introduce ZoomHandler

Signed-off-by: kernelkind <kernelkind@gmail.com>

crates/notedeck_chrome/src/persist_zoom.rs

@@ -0,0 +1,26 @@
+use egui::Context;
+use notedeck::{DataPath, DataPathType};
+
+use crate::timed_serializer::TimedSerializer;
+
+pub struct ZoomHandler {
+    serializer: TimedSerializer<f32>,
+}
+
+impl ZoomHandler {
+    pub fn new(path: &DataPath) -> Self {
+        let serializer =
+            TimedSerializer::new(path, DataPathType::Setting, "zoom_level.json".to_owned());
+
+        Self { serializer }
+    }
+
+    pub fn try_save_zoom_factor(&mut self, ctx: &Context) {
+        let cur_zoom_level = ctx.zoom_factor();
+        self.serializer.try_save(cur_zoom_level);
+    }
+
+    pub fn get_zoom_factor(&self) -> Option<f32> {
+        self.serializer.get_item()
+    }
+}