--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2018 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.layout;
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.widgets.*;
+
+/**
+ * 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:
+ * </p>
+ * <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>
+ * 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
+ * points, from the attachment position. For example:</p>
+ * <pre>
+ * FormAttachment attach = new FormAttachment (20, -5);
+ * </pre>
+ * <p>
+ * specifies that the side to which the <code>FormAttachment</code>
+ * object belongs will lie at 20% of the parent composite, minus 5 points.
+ * </p>
+ * <p>
+ * Control sides can also be attached to another control.
+ * For example:</p>
+ * <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 points. 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, SWT.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, SWT.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.
+ *
+ * @see FormLayout
+ * @see FormData
+ * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
+ *
+ * @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 points, 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>{@link SWT#TOP}: Attach the side to the top side of the specified control.</li>
+ * <li>{@link SWT#BOTTOM}: Attach the side to the bottom side of the specified control.</li>
+ * <li>{@link SWT#LEFT}: Attach the side to the left side of the specified control.</li>
+ * <li>{@link SWT#RIGHT}: Attach the side to the right side of the specified control.</li>
+ * <li>{@link SWT#CENTER}: Attach the side at a position which will center the control on the specified control.</li>
+ * <li>{@link SWT#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 FormAttachment () {
+}
+
+/**
+ * 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 FormAttachment (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 FormAttachment (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 FormAttachment (int numerator, int denominator, int offset) {
+ if (denominator == 0) SWT.error (SWT.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 FormAttachment (Control control) {
+ this (control, 0, SWT.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 FormAttachment (Control control, int offset) {
+ this (control, offset, SWT.DEFAULT);
+}
+
+/**
+ * Constructs a new instance of this class given a control,
+ * an offset and an alignment. The possible alignment values are:
+ * <dl>
+ * <dt><b>{@link SWT#TOP}</b></dt>
+ * <dd>the side will be attached to the top side of the specified control</dd>
+ * <dt><b>{@link SWT#BOTTOM}</b></dt>
+ * <dd>the side will be attached to the bottom side of the specified control</dd>
+ * <dt><b>{@link SWT#LEFT}</b></dt>
+ * <dd>the side will be attached to the left side of the specified control</dd>
+ * <dt><b>{@link SWT#RIGHT}</b></dt>
+ * <dd>the side will be attached to the right side of the specified control</dd>
+ * <dt><b>{@link SWT#CENTER}</b></dt>
+ * <dd>the side will be centered on the same side of the specified control</dd>
+ * <dt><b>{@link SWT#DEFAULT}</b></dt>
+ * <dd>the side will be attached to the adjacent side of the specified control</dd>
+ * </dl>
+ *
+ * @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,
+ * one of TOP, BOTTOM, LEFT, RIGHT, CENTER, or DEFAULT
+ */
+public FormAttachment (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) SWT.error (SWT.ERROR_CANNOT_BE_ZERO);
+ return ((numerator * value) / denominator) + offset;
+}
+
+int solveY (int value) {
+ if (numerator == 0) SWT.error (SWT.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
+ */
+@Override
+public String toString () {
+ String string = control != null ? control.toString () : numerator + "/" + denominator;
+ return "{y = (" + string + (offset >= 0 ? ")x + " + offset: ")x - " + (-offset))+"}";
+}
+
+}
Code Review / simantics / platform.git / blobdiff