guint insert_text ( GtkEntryBuffer* buffer, guint position, const char* chars, guint n_chars )
n_chars characters of
chars into the contents of the
buffer, at position
n_chars is negative, then characters from chars will be inserted
until a null-terminator is found. If
n_chars are out of
bounds, or the maximum buffer text length is exceeded, then they are
coerced to sane values.
Note that the position and length are in characters, not in bytes.
The position at which to insert text.
The text to insert into the buffer.
The data is owned by the caller of the method. The value is a NUL terminated UTF-8 string.
The length of the text in characters, or -1