some sort of ui

crates/ui/src/widgets/knob.rs

@@ -0,0 +1,135 @@
+use crate::app::AppEvent;
+use params::ParamId;
+use std::f32::consts::PI;
+use vizia::prelude::*;
+use vizia::vg;
+
+const ARC_START: f32 = PI * 0.75;
+const ARC_RANGE: f32 = PI * 1.5;
+
+pub struct TenkoKnob {
+    pub param: ParamId,
+    value: f32,
+    drag_origin_y: Option<f32>,
+    drag_origin_v: f32,
+}
+
+impl TenkoKnob {
+    pub fn new(cx: &mut Context, param: ParamId) -> Handle<Self> {
+        let init = cx
+            .data::<crate::app::AppData>()
+            .map(|d| d.params[param as usize])
+            .unwrap_or(param.default_value());
+
+        Self {
+            param,
+            value: init,
+            drag_origin_y: None,
+            drag_origin_v: 0.0,
+        }
+        .build(cx, |_| {})
+        .bind(
+            crate::app::AppData::params.idx(param as usize),
+            |h, lens| {
+                let v = lens.get(&h);
+                h.modify(|k: &mut TenkoKnob| k.value = v);
+            },
+        )
+        .width(Pixels(46.0))
+        .height(Pixels(46.0))
+        .cursor(CursorIcon::NsResize)
+    }
+}
+
+impl View for TenkoKnob {
+    fn element(&self) -> Option<&'static str> {
+        Some("tenko-knob")
+    }
+
+    fn event(&mut self, cx: &mut EventContext, event: &mut Event) {
+        event.map(|we: &WindowEvent, _| match we {
+            WindowEvent::MouseDown(MouseButton::Left) => {
+                cx.capture();
+                self.drag_origin_y = Some(cx.mouse().cursor_y);
+                self.drag_origin_v = self.value;
+            }
+            WindowEvent::MouseUp(MouseButton::Left) => {
+                cx.release();
+                self.drag_origin_y = None;
+            }
+            WindowEvent::MouseMove(_, y) => {
+                if let Some(oy) = self.drag_origin_y {
+                    let sens = if cx.modifiers().shift() {
+                        0.0015
+                    } else {
+                        0.004
+                    };
+                    let new_v = (self.drag_origin_v + (oy - y) * sens).clamp(0.0, 1.0);
+                    cx.emit(AppEvent::SetParam(self.param, new_v));
+                }
+            }
+            WindowEvent::MouseDoubleClick(MouseButton::Left) => {
+                cx.emit(AppEvent::SetParam(self.param, self.param.default_value()));
+            }
+            _ => {}
+        });
+    }
+
+    fn draw(&self, cx: &mut DrawContext, canvas: &Canvas) {
+        let b = cx.bounds();
+        let kx = b.x + b.w * 0.5;
+        let ky = b.y + b.h * 0.5;
+        let r = b.w.min(b.h) * 0.5 - 5.0;
+        let val_end = ARC_START + self.value * ARC_RANGE;
+
+        let mut paint = vg::Paint::default();
+        paint.set_anti_alias(true);
+        paint.set_style(vg::PaintStyle::Stroke);
+        paint.set_stroke_width(3.5);
+        paint.set_stroke_cap(vg::paint::Cap::Round);
+        paint.set_color(vg::Color::from_argb(255, 45, 45, 65));
+
+        let track_rect = vg::Rect::from_xywh(kx - r, ky - r, r * 2.0, r * 2.0);
+        let mut path = vg::Path::new();
+        path.add_arc(track_rect, ARC_START.to_degrees(), ARC_RANGE.to_degrees());
+        canvas.draw_path(&path, &paint);
+
+        if self.value > 0.001 {
+            paint.set_color(vg::Color::from_argb(255, 255, 120, 48));
+            let mut vpath = vg::Path::new();
+            vpath.add_arc(
+                track_rect,
+                ARC_START.to_degrees(),
+                (self.value * ARC_RANGE).to_degrees(),
+            );
+            canvas.draw_path(&vpath, &paint);
+        }
+
+        paint.set_style(vg::PaintStyle::Fill);
+        paint.set_color(vg::Color::from_argb(255, 30, 30, 48));
+        canvas.draw_circle((kx, ky), r - 6.0, &paint);
+
+        let px = kx + val_end.cos() * (r - 9.0);
+        let py = ky + val_end.sin() * (r - 9.0);
+        paint.set_style(vg::PaintStyle::Stroke);
+        paint.set_stroke_width(2.0);
+        paint.set_color(vg::Color::from_argb(255, 220, 220, 235));
+        let mut ptr = vg::Path::new();
+        ptr.move_to((kx, ky));
+        ptr.line_to((px, py));
+        canvas.draw_path(&ptr, &paint);
+    }
+}
+
+pub fn labeled_knob(cx: &mut Context, param: ParamId) {
+    VStack::new(cx, |cx| {
+        TenkoKnob::new(cx, param);
+        Label::new(cx, param.label())
+            .class("knob-label")
+            .text_align(TextAlign::Center)
+            .width(Stretch(1.0));
+    })
+    .width(Pixels(50.0))
+    .height(Pixels(62.0))
+    .padding(Pixels(2.0));
+}