Html.ImageGetter TextView

the easiest solution is:

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.pskink.soom.R;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LevelListDrawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Html;
import android.text.Html.ImageGetter;
import android.text.Spanned;
import android.util.Log;
import android.widget.TextView;

public class TestImageGetter extends Activity implements ImageGetter {
    private final static String TAG = "TestImageGetter";
    private TextView mTv;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test_image_getter);
        String source = "this is a test of <b>ImageGetter</b> it contains " +
                "two images: <br/>" +
                "<img src=\"http://developer.android.com/assets/images/dac_logo.png\"><br/>and<br/>" +
                "<img src=\"http://developer.android.com/assets/images/icon_search.png\">";

        Spanned spanned = Html.fromHtml(source, this, null);
        mTv = (TextView) findViewById(R.id.text);
        mTv.setText(spanned);
    }

    @Override
    public Drawable getDrawable(String source) {
        LevelListDrawable d = new LevelListDrawable();
        Drawable empty = getResources().getDrawable(R.drawable.ic_launcher);
        d.addLevel(0, 0, empty);
        d.setBounds(0, 0, empty.getIntrinsicWidth(), empty.getIntrinsicHeight());

        new LoadImage().execute(source, d);

        return d;
    }

    class LoadImage extends AsyncTask<Object, Void, Bitmap> {

        private LevelListDrawable mDrawable;

        @Override
        protected Bitmap doInBackground(Object... params) {
            String source = (String) params[0];
            mDrawable = (LevelListDrawable) params[1];
            Log.d(TAG, "doInBackground " + source);
            try {
                InputStream is = new URL(source).openStream();
                return BitmapFactory.decodeStream(is);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            Log.d(TAG, "onPostExecute drawable " + mDrawable);
            Log.d(TAG, "onPostExecute bitmap " + bitmap);
            if (bitmap != null) {
                BitmapDrawable d = new BitmapDrawable(bitmap);
                mDrawable.addLevel(1, 1, d);
                mDrawable.setBounds(0, 0, bitmap.getWidth(), bitmap.getHeight());
                mDrawable.setLevel(1);
                // i don't know yet a better way to refresh TextView
                // mTv.invalidate() doesn't work as expected
                CharSequence t = mTv.getText();
                mTv.setText(t);
            }
        }
    }
}

there is one not quite elegant way to re-layout a TextView after image downloading:

// i don't know yet a better way to refresh TextView
// mTv.invalidate() doesn't work as expected
CharSequence t = mTv.getText();
mTv.setText(t);

if anybody knows better solution please let me know

An alternative solution using Glide and Coroutines with the assumption that a retry is not required:

import android.content.res.Resources
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.drawable.BitmapDrawable
import android.graphics.drawable.Drawable
import android.text.Html
import android.widget.TextView
import androidx.lifecycle.LifecycleCoroutineScope
import com.bumptech.glide.RequestManager
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import kotlin.math.roundToInt

class HtmlImageGetter(
    private val scope: LifecycleCoroutineScope,
    private val res: Resources,
    private val glide: RequestManager,
    private val htmlTextView: TextView
) : Html.ImageGetter {

    override fun getDrawable(url: String): Drawable {
        val holder = BitmapDrawablePlaceHolder(res, null)

        scope.launch(Dispatchers.IO) {
            runCatching {
                val bitmap = glide
                    .asBitmap()
                    .load(url)
                    .submit()
                    .get()

                val drawable = BitmapDrawable(res, bitmap)

                val scale = 1.25 // This makes the image scale in size.
                val width = (drawable.intrinsicWidth * scale).roundToInt()
                val height = (drawable.intrinsicHeight * scale).roundToInt()
                drawable.setBounds(0, 0, width, height)

                holder.setDrawable(drawable)
                holder.setBounds(0, 0, width, height)

                withContext(Dispatchers.Main) { htmlTextView.text = htmlTextView.text }
            }
        }

        return holder
    }

    internal class BitmapDrawablePlaceHolder(res: Resources, bitmap: Bitmap?) : BitmapDrawable(res, bitmap) {
        private var drawable: Drawable? = null

        override fun draw(canvas: Canvas) {
            drawable?.run { draw(canvas) }
        }

        fun setDrawable(drawable: Drawable) {
            this.drawable = drawable
        }
    }
}

In a Fragment or Activity use with HtmlCompat

val imageGetter = HtmlImageGetter(lifecycleScope, resources, glide, htmlTextView)
val styledText = HtmlCompat.fromHtml(htmlString, flags, imageGetter, null)
htmlTextView.text = styledText