/*******************************************************************************
 * Copyright (c) 2000, 2015 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.jface.preference;

import org.eclipse.jface.dialogs.IDialogPage;
import org.eclipse.swt.graphics.Point;

/**
 * An interface for a preference page. This interface
 * is used primarily by the page's container
 */
public interface IPreferencePage extends IDialogPage {

	/**
	 * Computes a size for this page's UI component.
	 *
	 * @return the size of the preference page encoded as
	 *   <code>new Point(width,height)</code>, or
	 *   <code>(0,0)</code> if the page doesn't currently have any UI component
	 */
	public Point computeSize();

	/**
	 * Returns whether this dialog page is in a valid state.
	 *
	 * @return <code>true</code> if the page is in a valid state,
	 *   and <code>false</code> if invalid
	 */
	public boolean isValid();

	/**
	 * Checks whether it is alright to leave this page.
	 *
	 * @return <code>false</code> to abort page flipping and the
	 *  have the current page remain visible, and <code>true</code>
	 *  to allow the page flip
	 */
	public boolean okToLeave();

	/**
	 * Notifies that the container of this preference page has been canceled.
	 *
	 * @return <code>false</code> to abort the container's cancel
	 *  procedure and <code>true</code> to allow the cancel to happen
	 */
	public boolean performCancel();

	/**
	 * Notifies that the OK button of this page's container has been pressed.
	 *
	 * @return <code>false</code> to abort the container's OK
	 *  processing and <code>true</code> to allow the OK to happen
	 */
	public boolean performOk();

	/**
	 * Sets or clears the container of this page.
	 *
	 * @param preferencePageContainer the preference page container, or <code>null</code>
	 */
	public void setContainer(IPreferencePageContainer preferencePageContainer);

	/**
	 * Sets the size of this page's UI component.
	 *
	 * @param size the size of the preference page encoded as
	 *   <code>new Point(width,height)</code>
	 */
	public void setSize(Point size);
}
