /** Return the priority that defines the order in which previews are
  79         created for different keys/pages.  Typically the visible pages come
  80         first, then top-down, left-to-right.
  81     */
  82     virtual sal_Int32 GetPriority (CacheKey aKey) = 0;
  83
  84     /** Return the model to which the pages belong for which the called
  85         cache manages the previews.  Different caches that belong to the
  86         same model but have different preview sizes may access previews of
  87         each other in order to create fast previews of the previews.
  88     */
  89     virtual css::uno::Reference<css::uno::XInterface> GetModel() = 0;
  90 };
  91
  92 typedef std::shared_ptr<CacheContext> SharedCacheContext;
  93
  94 } } } // end of namespace ::sd::slidesorter::cache
  95
  96 #endif
  97
  98 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */