Add state management to display selections correctly

src/canvas.rs

@@ -128,12 +128,26 @@ impl CanvasElement {
             }
         }
     }
+
+    pub fn draw_selected(&self, ctx: &mut druid::PaintCtx) {
+        match self {
+            CanvasElement::Freehand {
+                path,
+                thickness,
+                ..
+            } => {
+                use druid::RenderContext;
+                ctx.stroke(&path.kurbo_path, &druid::Color::rgb(10.0, 0.0, 255.0), *thickness * 1.4);
+            }
+        }
+    }
 }
 
 #[derive(Clone, druid::Data)]
 pub struct Canvas {
     elements: Vector<CanvasElement>,
     content_size: druid::Size,
+    selected_elements: Vector<usize>,
 }
 
 impl Canvas {
@@ -141,6 +155,7 @@ impl Canvas {
         Canvas {
             elements: vector![],
             content_size: druid::Size::new(0.0, 0.0),
+            selected_elements: vector![],
         }
     }
 
@@ -184,6 +199,14 @@ impl Canvas {
     pub fn content_size(&self) -> druid::Size {
         self.content_size
     }
+
+    pub fn selected_elements(&self) -> &Vector<usize> {
+        &self.selected_elements
+    }
+
+    pub fn selected_elements_mut(&mut self) -> &mut Vector<usize> {
+        &mut self.selected_elements
+    }
 }
 
 impl Serialize for Path {

src/lib.rs

@@ -23,6 +23,11 @@ pub mod tool;
 pub mod widget;
 pub mod migration;
 
+pub mod colors {
+    use druid::Color;
+    //pub const SELECTED_STROKE: Color = Color::rgb(10.0, 0.0, 255.0);
+}
+
 pub mod commands {
     use druid::Selector;
 

src/main.rs

@@ -104,9 +104,9 @@ impl StilettoState {
         self.tool_icons.get_mut(old_tool).unwrap().selected = false;
         self.tool_icons.get_mut(new_tool).unwrap().selected = true;
         self.current_tool = new_tool;
-        self.canvas.set_tool_ctx(CanvasToolCtx::new(
+        self.canvas.change_tool(
             self.tool_icons.get(new_tool).unwrap().tool_params.clone(),
-        ));
+        );
     }
 }
 

src/widget/canvas.rs

@@ -16,8 +16,9 @@
 
 use im::Vector;
 
-use super::tool_ctx::{CanvasToolCtx};
+use super::tool_ctx::{CanvasToolCtx, CanvasToolState};
 use crate::canvas::Canvas;
+use crate::tool::CanvasToolParams;
 use crate::{DocumentSnapshot, VersionedCanvas};
 
 use druid::widget::prelude::*;
@@ -41,12 +42,14 @@ impl CanvasState {
     pub fn perform_undo(&mut self) {
         //if !self.is_drawing() {
         self.versioned_canvas.undo();
+        self.set_ctx_selection_state();
         //}
     }
 
     pub fn perform_redo(&mut self) {
         //if !self.is_drawing() {
         self.versioned_canvas.redo();
+        self.set_ctx_selection_state();
         //}
     }
 
@@ -70,6 +73,17 @@ impl CanvasState {
         )));
     }
 
+    fn set_ctx_selection_state(&mut self) {
+        if !self.versioned_canvas.get().selected_elements().is_empty() {
+            self.tool_ctx.set_state(CanvasToolState::ActiveSelection);
+        }
+    }
+
+    /// Changes tool while mantaining the current CanvasToolCtx
+    pub fn change_tool(&mut self, tool_params: CanvasToolParams) {
+        self.tool_ctx.set_params(tool_params);
+    }
+
     pub fn set_tool_ctx(&mut self, ctx: CanvasToolCtx) {
         self.tool_ctx = ctx;
     }
@@ -177,11 +191,20 @@ impl Widget<CanvasState> for CanvasWidget {
         let rect = size.to_rect();
 
