gecko/gfx/thebes/public/gfxPlatform.h

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
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 * License.
 *
 * The Original Code is Mozilla Foundation code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Vladimir Vukicevic <vladimir@pobox.com>
 *   Masayuki Nakano <masayuki@d-toybox.com>
 *
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#ifndef GFX_PLATFORM_H
#define GFX_PLATFORM_H

#include "prtypes.h"
#include "nsVoidArray.h"

#include "gfxTypes.h"
#include "gfxASurface.h"

class gfxImageSurface;
class gfxFontGroup;
struct gfxFontStyle;

class THEBES_API gfxPlatform {
public:
    /**
     * Return a pointer to the current active platform.
     * This is a singleton; it contains mostly convenience
     * functions to obtain platform-specific objects.
     */
    static gfxPlatform *GetPlatform();

    /**
     * Start up Thebes. This can fail.
     */
    static nsresult Init();

    /**
     * Clean up static objects to shut down thebes.
     */
    static void Shutdown();

    /**
     * Return PR_TRUE if we're to use Glitz for acceleration.
     */
    static PRBool UseGlitz();

    /**
     * Force the glitz state to on or off
     */
    static void SetUseGlitz(PRBool use);

    /**
     * Create an offscreen surface of the given dimensions
     * and image format.  If fastPixelAccess is TRUE,
     * create a surface that is optimized for rapid pixel
     * changing.
     */
    virtual already_AddRefed<gfxASurface> CreateOffscreenSurface(const gfxIntSize& size,
                                                                 gfxASurface::gfxImageFormat imageFormat) = 0;


    virtual already_AddRefed<gfxASurface> OptimizeImage(gfxImageSurface *aSurface);

    /*
     * Font bits
     */

    /**
     * Fill aListOfFonts with the results of querying the list of font names
     * that correspond to the given language group or generic font family
     * (or both, or neither).
     */
    virtual nsresult GetFontList(const nsACString& aLangGroup,
                                 const nsACString& aGenericFamily,
                                 nsStringArray& aListOfFonts);

    /**
     * Rebuilds the any cached system font lists
     */
    virtual nsresult UpdateFontList();

    /**
     * Font name resolver, this returns actual font name(s) by the callback
     * function. If the font doesn't exist, the callback function is not called.
     * If the callback function returns PR_FALSE, the aAborted value is set to
     * PR_TRUE, otherwise, PR_FALSE.
     */
    typedef PRBool (*FontResolverCallback) (const nsAString& aName,
                                            void *aClosure);
    virtual nsresult ResolveFontName(const nsAString& aFontName,
                                     FontResolverCallback aCallback,
                                     void *aClosure,
                                     PRBool& aAborted) = 0;

    /**
     * Create the appropriate platform font group
     */
    virtual gfxFontGroup *CreateFontGroup(const nsAString &aFamilies,
                                          const gfxFontStyle *aStyle) = 0;

    /* Returns PR_TRUE if the given block of ARGB32 data really has alpha, otherwise PR_FALSE */
    static PRBool DoesARGBImageDataHaveAlpha(PRUint8* data,
                                             PRUint32 width,
                                             PRUint32 height,
                                             PRUint32 stride);

    void GetPrefFonts(const char *aLangGroup, nsString& array);

protected:
    gfxPlatform() { }
    virtual ~gfxPlatform();

};

#endif /* GFX_PLATFORM_H */