/*
 * Copyright 2009, The Android Open Source Project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef android_EmojiFont_DEFINED
#define android_EmojiFont_DEFINED

#include "SkScalar.h"
#include "SkUtils.h"

class SkCanvas;
class SkPaint;

namespace android {

    class EmojiFont {
    public:
        /** Returns true if the underlying emoji font mechanism is available.
         */
        static bool IsAvailable();

        /** Return index for the corresponding index to the emoji table, or 0
            if there is no matching emoji form.
         */
        static uint16_t UnicharToGlyph(int32_t unichar);

        /** Returns true if the specified glyph is in the emoji range, i.e. was
            returned by UnicharToGlyph or UTF16ToGlyph.
         */
        static bool IsEmojiGlyph(uint16_t index) {
            return index >= kGlyphBase;
        }
        
        /** Returns the advance width for the specified emoji form.
         */
        static SkScalar GetAdvanceWidth(uint16_t index, const SkPaint& paint);
        
        /** Draw the specified emoji form, given the x,y origin of the text
            version. The paint is the one associated with the text that has
            the emoji in it.
         */
        static void Draw(SkCanvas*, uint16_t index, SkScalar x, SkScalar y,
                         const SkPaint& paint);
        
    private:
        enum {
            /*  this is our internal trick to embedded private emoji glyph IDs
                along side normal glyphs IDs that come from real fonts. The
                assumption is that normal fonts never will report a glyph ID
                above 20K or 30K, so 64000 should always be a safe starting
                index. We also assume the the number of emoji will not overflow
                16bits starting at 64000 i.e. 65535 - 64000 > total emoji count
             */
            kGlyphBase = 64000
        };
    };
}

#endif