This method is called when the buffer is going to replace the
dstart … dend
with the new text from the range
start … end
. Return the CharSequence that you would
like to have placed there instead, including an empty string
if appropriate, or
to accept the original
replacement. Be careful to not to reject 0-length replacements,
as this is what happens when you delete text. Also beware that
you should not attempt to make any changes to
from this method; you may only examine it for context.
Note: If source
is an instance of
, the span objects in the source
copied into the filtered result (i.e. the non-null return value).
TextUtils.copySpansFrom(android.text.Spanned, int, int, java.lang.Class, android.text.Spannable, int)
can be used for convenience.