Implement ui::label link tag

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

@@ -62,9 +62,16 @@ namespace psemek::ui
 		virtual struct image_provider * set_image_provider(struct image_provider * provider);
 		virtual struct image_provider * image_provider() const { return image_provider_; }
 
+		using link_callback = std::function<void(std::string_view)>;
+
+		virtual void on_link_click(link_callback callback);
+
 		struct shape const & shape() const override { return shape_; }
 		void reshape(geom::box<float, 2> const & bbox) override;
 
+		bool on_event(ui::mouse_move const & e) override;
+		bool on_event(ui::mouse_click const & e) override;
+
 		geom::box<float, 2> size_constraints() const override;
 
 		geom::interval<float> width_constraints(float height) const override;
@@ -89,6 +96,8 @@ namespace psemek::ui
 
 		struct image_provider * image_provider_ = nullptr;
 
+		link_callback link_callback_;
+
 		box_shape shape_;
 
 		struct text_chunk
@@ -96,12 +105,14 @@ namespace psemek::ui
 			std::string_view text;
 			text_style style; // to be OR'd with base style
 			std::optional<gfx::color_rgba> color;
+			std::optional<std::string_view> link;
 		};
 
 		struct image_chunk
 		{
 			std::string_view id;
 			std::optional<gfx::color_rgba> color;
+			std::optional<std::string_view> link;
 		};
 
 		using chunk = std::variant<text_chunk, image_chunk>;
@@ -127,10 +138,14 @@ namespace psemek::ui
 
 			std::vector<batch> batches;
 			geom::vector<float, 2> size{0.f, 0.f};
+
+			std::vector<std::pair<geom::box<float, 2>, std::string_view>> link_bboxes;
 		};
 
 		mutable std::optional<cached_state> cached_state_;
 		mutable std::optional<cached_state> cached_state_inf_;
+		std::optional<std::string_view> selected_link_;
+		bool mouse_down_ = false;
 
 		void update_cached_state() const;
 		cached_state cached_state_for(geom::box<float, 2> const & bbox) const;

libs/ui/include/psemek/ui/style.hpp

@@ -58,9 +58,17 @@ namespace psemek::ui
 
 		std::optional<gfx::color_rgba> text_color;
 		std::optional<int> text_scale;
+		std::optional<ui::text_style> text_style;
 		std::optional<geom::vector<int, 2>> text_shadow_offset;
 
-		std::optional<ui::text_style> text_style;
+		std::optional<gfx::color_rgba> link_color;
+		std::optional<ui::text_style> link_style;
+
+		std::optional<gfx::color_rgba> link_hover_color;
+		std::optional<ui::text_style> link_hover_style;
+
+		std::optional<gfx::color_rgba> link_click_color;
+		std::optional<ui::text_style> link_click_style;
 
 		std::shared_ptr<struct font> font;
 		std::shared_ptr<struct font> bold_font;

libs/ui/source/label.cpp

@@ -1,5 +1,7 @@
 #include <psemek/ui/label.hpp>
 
+#include <psemek/geom/contains.hpp>
+
 #include <stdexcept>
 #include <cctype>
 #include <unordered_map>
@@ -17,7 +19,7 @@ namespace psemek::ui
 		text_ = std::move(text);
 
 		chunks_.clear();
-		chunks_.push_back(text_chunk{{text_.data(), text_.size()}, text_style{}, std::nullopt});
+		chunks_.push_back(text_chunk{{text_.data(), text_.size()}, text_style{}, std::nullopt, std::nullopt});
 
 		on_state_changed();
 	}
@@ -28,6 +30,7 @@ namespace psemek::ui
 		"uline",
 		"strike",
 		"color",
+		"link",
 	};
 
 	void check_attribute(std::string_view tag, std::optional<std::string_view> const & attribute)
@@ -44,11 +47,17 @@ namespace psemek::ui
 			if (!gfx::parse_color(*attribute))
 				throw std::runtime_error("failed to parse color \"" + std::string(*attribute) + "\"");
 		}
+		else if (tag == "link")
+		{
+			if (!attribute)
+				throw std::runtime_error("tag [link] requires an attribute");
+		}
 	}
 
 	void label::set_tagged_text(std::string text)
 	{
 		text_ = std::move(text);
+		selected_link_ = std::nullopt;
 
 		chunks_.clear();
 