         ctx.fill(rect, &Color::WHITE);
-        for element in data.versioned_canvas.get().elements().iter() {
+        let canvas = data.versioned_canvas.get();
+        let selected = canvas.selected_elements();
+
+        for (pos, element) in canvas.elements().iter().enumerate() {
+            if data.tool_ctx.has_active_selection() && selected.contains(&pos) {
+                element.draw_selected(ctx);
+            } else {
                 element.draw(ctx);
             }
+        }
         if data.tool_ctx.needs_repaint() {
             data.tool_ctx.paint(ctx, env);
         }
+
+
     }
 }

src/widget/tool_ctx.rs

@@ -21,7 +21,7 @@ use crate::VersionedCanvas;
 use druid::kurbo::BezPath;
 use druid::{Color, Data, Env, Event, EventCtx, MouseButton, MouseEvent, PaintCtx, RenderContext};
 
-use im::Vector;
+use im::{vector, Vector};
 
 #[derive(Clone, Data)]
 pub enum CanvasToolState {
@@ -34,7 +34,8 @@ pub enum CanvasToolState {
     SelectingRect {
         origin: druid::Point,
         current_rect: druid::Rect,
-    }
+    },
+    ActiveSelection,
 }
 
 #[derive(Clone, Data)]
@@ -66,6 +67,19 @@ impl CanvasToolCtx {
         }
     }
 
+    pub fn set_params(&mut self, params: CanvasToolParams) {
+        self.initial_params = params;
+        // TODO(enrico) is this necessary?
+        match self.state {
+            CanvasToolState::Idle | CanvasToolState::ActiveSelection => {}
+            _ => { self.state = CanvasToolState::Idle; }
+        }
+    }
+
+    pub fn set_state(&mut self, state: CanvasToolState) {
+        self.state = state;
+    }
+
     pub fn handle_event(
         &mut self,
         ctx: &EventCtx,
@@ -88,6 +102,7 @@ impl CanvasToolCtx {
         _env: &Env,
     ) {
         match (&mut self.state, event) {
+            (CanvasToolState::ActiveSelection, Event::MouseDown(mouse_event)) |
             (CanvasToolState::Idle, Event::MouseDown(mouse_event)) if pressed(mouse_event) => {
                 self.state = CanvasToolState::Erasing;
             }
@@ -125,6 +140,7 @@ impl CanvasToolCtx {
         _env: &Env,
     ) {
         match (&mut self.state, event) {
+            (CanvasToolState::ActiveSelection, Event::MouseDown(mouse_event)) |
             (CanvasToolState::Idle, Event::MouseDown(mouse_event)) if pressed(mouse_event) => {
                 let mut kurbo_path = BezPath::new();
                 kurbo_path.move_to((mouse_event.pos.x, mouse_event.pos.y));
@@ -166,6 +182,7 @@ impl CanvasToolCtx {
                                 thickness,
                                 stroke_color,
                             });
+                            *canvas.selected_elements_mut() = vector![];
                         }
                     }
                 });
@@ -182,6 +199,7 @@ impl CanvasToolCtx {
         _env: &Env,
     ) {
         match (&mut self.state, event) {
+            (CanvasToolState::ActiveSelection, Event::MouseDown(mouse_event)) |
             (CanvasToolState::Idle, Event::MouseDown(mouse_event)) if pressed(mouse_event) => {
                 self.state = CanvasToolState::SelectingRect {
                     origin: mouse_event.pos,
@@ -208,8 +226,12 @@ impl CanvasToolCtx {
                         }
                         None
                     }).collect::<Vector<usize>>();
-                dbg!(selected_elements_idx);
-                self.state = CanvasToolState::Idle;
+                if !elements.is_empty() {
+                    vcanvas.update(move |canvas: &mut Canvas| {
+                        *canvas.selected_elements_mut() = selected_elements_idx;
+                    });
+                }
+                self.state = CanvasToolState::ActiveSelection;
             }
             _ => {}
         }
@@ -219,6 +241,13 @@ impl CanvasToolCtx {
         true
     }
 
+    pub fn has_active_selection(&self) -> bool {
+        match self.state {
+            CanvasToolState::ActiveSelection => true,
+            _ => false,
+        }
+    }
+
     pub fn paint(&self, ctx: &mut PaintCtx, _env: &Env) {
         match &self.state {
             CanvasToolState::DrawingFreehand { current_path, .. } => current_path.draw(ctx),