Link spans are lost from ListView's convertView

Question

Why links in ListView are lost, when scrolling? From debugging it's clear, that spans are not added second time on a TextView from the convertView.

Here's a piece of code which is called from adapter's getView.

    ...
    String body = MyItemDetails.getBody(); // String to linkify

    final Spannable spannable = MyCustomUri.addHashtagSpans(context, body);
    viewHolder.textView.setText(spannable);

    viewHolder.textView.setTextIsSelectable(true); // adds additional spans
    viewHolder.textView.setMovementMethod(ArrowKeyMovementMethod.getInstance());
    viewHolder.textView.setAutoLinkMask(Linkify.WEB_URLS);
    ...

MyCustomUri.addHashtagSpans() creates a SpannableString with MyCustomSpan with extends URLSpan.

Problem is that when I scroll up and down in the ListView links are lost. Whereas when screen is opened 1st time it's set correctly.

Now I made a dirty fix by disabling reuse of convertView :( Any ideas how to solve this problem better?

Answer 1

Some of the spannable information is likely being lost when the textview's data is written to a parcel for retention.

See TextView.onSaveInstanceState(), TextView.onRestoreInstanceState(), and TextView.SavedState.

It can often be very frustrating to determine what android will and will not retain. I often just setSaveEnabled(false) on my views to disable the unpredictable default behaviours of the base widgets.

Also, the viewholder pattern is only really intended for retaining view/layout instance hierarchies. To save you from having to inflate or find your views every getView(). It's always your responsibility to update a view's data when presenting it from getView().

You don't need to completely disable the viewholder pattern, instead just simply update the text every getView(), as you may already be doing.