bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/layout/FormAttachment.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * 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:
  * <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
  * points, 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 points.
  * </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 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.
  * </p>
  *
  * @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))+"}";
 }

 }
	/*******************************************************************************
	* 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:
	* <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
	* points, 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 points.
	* </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 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.
	* </p>
	*
	* @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))+"}";
	}

	}