diff options
Diffstat (limited to 'sd/source/ui/slidesorter/inc/cache/SlsPageCache.hxx')
-rwxr-xr-x | sd/source/ui/slidesorter/inc/cache/SlsPageCache.hxx | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/sd/source/ui/slidesorter/inc/cache/SlsPageCache.hxx b/sd/source/ui/slidesorter/inc/cache/SlsPageCache.hxx new file mode 100755 index 000000000000..4a5c2b51ac28 --- /dev/null +++ b/sd/source/ui/slidesorter/inc/cache/SlsPageCache.hxx @@ -0,0 +1,148 @@ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * This file is part of OpenOffice.org. + * + * OpenOffice.org is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 3 + * only, as published by the Free Software Foundation. + * + * OpenOffice.org is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License version 3 for more details + * (a copy is included in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU Lesser General Public License + * version 3 along with OpenOffice.org. If not, see + * <http://www.openoffice.org/license.html> + * for a copy of the LGPLv3 License. + * + ************************************************************************/ + +#ifndef SD_SLIDESORTER_PAGE_CACHE_HXX +#define SD_SLIDESORTER_PAGE_CACHE_HXX + +#include "cache/SlsCacheContext.hxx" +#include <sal/types.h> +#include <vcl/bitmapex.hxx> +#include <boost/function.hpp> +#include <boost/scoped_ptr.hpp> +#include <boost/shared_ptr.hpp> + +namespace sd { namespace slidesorter { namespace view { +class PageObjectViewObjectContact; +} } } + +namespace sd { namespace slidesorter { namespace cache { + +class GenericPageCache; +class RequestData; + +/** The page cache is responsible for the creation and storage of preview + bitmaps of pages that are shown by the slide sorter. + + <p>Bitmaps for previews and a cache are used to speed up the display + (painting) of the slide sorter. But, of course, we have to limit this + time-space-tradeoff by limiting the amount of space that can be use to + store bitmaps.</p> + + <p>There are several strategies employed by this class to shorten the + perceived time that is used to paint the slide sorter: + <ul> + <li>Rendering pages ahead of time. Additionally to rendering the + visible slides we try to render part or all of the slides that are not + (yet) visible. This, of course, makes sense only when the computer is + ohterwise idle while doing that.</li> + <li>When the size of the slides on the screen changes we mark the + bitmaps as needing an update but use them while the new bitmap in the + correct size is not available.</li> + <li>Give the UI the chance to handle user events between the rendering + of differe slides.</li> + <li>Limit the amount of space that may be used for storing preview + bitmaps and throw.</li> + </p> + + <p>There is another somewhat similar methods for requesting new previews: + GetPreviewBitmap() schedules a re-rendering (when necessary) and + returns the preview what is currently available, either as a preview of + the preview or, when nothing has changed since the last call, as the + final thing. + </p> +*/ +class PageCache +{ +public: + /** The page chache is created with a reference to the slide sorter so + that it has access to both the view and the model and so can fill + itself with requests for all or just the visible pages. + + It is the task of the PageCacheManager to create new objects of this + class. + */ + PageCache ( + const Size& rPreviewSize, + const SharedCacheContext& rpCacheContext); + + ~PageCache (void); + + void ChangeSize(const Size& rPreviewSize); + + /** Request a preview bitmap for the specified page object in the + specified size. The returned bitmap may be a preview of the + preview, i.e. either a scaled (up or down) version of a previous + preview (of the wrong size) or an empty bitmap. In this case a + request for the generation of a new preview is created and inserted + into the request queue. When the preview is available the page + shape will be told to paint itself again. When it then calls this + method again if receives the correctly sized preview bitmap. + @param rRequestData + This data is used to determine the preview. + @param rSize + The size of the requested preview bitmap. + @return + Returns a bitmap that is either empty, contains a scaled (up or + down) version or is the requested bitmap. + */ + BitmapEx GetPreviewBitmap ( + CacheKey aKey, + const Size& rSize); + + /** Call this method when a view-object-contact object is being deleted + and does not need (a) its current bitmap in the cache and (b) a + requested new bitmap. + */ + void ReleasePreviewBitmap (CacheKey aKey); + + /** Call this method when all preview bitmaps have to be generated anew. + This is the case when the size of the page objects on the screen has + changed or when the model has changed. + @param bUpdateCache + When this flags is <TRUE/> then requests for updated previews + are created. When it is <FALSE/> the existing previews are only + marked as not being up-to-date anymore. + */ + void InvalidateCache (bool bUpdateCache = true); + + /** With the precious flag you can control whether a bitmap can be + removed or reduced in size to make room for other bitmaps or is so + precious that it will not touched. A typical use is to set the + precious flag for exactly the visible pages. + */ + void SetPreciousFlag (CacheKey aKey, bool bIsPrecious); + + void Pause (void); + void Resume (void); + +private: + ::boost::scoped_ptr<GenericPageCache> mpImplementation; +}; + +} } } // end of namespace ::sd::slidesorter::cache + +#endif |