--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/text/link/LinkedPositionGroup.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,421 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2008 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
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.jface.text.link.LinkedPositionGroup;
+
+import dwt.dwthelper.utils;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import dwtx.core.runtime.Assert;
+import dwtx.jface.text.BadLocationException;
+import dwtx.jface.text.DocumentEvent;
+import dwtx.jface.text.IDocument;
+import dwtx.jface.text.IRegion;
+import dwtx.jface.text.Position;
+import dwtx.jface.text.Region;
+import dwtx.text.edits.MalformedTreeException;
+import dwtx.text.edits.MultiTextEdit;
+import dwtx.text.edits.ReplaceEdit;
+import dwtx.text.edits.TextEdit;
+
+
+/**
+ * A group of positions in multiple documents that are simultaneously modified -
+ * if one gets edited, all other positions in a group are edited the same way.
+ * All linked positions in a group have the same content.
+ * <p>
+ * Normally, new positions are given a tab stop weight which can be used by
+ * clients, e.g. the UI. If no weight is given, a position will not be visited.
+ * If no weights are used at all, the first position in a document is taken as
+ * the only stop as to comply with the behavior of the old linked position
+ * infrastructure.
+ * </p>
+ * <p>
+ * Clients may instantiate this class.
+ * </p>
+ *
+ * @since 3.0
+ * @noextend This class is not intended to be subclassed by clients.
+ */
+public class LinkedPositionGroup {
+
+    /** Sequence constant declaring that a position should not be stopped by. */
+    public static final int NO_STOP= -1;
+
+    /* members */
+
+    /** The linked positions of this group. */
+    private final List fPositions= new LinkedList();
+    /** Whether we are sealed or not. */
+    private bool fIsSealed= false;
+    /**
+     * <code>true</code> if there are custom iteration weights. For backward
+     * compatibility.
+     */
+    private bool fHasCustomIteration= false;
+
+    /*
+     * iteration variables, set to communicate state between isLegalEvent and
+     * handleEvent
+     */
+    /** The position including the most recent <code>DocumentEvent</code>. */
+    private LinkedPosition fLastPosition;
+    /** The region covered by <code>fLastPosition</code> before the document
+     * change.
+     */
+    private IRegion fLastRegion;
+
+    /**
+     * Adds a position to this group. The document region defined by the
+     * position must contain the same content (and thus have the same length) as
+     * any of the other positions already in this group. Additionally, all
+     * positions added must be disjoint; otherwise a
+     * <code>BadLocationException</code> is thrown.
+     * <p>
+     * Positions added using this method are owned by this group afterwards and
+     * may not be updated or modified thereafter.
+     * </p>
+     * <p>
+     * Once a group has been added to a <code>LinkedModeModel</code>, it
+     * becomes <em>sealed</em> and no positions may be added any more.
+     * </p>
+     *
+     * @param position the position to add
+     * @throws BadLocationException if the position is invalid or conflicts with
+     *         other positions in the group
+     * @throws IllegalStateException if the group has already been added to a
+     *         model
+     */
+    public void addPosition(LinkedPosition position) throws BadLocationException {
+        /*
+         * Enforces constraints and sets the custom iteration flag. If the
+         * position is already in this group, nothing happens.
+         */
+        Assert.isNotNull(position);
+        if (fIsSealed)
+            throw new IllegalStateException("cannot add positions after the group is added to an model"); //$NON-NLS-1$
+
+        if (!fPositions.contains(position)) {
+            enforceDisjoint(position);
+            enforceEqualContent(position);
+            fPositions.add(position);
+            fHasCustomIteration |= position.getSequenceNumber() !is LinkedPositionGroup.NO_STOP;
+        } else
+            return; // nothing happens
+    }
+
+    /**
+     * Enforces the invariant that all positions must contain the same string.
+     *
+     * @param position the position to check
+     * @throws BadLocationException if the equal content check fails
+     */
+    private void enforceEqualContent(LinkedPosition position) throws BadLocationException {
+        if (fPositions.size() > 0) {
+            LinkedPosition groupPosition= (LinkedPosition) fPositions.get(0);
+            String groupContent= groupPosition.getContent();
+            String positionContent= position.getContent();
+            if (!groupContent.equals(positionContent))
+                throw new BadLocationException(
+                        "First position: '" + groupContent + "' at " + groupPosition.getOffset() + //$NON-NLS-1$ //$NON-NLS-2$
+                        ", this position: '" + positionContent + "' at " + position.getOffset()); //$NON-NLS-1$ //$NON-NLS-2$
+        }
+    }
+
+    /**
+     * Enforces the invariant that all positions must be disjoint.
