now use single settings file instead of many; minor refactoring

src/app/settings.rs

@@ -0,0 +1,50 @@
+use serde::{Deserialize, Serialize};
+use std::fs;
+use std::io::{Read, Write};
+use std::path::PathBuf;
+
+#[derive(Serialize, Deserialize, Debug, PartialEq)]
+pub struct Settings {
+    pub saved_dirs: Vec<PathBuf>,
+    pub saved_mic: String,
+    pub saved_volume: f32,
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        Settings {
+            saved_dirs: Vec::new(),
+            saved_mic: String::new(),
+            saved_volume: 1.0,
+        }
+    }
+}
+
+impl Clone for Settings {
+    fn clone(&self) -> Self {
+        Settings {
+            saved_dirs: self.saved_dirs.clone(),
+            saved_mic: self.saved_mic.clone(),
+            saved_volume: self.saved_volume,
+        }
+    }
+}
+
+impl Settings {
+    pub fn save_to_file(&self, file_path: &PathBuf) {
+        let mut file = fs::File::create(file_path).unwrap();
+        let buf = serde_json::to_vec(&self).unwrap();
+        file.write_all(&buf[..]).ok();
+    }
+}
+
+pub fn load_from_file(file_path: &PathBuf) -> Settings {
+    let mut file = fs::File::open(file_path).unwrap();
+    let mut buf: Vec<u8> = vec![];
+    file.read_to_end(&mut buf).ok();
+
+    let mut settings: Settings = serde_json::from_slice(&buf[..]).unwrap();
+    settings.saved_volume = settings.saved_volume.clamp(0.0, 1.0);
+
+    settings
+}