/*******************************************************************************
 * Copyright (c) 2008 Oracle. 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:
 *     Oracle - initial API and implementation
 ******************************************************************************/
package org.eclipse.jpt.ui.internal.util;

import java.util.Collection;
import java.util.Iterator;
import org.eclipse.jpt.utility.internal.CollectionTools;
import org.eclipse.jpt.utility.internal.iterators.TransformationIterator;
import org.eclipse.jpt.utility.model.value.PropertyValueModel;
import org.eclipse.swt.widgets.Control;

/**
 * This <code>ControlVisibilityEnabler</code> keeps the "visible" state of a
 * collection of controls in synch with the provided boolean holder.
 *
 * @version 2.0
 * @since 2.0
 */
public class ControlVisibilityEnabler extends StateController
{
	/**
	 * Creates a new <code>ControlVisibilityEnabler</code> with a default value
	 * of <code>false</code> (i.e. not visible).
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param controls The collection of controls whose "visible" state is
	 * kept in sync with the boolean holder's value
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Collection<? extends Control> controls) {

		this(booleanHolder, controls, false);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code>.
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param controls The collection of controls whose "visible" state is
	 * kept in sync with the boolean holder's value
	 * @param defaultValue The value to use when the underlying model is
	 * <code>null</code>
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Collection<? extends Control> controls,
	                                boolean defaultValue) {

		this(booleanHolder, controls.iterator(), defaultValue);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code> with a default value of
	 * <code>false</code> (i.e. not visible).
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param control The control whose "visible" state is
	 * kept in sync with the boolean holder's value
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Control control) {

		this(booleanHolder, control, false);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code> with a default value of
	 * <code>false</code> (i.e. not visible).
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param controls The collection of controls whose "visible" state is
	 * kept in sync with the boolean holder's value
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Control... controls) {

		this(booleanHolder, CollectionTools.iterator(controls), false);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code>.
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param control The control whose "visible" state is kept in sync with the
	 * boolean holder's value
	 * @param defaultValue The value to use when the underlying model is
	 * <code>null</code>
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Control control,
	                                boolean defaultValue) {

		this(booleanHolder, CollectionTools.singletonIterator(control), false);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code>.
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param controls The collection of controls whose "visible" state is kept
	 * in sync with the boolean holder's value
	 * @param defaultValue The value to use when the underlying model is
	 * <code>null</code>
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Control[] controls,
	                                boolean defaultValue) {

		this(booleanHolder, CollectionTools.iterator(controls), defaultValue);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code> with a default value
	 * of <code>false</code> (i.e. not visible).
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param controls An iterator on the collection of controls whose "visible"
	 * state is kept in sync with the boolean holder's value
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Iterator<? extends Control> controls) {

		this(booleanHolder, controls, false);
	}

	/**
	 * Creates a new <code>ControlVisibilityEnabler</code>.
	 *
	 * @param booleanHolder A value model on the underlying boolean model
	 * @param controls An iterator on the collection of controls whose "visible"
	 * state is kept in sync with the boolean holder's value
	 * @param defaultValue The value to use when the underlying model is
	 * <code>null</code>
	 */
	public ControlVisibilityEnabler(PropertyValueModel<Boolean> booleanHolder,
	                                Iterator<? extends Control> controls,
	                                boolean defaultValue) {

		super(booleanHolder, wrap(controls), defaultValue);
	}

	private static Collection<ControlHolder> wrap(Iterator<? extends Control> controls) {
		return CollectionTools.collection(new TransformationIterator<Control, ControlHolder>(controls) {
			@Override
			protected ControlHolder transform(Control control) {
				return new ControlVisibilityHolder(control);
			}
		});
	}

	/**
	 * This holder holds onto a <code>Control</code> and update its visible state.
	 */
	private static class ControlVisibilityHolder implements ControlHolder {
		private final Control control;

		ControlVisibilityHolder(Control control) {
			super();
			this.control = control;
		}

		public void updateState(boolean state) {
			if (!this.control.isDisposed()) {
				this.control.setVisible(state);
			}
		}
	}
}