Using reflection in android for backwards compatability

Question

I was reading over at the android dev website about using reflections. But I'm really not grasping how to use it. I need this java file to run on a 1.5(SDK3) device but just ignore the new code and work fine on a 2.0(SDK5) and up phone. I have this Activity (posted below) and it's a simple webview. However, I want to have geolocation enabled(even if it is only for 2.0 and up phones), since these api's weren't introduced until SDK 5 and I would like the webview to be able to at the very least be able to load on a 1.5 phone rather than just crashing. Could someone possibly show me how I would take my code and set it up using reflections?

    package com.my.app;

    import com.facebook.android.R;
    //NEEDS TO BE IGNORED**********************************************************
    import android.webkit.GeolocationPermissions;
    import android.webkit.GeolocationPermissions.Callback;
    //END**************************************************************************
    import android.app.Activity;
    import android.app.ProgressDialog;
    import android.content.Intent;
    import android.net.Uri;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.KeyEvent; 
    import android.view.Menu;
    import android.view.MenuInflater;
    import android.view.MenuItem;
    import android.webkit.CookieSyncManager;
    import android.webkit.WebChromeClient;
    import android.webkit.WebView;
    import android.webkit.WebViewClient;
    import android.widget.Toast;

    //GeolocationPermissionsCallback NEEDS TO BE IGNORED**********************************************************
    public class Places extends Activity implements GeolocationPermissions.Callback{ 
            private ProgressDialog progressBar;
            public WebView webview;
            private static final String TAG = "Main";
            String geoWebsiteURL = "http://google.com";

            @Override 
             public void onStart()
            {
               super.onStart();
                CookieSyncManager.getInstance().sync();

            }




        public void onCreate(Bundle savedInstanceState) { 
            super.onCreate(savedInstanceState); 
            setContentView(R.layout.main);
            CookieSyncManager.createInstance(this);
            CookieSyncManager.getInstance().startSync();

            webview = (WebView) findViewById(R.id.webview);
            webview.setWebViewClient(new testClient());
            webview.getSettings().setJavaScriptEnabled(true);
            webview.getSettings().setPluginsEnabled(true);
            webview.loadUrl("http://google.com");

            progressBar = ProgressDialog.show(Places.this, "", "Loading Page...");

            //START GROUP OF CODE THAT NEEDS TO BE IGNORED************************************************************
            webview.getSettings().setGeolocationEnabled(true);



            GeoClient geo = new GeoClient();
            webview.setWebChromeClient(geo);        

        }

        public void invoke(String origin, boolean allow, boolean remember) {

        }

        final class GeoClient extends WebChromeClient {


        @Override
        public void onGeolocationPermissionsShowPrompt(String origin,
        Callback callback) {
        super.onGeolocationPermissionsShowPrompt(origin, callback);
        callback.invoke(origin, true, false);
        }
    //END OF CODE THAT NEEDS TO BE IGNORED************************************************


}


        private class testClient extends WebViewClient { 
            @Override 
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                Log.i(TAG, "Processing webview url click...");
                view.loadUrl(url);
                return true;  



            }





            public void onPageFinished(WebView view, String url) {
                Log.i(TAG, "Finished loading URL: " +url);
                if (progressBar.isShowing()) {
                    progressBar.dismiss();
                }

                if (url.startsWith("mailto:") || url.startsWith("geo:") ||
                        url.startsWith("tel:")) {
                                                    Intent intent = new Intent
                        (Intent.ACTION_VIEW, Uri.parse(url));
                                                    startActivity(intent);
                        }
            }
        }



            public boolean onKeyDown(int keyCode, KeyEvent event) { 
                if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) { 
                    webview.goBack(); 
                    return true; 
                }
                    if (keyCode == KeyEvent.KEYCODE_SEARCH) {

                        Intent z = new Intent(this, Search.class);
                        startActivity(z);

                      }  
                return super.onKeyDown(keyCode, event);  
                }




            public boolean onCreateOptionsMenu (Menu menu) {
                super.onCreateOptionsMenu(menu);
                MenuInflater inflater = getMenuInflater();
                inflater.inflate(R.menu.menu, menu);
                return true;
            }

        @Override
        public boolean onOptionsItemSelected (MenuItem item) {
                switch (item.getItemId()) {
                case R.id.home:
                    Intent m = new Intent(this, Home.class);
                    startActivity(m);
                    return true;

                case R.id.refresh:
                    webview.reload();
                    Toast.makeText(this, "Refreshing...", Toast.LENGTH_SHORT).show();
                    return true;


        }
        return false;
            }

        public void onStop()
        {
           super.onStop();
    CookieSyncManager.getInstance().sync();

        }




    } 

Answer 1

Step #1: Do not implement GeolocationPermissions.Callback on the activity. Use some other object for GeolocationPermissions.Callback, one implemented in a public Java class that you would not load if you are running on older versions of the OS.

Step #2: Read the answers and comments on the question you asked previously, which covers what you need to know for the rest. Notably, you would make GeoClient be a public Java class in its own file, so you can avoid loading it on older versions of the OS. Personally, I like the Stephen C answer, and I demonstrate its use here.