I spent several hours tweaking my own loading of images into an Android ListView. The problem was that the images would not load until I scrolled the screen and even then the lag was unacceptable.
My program performed the following:
Essentially, this produces statements like the following:
holder.imageView = (ImageView) convertView.findViewById(R.id.row_image);
holder.imageView.setImageBitmap(rowdata.getBitmap());
This is from inside the object rowdata
public Bitmap getBitmap() {
if (bitmapurl != null && !bitmapurl.equals("")) {
new ImageLoadAsync(context).execute(bitmapurl);
} else {
// default image if nothing from url
bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.war4a);
}
return bitmap;
}
This is the background thread portion of the Async call:
@Override
protected Bitmap doInBackground(String... urls) {
String surl = urls[0];
Bitmap bm = null;
try {
URL imageUrl = new URL(surl);
bm = BitmapFactory.decodeStream(imageUrl.openStream());
} catch (IOException e) {
e.printStackTrace();
bm = BitmapFactory.decodeResource(context.getResources(), R.drawable.war4a);
}
return bm;
}
This is just a portion of the cumbersome code. As an experienced programmer, I should have known not to reinvent the wheel, but I just could not help myself
At the end of the day, this line of code replaced all that nonsense
Picasso.with(context).load(rowdata.getBitmapUrl()).into(holder.imageView);
