C++ FontMetrics::get_external_leading方法代码示例

Size Font::get_text_size(Canvas &canvas, const std::string &text)
{
	Size total_size;

	if (impl)
	{
		FontMetrics fm = get_font_metrics();
		int line_spacing = fm.get_external_leading();
		std::vector<std::string> lines = StringHelp::split_text(text, "\n", false);
		for (std::vector<std::string>::size_type i=0; i<lines.size(); i++)
		{
			Size line_size = impl->get_text_size(canvas, lines[i]);

			if ((line_size.width == 0) && (line_size.height == 0) && (lines.size() > 1)) // blank line
				line_size.height = fm.get_descent() + fm.get_ascent(); 

			if ((i+1) != lines.size())	// Do not add the line spacing on the last line
				line_size.height += line_spacing;

			if (total_size.width < line_size.width)	// Find the widest line
				total_size.width = line_size.width;

			total_size.height += line_size.height;
		}
	}
	
	return total_size;
}

void Font::draw_text_ellipsis(Canvas &canvas, float dest_x, float dest_y, Rectf content_box, const std::string &text, const Colorf &color)
{
	if (impl)
	{
		FontMetrics fm = get_font_metrics();
		int ascent = fm.get_ascent();
		int descent = fm.get_descent();
		int line_spacing = fm.get_height() + fm.get_external_leading();
		std::vector<std::string> lines = StringHelp::split_text(text, "\n", false);
		for (std::vector<std::string>::size_type i=0; i<lines.size(); i++)
		{
			if (i == 0 || (dest_y - ascent >= content_box.top && dest_y + descent < content_box.bottom))
			{
				Size size = get_text_size(canvas, lines[i]);
				if (dest_x + size.width <= content_box.right)
				{
					draw_text(canvas, dest_x, dest_y, lines[i], color);
				}
				else
				{
					Size ellipsis = get_text_size(canvas, "...");

					int seek_start = 0;
					int seek_end = lines[i].size();
					int seek_center = (seek_start + seek_end) / 2;

					UTF8_Reader utf8_reader(lines[i].data(), lines[i].length());
					while (true)
					{
						utf8_reader.set_position(seek_center);
						utf8_reader.move_to_leadbyte();
						if (seek_center != utf8_reader.get_position())
							utf8_reader.next();
						seek_center = utf8_reader.get_position();
						if (seek_center == seek_end)
							break;

						utf8_reader.set_position(seek_start);
						utf8_reader.next();
						if (utf8_reader.get_position() == seek_end)
							break;

						Size text_size = get_text_size(canvas, lines[i].substr(0, seek_center));

						if (dest_x + text_size.width + ellipsis.width >= content_box.right)
							seek_end = seek_center;
						else
							seek_start = seek_center;
						seek_center = (seek_start+seek_end)/2;
					}

					draw_text(canvas, dest_x, dest_y, lines[i].substr(0, seek_center) + "...", color);
				}

				dest_y += line_spacing;
			}
		}
	}
}

void Font::draw_text(Canvas &canvas, float dest_x, float dest_y, const std::string &text, const Colorf &color)
{
	if (impl)
	{
		FontMetrics fm = get_font_metrics();
		int line_spacing = fm.get_height() + fm.get_external_leading();
		std::vector<std::string> lines = StringHelp::split_text(text, "\n", false);
		for (std::vector<std::string>::size_type i=0; i<lines.size(); i++)
		{
			impl->draw_text(canvas, dest_x, dest_y, lines[i], color);
			dest_y += line_spacing;
		}
	}
}

int GlyphCache::get_character_index(FontEngine *font_engine, GraphicContext &gc, const std::string &text, const Point &point)
{
	int dest_x = 0;
	int dest_y = 0;

	int character_counter = 0;

	FontMetrics fm = get_font_metrics();
	int font_height = fm.get_height();
	int font_ascent = fm.get_ascent();
	int font_external_leading = fm.get_external_leading();

	std::vector<std::string> lines = StringHelp::split_text(text, "\n", false);
	for (std::vector<std::string>::size_type i=0; i<lines.size(); i++)
	{
		int xpos = dest_x;
		int ypos = dest_y;

		std::string &textline = lines[i];
		std::string::size_type string_length = textline.length();

		// Scan the string

		UTF8_Reader reader(textline.data(), textline.length());
		while(!reader.is_end())
		{
			unsigned int glyph = reader.get_char();
			std::string::size_type glyph_pos = reader.get_position();
			reader.next();

			Font_TextureGlyph *gptr = get_glyph(font_engine, gc, glyph);
			if (gptr == NULL) continue;

			Rect position(xpos, ypos - font_ascent, Size(gptr->increment.x, gptr->increment.y + font_height + font_external_leading));
			if (position.contains(point))
			{
				return glyph_pos + character_counter;
			}
		
			xpos += gptr->increment.x;
			ypos += gptr->increment.y;
		}

		dest_y += font_height + font_external_leading;

		character_counter += string_length + 1;		// (Including the '\n')

	}
	return -1;	// Not found
}

int FontProvider_Sprite::get_character_index(GraphicContext &gc, const std::string &text, const Point &point)
{
	int dest_x = 0;
	int dest_y = 0;
	int character_counter = 0;

	FontMetrics fm = get_font_metrics();
	int font_height = fm.get_height();
	int font_external_leading = fm.get_external_leading();

	std::vector<std::string> lines = StringHelp::split_text(text, "\n", false);
	for (std::vector<std::string>::size_type i=0; i<lines.size(); i++)
	{
		int xpos = dest_x;
		int ypos = dest_y;

		std::string &textline = lines[i];
		std::string::size_type string_length = textline.length();

		// Scan the string
		for (std::string::size_type p = 0; p < string_length; p++)
		{
			Font_Sprite_Glyph *gptr = get_glyph(textline[p]);

			int glyph_width;
			if (gptr)
			{
				glyph_width = spr_glyphs.get_frame_size(gptr->sprite_index).width;
			}
			else
			{
				glyph_width = spacelen;
			}


			Rect position(xpos, ypos - font_height, Size(glyph_width, font_height + font_external_leading));
			if (position.contains(point))
				return ((int) p) + character_counter;

			xpos += glyph_width;
		}

		dest_y += font_height + font_external_leading;

		character_counter += string_length + 1;		// (Including the '\n')

	}
	return -1;	// Not found
}