public String toString() {
return RegionToStringUtil.toString(this);
}
public StructuredDocumentEvent updateRegion(Object requester, IStructuredDocumentRegion parent, String changes, int requestStart, int lengthToReplace) {
RegionChangedEvent result = null;
// if the region is an easy type (e.g. attribute value),
// and the requested changes are all
// alphanumeric, then make the change here locally.
// (This can obviously be made more sophisticated as the need arises,
// but should
// always follow this pattern.)
if (Debug.debugStructuredDocument) {
System.out.println("\t\tContextRegion::updateModel"); //$NON-NLS-1$
System.out.println("\t\t\tregion type is " + fType); //$NON-NLS-1$
}
boolean canHandle = false;
// note: we'll always handle deletes from these
// regions ... if its already that region,
// deleting something from it won't change its
// type. (remember, the calling program needs
// to insure we are not called, if not all contained
// on one region.
if ((changes == null) || (changes.length() == 0)) {
// delete case
// We can not do the quick delete, if
// if all the text in a region is to be deleted.
// Or, if the delete starts in the white space region.
// In these cases, a reparse is needed.
// Minor note, we use textEnd-start since it always
// less than or equal to end-start. This might
// cause us to miss a few cases we could have handled,
// but will prevent us from trying to handle funning cases
// involving whitespace.
if ((fStart >= getTextEnd()) || (Math.abs(lengthToReplace) >= getTextEnd() - getStart())) {
canHandle = false;
} else {
canHandle = true;
}
} else {
if ((RegionUpdateRule.canHandleAsWhiteSpace(this, parent, changes, requestStart, lengthToReplace)) || RegionUpdateRule.canHandleAsLetterOrDigit(this, parent, changes, requestStart, lengthToReplace)) {
canHandle = true;
} else {
canHandle = false;
}
}
if (canHandle) {
// at this point, we still have the old region. We won't create a
// new instance, we'll just update the one we have, by changing
// its end postion,
// The parent flatnode, upon return, has responsibility
// for updating sibling regions.
// and in turn, the structuredDocument itself has responsibility
// for
// updating the text store and down stream flatnodes.
if (Debug.debugStructuredDocument) {
System.out.println("change handled by region"); //$NON-NLS-1$
}
int lengthDifference = Utilities.calculateLengthDifference(changes, lengthToReplace);
// Note: we adjust both end and text end, because for any change
// that is in only the trailing whitespace region, we should not
// do a quick change,
// so 'canHandle' should have been false for those case.
// TO_DO_FUTURE: cache value of canHandleAsWhiteSpace from above
// If we are handling as whitespace, there is no need to increase
// the text length, only
// the total length is changing.
if (!RegionUpdateRule.canHandleAsWhiteSpace(this, parent, changes, requestStart, lengthToReplace)) {
fTextLength += lengthDifference;
}
// update length (and end) after above check for white space,
// since
// it looks to determine if at end of region.
fLength += lengthDifference;
result = new RegionChangedEvent(parent.getParentDocument(), requester, parent, this, changes, requestStart, lengthToReplace);
}
return result;
}