/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#ifndef INCLUDED_VCL_GLYPHITEMCACHE_HXX
#define INCLUDED_VCL_GLYPHITEMCACHE_HXX

#include <sal/types.h>
#include <vcl/dllapi.h>

#include <o3tl/lru_map.hxx>
#include <o3tl/hash_combine.hxx>
#include <vcl/glyphitem.hxx>
#include <vcl/outdev.hxx>
#include <vcl/vclptr.hxx>
#include <tools/gen.hxx>

/**
A cache for SalLayoutGlyphs objects.

Allows caching for OutputDevice::DrawText() and similar calls. Pass the text and the output device
for the call to OutputDevice::ImplLayout(). Items are cached per output device and its font.
If something more changes, call clear().
*/
class VCL_DLLPUBLIC SalLayoutGlyphsCache final
{
public:
    SalLayoutGlyphsCache(int size = 1000)
        : mCachedGlyphs(size)
    {
    }
    const SalLayoutGlyphs* GetLayoutGlyphs(VclPtr<const OutputDevice> outputDevice,
                                           const OUString& text) const
    {
        return GetLayoutGlyphs(outputDevice, text, 0, text.getLength());
    }
    const SalLayoutGlyphs* GetLayoutGlyphs(VclPtr<const OutputDevice> outputDevice,
                                           const OUString& text, sal_Int32 nIndex, sal_Int32 nLen,
                                           const Point& rLogicPos = Point(0, 0),
                                           tools::Long nLogicWidth = 0) const;
    void clear() { mCachedGlyphs.clear(); }

private:
    struct CachedGlyphsKey
    {
        VclPtr<const OutputDevice> outputDevice;
        OUString text;
        sal_Int32 index;
        sal_Int32 len;
        Point logicPos;
        tools::Long logicWidth;
        size_t hashValue;
        CachedGlyphsKey(const VclPtr<const OutputDevice>& dev, const OUString& t, sal_Int32 i,
                        sal_Int32 l, const Point& p, tools::Long w);
        bool operator==(const CachedGlyphsKey& other) const;
    };
    struct CachedGlyphsHash
    {
        size_t operator()(const CachedGlyphsKey& key) const { return key.hashValue; }
    };
    mutable o3tl::lru_map<CachedGlyphsKey, SalLayoutGlyphs, CachedGlyphsHash> mCachedGlyphs;

    SalLayoutGlyphsCache(const SalLayoutGlyphsCache&) = delete;
    SalLayoutGlyphsCache& operator=(const SalLayoutGlyphsCache&) = delete;
};

#endif // INCLUDED_VCL_GLYPHITEMCACHE_HXX

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