--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/text/SequentialRewriteTextStore.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,275 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2006 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.SequentialRewriteTextStore;
+
+import dwt.dwthelper.utils;
+
+
+import java.util.Iterator;
+import java.util.LinkedList;
+
+
+/**
+ * A text store that optimizes a given source text store for sequential rewriting.
+ * While rewritten it keeps a list of replace command that serve as patches for
+ * the source store. Only on request, the source store is indeed manipulated
+ * by applying the patch commands to the source text store.
+ *
+ * @since 2.0
+ * @deprecated since 3.3 as {@link GapTextStore} performs better even for sequential rewrite scenarios
+ */
+public class SequentialRewriteTextStore : ITextStore {
+
+    /**
+     * A buffered replace command.
+     */
+    private static class Replace {
+        public int newOffset;
+        public final int offset;
+        public final int length;
+        public final String text;
+
+        public Replace(int offset, int newOffset, int length, String text) {
+            this.newOffset= newOffset;
+            this.offset= offset;
+            this.length= length;
+            this.text= text;
+        }
+    }
+
+    /** The list of buffered replacements. */
+    private LinkedList fReplaceList;
+    /** The source text store */
+    private ITextStore fSource;
+    /** A flag to enforce sequential access. */
+    private static final bool ASSERT_SEQUENTIALITY= false;
+
+
+    /**
+     * Creates a new sequential rewrite store for the given source store.
+     *
+     * @param source the source text store
+     */
+    public SequentialRewriteTextStore(ITextStore source) {
+        fReplaceList= new LinkedList();
+        fSource= source;
+    }
+
+    /**
+     * Returns the source store of this rewrite store.
+     *
+     * @return  the source store of this rewrite store
+     */
+    public ITextStore getSourceStore() {
+        commit();
+        return fSource;
+    }
+
+    /*
+     * @see dwtx.jface.text.ITextStore#replace(int, int, java.lang.String)
+     */
+    public void replace(int offset, int length, String text) {
+        if (text is null)
+            text= ""; //$NON-NLS-1$
+
+        if (fReplaceList.size() is 0) {
+            fReplaceList.add(new Replace(offset, offset, length, text));
+
+        } else {
+            Replace firstReplace= (Replace) fReplaceList.getFirst();
+            Replace lastReplace= (Replace) fReplaceList.getLast();
+
+            // backward
+            if (offset + length <= firstReplace.newOffset) {
+                int delta= text.length() - length;
+                if (delta !is 0) {
+                    for (Iterator i= fReplaceList.iterator(); i.hasNext(); ) {
+                        Replace replace= (Replace) i.next();
+                        replace.newOffset += delta;
+                    }
+                }
+
+                fReplaceList.addFirst(new Replace(offset, offset, length, text));
+
+            // forward
+            } else if (offset >= lastReplace.newOffset + lastReplace.text.length()) {
+                int delta= getDelta(lastReplace);
+                fReplaceList.add(new Replace(offset - delta, offset, length, text));
+
+            } else if (ASSERT_SEQUENTIALITY) {
+                throw new IllegalArgumentException();
+
+            } else {
+                commit();
+                fSource.replace(offset, length, text);
+            }
+        }
+    }
+
+    /*
+     * @see dwtx.jface.text.ITextStore#set(java.lang.String)
+     */
+    public void set(String text) {
+        fSource.set(text);
+        fReplaceList.clear();
+    }
+
+    /*
+     * @see dwtx.jface.text.ITextStore#get(int, int)
+     */
+    public String get(int offset, int length) {
+
+        if (fReplaceList.isEmpty())
+            return fSource.get(offset, length);
+
+
+        Replace firstReplace= (Replace) fReplaceList.getFirst();
+        Replace lastReplace= (Replace) fReplaceList.getLast();
+
+        // before
+        if (offset + length <= firstReplace.newOffset) {
+            return fSource.get(offset, length);
+
+            // after
+        } else if (offset >= lastReplace.newOffset + lastReplace.text.length()) {
+            int delta= getDelta(lastReplace);
+            return fSource.get(offset - delta, length);
+
+        } else if (ASSERT_SEQUENTIALITY) {
+            throw new IllegalArgumentException();
+
+        } else {
+
+            int delta= 0;
+            for (Iterator i= fReplaceList.iterator(); i.hasNext(); ) {
+                Replace replace= (Replace) i.next();
+
+                if (offset + length < replace.newOffset) {
+                    return fSource.get(offset - delta, length);
+
+                } else if (offset >= replace.newOffset && offset + length <= replace.newOffset + replace.text.length()) {
+                    return replace.text.substring(offset - replace.newOffset, offset - replace.newOffset + length);
+
+                } else if (offset >= replace.newOffset + replace.text.length()) {
+                    delta= getDelta(replace);
+                    continue;
+
+                } else {
+                    commit();
+                    return fSource.get(offset, length);
+                }
+            }
+
+            return fSource.get(offset - delta, length);
+        }
+
+    }
+
+    /**
+     * Returns the difference between the offset in the source store and the "same" offset in the
+     * rewrite store after the replace operation.
