move some logic to FunctionOutput

src/function_output.rs

@@ -0,0 +1,77 @@
+use eframe::{
+    egui::{
+        plot::{BarChart, Line, PlotUi, Value, Values},
+        widgets::plot::Bar,
+    },
+    epaint::Color32,
+};
+
+use crate::misc::digits_precision;
+
+#[derive(Clone)]
+pub struct FunctionOutput {
+    pub(crate) back: Option<Vec<Value>>,
+    pub(crate) integral: Option<(Vec<Bar>, f64)>,
+    pub(crate) derivative: Option<Vec<Value>>,
+}
+
+impl FunctionOutput {
+    pub fn new(
+        back: Option<Vec<Value>>, integral: Option<(Vec<Bar>, f64)>, derivative: Option<Vec<Value>>,
+    ) -> Self {
+        Self {
+            back,
+            integral,
+            derivative,
+        }
+    }
+
+    pub fn new_empty() -> Self {
+        Self {
+            back: None,
+            integral: None,
+            derivative: None,
+        }
+    }
+
+    pub fn invalidate_whole(&mut self) {
+        self.back = None;
+        self.integral = None;
+        self.derivative = None;
+    }
+
+    pub fn invalidate_back(&mut self) { self.back = None; }
+
+    pub fn invalidate_integral(&mut self) { self.integral = None; }
+
+    pub fn invalidate_derivative(&mut self) { self.derivative = None; }
+
+    pub fn display(
+        &self, plot_ui: &mut PlotUi, func_str: &str, derivative_str: &str, step: f64,
+    ) -> f64 {
+        plot_ui.line(
+            Line::new(Values::from_values(self.back.clone().unwrap()))
+                .color(Color32::RED)
+                .name(func_str),
+        );
+        if let Some(derivative_data) = self.derivative.clone() {
+            plot_ui.line(
+                Line::new(Values::from_values(derivative_data))
+                    .color(Color32::GREEN)
+                    .name(derivative_str),
+            );
+        }
+
+        if let Some(integral_data) = self.integral.clone() {
+            plot_ui.bar_chart(
+                BarChart::new(integral_data.0)
+                    .color(Color32::BLUE)
+                    .width(step),
+            );
+
+            digits_precision(integral_data.1, 8)
+        } else {
+            f64::NAN
+        }
+    }
+}