font.h

/*
**  UICore
**  Copyright (c) 1997-2015 The UICore Team
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
**  Note: Some of the libraries UICore may link to may have additional
**  requirements or restrictions.
**
**  File Author(s):
**
**    Magnus Norddahl
**    Mark Page
*/

#pragma once

#include <memory>
#include "UICore/Display/Render/graphic_context.h"
#include "../Image/pixel_buffer.h"
#include "font_description.h"
#include "glyph_metrics.h"

namespace uicore
{
    class FontProvider;
    class FontFamily;
    typedef std::shared_ptr<FontFamily> FontFamilyPtr;
    class Canvas;
    typedef std::shared_ptr<Canvas> CanvasPtr;
    class GlyphMetrics;

    class FontHandle
    {
    public:
        virtual ~FontHandle() { }
    };

    class Font
    {
    public:
        // \brief Create font using the specified font family
        static std::shared_ptr<Font> create(const FontFamilyPtr &font_family, float height);

        // \brief Create font using the specified font family
        static std::shared_ptr<Font> create(const FontFamilyPtr &font_family, const FontDescription &desc);

        static std::shared_ptr<Font> create(const std::string &typeface_name, float height);

        // \brief Constructs standard font
        static std::shared_ptr<Font> create(const std::string &typeface_name, const FontDescription &desc);

        // \brief Constructs standard font
        static std::shared_ptr<Font> create(const FontDescription &desc, const std::string &ttf_filename);

        virtual void set_height(float value) = 0;

        virtual void set_weight(FontWeight value = FontWeight::normal) = 0;

        virtual void set_line_height(float height) = 0;

        virtual void set_style(FontStyle setting = FontStyle::normal) = 0;

        virtual void set_scalable(float height_threshold = 64.0f) = 0;

        virtual void draw_text(const CanvasPtr &canvas, const Pointf &position, const std::string &text, const Colorf &color = Colorf::white) = 0;
        void draw_text(const CanvasPtr &canvas, float xpos, float ypos, const std::string &text, const Colorf &color = Colorf::white) { draw_text(canvas, Pointf(xpos, ypos), text, color); }

        virtual GlyphMetrics metrics(const CanvasPtr &canvas, unsigned int glyph) = 0;

        virtual GlyphMetrics measure_text(const CanvasPtr &canvas, const std::string &string) = 0;

        virtual const FontMetrics &font_metrics(const CanvasPtr &canvas) = 0;

        std::string clipped_text(const CanvasPtr &canvas, const Sizef &box_size, const std::string &text, const std::string &ellipsis_text = "...");

        virtual int character_index(const CanvasPtr &canvas, const std::string &text, const Pointf &point) = 0;

        virtual std::vector<Rectf> character_indices(const CanvasPtr &canvas, const std::string &text) = 0;

        // Finds the offset for the last visible character when clipping the head
        size_t clip_from_left(const CanvasPtr &canvas, const std::string &text, float width);

        // Finds the offset for the first visible character when clipping the tail
        size_t clip_from_right(const CanvasPtr &canvas, const std::string &text, float width);

        virtual FontHandle *handle(const CanvasPtr &canvas) = 0;
    };

    typedef std::shared_ptr<Font> FontPtr;

    #ifdef WIN32
    class FontHandle_Win32 : public FontHandle
    {
    public:
        HFONT hfont();
    private:
        friend class FontEngine_Win32;
        FontEngine_Win32 *engine = nullptr;
    };
    #endif
}