@@ -69,6 +78,8 @@ namespace psemek::ui
 					chunk.style.set(text_style_flag::strikethrough);
 				if (!tags_stack["color"].empty())
 					chunk.color = *gfx::parse_color(*tags_stack["color"].back());
+				if (!tags_stack["link"].empty())
+					chunk.link = tags_stack["link"].back();
 				chunk.text = *text;
 				chunks_.push_back(chunk);
 			}
@@ -82,11 +93,15 @@ namespace psemek::ui
 					chunk.id = *tag->attribute;
 					if (!tags_stack["color"].empty())
 						chunk.color = *gfx::parse_color(*tags_stack["color"].back());
+					if (!tags_stack["link"].empty())
+						chunk.link = tags_stack["link"].back();
 					chunks_.push_back(chunk);
 				}
 				else if (known_tags.contains(tag->type))
 				{
 					check_attribute(tag->type, tag->attribute);
+					if (tag->type == "link" && !tags_stack["link"].empty())
+						throw std::runtime_error("tag [link] cannot be nested");
 					tags_stack[tag->type].push_back(tag->attribute);
 				}
 				else
@@ -136,6 +151,11 @@ namespace psemek::ui
 		return provider;
 	}
 
+	void label::on_link_click(link_callback callback)
+	{
+		link_callback_ = std::move(callback);
+	}
+
 	void label::set_overflow(overflow_mode value)
 	{
 		overflow_ = value;
@@ -148,6 +168,63 @@ namespace psemek::ui
 		cached_state_.reset();
 	}
 
+	bool label::on_event(ui::mouse_move const & e)
+	{
+		if (cached_state_)
+		{
+			std::optional<std::string_view> new_selected_link;
+			auto const p = geom::cast<float>(e.position);
+			for (auto const & b : cached_state_->link_bboxes)
+			{
+				if (geom::contains(b.first, p))
+				{
+					new_selected_link = b.second;
+					break;
+				}
+			}
+
+			if (new_selected_link != selected_link_)
+			{
+				selected_link_ = new_selected_link;
+				mouse_down_ = false;
+				on_state_changed();
+			}
+		}
+
+		return false;
+	}
+
+	bool label::on_event(ui::mouse_click const & e)
+	{
+		if (e.button == mouse_button::left)
+		{
+			if (e.down)
+			{
+				if (selected_link_)
+				{
+					if (!mouse_down_)
+					{
+						mouse_down_ = true;
+						if (link_callback_)
+							post([cb = link_callback_, text = *selected_link_]{ cb(text); });
+						on_state_changed();
+						return true;
+					}
+				}
+			}
+			else
+			{
+				if (mouse_down_)
+				{
+					mouse_down_ = false;
+					on_state_changed();
+				}
+			}
+		}
+
+		return false;
+	}
+
 	geom::box<float, 2> label::size_constraints() const
 	{
 		static float const inf = std::numeric_limits<float>::infinity();
@@ -256,6 +333,7 @@ namespace psemek::ui
 			text_style style;
 			gfx::color_rgba color;
 			gfx::texture_view_2d image;
+			std::optional<std::string_view> link;
 		};
 
 		std::vector<item> items;
@@ -270,21 +348,50 @@ namespace psemek::ui
 			{
 				if (auto text = std::get_if<text_chunk>(&chunk))
 				{
-					auto const merged_text_style = *st->text_style | text->style;
+					auto text_style = *st->text_style | text->style;
 
