dial

examples/draw.rs

@@ -20,7 +20,8 @@ use druid::kurbo::{BezPath, Line};
 use druid::widget::{Flex, Label, WidgetExt};
 use druid::{
     AppLauncher, BoxConstraints, Color, Env, Event, EventCtx, LayoutCtx, LinearGradient, PaintCtx,
-    PlatformError, Point, RenderContext, Size, UnitPoint, UpdateCtx, Vec2, Widget, WindowDesc,
+    PlatformError, Point, RenderContext, Size, UnitPoint, UpdateCtx, Vec2, WheelEvent, Widget,
+    WindowDesc,
 };
 
 use log::info;
@@ -32,7 +33,6 @@ enum MouseState {
 struct DrawWidget {
     state: MouseState,
     points: Vec<Point>,
-    t: f64,
 }
 
 impl Widget<()> for DrawWidget {
@@ -42,7 +42,6 @@ impl Widget<()> for DrawWidget {
                 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);
                 ctx.invalidate();
             }
@@ -55,11 +54,8 @@ impl Widget<()> for DrawWidget {
             Event::MouseUp(m) => {
                 info!("up:pos {:?}", m.pos);
                 self.state = MouseState::Up;
-                self.t = 0.0;
             }
-
-            Event::AnimFrame(interval) => {}
-            _ => (),
+            _ => {}
         }
     }
 
@@ -94,6 +90,91 @@ impl Widget<()> for DrawWidget {
     }
 }
 
+#[derive(Debug)]
+struct DialWidget {
+    size: Size,
+    down_pos: Option<Point>,
+    cur_pos: Point,
+    value: f64, // in range 0.0..= 1.0
+}
+
+impl Widget<()> for DialWidget {
+    fn event(&mut self, ctx: &mut EventCtx, event: &Event, _data: &mut (), _env: &Env) {
+        match event {
+            Event::MouseDown(m) => {
+                info!("down: pos {:?}", m.pos);
+                //info!("down: pos {:?}, pos_rel {:?}", m.pos);
+                self.down_pos = Some(m.pos);
+            }
+            Event::MouseMoved(m) => match self.down_pos {
+                Some(down_pos) => {
+                    self.cur_pos = m.pos;
+                    info!("down_pos {:?}, cur_pos {:?}", down_pos, m.pos);
+                }
+                _ => {}
+            },
+            Event::MouseUp(m) => {
+                info!("up:pos {:?}", m.pos);
+
+                self.value = self.value + 1.0;
+            }
+            Event::Wheel(w) => {
+                info!("Event {:?}", w.delta);
+                let mut delta = w.delta.y / (120 * 10) as f64; // 1% for my machine
+                if w.mods.shift {
+                    delta = delta / 10.0;
+                };
+                if w.mods.ctrl {
+                    delta = delta / 10.0;
+                };
+
+                self.value -= delta;
+                self.value = f64::max(0.0, f64::min(1.0, self.value));
+                ctx.invalidate();
+            }
+            _ => (),
+        }
+    }
+
+    fn update(&mut self, ctx: &mut UpdateCtx, _old_data: Option<&()>, _data: &(), env: &Env) {
+        //info!("update {:?}", env.get());
+        ctx.invalidate();
+    }
+
+    fn layout(
+        &mut self,
+        _layout_ctx: &mut LayoutCtx,
+        bc: &BoxConstraints,
+        _data: &(),
+        _env: &Env,
+    ) -> Size {
+        bc.constrain(self.size) // size of dial
+    }
+
+    fn paint(&mut self, paint_ctx: &mut PaintCtx, _data: &(), _env: &Env) {
+        info!("dial paint");
+        // far some reason origin (0,0) seems not to point to the border not the interior
+        let center = Point::new(self.size.width / 2.0, self.size.height / 2.0);
+        let diameter = 0.8 * self.size.width / 2.0;
+        let mut path = BezPath::new();
+        let ambit0 = center + diameter * Vec2::from_angle(0.0);
+        path.move_to(ambit0);
+        for v in (0..360).step_by(10) {
+            let ambit = center + diameter * Vec2::from_angle(v as f64 / 360.0 * 2.0 * PI);
+            path.line_to(ambit);
+        }
+        path.close_path();
+        paint_ctx.stroke(path, &Color::WHITE, 1.0);
+
+        let mut path = BezPath::new();
+        path.move_to(center);
+        path.line_to(
+            center + diameter * Vec2::from_angle(self.value * 2.0 * 0.75 * PI + 2.0 * PI * 0.375),
+        );
+        paint_ctx.stroke(path, &Color::WHITE, 1.0);
+    }
+}
+
 fn build_app() -> impl Widget<()> {
     let solid = Color::rgb8(0x3a, 0x3a, 0x3a);
     let gradient = LinearGradient::new(
@@ -106,16 +187,20 @@ fn build_app() -> impl Widget<()> {
         .with_child(
             Flex::row()
                 .with_child(
-                    Label::new("top left")
+                    DialWidget {
+                        size: Size::new(100.0, 100.0),
+                        down_pos: None,
+                        cur_pos: Point::new(0.0, 0.0),
+                        value: 0.0,
+                    }
                     .border(gradient.clone(), 4.0)
                     .padding(10.0),
-                    1.0, // horizontal
+                    0.0, // horizontal
                 )
                 .with_child(
                     DrawWidget {
                         state: MouseState::Up,
                         points: Vec::new(),
-                        t: 0.0,
                     }
                     .border(gradient.clone(), 4.0)
                     .padding(10.0),