Tips for LoadingUrl in WebView from a Different Class on Android App

I am a beginner in Android app development and Java. I want my app to use a WebView to display its content. The user should be able to interact with HTML elements, such as buttons or links, which will then send requests to my Android Java class to navigate to different pages.

To achieve this, my main class loads the WebView using the following code:

WebView myWebView = (WebView) findViewById(R.id.webview);
myWebView.addJavascriptInterface(new JavaScriptInterface(this), "Android");
myWebView.setWebViewClient(new WebViewClient());
WebSettings webSettings = myWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
myWebView.loadUrl("file:///android_asset/html/status01.html");

Inside the public class JavaScriptInterface, I would like to create a function that loads another URL:

public void showOffers() {
    WebView myWebView = (WebView) ((Activity) mContext).findViewById(R.id.webview);
    myWebView.loadUrl("file:///android_asset/html/offers.html");
}

However, I encounter an error stating: 

Activity cannot be resolved to a type

How can I access the WebView from my JavaScriptInterface class in order to load another URL?

javajavascriptandroidwebview

Answer №1

Declare the class JavaScriptInterface as an inner class within your Activity and save the reference to the WebView as a member variable of your Activity.

Since inner classes have access to the member variables of the class they are defined in, you can modify your code like this: 

MyWebActivity extends Activity{
    private WebView myWebView;
    protected void onCreate(Bundle bundle){
        myWebView = (WebView) findViewById(R.id.webview);
        myWebView.addJavascriptInterface(new JavaScriptInterface(), "Android");
        myWebView.setWebViewClient(new WebViewClient());
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        myWebView.loadUrl("file:///android_asset/html/status01.html");
    }

    private class JavaScriptInterface{
        JavaScriptInterface(){
        }
        public void showOffers() {                
            myWebView.loadUrl("file:///android_asset/html/offers.html");
        }
    }
}

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