Render Html Elements on WebView for EPub Reader

Question

I'm making an EPub Reader with the the library from Paul Siegmann http://www.siegmann.nl/epublib/android

I extracted the Table of Contents into a ListView, and the item is linked to a WebView which displays the content of the chosen chapter.

I don't find any problem in displaying E-Pub file which only has pure text elements, but when it comes to an E-Pub file containing Html elements (links, images), it can't be displayed.

Does anybody know how to render Html elements on WebView according to my case?

Here are my classes:

public class EPubReaderActivity extends ListActivity 
{

private LayoutInflater inflater;
private List<RowData> contentDetails;
public static final String BOOK_NAME = "ferring.epub";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    inflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
    contentDetails = new ArrayList<RowData>();
    AssetManager assetManager = getAssets();
    try {
        InputStream epubInputStream = assetManager.open(BOOK_NAME);
        Book book = (new EpubReader()).readEpub(epubInputStream);
        logContentsTable(book.getTableOfContents().getTocReferences(), 0);
    } catch (IOException e) {
        Log.e("epublib", e.getMessage());
    }

    CustomAdapter adapter = new CustomAdapter(this, R.layout.list,
            R.id.title, contentDetails);
    setListAdapter(adapter);
    getListView().setTextFilterEnabled(true);
}

private class CustomAdapter extends ArrayAdapter<RowData>{

    public CustomAdapter(Context context, int resource,
            int textViewResourceId, List<RowData> objects) {
        super(context, resource, textViewResourceId, objects);
    }

    private class ViewHolder{
        private View row;
        private TextView titleHolder = null;

        public ViewHolder(View row) {
            super();
            this.row = row;
        }

        public TextView getTitle() {
            if(null == titleHolder)
                titleHolder = (TextView) row.findViewById(R.id.title);
            return titleHolder;
        }
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        TextView title = null;
        RowData rowData = getItem(position);
        if(null == convertView){
            convertView = inflater.inflate(R.layout.list, null);
            holder = new ViewHolder(convertView);
            convertView.setTag(holder);
        }
        holder = (ViewHolder) convertView.getTag();
        title = holder.getTitle();
        title.setText(rowData.getTitle());
        return convertView;
    }

}

private void logContentsTable(List<TOCReference> tocReferences, int depth) {
    if (tocReferences == null) {
        return;
    }
    for (TOCReference tocReference:tocReferences) {
        StringBuilder tocString = new StringBuilder();
        for (int i = 0; i < depth; i++) {
            tocString.append("\t");
        }
        tocString.append(tocReference.getTitle());
        RowData row = new RowData();
        row.setTitle(tocString.toString());
        row.setResource(tocReference.getResource());
        contentDetails.add(row);
        logContentsTable(tocReference.getChildren(), depth + 1);
    }
}

private class RowData{
    private String title;
    private Resource resource;

    public RowData() {
        super();
    }

    public String getTitle() {
        return title;
    }

    public Resource getResource() {
        return resource;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public void setResource(Resource resource) {
        this.resource = resource;
    }

}



@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    RowData rowData = contentDetails.get(position);
    Intent intent = new Intent(EPubReaderActivity.this, ContentViewActivity.class);
    try {
        intent.putExtra("display", new String(rowData.getResource().getData()));
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    startActivity(intent);

}

}

Content class:

public class ContentViewActivity extends Activity {

WebView webView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.content);

    webView = (WebView) findViewById(R.id.web);
    webView.getSettings().setJavaScriptEnabled(true);

    String displayString = getIntent().getExtras().getString("display");
    if(displayString != null)
        webView.loadData(displayString, "text/html", "utf-8");
}   
}

P.S: I don't wanna use PageTurner (http://www.pageturner-reader.org/) or FBReader (http://www.fbreader.org/FBReaderJ), since both of them need GPL license for commercial use.

Answer 1

Actually, the Html-rendering part of PageTurner is split off into a separate library which is Apache licensed.

I specifically did that since I figured it would be useful for commercial projects as well.

The rendering library is here: http://github.com/nightwhistler/htmlspanner