+     *
+     * @param position the position to check
+     * @throws BadLocationException if the disjointness check fails
+     */
+    private void enforceDisjoint(LinkedPosition position) throws BadLocationException {
+        for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition p= (LinkedPosition) it.next();
+            if (p.overlapsWith(position))
+                throw new BadLocationException();
+        }
+    }
+
+    /**
+     * Enforces the disjointness for another group
+     *
+     * @param group the group to check
+     * @throws BadLocationException if the disjointness check fails
+     */
+    void enforceDisjoint(LinkedPositionGroup group) throws BadLocationException {
+        Assert.isNotNull(group);
+        for (Iterator it= group.fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition p= (LinkedPosition) it.next();
+            enforceDisjoint(p);
+        }
+    }
+
+    /**
+     * Checks whether <code>event</code> is a legal event for this group. An
+     * event is legal if it touches at most one position contained within this
+     * group.
+     *
+     * @param event the document event to check
+     * @return <code>true</code> if <code>event</code> is legal
+     */
+    bool isLegalEvent(DocumentEvent event) {
+        fLastPosition= null;
+        fLastRegion= null;
+
+        for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition pos= (LinkedPosition) it.next();
+            if (overlapsOrTouches(pos, event)) {
+                if (fLastPosition !is null) {
+                    fLastPosition= null;
+                    fLastRegion= null;
+                    return false;
+                }
+
+                fLastPosition= pos;
+                fLastRegion= new Region(pos.getOffset(), pos.getLength());
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Checks whether the given event touches the given position. To touch means
+     * to overlap or come up to the borders of the position.
+     *
+     * @param position the position
+     * @param event the event
+     * @return <code>true</code> if <code>position</code> and
+     *         <code>event</code> are not absolutely disjoint
+     * @since 3.1
+     */
+    private bool overlapsOrTouches(LinkedPosition position, DocumentEvent event) {
+        return position.getDocument().equals(event.getDocument()) && position.getOffset() <= event.getOffset() + event.getLength() && position.getOffset() + position.getLength() >= event.getOffset();
+    }
+
+    /**
+     * Creates an edition of a document change that will forward any
+     * modification in one position to all linked siblings. The return value is
+     * a map from <code>IDocument</code> to <code>TextEdit</code>.
+     *
+     * @param event the document event to check
+     * @return a map of edits, grouped by edited document, or <code>null</code>
+     *         if there are no edits
+     */
+    Map handleEvent(DocumentEvent event) {
+
+        if (fLastPosition !is null) {
+
+            Map map= new HashMap();
+
+
+            int relativeOffset= event.getOffset() - fLastRegion.getOffset();
+            if (relativeOffset < 0) {
+                relativeOffset= 0;
+            }
+
+            int eventEnd= event.getOffset() + event.getLength();
+            int lastEnd= fLastRegion.getOffset() + fLastRegion.getLength();
+            int length;
+            if (eventEnd > lastEnd)
+                length= lastEnd - relativeOffset - fLastRegion.getOffset();
+            else
+                length= eventEnd - relativeOffset - fLastRegion.getOffset();
+
+            String text= event.getText();
+            if (text is null)
+                text= ""; //$NON-NLS-1$
+
+            for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+                LinkedPosition p= (LinkedPosition) it.next();
+                if (p is fLastPosition || p.isDeleted())
+                    continue; // don't re-update the origin of the change
+
+                List edits= (List) map.get(p.getDocument());
+                if (edits is null) {
+                    edits= new ArrayList();
+                    map.put(p.getDocument(), edits);
+                }
+
+                edits.add(new ReplaceEdit(p.getOffset() + relativeOffset, length, text));
+            }
+
+            try {
+                for (Iterator it= map.keySet().iterator(); it.hasNext();) {
+                    IDocument d= (IDocument) it.next();
+                    TextEdit edit= new MultiTextEdit(0, d.getLength());
+                    edit.addChildren((TextEdit[]) ((List) map.get(d)).toArray(new TextEdit[0]));
+                    map.put(d, edit);
+                }
+
+                return map;
+            } catch (MalformedTreeException x) {
+                // may happen during undo, as LinkedModeModel does not know 
+                // that the changes technically originate from a parent environment
+                // if this happens, post notification changes are not accepted anyway and
+                // we can simply return null - any changes will be undone by the undo
+                // manager
+                return null;
+            }
+
+        }
+
+        return null;
+    }
+
+    /**
+     * Sets the model of this group. Once a model has been set, no
+     * more positions can be added and the model cannot be changed.
