From b9187c6b75628f4dbdafd6bceca6ec4aa4c52013 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Fri, 8 Apr 2022 15:06:52 +0300
Subject: [PATCH] Compute proper caret position after clicking on ui::edit

---
 libs/ui/include/psemek/ui/edit.hpp |  1 +
 libs/ui/source/edit.cpp            | 30 +++++++++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/libs/ui/include/psemek/ui/edit.hpp b/libs/ui/include/psemek/ui/edit.hpp
index 304e3417..638e8e2f 100644
--- a/libs/ui/include/psemek/ui/edit.hpp
+++ b/libs/ui/include/psemek/ui/edit.hpp
@@ -84,6 +84,7 @@ namespace psemek::ui
 
 		bool editing_ = false;
 		bool mouseover_ = false;
+		std::optional<float> mouse_x_;
 
 		std::size_t caret_ = 0;
 		float caret_blink_period_ = 0.5f;
diff --git a/libs/ui/source/edit.cpp b/libs/ui/source/edit.cpp
index 76b25e7c..41a75050 100644
--- a/libs/ui/source/edit.cpp
+++ b/libs/ui/source/edit.cpp
@@ -90,7 +90,10 @@ namespace psemek::ui
 
 	bool edit::on_event(mouse_move const & e)
 	{
-		bool new_mouseover = shape_.contains(geom::cast<float>(e.position));
+		auto m = geom::cast<float>(e.position);
+		mouse_x_ = m[0];
+
+		bool new_mouseover = shape_.contains(m);
 		if (!mouseover_ && new_mouseover)
 			sdl2::set_cursor(sdl2::cursor_type::beam);
 		else if (mouseover_ && !new_mouseover)
@@ -113,6 +116,31 @@ namespace psemek::ui
 					start_text_input();
 					reset_caret();
 				}
+
+				if (cached_state_ && mouse_x_)
+				{
+					float x_offset = 0.f;
+
+					switch (halign_)
+					{
+					case halignment::left:
+						x_offset = text_box_[0].min;
+						break;
+					case halignment::center:
+						x_offset = text_box_[0].center() - cached_state_->size[0] * 0.5f;
+						break;
+					case halignment::right:
+						x_offset = text_box_[0].max - cached_state_->size[0];
+						break;
+					}
+
+					auto it = std::lower_bound(cached_state_->glyphs.begin(), cached_state_->glyphs.end(), *mouse_x_, [&](glyph const & g, float x){
+						return g.position[0].center() + x_offset < x;
+					});
+
+					caret_ = it - cached_state_->glyphs.begin();
+				}
+
 				return true;
 			}
 			else