+ case "default_font_size":
+ // Get the default font size as a string. The default is `100`.
+ String newDefaultFontSizeString = sharedPreferences.getString("default_font_size", "100");
+
+ // Update the font size on `mainWebView`. The default is `100`.
+ MainWebViewActivity.mainWebView.getSettings().setTextZoom(Integer.valueOf(newDefaultFontSizeString));
+
+ // Update the summary text of `default_font_size`.
+ defaultFontSizePreference.setSummary(newDefaultFontSizeString + "%%");
+