From fd7fbd4d87bf6136b6a3efabfc9ff7751ba3e073 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Thu, 25 Feb 2021 15:15:42 +0300
Subject: [PATCH] Label properties change triggers reshape

---
 libs/ui/include/psemek/ui/label.hpp |  6 +++
 libs/ui/source/label.cpp            | 66 +++++++++++++++++++----------
 2 files changed, 49 insertions(+), 23 deletions(-)

diff --git a/libs/ui/include/psemek/ui/label.hpp b/libs/ui/include/psemek/ui/label.hpp
index 0485ef32..2b077bad 100644
--- a/libs/ui/include/psemek/ui/label.hpp
+++ b/libs/ui/include/psemek/ui/label.hpp
@@ -57,6 +57,9 @@ namespace psemek::ui
 
 		struct shape const & shape() const override { return shape_; }
 		void reshape(geom::box<float, 2> const & bbox) override;
+
+		geom::box<float, 2> size_constraints() const override;
+
 		void draw(painter & p) const override;
 
 	protected:
@@ -75,9 +78,12 @@ namespace psemek::ui
 		{
 			struct font const * font = nullptr;
 			std::vector<glyph> glyphs;
+			geom::vector<float, 2> size{0.f, 0.f};
 		};
 
 		mutable std::optional<cached_state> cached_state_;
+
+		void update_cached_state() const;
 	};
 
 }
diff --git a/libs/ui/source/label.cpp b/libs/ui/source/label.cpp
index 36de8d35..c77f2099 100644
--- a/libs/ui/source/label.cpp
+++ b/libs/ui/source/label.cpp
@@ -39,43 +39,63 @@ namespace psemek::ui
 		cached_state_.reset();
 	}
 
+	geom::box<float, 2> label::size_constraints() const
+	{
+		if (!cached_state_)
+			update_cached_state();
+
+		static float const inf = std::numeric_limits<float>::infinity();
+		return {{{cached_state_->size[0], inf}, {cached_state_->size[1], inf}}};
+	}
+
 	void label::draw(painter & p) const
 	{
+		if (!cached_state_)
+			update_cached_state();
+
+		if (!cached_state_->font) return;
+
+		auto st = style();
+		if (!st) return;
+
+		for (auto & g : cached_state_->glyphs)
+			p.draw_glyph(*(cached_state_->font), g.character, g.position, st->text_color);
+	}
+
+	void label::on_state_changed()
+	{
+		cached_state_.reset();
+		post_reshape();
+	}
+
+	void label::update_cached_state() const
+	{
+		cached_state_ = cached_state{};
+
 		if (text_.empty()) return;
 
 		auto st = style();
 		if (!st) return;
 		if (!st->font) return;
 
-		if (!cached_state_ || cached_state_->font != st->font.get())
-		{
-			cached_state_ = cached_state{};
-			cached_state_->font = st->font.get();
+		cached_state_->font = st->font.get();
 
-			shape_options opts;
-			opts.scale = st->text_scale;
-			cached_state_->glyphs = st->font->shape(text_, opts);
+		shape_options opts;
+		opts.scale = st->text_scale;
+		cached_state_->glyphs = st->font->shape(text_, opts);
 
-			geom::box<float, 2> bbox;
-			for (auto const & g : cached_state_->glyphs)
-				bbox |= g.position;
+		geom::box<float, 2> bbox;
+		for (auto const & g : cached_state_->glyphs)
+			bbox |= g.position;
 
-			geom::vector<float, 2> offset;
-			offset[0] = shape_.box[0].center() - bbox[0].length() / 2.f;
-			offset[1] = shape_.box[1].center() - st->text_scale * st->font->size()[1] / 2.f;
-
-			for (auto & g : cached_state_->glyphs)
-				g.position += offset;
-		}
+		geom::vector<float, 2> offset;
+		offset[0] = shape_.box[0].center() - bbox[0].length() / 2.f;
+		offset[1] = shape_.box[1].center() - st->text_scale * st->font->size()[1] / 2.f;
 
 		for (auto & g : cached_state_->glyphs)
-			p.draw_glyph(*st->font, g.character, g.position, st->text_color);
-	}
+			g.position += offset;
 
-	void label::on_state_changed()
-	{
-		// TODO: changes should notify parent about content change
-		element::reshape();
+		cached_state_->size = bbox.dimensions();
 	}
 
 }