saved preference working, not updating currency on change

app/src/main/assets/js/main.js

@@ -13,10 +13,23 @@ function updateBitcoinPrice(selectedCurrency) {
 function handleThemeChange() {
     var selectedTheme = document.getElementById("theme-select").value;
     document.documentElement.setAttribute("data-theme", selectedTheme);
+    savePreference("theme", selectedTheme);
+  }
+
+function handleCurrencyChange() {
+    var selectedCurrency = document.getElementById("currency-select").value;
+    savePreference("currency", selectedCurrency);
+}
+
+function savePreference(key, value) {
+    if (typeof Android !== 'undefined' && Android !== null) {
+        Android.savePreference(key, value);
+    }
 }
 
   // Event listener for theme select change
 document.getElementById("theme-select").addEventListener("change", handleThemeChange);
+document.getElementById("currency-select").addEventListener("change", handleCurrencyChange);
 
 
 //function refreshBitcoinPrice(selectedCurrency) {
@@ -65,22 +78,19 @@ function updateFiatToSatsConversion(selectedCurrency) {
 }
 
 document.addEventListener('DOMContentLoaded', () => {
-    const satsInputElement = document.getElementById('sats-input');
+    const savedTheme = (typeof Android !== 'undefined' && Android !== null) ? Android.getPreference("theme") : null;
-    const currencySelect = document.getElementById('currency-select');
+    if (savedTheme) {
-    const selectedCurrency = currencySelect.value;
+        document.getElementById("theme-select").value = savedTheme;
-    // Initially fetch Bitcoin price in USD
+        document.documentElement.setAttribute("data-theme", savedTheme);
-    updateBitcoinPrice(selectedCurrency);
+    }
-    updateFiatToSatsConversion(selectedCurrency)
 
-    satsInputElement.addEventListener('input', updateSatsToDollarsConversion);
+    const savedCurrency = (typeof Android !== 'undefined' && Android !== null) ? Android.getPreference("currency") : null;
-
+    if (savedCurrency) {
-    currencySelect.addEventListener('change', () => {
+        document.getElementById("currency-select").value = savedCurrency;
-        const selectedCurrency = currencySelect.value;
+        updateBitcoinPrice(savedCurrency);
-        updateBitcoinPrice(selectedCurrency);
+        updateFiatToSatsConversion(savedCurrency);
-        updateFiatToSatsConversion(selectedCurrency);
+        updateSatsToDollarsConversion(savedCurrency);
-        updateSatsToDollarsConversion(selectedCurrency);
+    }
-        updateFiatToSatsConversion(selectedCurrency)
-    });
 });
 
 

app/src/main/java/com/example/satworth/MainActivity.kt

@@ -6,6 +6,8 @@ import android.os.Bundle
 import android.webkit.WebView
 import android.webkit.WebSettings
 import java.io.IOException
+import android.content.Context
+import android.webkit.JavascriptInterface
 
 class MainActivity : AppCompatActivity() {
 
@@ -23,6 +25,9 @@ class MainActivity : AppCompatActivity() {
         val webSettings: WebSettings = webView.settings
         webSettings.javaScriptEnabled = true
 
+        // Add JavaScript interface
+        webView.addJavascriptInterface(WebAppInterface(this), "Android")
+
         // Clear the WebView cache (optional)
         webView.clearCache(true)
 
@@ -84,3 +89,20 @@ class MainActivity : AppCompatActivity() {
         webView.loadDataWithBaseURL(null, finalHtmlContent, "text/html", "UTF-8", null)
     }
 }
+class WebAppInterface(private val context: Context) {
+
+    private val sharedPreferences = context.getSharedPreferences("AppPrefs", Context.MODE_PRIVATE)
+
+    @JavascriptInterface
+    fun savePreference(key: String, value: String) {
+        with(sharedPreferences.edit()) {
+            putString(key, value)
+            apply()
+        }
+    }
+
+    @JavascriptInterface
+    fun getPreference(key: String): String? {
+        return sharedPreferences.getString(key, null)
+    }
+}