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

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   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
  13  *   with this work for additional information regarding copyright
  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
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <sal/types.h>
  23 #include <com/sun/star/uno/Reference.hxx>
  24 #include <memory>
  25 #include <vector>
  26
  27 namespace com::sun::star::uno
  28 {
  29 class XInterface;
  30 }
  31
  32 class SdrPage;
  33
  34 namespace sd::slidesorter::cache
  35 {
  36 typedef const SdrPage* CacheKey;
  37
  38 /** This interface allows the individualisation of different instances of
  39     the PreviewCache.
  40 */
  41 class CacheContext
  42 {
  43 public:
  44     virtual ~CacheContext() {}
  45
  46     /** This method is called when the asynchronous creation of a preview
  47         has been finished.
  48         @param aKey
  49             The key of the page for which the preview has been created.
  50     */
  51     virtual void NotifyPreviewCreation(CacheKey aKey) = 0;
  52
  53     /** Called to determine whether the system is idle and a preview can be
  54         created without annoying the user.
  55     */
  56     virtual bool IsIdle() = 0;
  57
  58     /** This method is used to determine whether a page is currently visible
  59         or not.  It is called when the cache becomes too large and some
  60         previews have to be released or scaled down.
  61     */
  62     virtual bool IsVisible(CacheKey aKey) = 0;
  63
  64     /** Return the page associated with the given key.  Note that different
  65         keys may map to a single page (this may be the case with custom
  66         slide shows.)
  67     */
  68     virtual const SdrPage* GetPage(CacheKey aKey) = 0;
  69
  70     /** This method is used when the request queue is filled.  It asks for
  71         the list of visible entries and maybe for the list of not visible
  72         entries and creates preview creation requests for them.
  73         @param bVisible
  74             When this is <FALSE/> then the implementation can decide whether
  75             to allow rendering of previews that are not visible (ahead of
  76             time). When not then return an empty pointer or an empty vector.
  77     */
  78     virtual std::shared_ptr<std::vector<CacheKey>> GetEntryList(bool bVisible) = 0;
  79
  80     /** Return the priority that defines the order in which previews are
  81         created for different keys/pages.  Typically the visible pages come
  82         first, then top-down, left-to-right.
  83     */
  84     virtual sal_Int32 GetPriority(CacheKey aKey) = 0;
  85
  86     /** Return the model to which the pages belong for which the called
  87         cache manages the previews.  Different caches that belong to the
  88         same model but have different preview sizes may access previews of
  89         each other in order to create fast previews of the previews.
  90     */
  91     virtual css::uno::Reference<css::uno::XInterface> GetModel() = 0;
  92 };
  93
  94 typedef std::shared_ptr<CacheContext> SharedCacheContext;
  95
  96 } // end of namespace ::sd::slidesorter::cache
  97
  98 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */