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

   1 /*************************************************************************
   2  *
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * Copyright 2008 by Sun Microsystems, Inc.
   6  *
   7  * OpenOffice.org - a multi-platform office productivity suite
   8  *
   9  * $RCSfile: SlsGenericPageCache.hxx,v $
  10  * $Revision: 1.11 $
  11  *
  12  * This file is part of OpenOffice.org.
  13  *
  14  * OpenOffice.org is free software: you can redistribute it and/or modify
  15  * it under the terms of the GNU Lesser General Public License version 3
  16  * only, as published by the Free Software Foundation.
  17  *
  18  * OpenOffice.org is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU Lesser General Public License version 3 for more details
  22  * (a copy is included in the LICENSE file that accompanied this code).
  23  *
  24  * You should have received a copy of the GNU Lesser General Public License
  25  * version 3 along with OpenOffice.org.  If not, see
  26  * <http://www.openoffice.org/license.html>
  27  * for a copy of the LGPLv3 License.
  28  *
  29  ************************************************************************/
  30
  31 #ifndef SD_SLIDESORTER_GENERIC_PAGE_CACHE_HXX
  32 #define SD_SLIDESORTER_GENERIC_PAGE_CACHE_HXX
  33
  34 #include "SlideSorter.hxx"
  35 #include "SlsRequestQueue.hxx"
  36 #include "SlsQueueProcessor.hxx"
  37 #include <boost/function.hpp>
  38 #include <boost/scoped_ptr.hpp>
  39
  40 namespace sd { namespace slidesorter { namespace cache {
  41
  42 class BitmapCache;
  43 class QueueProcessor;
  44
  45 /** This basically is the implementation class for the PageCache class.
  46 */
  47 class GenericPageCache
  48 {
  49 public:
  50     /** The page chache is created with references both to the SlideSorter.
  51         This allows access to both view and model and the cache can so fill
  52         itself with requests for all or just the visible pages.
  53     */
  54     GenericPageCache (
  55         const Size& rPreviewSize,
  56         const SharedCacheContext& rpCacheContext);
  57
  58     ~GenericPageCache (void);
  59
  60     /** Change the size of the preview bitmaps.  This may be caused by a
  61         resize of the slide sorter window or a change of the number of
  62         columns.
  63     */
  64     void ChangePreviewSize (const Size& rPreviewSize);
  65
  66     /** Request a preview bitmap for the specified page object in the
  67         specified size.  The returned bitmap may be preview of the preview,
  68         i.e. either a scaled (up or down) version of a previous preview (of
  69         the wrong size) or an empty bitmap.  In this case a request for the
  70         generation of a new preview is created and inserted into the request
  71         queue.  When the preview is available the page shape will be told to
  72         paint itself again.  When it then calls this method again if
  73         receives the correctly sized preview bitmap.
  74         @param rRequestData
  75             This data is used to determine the preview.
  76         @param rSize
  77             The size of the requested preview bitmap.
  78         @return
  79             Returns a bitmap that is either empty, contains a scaled (up or
  80             down) version or is the requested bitmap.
  81     */
  82     BitmapEx GetPreviewBitmap (
  83         CacheKey aKey,
  84         const Size& rSize);
  85
  86     /** When the requested preview bitmap does not yet exist or is not
  87         up-to-date then the rendering of one is scheduled.  Otherwise this
  88         method does nothing.
  89         @param rRequestData
  90             This data is used to determine the preview.
  91         @param rSize
  92             The size of the requested preview bitmap in pixel coordinates.
  93         @param bMayBeUpToDate
  94             This flag helps the method to determine whether an existing
  95             preview that matches the request is up to date.  If the caller
  96             know that it is not then by passing <FALSE/> he tells us that we
  97             do not have to check the up-to-date flag a second time.  If
  98             unsure pass <TRUE/>.
  99     */
 100     void RequestPreviewBitmap (
 101         CacheKey aKey,
 102         const Size& rSize,
 103         bool bMayBeUpToDate = true);
 104
 105     /** Tell the cache to replace the bitmap associated with the given
 106         request data with a new one that reflects recent changes in the
 107         content of the page object.
 108     */
 109     void InvalidatePreviewBitmap (CacheKey aKey);
 110
 111     /** Call this method when a view-object-contact object is being deleted
 112         and does not need (a) its current bitmap in the cache and (b) a
 113         requested a new bitmap.
 114     */
 115     void ReleasePreviewBitmap (CacheKey aKey);
 116
 117     /** Call this method when all preview bitmaps have to be generated anew.
 118         This is the case when the size of the page objects on the screen has
 119         changed or when the model has changed.
 120     */
 121     void InvalidateCache (bool bUpdateCache);
 122
 123     /** With the precious flag you can control whether a bitmap can be
 124         removed from the cache or reduced in size to make room for other
 125         bitmaps or is so precious that it will not be touched.  A typical
 126         use is to set the precious flag for the visible pages.
 127     */
 128     void SetPreciousFlag (CacheKey aKey, bool bIsPrecious);
 129
 130     /** Return <TRUE/> when there is no preview bitmap in the cache.
 131     */
 132     bool IsEmpty (void) const;
 133
 134     void Pause (void);
 135     void Resume (void);
 136
 137 private:
 138     ::boost::shared_ptr<BitmapCache> mpBitmapCache;
 139
 140     RequestQueue maRequestQueue;
 141
 142     ::boost::scoped_ptr<QueueProcessor> mpQueueProcessor;
 143
 144     SharedCacheContext mpCacheContext;
 145
 146     /** The current size of preview bitmaps.
 147     */
 148     Size maPreviewSize;
 149
 150     /** Both bitmap cache and queue processor are created on demand by this
 151         method.
 152     */
 153     void ProvideCacheAndProcessor (void);
 154 };
 155
 156
 157 } } } // end of namespace ::sd::slidesorter::cache
 158
 159 #endif