ui::label tagged text support: implement color tag

libs/ui/include/psemek/ui/label.hpp

@@ -89,6 +89,7 @@ namespace psemek::ui
 		{
 			std::string_view text;
 			text_style style; // to be OR'd with base style
+			std::optional<gfx::color_rgba> color;
 		};
 
 		using chunk = std::variant<text_chunk>;
@@ -107,6 +108,7 @@ namespace psemek::ui
 			struct batch
 			{
 				gfx::texture_2d const * texture;
+				gfx::color_rgba color;
 				std::vector<image> images;
 			};
 

libs/ui/source/label.cpp

@@ -17,11 +17,35 @@ namespace psemek::ui
 		text_ = std::move(text);
 
 		chunks_.clear();
-		chunks_.push_back(text_chunk{{text_.data(), text_.size()}, text_style{}});
+		chunks_.push_back(text_chunk{{text_.data(), text_.size()}, text_style{}, std::nullopt});
 
 		on_state_changed();
 	}
 
+	static std::unordered_set<std::string_view> const known_tags
+	{
+		"bold",
+		"uline",
+		"strike",
+		"color",
+	};
+
+	void check_attribute(std::string_view tag, std::optional<std::string_view> const & attribute)
+	{
+		if (tag == "bold" || tag == "uline" || tag == "strike")
+		{
+			if (attribute)
+				throw std::runtime_error("tag [" + std::string(tag) + " doesn't support attributes");
+		}
+		else if (tag == "color")
+		{
+			if (!attribute)
+				throw std::runtime_error("tag [color] requires an attribute");
+			if (!gfx::parse_color(*attribute))
+				throw std::runtime_error("failed to parse color \"" + std::string(*attribute) + "\"");
+		}
+	}
+
 	void label::set_tagged_text(std::string text)
 	{
 		text_ = std::move(text);
@@ -30,47 +54,41 @@ namespace psemek::ui
 
 		auto parse_result = tagged_text::parse(text_);
 
-		std::unordered_map<std::string_view, int> tags_stack;
+		std::unordered_map<std::string_view, std::vector<std::optional<std::string_view>>> tags_stack;
-		tags_stack["bold"] = 0;
-		tags_stack["uline"] = 0;
-		tags_stack["strike"] = 0;
 
 		for (auto const & token : parse_result.tokens)
 		{
 			if (auto text = std::get_if<std::string_view>(&token))
 			{
 				text_chunk chunk;
-				if (tags_stack["bold"] > 0)
+				if (!tags_stack["bold"].empty())
 					chunk.style.set(text_style_flag::bold);
-				if (tags_stack["uline"] > 0)
+				if (!tags_stack["uline"].empty())
 					chunk.style.set(text_style_flag::underline);
-				if (tags_stack["strike"] > 0)
+				if (!tags_stack["strike"].empty())
 					chunk.style.set(text_style_flag::strikethrough);
+				if (!tags_stack["color"].empty())
+					chunk.color = *gfx::parse_color(*tags_stack["color"].back());
 				chunk.text = *text;
 				chunks_.push_back(chunk);
 			}
 			else if (auto tag = std::get_if<tagged_text::opening_tag>(&token))
 			{
-				if (tag->type == "bold")
+				if (known_tags.contains(tag->type))
 				{
-					tags_stack["bold"] += 1;
+					check_attribute(tag->type, tag->attribute);
-				}
+					tags_stack[tag->type].push_back(tag->attribute);
-				else if (tag->type == "uline")
-				{
-					tags_stack["uline"] += 1;
-				}
-				else if (tag->type == "strike")
-				{
-					tags_stack["strike"] += 1;
 				}
 				else
 					throw std::runtime_error("unknown tag [" + std::string(tag->type) + "]");
 			}
 			else if (auto tag = std::get_if<tagged_text::closing_tag>(&token))
 			{
-				if (tags_stack[tag->type] == 0)
+				if (!known_tags.contains(tag->type))
+					throw std::runtime_error("unknown tag [" + std::string(tag->type) + "]");
+				if (tags_stack[tag->type].empty())
 					throw std::runtime_error("mismatched opening & closing tags for [" + std::string(tag->type) + "]");
-				tags_stack[tag->type] -= 1;
+				tags_stack[tag->type].pop_back();
 			}
 		}
 
