Need help in Insertion of Element in DefaultStyledDocument

Question

Hello:
I am developing an XML editor by extending the DefaultStyledDocument of javax.swing.text package. I am not able to insert an element in the document.
This is what I have done: (I need to insert one BranchElement, with two leaf child elements.)
I inserted the text in the document corresponding to the first child element using insertString() method. In the insertUpdate() method of the document, I am creating the branch element and its first child covering the inserted text. I then call the insertUpdate() method of DefaultStyledDocument. Similarly, I insert text corresponding to the second child and modify the element structure inside insertUpdate() and then call the insertUpdate() of DefaultStyledDocument().
At the end of the execution, the element structure is okay, but all the inserted text also becomes a part of the previous element.
for example,
if I have the following element structure at the beginning: (element offsets are in the square brackets besides their names, child elements are indented.)
html [0 2]
start-leaf [0 1]
end-leaf [1 2]
and I insert body at position 1 with its two children (each of length 1)
I get the following element structure:
html [0 4]
start-leaf [0 3] //why this?
body [1 3]
start-leaf[1 3] //why this instead of [1 2]?
end-leaf [2 3]
end-leaf [3 4]
And, I am not able to see the Views corresponding to the inserted elements.
(I tried without modifying the element structure explicitely, but it doesn't work that way.Also, I am able to remove elements from the document. In that case also I am following a similar logic: remove the data from the document using remove() method and modify the element structure inside removeUpdate(). and it seems to work fine.)
Can anyone please help me understand why this is happening?
Thanks a lot!

Answer 1

like this ??
SQL> Create Table t1
  2  (a Number,
  3   b Number);
Table created
SQL>  Create Table t2
  2  (a Number,
  3   b Number,
  4   c Number Not Null);
Table created
SQL>  Insert Into t1 Values (1,2);
1 row inserted
SQL> commit;
Commit complete
SQL>  Insert Into t2 Select t.*,3 From t1 t;
1 row inserted
SQL> commit;
Commit complete
SQL> select * from t1;
         A          B
         1          2
SQL> select * from t2;
         A          B          C
         1          2          3
SQL> hope this helps you