WebView Placed in a Fragment doesn't load

Question

let's start with the code. This is my main activity:

package it.mdibonito.futuroremoto;

import android.app.Activity;
import android.graphics.Bitmap;
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    /**
     * The {@link android.support.v4.view.PagerAdapter} that will provide
     * fragments for each of the sections. We use a
     * {@link FragmentPagerAdapter} derivative, which will keep every
     * loaded fragment in memory. If this becomes too memory intensive, it
     * may be best to switch to a
     * {@link android.support.v4.app.FragmentStatePagerAdapter}.
     */
    private SectionsPagerAdapter mSectionsPagerAdapter;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    private ViewPager mViewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(mViewPager);
        //set the icons for the tabs after the  tablayout.setupWithViewPager(ViewPager)
        int number_of_tabs = 5; //this is the fixed number of tabs in the tablayout, as returned by *SectionsPagerAdapter.getCount()*
        final int[] tabIcons = new int[]{R.drawable.ic_format_list_bulleted_white_48dp, R.drawable.ic_add_location_white_48dp, R.drawable.ic_public_white_48dp, R.drawable.ic_share_white_48dp, R.drawable.ic_info_white_24dp};
        for(int i=0;i<number_of_tabs;i++){
            tabLayout.getTabAt(i).setIcon(tabIcons[i]);
        }

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        public PlaceholderFragment() {
        }

        /**
         * Returns a new instance of this fragment for the given section
         * number.
         */
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            if (getArguments().getInt(ARG_SECTION_NUMBER) == 1) {
                View rootView = inflater.inflate(R.layout.fragment_programma, container, false);
                return rootView;
            } else {
                if (getArguments().getInt(ARG_SECTION_NUMBER) == 2) {
                    View rootView = inflater.inflate(R.layout.fragment_programma, container, false);
                    return rootView;
                } else if (getArguments().getInt(ARG_SECTION_NUMBER) == 3) {
                    View rootView = inflater.inflate(R.layout.fragment_programma, container, false);
                    return rootView;
                } else if (getArguments().getInt(ARG_SECTION_NUMBER) == 4) {
                    View rootView = inflater.inflate(R.layout.fragment_programma, container, false);
                    return rootView;
                } else if (getArguments().getInt(ARG_SECTION_NUMBER) == 5) {
                    View rootView = inflater.inflate(R.layout.fragment_programma, container, false);

                    return rootView;
                } else {
                    View rootView = inflater.inflate(R.layout.fragment_main, container, false);
                    return rootView;
                }
            }
        }
    }

    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a PlaceholderFragment (defined as a static inner class below).
            return PlaceholderFragment.newInstance(position + 1);
        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            return 5;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            switch (position) {
                case 0:
                    return "Programma";
                case 1:
                    return "Mappe";
                case 2:
                    return "Domes";
                case 3:
                    return "Social";
                case 4:
                    return "Info";
            }
            return null;
        }
    }
}

This is programma.java

package it.mdibonito.futuroremoto;


import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.TextView;

/**
 * A simple {@link Fragment} subclass.
 */
public class programma extends Fragment {


    public programma() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_programma, container, false);
        WebView heroespage = (WebView) rootView.findViewById(R.id.progwebview);
        WebSettings webSettings = heroespage.getSettings();
        webSettings.setJavaScriptEnabled(true);
        heroespage.loadUrl("http://www.google.it/");

        return rootView;
    }

Fragment_programma.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="it.mdibonito.futuroremoto.programma">

    <!-- TODO: Update blank fragment layout -->

    <WebView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/progwebview"
        android:layout_gravity="left|top" />

</FrameLayout>

More details: I'm using the standard Android Studio 2.1.3 Tabbed Activity Style, and I would prefer to keep it.As the title, the problem is that the WebView doesn't load anything, it just display a white webview. Of course, I've already added the permissions to use internet into the android manifest... Any help?

Answer 1

add this code in your fragment

 @Override
public void onStart() {
    super.onStart();
    View view = getView();
    if (view != null){

      
        WebView  webView=(WebView) view.findViewById(R.id.webView);
        webView.getSettings().setJavaScriptEnabled(true);
        // Navigate anywhere you want, but consider that this classes have only been tested on YouTube's mobile site
        webView.loadUrl("www.example.com");

        // Force links and redirects to open in the WebView instead of in a browser
        webView.setWebViewClient(new WebViewClient());
    }
}

Answer 2

1. In your myWebClient you've overriden shouldOverrideUrlLoading() and you always return true.

This means that you don't want WebView to handle this url, and you'll handle it yourself.

If you want WebView to load requested url, return false in `shouldOverrideUrlLoading(). Or even better, don't override it at all.

2. Are you sure that Programma class is even started? It is an Activity, not Fragment. You use the same layout (fragment_main) in both ProgrammaActivity and in PlaceholderFragment. However, only in ProgrammaActivity you are loading url. PlaceholderFragment does nothing with its WebView

3. This is how your PlaceholderFragment should look like

public static class PlaceholderFragment extends Fragment { /** * The fragment argument representing the section number for this * fragment. */ private static final String ARG_SECTION_NUMBER = "section_number";

    public PlaceholderFragment() {
    }

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_programma, container, false);
        WebView heroespage = (WebView) rootView.findViewById(R.id.progwebview);
        WebSettings webSettings = heroespage.getSettings();
        webSettings.setJavaScriptEnabled(true);
        heroespage.loadUrl("http://www.google.it/");

        return rootView;
    }
}