--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwt/layout/FormAttachment.d	Sun Jan 20 21:50:55 2008 -0800
@@ -0,0 +1,306 @@
+/*******************************************************************************
+ * 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 dwt.layout.FormAttachment;
+
+import dwt.DWT;
+import dwt.widgets.Control;
+import dwt.layout.FormLayout;
+import dwt.layout.FormData;
+
+import tango.text.convert.Format;
+
+/**
+ * Instances of this class are used to define the edges of a control
+ * within a <code>FormLayout</code>.
+ * <p>
+ * <code>FormAttachments</code> are set into the top, bottom, left,
+ * and right fields of the <code>FormData</code> for a control.
+ * For example:
+ * <pre>
+ *      FormData data = new FormData();
+ *      data.top = new FormAttachment(0,5);
+ *      data.bottom = new FormAttachment(100,-5);
+ *      data.left = new FormAttachment(0,5);
+ *      data.right = new FormAttachment(100,-5);
+ *      button.setLayoutData(data);
+ * </pre>
+ * </p>
+ * <p>
+ * A <code>FormAttachment</code> defines where to attach the side of
+ * a control by using the equation, y = ax + b. The "a" term represents
+ * a fraction of the parent composite's width (from the left) or height
+ * (from the top). It can be defined using a numerator and denominator,
+ * or just a percentage value. If a percentage is used, the denominator
+ * is set to 100. The "b" term in the equation represents an offset, in
+ * pixels, from the attachment position. For example:
+ * <pre>
+ *      FormAttachment attach = new FormAttachment (20, -5);
+ * </pre>
+ * specifies that the side to which the <code>FormAttachment</code>
+ * object belongs will lie at 20% of the parent composite, minus 5 pixels.
+ * </p>
+ * <p>
+ * Control sides can also be attached to another control.
+ * For example:
+ * <pre>
+ *      FormAttachment attach = new FormAttachment (button, 10);
+ * </pre>
+ * specifies that the side to which the <code>FormAttachment</code>
+ * object belongs will lie in the same position as the adjacent side of
+ * the <code>button</code> control, plus 10 pixels. The control side can
+ * also be attached to the opposite side of the specified control.
+ * For example:
+ * <pre>
+ *      FormData data = new FormData ();
+ *      data.left = new FormAttachment (button, 0, DWT.LEFT);
+ * </pre>
+ * specifies that the left side of the control will lie in the same position
+ * as the left side of the <code>button</code> control. The control can also
+ * be attached in a position that will center the control on the specified
+ * control. For example:
+ * <pre>
+ *      data.left = new FormAttachment (button, 0, DWT.CENTER);
+ * </pre>
+ * specifies that the left side of the control will be positioned so that it is
+ * centered between the left and right sides of the <code>button</code> control.
+ * If the alignment is not specified, the default is to attach to the adjacent side.
+ * </p>
+ *
+ * @see FormLayout
+ * @see FormData
+ *
+ * @since 2.0
+ */
+public final class FormAttachment {
+    /**
+     * numerator specifies the numerator of the "a" term in the
+     * equation, y = ax + b, which defines the attachment.
+     */
+    public int numerator;
+
+    /**
+     * denominator specifies the denominator of the "a" term in the
+     * equation, y = ax + b, which defines the attachment.
+     *
+     * The default value is 100.
+     */
+    public int denominator = 100;
+
+    /**
+     * offset specifies the offset, in pixels, of the control side
+     * from the attachment position.
+     * If the offset is positive, then the control side is offset
+     * to the right of or below the attachment position. If it is
+     * negative, then the control side is offset to the left of or
+     * above the attachment position.
+     *
+     * This is equivalent to the "b" term in the equation y = ax + b.
+     * The default value is 0.
+     */
+    public int offset;
+
+    /**
+     * control specifies the control to which the control side is
+     * attached.
+     */
+    public Control control;
+
+    /**
+     * alignment specifies the alignment of the control side that is
+     * attached to a control.
+     * <p>
+     * For top and bottom attachments, TOP, BOTTOM and CENTER are used. For left
+     * and right attachments, LEFT, RIGHT and CENTER are used. If any other case
+     * occurs, the default will be used instead.
+     * </p>
+     *
+     * <br>Possible values are: <ul>
+     *    <li>TOP: Attach the side to the top side of the specified control.</li>
+     *    <li>BOTTOM : Attach the side to the bottom side of the specified control.</li>
+     *    <li>LEFT: Attach the side to the left side of the specified control.</li>
+     *    <li>RIGHT: Attach the side to the right side of the specified control.</li>
+     *    <li>CENTER: Attach the side at a position which will center the control on the specified control.</li>
+     *    <li>DEFAULT: Attach the side to the adjacent side of the specified control.</li>
+     * </ul>
+     */
+    public int alignment;
+
+/**
+ * Constructs a new instance of this class.
+ * Since no numerator, denominator or offset is specified,
+ * the attachment is treated as a percentage of the form.
+ * The numerator is zero, the denominator is 100 and the
+ * offset is zero.
