protected Operation transform(DeleteOperation delA, InsertOperation insB) {
int posA = delA.getPosition();
int lenA = delA.getTextLength();
int posB = insB.getPosition();
int lenB = insB.getTextLength();
if (posB >= (posA + lenA)) {
/*
* Operation B is completely after operation A.
*/
return delA;
} else if (posB <= posA) {
/*
* Operation B starts before or at the same position like operation
* A
*/
return new DeleteOperation(posA + lenB, delA.getText());
} else {
/*
* Operation B (insert) is in the range of operation A (delete).
* Operation A' must be split up into two delete operations. (A):
* "123456" (A'): "1" "23456"
*/
DeleteOperation del1 = new DeleteOperation(posA, delA.getText().substring(0, posB - posA));
DeleteOperation del2 =
new DeleteOperation(posA + lenB, delA.getText().substring(posB - posA, lenA));
return new SplitOperation(del1, del2);
}
}
protected Operation transform(
InsertOperation insA, InsertOperation insB, boolean isTransformPrivileged) {
int posA = insA.getPosition();
int posB = insB.getPosition();
int lenB = insB.getTextLength();
if ((posA < posB)
|| ((posA == posB) && (insA.getOrigin() < insB.getOrigin()))
|| ((posA == posB) && (insA.getOrigin() == insB.getOrigin()) && isTransformPrivileged)) {
/*
* Operation A starts before operation B.
*/
return insA;
} else {
/*
* Operation A starts in or behind operation B. Index of operation
* A' must be increased by the length of the text of operation B.
*/
return new InsertOperation(posA + lenB, insA.getText(), insA.getOrigin());
}
}