src/main.rs

@@ -17,125 +17,82 @@
 use druid::im::{vector, Vector};
 use druid::kurbo::BezPath;
 use druid::widget::prelude::*;
-use druid::{AppLauncher, Color, Data, Event, LocalizedString, Rect, WindowDesc};
-use std::rc::Rc;
+use druid::{AppLauncher, Color, Data, Event, LocalizedString, WindowDesc};
 
 mod stiletto {
     use druid::widget::prelude::*;
-    pub trait CanvasElement: CanvasElementData {
-        //: CanvasElementData {
-        /// returns the axis-aligned bounding box
-        fn bounding_box(&self) -> druid::Rect;
-
-        fn draw(&self, ctx: &mut druid::PaintCtx);
-
-        fn get_path(&self) -> Option<&CanvasPath> {
-            None
-        }
-
-        fn get_path_mut(&mut self) -> Option<&mut CanvasPath> {
-            None
-        }
-    }
-
-    pub trait CanvasElementData {
-        fn clone_box(&self) -> Box<dyn CanvasElement>;
-    }
-
-    impl<T> CanvasElementData for T
-    where
-        T: 'static + CanvasElement + druid::Data
-    {
-       fn clone_box(&self) -> Box<dyn CanvasElement> {
-           Box::new(self.clone())
-       }
-    }
-    impl Clone for Box<dyn CanvasElement> {
-        fn clone(&self) -> Self {
-            self.clone_box()
-        }
-    }
-
-    impl druid::Data for Box<dyn CanvasElement> {
-        fn same(&self, other: &Self) -> bool {
-            if let (Some(p1), Some(p2)) = (self.get_path(), other.get_path())
-            {
-                p1.same(p2)
-            } else {
-                false
-            }
-        }
-    }
 
     #[derive(Clone, druid::Data)]
-    pub struct CanvasPath {
+    pub struct Path {
         pub kurbo_path: druid::kurbo::BezPath,
     }
 
-    impl CanvasElement for CanvasPath {
-        fn bounding_box(&self) -> druid::Rect {
-            use druid::kurbo::Shape;
-            self.kurbo_path.bounding_box()
+    #[derive(Clone, druid::Data)]
+    pub enum CanvasElement {
+        Path(Path),
+    }
+
+    impl CanvasElement {
+        pub fn bounding_box(&self) -> druid::Rect {
+            match self {
+                CanvasElement::Path(p) => {
+                    use druid::kurbo::Shape;
+                    p.kurbo_path.bounding_box()
+                }
+            }
+        }
+        pub fn draw(&self, ctx: &mut druid::PaintCtx) {
+            match self {
+                CanvasElement::Path(p) => {
+                    let stroke_color = druid::Color::rgb8(0, 128, 0);
+                    ctx.stroke(&p.kurbo_path, &stroke_color, 2.0);
+                }
+            }
         }
 
-        fn draw(&self, ctx: &mut druid::PaintCtx) {
-            let stroke_color = druid::Color::rgb8(0, 128, 0);
-            ctx.stroke(&self.kurbo_path, &stroke_color, 2.0);
-        }
-
-        fn get_path(&self) -> Option<&CanvasPath> {
-            None
-        }
-
-        fn get_path_mut(&mut self) -> Option<&mut CanvasPath> {
-            Some(self)
+        pub fn get_path_mut(&mut self) -> Option<&mut Path> {
+            match self {
+                CanvasElement::Path(p) => Some(p),
+            }
         }
     }
 }
 
 struct CanvasWidget;
 
+use stiletto::CanvasElement;
+
 #[derive(Clone, Data)]
 struct CanvasData {
-    current_element: Option<Box<dyn stiletto::CanvasElement>>,
-    elements: Vector<Rc<Box<dyn stiletto::CanvasElement>>>,
+    current_element: Option<CanvasElement>,
+    elements: Vector<CanvasElement>,
     is_drawing: bool,
 }
 
 impl Widget<CanvasData> for CanvasWidget {
-    fn event(
-        &mut self,
-        _ctx: &mut EventCtx,
-        event: &Event,
-        data: &mut CanvasData,
-        _env: &Env,
-    ) {
+    fn event(&mut self, _ctx: &mut EventCtx, event: &Event, data: &mut CanvasData, _env: &Env) {
         match event {
             Event::MouseDown(mouse_event) => {
-                if true
-                /*&& mouse_event.pointer_type == druid::PointerType::Stylus || mouse_event.pointer_type == druid::PointerType::Mouse*/
-                {
-                    data.is_drawing = true;
-                    let mut kurbo_path = BezPath::new();
-                    kurbo_path.move_to((mouse_event.pos.x, mouse_event.pos.y));
-                    data.current_element = Some(Box::new(stiletto::CanvasPath { kurbo_path } ));
-                }
+                data.is_drawing = true;
+                let mut kurbo_path = BezPath::new();
+                kurbo_path.move_to((mouse_event.pos.x, mouse_event.pos.y));
+                data.current_element = Some(CanvasElement::Path(stiletto::Path { kurbo_path }));
             }
             Event::MouseMove(mouse_event) => {
-                if data.is_drawing
-                /*&& (mouse_event.pointer_type == druid::PointerType::Stylus || mouse_event.pointer_type == druid::PointerType::Mouse)*/
-                {
-                    let current_path = data.current_element.as_mut().unwrap().get_path_mut().unwrap();
-
-                    current_path
-                        .kurbo_path
-                        .line_to((mouse_event.pos.x, mouse_event.pos.y));
+                if data.is_drawing {
+                    if let Some(current_element) = data.current_element.as_mut() {
+                        current_element
+                            .get_path_mut()
+                            .unwrap()
+                            .kurbo_path
+                            .line_to((mouse_event.pos.x, mouse_event.pos.y));
+                    }
                 }
             }
             Event::MouseUp(_) => {
                 if data.is_drawing {
-                    if let Some(b) = data.current_element.as_mut() {
-                        data.elements.push_back(Rc::new(b));
+                    if let Some(current_element) = data.current_element.take() {
+                        data.elements.push_back(current_element);
                         data.is_drawing = false;
                     }
                 }
@@ -156,11 +113,21 @@ impl Widget<CanvasData> for CanvasWidget {
     fn update(
         &mut self,
         ctx: &mut UpdateCtx,
-        _old_data: &CanvasData,
-        _data: &CanvasData,
+        old_data: &CanvasData,
+        data: &CanvasData,
         _env: &Env,
     ) {
-        ctx.request_paint_rect(Rect::new(0., 0., 200., 200.));
+        // the current_element is moved to the elements array, no need to repaint
+        if old_data.is_drawing && !data.is_drawing {
+            return;
+        }
+        if data.is_drawing {
+            data.current_element.as_ref().map(|e| {
+                ctx.request_paint_rect(e.bounding_box());
+            });
+        } else {
+            ctx.request_paint();
+        }
     }
 
     fn layout(
@@ -195,6 +162,9 @@ impl Widget<CanvasData> for CanvasWidget {
         for element in &data.elements {
             element.draw(ctx);
         }
+        if let Some(element) = &data.current_element {
+            element.draw(ctx);
+        }
     }
 }
 
@@ -202,8 +172,7 @@ pub fn main() {
     let window = WindowDesc::new(|| CanvasWidget {})
         //.window_size((1024.0, 1400.0))
         .title(
-            LocalizedString::new("custom-widget-demo-window-title")
-                .with_placeholder("Fancy Colors"),
+            LocalizedString::new("custom-widget-demo-window-title").with_placeholder("Stiletto"),
         );
     let canvas_data = CanvasData {
         current_element: None,