--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/text/Position.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,202 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 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
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.jface.text.Position;
+
+import dwt.dwthelper.utils;
+
+import dwtx.core.runtime.Assert;
+
+
+/**
+ * Positions describe text ranges of a document. Positions are adapted to
+ * changes applied to that document. The text range is specified by an offset
+ * and a length. Positions can be marked as deleted. Deleted positions are
+ * considered to no longer represent a valid text range in the managing
+ * document.
+ * <p>
+ * Positions attached to documents are usually updated by position updaters.
+ * Because position updaters are freely definable and because of the frequency
+ * in which they are used, the fields of a position are made publicly
+ * accessible. Clients other than position updaters are not allowed to access
+ * these public fields.
+ * </p>
+ * <p>
+ * Positions cannot be used as keys in hash tables as they override
+ * <code>equals</code> and <code>hashCode</code> as they would be value
+ * objects.
+ * </p>
+ *
+ * @see dwtx.jface.text.IDocument
+ */
+public class Position {
+
+    /** The offset of the position */
+    public int offset;
+    /** The length of the position */
+    public int length;
+    /** Indicates whether the position has been deleted */
+    public bool isDeleted;
+
+    /**
+     * Creates a new position with the given offset and length 0.
+     *
+     * @param offset the position offset, must be >= 0
+     */
+    public Position(int offset) {
+        this(offset, 0);
+    }
+
+    /**
+     * Creates a new position with the given offset and length.
+     *
+     * @param offset the position offset, must be >= 0
+     * @param length the position length, must be >= 0
+     */
+    public Position(int offset, int length) {
+        Assert.isTrue(offset >= 0);
+        Assert.isTrue(length >= 0);
+        this.offset= offset;
+        this.length= length;
+    }
+
+    /**
+     * Creates a new, not initialized position.
+     */
+    protected Position() {
+    }
+
+     /*
+     * @see java.lang.Object#hashCode()
+     */
+    public int hashCode() {
+        int deleted= isDeleted ? 0 : 1;
+        return (offset << 24) | (length << 16) | deleted;
+     }
+
+    /**
+     * Marks this position as deleted.
+     */
+    public void delete() {
+        isDeleted= true;
+    }
+
+    /**
+     * Marks this position as not deleted.
+     *
+     * @since 2.0
+     */
+    public void undelete() {
+        isDeleted= false;
+    }
+
+    /*
+     * @see java.lang.Object#equals(java.lang.Object)
+     */
+    public bool equals(Object other) {
+        if (other instanceof Position) {
+            Position rp= (Position) other;
+            return (rp.offset is offset) && (rp.length is length);
+        }
+        return super.equals(other);
+    }
+
+    /**
+     * Returns the length of this position.
+     *
+     * @return the length of this position
+     */
+    public int getLength() {
+        return length;
+    }
+
+    /**
+     * Returns the offset of this position.
+     *
+     * @return the offset of this position
+     */
+    public int getOffset() {
+        return offset;
+    }
+
+    /**
+     * Checks whether the given index is inside
+     * of this position's text range.
+     *
+     * @param index the index to check
+     * @return <code>true</code> if <code>index</code> is inside of this position
+     */
+    public bool includes(int index) {
+
+        if (isDeleted)
+            return false;
+
+        return (this.offset <= index) && (index < this.offset + length);
+    }
+
+    /**
+     * Checks whether the intersection of the given text range
+     * and the text range represented by this position is empty
+     * or not.
+     *
+     * @param rangeOffset the offset of the range to check
+     * @param rangeLength the length of the range to check
+     * @return <code>true</code> if intersection is not empty
+     */
+    public bool overlapsWith(int rangeOffset, int rangeLength) {
+
+        if (isDeleted)
+            return false;
+
+        int end= rangeOffset + rangeLength;
+        int thisEnd= this.offset + this.length;
+
+        if (rangeLength > 0) {
+            if (this.length > 0)
+                return this.offset < end && rangeOffset < thisEnd;
+            return  rangeOffset <= this.offset && this.offset < end;
+        }
+
+        if (this.length > 0)
+            return this.offset <= rangeOffset && rangeOffset < thisEnd;
+        return this.offset is rangeOffset;
+    }
+
+    /**
+     * Returns whether this position has been deleted or not.
+     *
+     * @return <code>true</code> if position has been deleted
+     */
+    public bool isDeleted() {
+        return isDeleted;
+    }
+
+    /**
+     * Changes the length of this position to the given length.
+     *
+     * @param length the new length of this position
+     */
+    public void setLength(int length) {
+        Assert.isTrue(length >= 0);
+        this.length= length;
+    }
+
+    /**
+     * Changes the offset of this position to the given offset.
+     *
+     * @param offset the new offset of this position
+     */
+    public void setOffset(int offset) {
+        Assert.isTrue(offset >= 0);
+        this.offset= offset;
+    }
+}