+     *
+     * @param replace the replace command
+     * @return the difference
+     */
+    private static final int getDelta(Replace replace) {
+        return replace.newOffset - replace.offset + replace.text.length() - replace.length;
+    }
+
+    /*
+     * @see dwtx.jface.text.ITextStore#get(int)
+     */
+    public char get(int offset) {
+        if (fReplaceList.isEmpty())
+            return fSource.get(offset);
+
+        Replace firstReplace= (Replace) fReplaceList.getFirst();
+        Replace lastReplace= (Replace) fReplaceList.getLast();
+
+        // before
+        if (offset < firstReplace.newOffset) {
+            return fSource.get(offset);
+
+            // after
+        } else if (offset >= lastReplace.newOffset + lastReplace.text.length()) {
+            int delta= getDelta(lastReplace);
+            return fSource.get(offset - delta);
+
+        } else if (ASSERT_SEQUENTIALITY) {
+            throw new IllegalArgumentException();
+
+        } else {
+
+            int delta= 0;
+            for (Iterator i= fReplaceList.iterator(); i.hasNext(); ) {
+                Replace replace= (Replace) i.next();
+
+                if (offset < replace.newOffset)
+                    return fSource.get(offset - delta);
+
+                else if (offset < replace.newOffset + replace.text.length())
+                    return replace.text.charAt(offset - replace.newOffset);
+
+                delta= getDelta(replace);
+            }
+
+            return fSource.get(offset - delta);
+        }
+    }
+
+    /*
+     * @see dwtx.jface.text.ITextStore#getLength()
+     */
+    public int getLength() {
+        if (fReplaceList.isEmpty())
+            return fSource.getLength();
+
+        Replace lastReplace= (Replace) fReplaceList.getLast();
+        return fSource.getLength() + getDelta(lastReplace);
+    }
+
+    /**
+     * Disposes this rewrite store.
+     */
+    public void dispose() {
+        fReplaceList= null;
+        fSource= null;
+    }
+
+    /**
+     * Commits all buffered replace commands.
+     */
+    private void commit() {
+
+        if (fReplaceList.isEmpty())
+            return;
+
+        StringBuffer buffer= new StringBuffer();
+
+        int delta= 0;
+        for (Iterator i= fReplaceList.iterator(); i.hasNext(); ) {
+            Replace replace= (Replace) i.next();
+
+            int offset= buffer.length() - delta;
+            buffer.append(fSource.get(offset, replace.offset - offset));
+            buffer.append(replace.text);
+            delta= getDelta(replace);
+        }
+
+        int offset= buffer.length() - delta;
+        buffer.append(fSource.get(offset, fSource.getLength() - offset));
+
+        fSource.set(buffer.toString());
+        fReplaceList.clear();
+    }
+}