| public java.lang.CharSequence | filter(java.lang.CharSequence source, int start, int end, Spanned dest, int dstart, int dend)This method is called when the buffer is going to replace the
range dstart … dend of dest
with the new text from the range start … end
of source. Returns the CharSequence that we want
placed there instead, including an empty string
if appropriate, or null to accept the original
replacement. Be careful to not to reject 0-length replacements,
as this is what happens when you delete text.
onStart();
// Scan through beginning characters in dest, calling onInvalidCharacter()
// for each invalid character.
for (int i = 0; i < dstart; i++) {
char c = dest.charAt(i);
if (!isAllowed(c)) onInvalidCharacter(c);
}
// Scan through changed characters rejecting disallowed chars
SpannableStringBuilder modification = null;
int modoff = 0;
for (int i = start; i < end; i++) {
char c = source.charAt(i);
if (isAllowed(c)) {
// Character allowed.
modoff++;
} else {
if (mAppendInvalid) {
modoff++;
} else {
if (modification == null) {
modification = new SpannableStringBuilder(source, start, end);
modoff = i - start;
}
modification.delete(modoff, modoff + 1);
}
onInvalidCharacter(c);
}
}
// Scan through remaining characters in dest, calling onInvalidCharacter()
// for each invalid character.
for (int i = dend; i < dest.length(); i++) {
char c = dest.charAt(i);
if (!isAllowed(c)) onInvalidCharacter(c);
}
onStop();
// Either returns null if we made no changes,
// or what we wanted to change it to if there were changes.
return modification;
|
