Improve the API of the pie chart

dashboard/src/drawing/pie_chart.rs

@@ -1,4 +1,4 @@
-use cairo::{Context, Format, ImageSurface};
+use cairo::Context;
 use std::f64::consts::PI;
 
 #[derive(Clone, Debug)]
@@ -18,8 +18,9 @@ pub struct Wedge {
 pub struct PieChart {
     rotation: f64,
     wedges: Vec<Wedge>,
-    width: i32,
-    height: i32,
+    center_x: f64,
+    center_y: f64,
+    radius: f64,
 }
 
 impl PieChart {
@@ -27,8 +28,9 @@ impl PieChart {
         Self {
             rotation: 0.,
             wedges: vec![],
-            width: 0,
-            height: 0,
+            center_x: 0.,
+            center_y: 0.,
+            radius: 0.,
         }
     }
 
@@ -43,22 +45,18 @@ impl PieChart {
         self
     }
 
-    pub fn width(mut self, width: i32) -> Self {
-        self.width = width;
+    pub fn center(mut self, center_x: f64, center_y: f64) -> Self {
+        self.center_x = center_x;
+        self.center_y = center_y;
         self
     }
 
-    pub fn height(mut self, height: i32) -> Self {
-        self.height = height;
+    pub fn radius(mut self, radius: f64) -> Self {
+        self.radius = radius;
         self
     }
 
     pub fn draw(self, context: &Context) {
-        println!("drawing: {} {}", self.width, self.height);
-        let radius = self.width.min(self.height) as f64 / 2.;
-        let center_x = (self.width / 2) as f64;
-        let center_y = (self.height / 2) as f64;
-
         context.set_source_rgba(0., 0., 0., 0.);
         let _ = context.paint();
 
@@ -80,12 +78,12 @@ impl PieChart {
                     end_angle + self.rotation,
                     self.rotation
                 );
-                context.move_to(center_x, center_y);
+                context.move_to(self.center_x, self.center_y);
                 context.set_source_rgb(color.r, color.g, color.b);
                 context.arc(
-                    center_x,
-                    center_y,
-                    radius,
+                    self.center_x,
+                    self.center_y,
+                    self.radius,
                     start_angle + self.rotation,
                     end_angle + self.rotation,
                 );
@@ -94,7 +92,7 @@ impl PieChart {
         );
 
         context.set_source_rgb(1., 1., 1.);
-        context.arc(center_x, center_y, radius, 0., 2. * PI);
+        context.arc(self.center_x, self.center_y, self.radius, 0., 2. * PI);
         let _ = context.stroke();
     }
 }

dashboard/src/main.rs

@@ -259,8 +259,8 @@ impl TransitClock {
                     let sunset = info.sunset - NaiveTime::from_hms_opt(0, 0, 0).unwrap();
 
                     PieChart::new()
-                        .width(width)
-                        .height(height)
+                        .center(center_x, center_y)
+                        .radius(radius)
                         .rotation(-PI / 2.)
                         .wedges(
                             vec![Wedge {
@@ -280,7 +280,7 @@ impl TransitClock {
                         context.set_source_rgb(0., 0., 0.);
                         context.translate(center_x, center_y);
                         context.rotate(tick as f64 * (PI / 12.));
-                        context.move_to(radius, 0.);
+                        context.move_to(radius - 5., 0.);
                         context.line_to(radius - 10., 0.);
                         let _ = context.stroke();
                         context.identity_matrix();