refactor: remove app::Message type from Graph

I wonder, given the description of canvas::Program,
would the graph be better as a true widget?

I'll have to learn how to actually implement a widget though.

src/app/graph.rs

@@ -2,38 +2,36 @@ use std::collections::VecDeque;
 
 use iced::{Color, Point, Renderer, Theme, mouse, widget::canvas};
 
-use crate::app;
-
 const CYAN: Color = Color::from_rgb8(0, 255, 255);
 
 #[derive(Default)]
-pub struct CpuGraph {
+pub struct Graph {
     timeline: VecDeque<f32>,
 
     pub cache: canvas::Cache,
 }
 
-impl CpuGraph {
-    pub fn new(usage: f32) -> Self {
+impl Graph {
+    pub fn new(value: f32) -> Self {
         Self {
             timeline: {
                 let mut vec = VecDeque::new();
-                vec.push_front(usage);
+                vec.push_front(value);
                 vec
             },
             ..Default::default()
         }
     }
 
-    pub fn update(&mut self, usage: f32) {
-        self.timeline.push_back(usage);
+    pub fn update(&mut self, value: f32) {
+        self.timeline.push_back(value);
         if self.timeline.len() > 1000 {
             self.timeline.pop_front();
         }
     }
 }
 
-impl canvas::Program<app::Message, Theme, Renderer> for CpuGraph {
+impl canvas::Program<(), Theme, Renderer> for Graph {
     type State = ();
     fn draw(
         &self,

src/app/mod.rs

@@ -4,9 +4,9 @@ use iced::{
 };
 use smol::Timer;
 
-use crate::{app::cpu_graph::CpuGraph, sysinfo_snapshot::SysinfoSnapshot};
+use crate::{app::graph::Graph, sysinfo_snapshot::SysinfoSnapshot};
 
-mod cpu_graph;
+mod graph;
 
 enum Message {
     Info(SysinfoSnapshot),
@@ -14,8 +14,8 @@ enum Message {
 
 #[derive(Default)]
 struct State {
-    total_cpu_graph: CpuGraph,
-    cpu_graphs: Vec<CpuGraph>,
+    total_cpu_graph: Graph,
+    cpu_graphs: Vec<Graph>,
 }
 
 impl State {
@@ -51,12 +51,12 @@ impl State {
                     self.cpu_graphs = snapshot
                         .cpus
                         .into_iter()
-                        .map(|usage| CpuGraph::new(usage))
+                        .map(|value| Graph::new(value))
                         .collect();
                 } else {
-                    for (graph, usage) in self.cpu_graphs.iter_mut().zip(snapshot.cpus.into_iter())
+                    for (graph, value) in self.cpu_graphs.iter_mut().zip(snapshot.cpus.into_iter())
                     {
-                        graph.update(usage);
+                        graph.update(value);
                         graph.cache.clear();
                     }
                 }