gistfile1.java

private TextView htmlTextView;
private SpannableStringBuilder htmlSpannable;

@Override
public void onCreate(Bundle savedInstanceState) {

	// ...

	// first parse the html
	// replace getHtmlCode() with whatever generates/fetches your html
	Spanned spanned = Html.fromHtml(getHtmlCode());

	// we need a SpannableStringBuilder for later use
	if (spanned instanceof SpannableStringBuilder) {
		// for now Html.fromHtml() returns a SpannableStringBuiler
		// so we can just cast it
		htmlSpannable = (SpannableStringBuilder) spanned;
	} else {
		// but we have a fallback just in case this will change later
		// or a custom subclass of Html is used
		new SpannableStringBuilder(spanned);
	}

	// now we can call setText() on the next view.
	// this won't show any images yet
	htmlTextView.setText(htmlSpannable);

	// next we start a AsyncTask that loads the images
	new ImageLoadTask().execute();

	// ...

}

private class ImageLoadTask extends AsyncTask {

	DisplayMetrics metrics = new DisplayMetrics();

	@Override
	protected void onPreExecute() {

		// we need this to properly scale the images later
		getWindowManager().getDefaultDisplay().getMetrics(metrics);

	}

	@Override
	protected Void doInBackground(Void... params) {

		// iterate over all images found in the html
		for (ImageSpan img : htmlSpannable.getSpans(0,
					htmlSpannable.length(), ImageSpan.class)) {

			if (!getImageFile(img).isFile()) {
				
				// here you have to download the file

			}

			// we use publishProgress to run some code on the
			// UI thread to actually show the image
			// -> onProgressUpdate()
			publishProgress(img);

		}

		return null;

	}

	@Override
	protected void onProgressUpdate(ImageSpan... values) {

		// save ImageSpan to a local variable just for convenience
		ImageSpan img = values[0];

		// now we get the File object again. so remeber to always return
		// the same file for the same ImageSpan object
		File cache = getImageFile(img);

		// if the file exists, show it
		if (cache.isFile()) {

			// first we need to get a Drawable object
			Drawable d = new BitmapDrawable(getResources(),
					cache.getAbsolutePath());

			// next we do some scaling
			int width, height;
			int originalWidthScaled = (int) (d.getIntrinsicWidth() * metrics.density);
			int originalHeightScaled = (int) (d.getIntrinsicHeight() * metrics.density);
			if (originalWidthScaled > metrics.widthPixels) {
				height = d.getIntrinsicHeight() * metrics.widthPixels
					/ d.getIntrinsicWidth();
				width = metrics.widthPixels;
			} else {
				height = originalHeightScaled;
				width = originalWidthScaled;
			}

			// it's important to call setBounds otherwise the image will
			// have a size of 0px * 0px and won't show at all
			d.setBounds(0, 0, width, height);

			// now we create a new ImageSpan
			ImageSpan newImg = new ImageSpan(d, img.getSource());

			// find the position of the old ImageSpan
			int start = htmlSpannable.getSpanStart(img);
			int end = htmlSpannable.getSpanEnd(img);

			// remove the old ImageSpan
			htmlSpannable.removeSpan(img);

			// add the new ImageSpan
			htmlSpannable.setSpan(newImg, start, end,
					Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

			// finally we have to update the TextView with our
			// updates Spannable to display the image
			htmlTextView.setText(htmlSpannable);
		}
	}

	private File getImageFile(ImageSpan img) {

		// you need to implement this method yourself.
		// it must return a unique File object (or something
		// different if you also change the rest of the code)
		// for every image tag. use img.getSource() to get
		// the src="" attribute. you might want to use some
		// hash of the url as file name

	}

}

thank you for this

Hi, can you tell me why I got nullPointerException when it runs htmlTextView.setText(htmlSpannable);? The htmlSpannable is not null.

This is working like a charm. Thanks a lot