forbid resize of drawable surface

examples/draw.rs

@@ -16,7 +16,7 @@
 
 use std::f64::consts::PI;
 
-use druid::kurbo::Line;
+use druid::kurbo::{BezPath, Line};
 use druid::widget::{Flex, Label, WidgetExt};
 use druid::{
     AppLauncher, BoxConstraints, Color, Env, Event, EventCtx, LayoutCtx, LinearGradient, PaintCtx,
@@ -40,6 +40,7 @@ impl Widget<()> for DrawWidget {
         match event {
             Event::MouseDown(m) => {
                 info!("down: pos {:?}", m.pos);
+                //info!("down: pos {:?}, pos_rel {:?}", m.pos);
                 self.state = MouseState::Down;
                 self.t = 0.0;
                 self.points.push(m.pos);
@@ -62,7 +63,10 @@ impl Widget<()> for DrawWidget {
         }
     }
 
-    fn update(&mut self, _ctx: &mut UpdateCtx, _old_data: Option<&()>, _data: &(), _env: &Env) {}
+    fn update(&mut self, ctx: &mut UpdateCtx, _old_data: Option<&()>, _data: &(), env: &Env) {
+        //info!("update {:?}", env.get());
+        ctx.invalidate();
+    }
 
     fn layout(
         &mut self,
@@ -75,33 +79,21 @@ impl Widget<()> for DrawWidget {
     }
 
     fn paint(&mut self, paint_ctx: &mut PaintCtx, _data: &(), _env: &Env) {
-        // let center = Point::new(50.0, 50.0);
-        // let ambit = center + 45.0 * Vec2::from_angle((0.75 + self.t) * 2.0 * PI);
-        // paint_ctx.stroke(Line::new(center, ambit), &Color::WHITE, 10.0);
         info!("paint");
-        if let Some(mut old) = self.points.iter().next() {
-            for new in self.points.iter() {
-                let p1 = Point::new(1.0, 2.0);
-                let line = Line::new(*old, *new);
-                paint_ctx.stroke(line, &Color::WHITE, 1.0);
-                old = new;
+
+        if let Some(p) = self.points.iter().next() {
+            let mut path = BezPath::new();
+            path.move_to(*p);
+
+            for p in self.points.iter() {
+                path.line_to(*p);
             }
+
+            paint_ctx.stroke(path, &Color::WHITE, 1.0);
         }
     }
 }
 
-// fn main() {
-//     let window = WindowDesc::new(|| AnimWidget {
-//         state: MouseState::Up,
-//         points: Vec::new(),
-//         t: 0.0,
-//     });
-//     AppLauncher::with_window(window)
-//         .use_simple_logger()
-//         .launch(0)
-//         .expect("launch failed");
-// }
-
 fn build_app() -> impl Widget<()> {
     let solid = Color::rgb8(0x3a, 0x3a, 0x3a);
     let gradient = LinearGradient::new(
@@ -117,7 +109,7 @@ fn build_app() -> impl Widget<()> {
                     Label::new("top left")
                         .border(gradient.clone(), 4.0)
                         .padding(10.0),
-                    1.0,
+                    1.0, // horizontal
                 )
                 .with_child(
                     DrawWidget {
@@ -127,7 +119,7 @@ fn build_app() -> impl Widget<()> {
                     }
                     .border(gradient.clone(), 4.0)
                     .padding(10.0),
-                    1.0,
+                    0.0,
                 )
                 .with_child(
                     Label::new("top right")
@@ -135,7 +127,7 @@ fn build_app() -> impl Widget<()> {
                         .padding(10.0),
                     1.0,
                 ),
-            1.0,
+            0.0, // vertical
         )
         .with_child(
             Flex::row()
@@ -144,7 +136,7 @@ fn build_app() -> impl Widget<()> {
                         .background(gradient.clone())
                         .rounded(10.0)
                         .padding(10.0),
-                    1.0,
+                    0.0,
                 )
                 .with_child(
                     Label::new("bottom right")