Inital commit

src/handler/handler-global-settings.ts

@@ -0,0 +1,54 @@
+import { throttle } from "lodash";
+import type { GlobalSettings } from "../interface";
+import { BasicEventEmitter } from "../utils/eventEmitter";
+import { A4_HEIGHT, A4_WIDTH } from "../constants";
+
+function defaultGlobalSetting(): GlobalSettings {
+    return {
+        DPI: 96,
+        scale: 1,
+        paperHeight: A4_HEIGHT,
+        paperWidth: A4_WIDTH,
+        grid: "none",
+        landscape: false,
+    };
+}
+
+export class GlobalSettingsHandler {
+    private STORAGE_SETTINGS_KEY = "settings";
+    public readonly emitter = new BasicEventEmitter<{
+        "settings-update": [];
+    }>();
+    private _settings: GlobalSettings = defaultGlobalSetting();
+    private store!: LocalForage;
+
+    async init(store: LocalForage) {
+        this.store = store;
+        this._settings = (await this.store.getItem<GlobalSettings>(this.STORAGE_SETTINGS_KEY)) || this._settings;
+    }
+    setSettings(settings: Partial<GlobalSettings>) {
+        const entries = Object.entries(settings);
+        let emitUpdate = false;
+        for (const [key, value] of entries) {
+            const diff = (this._settings as any)[key] !== value;
+            (this._settings as any)[key] = value;
+            if (diff) {
+                emitUpdate = true;
+            }
+        }
+        if (emitUpdate) {
+            this.emitter.emit("settings-update");
+            this.save();
+        }
+    }
+    async clear() {
+        this._settings = defaultGlobalSetting();
+        await this.store.setItem(this.STORAGE_SETTINGS_KEY, this._settings);
+    }
+    get settings() {
+        return { ...this._settings };
+    }
+    private save = throttle(async () => {
+        await this.store.setItem(this.STORAGE_SETTINGS_KEY, this._settings);
+    }, 1000);
+}