feat(custom): slider widget

Resolves partially #68.

src/modules/custom/slider.rs

@@ -0,0 +1,131 @@
+use crate::modules::custom::{try_get_orientation, CustomWidget, CustomWidgetContext, ExecEvent};
+use crate::popup::Popup;
+use crate::script::{OutputStream, Script, ScriptInput};
+use crate::{send, try_send};
+use gtk::prelude::*;
+use gtk::{Orientation, Scale};
+use serde::Deserialize;
+use std::cell::Cell;
+use tokio::spawn;
+use tracing::error;
+
+#[derive(Debug, Deserialize, Clone)]
+pub struct SliderWidget {
+    name: Option<String>,
+    class: Option<String>,
+    orientation: Option<String>,
+    value: Option<ScriptInput>,
+    on_change: Option<String>,
+    #[serde(default = "default_min")]
+    min: f64,
+    #[serde(default = "default_max")]
+    max: f64,
+    length: Option<i32>,
+}
+
+const fn default_min() -> f64 {
+    0.0
+}
+
+const fn default_max() -> f64 {
+    100.0
+}
+
+impl CustomWidget for SliderWidget {
+    type Widget = Scale;
+
+    fn into_widget(self, context: CustomWidgetContext) -> Self::Widget {
+        let mut builder = Scale::builder();
+
+        if let Some(name) = self.name {
+            builder = builder.name(name);
+        }
+
+        if let Some(orientation) = self.orientation {
+            builder = builder
+                .orientation(try_get_orientation(&orientation).unwrap_or(context.bar_orientation));
+        }
+
+        if let Some(length) = self.length {
+            builder = match context.bar_orientation {
+                Orientation::Horizontal => builder.width_request(length),
+                Orientation::Vertical => builder.height_request(length),
+                _ => builder,
+            }
+        }
+
+        let scale = builder.build();
+
+        scale.set_range(self.min, self.max);
+
+        if let Some(class) = self.class {
+            scale.style_context().add_class(&class);
+        }
+
+        if let Some(on_change) = self.on_change {
+            let min = self.min;
+            let max = self.max;
+            let tx = context.tx.clone();
+
+            // GTK will spam the same value over and over
+            let prev_value = Cell::new(scale.value());
+
+            scale.connect_change_value(move |scale, _, val| {
+                // GTK will send values outside min/max range
+                let val = clamp(val, min, max);
+
+                if val != prev_value.get() {
+                    try_send!(
+                        tx,
+                        ExecEvent {
+                            cmd: on_change.clone(),
+                            args: Some(vec![val.to_string()]),
+                            geometry: Popup::widget_geometry(scale, context.bar_orientation),
+                        }
+                    );
+
+                    prev_value.set(val);
+                }
+
+                Inhibit(false)
+            });
+        }
+
+        if let Some(value) = self.value {
+            let script = Script::from(value);
+            let scale = scale.clone();
+
+            let (tx, rx) = glib::MainContext::channel(glib::PRIORITY_DEFAULT);
+
+            spawn(async move {
+                script
+                    .run(None, move |stream, _success| match stream {
+                        OutputStream::Stdout(out) => match out.parse() {
+                            Ok(value) => send!(tx, value),
+                            Err(err) => error!("{err:?}"),
+                        },
+                        OutputStream::Stderr(err) => error!("{err:?}"),
+                    })
+                    .await;
+            });
+
+            rx.attach(None, move |value| {
+                scale.set_value(value);
+                Continue(true)
+            });
+        }
+
+        scale
+    }
+}
+
+/// Ensures `num` is between `min` and `max` (inclusive).
+fn clamp(num: f64, min: f64, max: f64) -> f64 {
+    if num < min {
+        min
+    } else if num > max {
+        max
+    } else {
+        num
+    }
+}