/*******************************************************************************
* Copyright (c) 2001, 2007 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Jens Lukowski/Innoopract - initial renaming/restructuring
*
*******************************************************************************/
package org.eclipse.wst.xml.core.internal.parser.regions;
import org.eclipse.wst.sse.core.internal.provisional.events.RegionChangedEvent;
import org.eclipse.wst.sse.core.internal.provisional.events.StructuredDocumentEvent;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.sse.core.internal.util.Debug;
import org.eclipse.wst.sse.core.internal.util.Utilities;
/**
*
* This is a utility class to centralize 'region' update. Note: care must be
* taken that is is not used for StructuredDocumentRegions, or container
* regions, its only for "token regions"
*
*/
public class RegionUpdateRule {
static public boolean allLetterOrDigit(String changes) {
boolean result = true;
for (int i = 0; i < changes.length(); i++) {
// TO_DO_FUTURE: check that a Java Letter or Digit is
// the same thing as an XML letter or digit
if (!(Character.isLetterOrDigit(changes.charAt(i)))) {
result = false;
break;
}
}
return result;
}
static public boolean allWhiteSpace(String changes) {
boolean result = true;
for (int i = 0; i < changes.length(); i++) {
if (!Character.isWhitespace(changes.charAt(i))) {
result = false;
break;
}
}
return result;
}
static public boolean canHandleAsLetterOrDigit(ITextRegion region, IStructuredDocumentRegion parent, String changes, int requestStart, int lengthToReplace) {
if (parent == null)
return canHandleAsLetterOrDigit(region, changes, requestStart, lengthToReplace);
boolean result = false;
// Make sure we are in a non-white space area
if ((requestStart <= (parent.getTextEndOffset(region))) && (allLetterOrDigit(changes))) {
result = true;
}
return result;
}
static public boolean canHandleAsLetterOrDigit(ITextRegion region, String changes, int requestStart, int lengthToReplace) {
boolean result = false;
// Make sure we are in a non-white space area
if ((requestStart <= (region.getTextEnd())) && (allLetterOrDigit(changes))) {
result = true;
}
return result;
}
static public boolean canHandleAsWhiteSpace(ITextRegion region, IStructuredDocumentRegion parent, String changes, int requestStart, int lengthToReplace) {
// we don't explect a null parent, but just in case!
// (in which case, we must be dealing with regions that are
// structuredDocumentRegions).
if (parent == null)
return canHandleAsWhiteSpace(region, changes, requestStart, lengthToReplace);
boolean result = false;
// if we are in the "white space" area of a region, then
// we don't want to handle, a reparse is needed.
// the white space region is consider anywhere that would
// leave whitespace between this character and the text part.
// and of course, we can insert whitespace in whitespace region
//
// if there is no whitespace in this region, no need to look further
if (region.getEnd() > region.getTextEnd()) {
// no need to add one to end of text, as we used to, since we
// change definition of length to equate to offset plus one.
// https://bugs.eclipse.org/bugs/show_bug.cgi?id=105866
// watch out for whitespace at end of text
if (requestStart >= parent.getTextEndOffset(region)) {
// ok, we are in the whitespace region, so we can't handle,
// unless
// we are just inserting whitespace.
if (allWhiteSpace(changes)) {
result = true;
} else {
result = false;
}
}
}
return result;
}
static public boolean canHandleAsWhiteSpace(ITextRegion region, String changes, int requestStart, int lengthToReplace) {
boolean result = false;
// if we are in the "white space" area of a region, then
// we don't want to handle, a reparse is needed.
// the white space region is consider anywhere that would
// leave whitespace between this character and the text part.
// and of course, we can insert whitespace in whitespace region
//
// if there is no whitespace in this region, no need to look further
if (region.getEnd() > region.getTextEnd()) {
// no need to add one to end of text, as we used to, since we
// change definition of length to equate to offset plus one.
// https://bugs.eclipse.org/bugs/show_bug.cgi?id=105866
// watch out for whitespace at end of text
if (requestStart >= region.getTextEnd()) {
// ok, we are in the whitespace region, so we can't handle,
// unless
// we are just inserting whitespace.
if (allWhiteSpace(changes)) {
result = true;
} else {
result = false;
}
}
}
return result;
}
// need an adjust text length API before this can be used
static public StructuredDocumentEvent updateModel(ITextRegion region, 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 " + region.getType()); //$NON-NLS-1$
}
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 ((region.getStart() >= region.getTextEnd()) || (Math.abs(lengthToReplace) >= region.getTextEnd() - region.getStart())) {
canHandle = false;
} else {
canHandle = true;
}
} else {
if ((RegionUpdateRule.canHandleAsWhiteSpace(region, parent, changes, requestStart, lengthToReplace)) || RegionUpdateRule.canHandleAsLetterOrDigit(region, 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.
region.adjustLength(lengthDifference);
// 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(region, parent, changes, region.getStart(), lengthToReplace)) {
// region.adjustTextLength(lengthDifference);
}
result = new RegionChangedEvent(parent.getParentDocument(), requester, parent, region, changes, requestStart, lengthToReplace);
}
return result;
}
}