-					bool const bold = merged_text_style.is_set(text_style_flag::bold);
+					if (text->link)
+					{
+						if (selected_link_ && *text->link == *selected_link_)
+						{
+							if (mouse_down_)
+								text_style |= *st->link_click_style;
+							else
+								text_style |= *st->link_hover_style;
+						}
+						else
+							text_style |= *st->link_style;
+					}
+
+					gfx::color_rgba color;
+					if (text->color)
+						color = *text->color;
+					else if (text->link)
+					{
+						if (selected_link_ && *text->link == *selected_link_)
+						{
+							if (mouse_down_)
+								color = *st->link_click_color;
+							else
+								color = *st->link_hover_color;
+						}
+						else
+							color = *st->link_color;
+					}
+					else
+						color = *st->text_color;
+
+					bool const bold = text_style.is_set(text_style_flag::bold);
 
 					auto font = bold ? st->bold_font.get() : st->font.get();
 
-					auto color = text->color ? *text->color : *st->text_color;
-
 					auto glyphs = font->shape(text->text, opts, pen);
 
 					items.reserve(items.size() + glyphs.size());
 					for (auto const & g : glyphs)
 						items.push_back(item{g.position, g.character});
 
-					item_chunks.push_back({items.size(), merged_text_style, color, {}});
+					item_chunks.push_back({items.size(), text_style, color, {}, text->link});
 				}
 				else if (auto image = std::get_if<image_chunk>(&chunk))
 				{
@@ -306,7 +413,7 @@ namespace psemek::ui
 					pen[0] = position[0].max;
 
 					items.push_back({position, {}});
-					item_chunks.push_back({items.size(), {}, color, texture});
+					item_chunks.push_back({items.size(), {}, color, texture, image->link});
 				}
 			}
 		}
@@ -590,6 +697,24 @@ namespace psemek::ui
 			}
 		}
 
+		// Generate link bboxes
+		{
+			std::size_t begin = 0;
+			for (auto const & ch : item_chunks)
+			{
+				if (ch.link)
+				{
+					geom::box<float, 2> bbox;
+					for (std::size_t i = begin; i < ch.end; ++i)
+						bbox |= items[i].position;
+
+					state.link_bboxes.push_back({bbox, *ch.link});
+				}
+
+				begin = ch.end;
+			}
+		}
+
 		state.size = text_size;
 
 		return state;

libs/ui/source/style.cpp

@@ -71,8 +71,14 @@ namespace psemek::ui
 		merge(dst.outer_margin, src.outer_margin);
 		merge(dst.text_color, src.text_color);
 		merge(dst.text_scale, src.text_scale);
-		merge(dst.text_shadow_offset, src.text_shadow_offset);
 		merge(dst.text_style, src.text_style);
+		merge(dst.text_shadow_offset, src.text_shadow_offset);
+		merge(dst.link_color, src.link_color);
+		merge(dst.link_style, src.link_style);
+		merge(dst.link_hover_color, src.link_hover_color);
+		merge(dst.link_hover_style, src.link_hover_style);
+		merge(dst.link_click_color, src.link_click_color);
+		merge(dst.link_click_style, src.link_click_style);
 		merge(dst.font, src.font);
 		merge(dst.bold_font, src.bold_font);
 	}
@@ -125,9 +131,17 @@ namespace psemek::ui
 
 		s.text_color = {255, 255, 255, 255};
 		s.text_scale = 1;
+		s.text_style = text_style{};
 		s.text_shadow_offset = {1, 1};
 
-		s.text_style = text_style{};
+		s.link_color = {0, 0, 255, 255};
+		s.link_style = text_style{};
+
+		s.link_hover_color = {127, 127, 255, 255};
+		s.link_hover_style = text_style{};
+
+		s.link_click_color = {0, 0, 127, 255};
+		s.link_click_style = text_style{};
 
 		return s;
 	}