@@ -165,13 +183,16 @@ namespace psemek::ui
 		{
 			auto const offset = geom::cast<float>(*st->text_shadow_offset);
 			for (auto const & batch : cached_state_->batches)
+			{
+				if (batch.color[3] < 255) continue;
 				for (auto const & image : batch.images)
 					p.draw_image(image.position + offset, gfx::texture_view_2d{batch.texture, image.texcoords}, {*st->shadow_color, painter::color_mode::multiply});
 			}
+		}
 
 		for (auto const & batch : cached_state_->batches)
 			for (auto const & image : batch.images)
-				p.draw_image(image.position, gfx::texture_view_2d{batch.texture, image.texcoords}, {*st->text_color, painter::color_mode::multiply});
+				p.draw_image(image.position, gfx::texture_view_2d{batch.texture, image.texcoords}, {batch.color, painter::color_mode::multiply});
 	}
 
 	void label::on_state_changed()
@@ -209,6 +230,7 @@ namespace psemek::ui
 		{
 			std::size_t end;
 			text_style style;
+			gfx::color_rgba color;
 		};
 
 		std::vector<glyph> glyphs;
@@ -231,10 +253,12 @@ namespace psemek::ui
 
 					auto chunk_glyphs = font->shape(text->text, opts, pen);
 
+					auto color = text->color ? *text->color : *st->text_color;
+
 					glyphs.reserve(glyphs.size() + chunk_glyphs.size());
 					glyphs.insert(glyphs.end(), chunk_glyphs.begin(), chunk_glyphs.end());
 
-					glyph_chunks.push_back({glyphs.size(), merged_text_style});
+					glyph_chunks.push_back({glyphs.size(), merged_text_style, color});
 				}
 			}
 		}
@@ -400,6 +424,7 @@ namespace psemek::ui
 				auto font = ch.style.is_set(text_style_flag::bold) ? st->bold_font.get() : st->font.get();
 
 				batch.texture = &font->atlas();
+				batch.color = ch.color;
 
 				for (std::size_t i = begin; i < ch.end; ++i)
 				{
@@ -424,9 +449,6 @@ namespace psemek::ui
 		{
 			float const line_width = 1.f * (*st->text_scale);
 
-			auto & batch = state.batches.emplace_back();
-			batch.texture = single_white_pixel_texture().get();
-
 			std::size_t ch_begin = 0;
 			std::size_t ch = 0;
 			for (std::size_t l = 0; l < lines.size(); ++l)
@@ -434,19 +456,30 @@ namespace psemek::ui
 				float underline_y = std::round(line_offset[l][1] + font_height - line_width);
 				float strikethrough_y = std::round(line_offset[l][1] + font_height / 2.f - line_width / 2.f);
 
-				std::optional<geom::interval<float>> current_underline;
+				std::optional<std::pair<geom::interval<float>, gfx::color_rgba>> current_underline;
-				std::optional<geom::interval<float>> current_strikethrough;
+				std::optional<std::pair<geom::interval<float>, gfx::color_rgba>> current_strikethrough;
+
+				auto batch = [&](gfx::color_rgba const & color) -> cached_state::batch & {
+					auto texture = single_white_pixel_texture().get();
+					if (state.batches.empty() || state.batches.back().texture != texture || state.batches.back().color != color)
+					{
+						auto & b = state.batches.emplace_back();
+						b.texture = texture;
+						b.color = color;
+					}
+					return state.batches.back();
+				};
 
 				auto flush_underline = [&]{
-					auto & image = batch.images.emplace_back();
+					auto & image = batch(current_underline->second).images.emplace_back();
-					image.position[0] = *current_underline;
+					image.position[0] = current_underline->first;
 					image.position[1] = {underline_y, underline_y + line_width};
 					current_underline = std::nullopt;
 				};
 
 				auto flush_strikethrough = [&]{
-					auto & image = batch.images.emplace_back();
+					auto & image = batch(current_strikethrough->second).images.emplace_back();
-					image.position[0] = *current_strikethrough;
+					image.position[0] = current_strikethrough->first;
 					image.position[1] = {strikethrough_y, strikethrough_y + line_width};
 					current_strikethrough = std::nullopt;
 				};
@@ -469,11 +502,17 @@ namespace psemek::ui
 
 						if (underline && current_underline)
 						{
-							*current_underline |= x_range;
+							if (current_underline->second != chunk.color)
+							{
+								flush_underline();
+								current_underline = {x_range, chunk.color};
+							}
+							else
+								current_underline->first |= x_range;
 						}
 						else if (underline && !current_underline)
 						{
-							current_underline = x_range;
+							current_underline = {x_range, chunk.color};
 						}
 						else if (!underline && current_underline)
 						{
@@ -482,11 +521,17 @@ namespace psemek::ui
 
 						if (strikethrough && current_strikethrough)
 						{
-							*current_strikethrough |= x_range;
+							if (current_strikethrough->second != chunk.color)
+							{
+								flush_strikethrough();
+								current_strikethrough = {x_range, chunk.color};
+							}
+							else
+								current_strikethrough->first |= x_range;
 						}
 						else if (strikethrough && !current_strikethrough)
 						{
-							current_strikethrough = x_range;
+							current_strikethrough = {x_range, chunk.color};
 						}
 						else if (!strikethrough && current_strikethrough)
 						{