+ *
+ * @since 3.2
+ */
+public this () {
+}
+
+/**
+ * Constructs a new instance of this class given a numerator
+ * Since no denominator or offset is specified, the default
+ * is to treat the numerator as a percentage of the form, with a
+ * denominator of 100. The offset is zero.
+ *
+ * @param numerator the percentage of the position
+ *
+ * @since 3.0
+ */
+public this (int numerator) {
+    this (numerator, 100, 0);
+}
+
+/**
+ * Constructs a new instance of this class given a numerator
+ * and an offset. Since no denominator is specified, the default
+ * is to treat the numerator as a percentage of the form, with a
+ * denominator of 100.
+ *
+ * @param numerator the percentage of the position
+ * @param offset the offset of the side from the position
+ */
+public this (int numerator, int offset) {
+    this (numerator, 100, offset);
+}
+
+/**
+ * Constructs a new instance of this class given a numerator
+ * and denominator and an offset. The position of the side is
+ * given by the fraction of the form defined by the numerator
+ * and denominator.
+ *
+ * @param numerator the numerator of the position
+ * @param denominator the denominator of the position
+ * @param offset the offset of the side from the position
+ */
+public this (int numerator, int denominator, int offset) {
+    if (denominator == 0) DWT.error (DWT.ERROR_CANNOT_BE_ZERO);
+    this.numerator = numerator;
+    this.denominator = denominator;
+    this.offset = offset;
+}
+
+/**
+ * Constructs a new instance of this class given a control.
+ * Since no alignment is specified, the default alignment is
+ * to attach the side to the adjacent side of the specified
+ * control. Since no offset is specified, an offset of 0 is
+ * used.
+ *
+ * @param control the control the side is attached to
+ */
+public this (Control control) {
+    this (control, 0, DWT.DEFAULT);
+}
+
+/**
+ * Constructs a new instance of this class given a control
+ * and an offset. Since no alignment is specified, the default
+ * alignment is to attach the side to the adjacent side of the
+ * specified control.
+ *
+ * @param control the control the side is attached to
+ * @param offset the offset of the side from the control
+ */
+public this (Control control, int offset) {
+    this (control, offset, DWT.DEFAULT);
+}
+
+/**
+ * Constructs a new instance of this class given a control,
+ * an offset and an alignment.
+ *
+ * @param control the control the side is attached to
+ * @param offset the offset of the side from the control
+ * @param alignment the alignment of the side to the control it is attached to
+ */
+public this (Control control, int offset, int alignment) {
+    this.control = control;
+    this.offset = offset;
+    this.alignment = alignment;
+}
+
+FormAttachment divide (int value) {
+    return new FormAttachment (numerator, denominator * value, offset / value);
+}
+
+int gcd (int m, int n) {
+    int temp;
+    m = Math.abs (m);
+    n = Math.abs (n);
+    if (m < n) {
+        temp = m;
+        m = n;
+        n = temp;
+    }
+    while (n != 0){
+        temp = m;
+        m = n;
+        n = temp % n;
+    }
+    return m;
+}
+
+FormAttachment minus (FormAttachment attachment) {
+    FormAttachment solution = new FormAttachment ();
+    solution.numerator = numerator * attachment.denominator - denominator * attachment.numerator;
+    solution.denominator = denominator * attachment.denominator;
+    int gcd = gcd (solution.denominator, solution.numerator);
+    solution.numerator = solution.numerator / gcd;
+    solution.denominator = solution.denominator / gcd;
+    solution.offset = offset - attachment.offset;
+    return solution;
+}
+
+FormAttachment minus (int value) {
+    return new FormAttachment (numerator, denominator, offset - value);
+}
+
+FormAttachment plus (FormAttachment attachment) {
+    FormAttachment solution = new FormAttachment ();
+    solution.numerator = numerator * attachment.denominator + denominator * attachment.numerator;
+    solution.denominator = denominator * attachment.denominator;
+    int gcd = gcd (solution.denominator, solution.numerator);
+    solution.numerator = solution.numerator / gcd;
+    solution.denominator = solution.denominator / gcd;
+    solution.offset = offset + attachment.offset;
+    return solution;
+}
+
+FormAttachment plus (int value) {
+    return new FormAttachment (numerator, denominator, offset + value);
+}
+
+int solveX (int value) {
+    if (denominator == 0) DWT.error (DWT.ERROR_CANNOT_BE_ZERO);
+    return ((numerator * value) / denominator) + offset;
+}
+
+int solveY (int value) {
+    if (numerator == 0) DWT.error (DWT.ERROR_CANNOT_BE_ZERO);
+    return (value - offset) * denominator / numerator;
+}
+
+/**
+ * Returns a string containing a concise, human-readable
+ * description of the receiver.
+ *
+ * @return a string representation of the FormAttachment
+ */
+public char[] toString () {
+    char[] string = control != null ? control.toString () : Format( "{}/{}", numerator, denominator );
+    return Format("{{y = ({})x + {}}", string, ( offset >= 0 ? Format(")x + {}", offset ) : Format( ")x - {}", -offset)));
+}
+
+}