From 19ce3657fa4b7f29dc0e949fa4742dfa7155817a Mon Sep 17 00:00:00 2001
From: Enrico Lumetti <enrico.lumetti@gmail.com>
Date: Sun, 8 Nov 2020 14:48:30 +0100
Subject: [PATCH] Account for stroke thickness in bounding box

---
 src/main.rs | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 20e2238..0e87c24 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -29,30 +29,33 @@ mod stiletto {
 
     #[derive(Clone, druid::Data)]
     pub enum CanvasElement {
-        Freehand(Path),
+        Freehand {
+            path: Path,
+            thickness: f64
+        }
     }
 
     impl CanvasElement {
         pub fn bounding_box(&self) -> druid::Rect {
             match self {
-                CanvasElement::Freehand(p) => {
+                CanvasElement::Freehand{ path, thickness } => {
                     use druid::kurbo::Shape;
-                    p.kurbo_path.bounding_box()
+                    path.kurbo_path.bounding_box().inflate(*thickness, *thickness)
                 }
             }
         }
         pub fn draw(&self, ctx: &mut druid::PaintCtx) {
             match self {
-                CanvasElement::Freehand(p) => {
+                CanvasElement::Freehand{ path, thickness } => {
                     let stroke_color = druid::Color::rgb8(0, 128, 0);
-                    ctx.stroke(&p.kurbo_path, &stroke_color, 2.0);
+                    ctx.stroke(&path.kurbo_path, &stroke_color, *thickness);
                 }
             }
         }
 
         pub fn get_path_mut(&mut self) -> Option<&mut Path> {
             match self {
-                CanvasElement::Freehand(p) => Some(p),
+                CanvasElement::Freehand{ path, .. } => Some(path),
             }
         }
     }
@@ -80,7 +83,10 @@ impl Widget<CanvasData> for CanvasWidget {
             Event::MouseDown(mouse_event) => {
                 let mut kurbo_path = BezPath::new();
                 kurbo_path.move_to((mouse_event.pos.x, mouse_event.pos.y));
-                data.current_element = Some(CanvasElement::Freehand(stiletto::Path { kurbo_path }));
+                data.current_element = Some(CanvasElement::Freehand{
+                    path: stiletto::Path { kurbo_path },
+                    thickness: 2.0,
+                });
             }
             Event::MouseMove(mouse_event) => {
                 if data.is_drawing() {
@@ -125,9 +131,9 @@ impl Widget<CanvasData> for CanvasWidget {
             return;
         }
         if data.is_drawing() {
-            data.current_element.as_ref().map(|e| {
+            if let Some(e) = data.current_element.as_ref() {
                 ctx.request_paint_rect(e.bounding_box());
-            });
+            }
         } else {
             ctx.request_paint();
         }