+     */
+    void seal() {
+        Assert.isTrue(!fIsSealed);
+        fIsSealed= true;
+
+        if (fHasCustomIteration is false && fPositions.size() > 0) {
+            ((LinkedPosition) fPositions.get(0)).setSequenceNumber(0);
+        }
+    }
+
+    IDocument[] getDocuments() {
+        IDocument[] docs= new IDocument[fPositions.size()];
+        int i= 0;
+        for (Iterator it= fPositions.iterator(); it.hasNext(); i++) {
+            LinkedPosition pos= (LinkedPosition) it.next();
+            docs[i]= pos.getDocument();
+        }
+        return docs;
+    }
+
+    void register(LinkedModeModel model) throws BadLocationException {
+        for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition pos= (LinkedPosition) it.next();
+            model.register(pos);
+        }
+    }
+
+    /**
+     * Returns the position in this group that encompasses all positions in
+     * <code>group</code>.
+     *
+     * @param group the group to be adopted
+     * @return a position in the receiver that contains all positions in <code>group</code>,
+     *         or <code>null</code> if none can be found
+     * @throws BadLocationException if more than one position are affected by
+     *         <code>group</code>
+     */
+    LinkedPosition adopt(LinkedPositionGroup group) throws BadLocationException {
+        LinkedPosition found= null;
+        for (Iterator it= group.fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition pos= (LinkedPosition) it.next();
+            LinkedPosition localFound= null;
+            for (Iterator it2= fPositions.iterator(); it2.hasNext(); ) {
+                LinkedPosition myPos= (LinkedPosition) it2.next();
+                if (myPos.includes(pos)) {
+                    if (found is null)
+                        found= myPos;
+                    else if (found !is myPos)
+                        throw new BadLocationException();
+                    if (localFound is null)
+                        localFound= myPos;
+                }
+            }
+
+            if (localFound !is found)
+                throw new BadLocationException();
+        }
+        return found;
+    }
+
+    /**
+     * Finds the closest position to <code>toFind</code>.
+     *
+     * @param toFind the linked position for which to find the closest position
+     * @return the closest position to <code>toFind</code>.
+     */
+    LinkedPosition getPosition(LinkedPosition toFind) {
+        for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition p= (LinkedPosition) it.next();
+            if (p.includes(toFind))
+                return p;
+        }
+        return null;
+    }
+
+    /**
+     * Returns <code>true</code> if <code>offset</code> is contained in any
+     * position in this group.
+     *
+     * @param offset the offset to check
+     * @return <code>true</code> if offset is contained by this group
+     */
+    bool contains(int offset) {
+        for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition pos= (LinkedPosition) it.next();
+            if (pos.includes(offset)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Returns whether this group contains any positions.
+     *
+     * @return <code>true</code> if this group is empty, <code>false</code> otherwise
+     * @since 3.1
+     */
+    public bool isEmpty() {
+        return fPositions.size() is 0;
+    }
+    
+    /**
+     * Returns whether this group contains any positions.
+     *
+     * @return <code>true</code> if this group is empty, <code>false</code> otherwise
+     * @deprecated As of 3.1, replaced by {@link #isEmpty()}
+     */
+    public bool isEmtpy() {
+        return isEmpty();
+    }
+
+    /**
+     * Returns the positions contained in the receiver as an array. The
+     * positions are the actual positions and must not be modified; the array
+     * is a copy of internal structures.
+     *
+     * @return the positions of this group in no particular order
+     */
+    public LinkedPosition[] getPositions() {
+        return (LinkedPosition[]) fPositions.toArray(new LinkedPosition[0]);
+    }
+
+    /**
+     * Returns <code>true</code> if the receiver contains <code>position</code>.
+     *
+     * @param position the position to check
+     * @return <code>true</code> if the receiver contains <code>position</code>
+     */
+    bool contains(Position position) {
+        for (Iterator it= fPositions.iterator(); it.hasNext(); ) {
+            LinkedPosition p= (LinkedPosition) it.next();
+            if (position.equals(p))
+                return true;
+        }
+        return false;
+    }
+}