android – Best way to get a SpannableString from a SpannableStringBuilder-ThrowExceptions

Exception or error:

I am working in a wiki-like parser that creates spans for a set of markup tokens. It is working, but inside the token iterator I frequently need to convert the partial results on a SpannableStringBuilder to a SpannableString. This is called pretty frequently, so I’m after the most efficient solution to do it, and avoid creating extra objects.

At the moment I’m using;

SpannableStringBuilder stuff=complex_routine_that_builds_it();
SpannableString result=SpannableString.valueOf(stuff);

However this valueOf call internally builds a SpannableString kind of from scratch, doing a toString and a loop to copy assigned spans.

As SpannableStringBuilder name suggests, I think that maybe there’s a quicker way to get the SpannableString from the builder. Is it true?

How to solve:

There is no need to convert a SpannableStringBuilder to a SpannableString when you can use it directly, as in a TextView:

SpannableStringBuilder stuff = complex_routine_that_builds_it();
textView.setText(stuff);

As the question already showed, you could make the conversion if you absolutely had to by

SpannableStringBuilder stuff = complex_routine_that_builds_it();
SpannableString result = SpannableString.valueOf(stuff);

but you should consider why you would even need to make that conversion? Just use the original SpannableStringBuilder.

SpannableString vs SpannableStringBuilder

The difference between these two is similar to the difference between String and StringBuilder. A String is immutable but you can change the text in a StringBuilder.

Similarly, the text in a SpannableString is immutable while the text in a SpannableStringBuilder is changeable. It is important to note, though, that this only applies to the text. The spans on both of them (even a SpannableString) can be changed.

Related

Leave a Reply

Your email address will not be published. Required fields are marked *