/*******************************************************************************
 * Copyright (c) 2005, 2008 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
 *******************************************************************************/
package org.eclipse.ui.dialogs;

import java.util.Collection;
import java.util.List;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.jface.preference.IPreferenceNode;
import org.eclipse.jface.preference.IPreferencePage;
import org.eclipse.jface.preference.PreferenceDialog;
import org.eclipse.jface.preference.PreferenceManager;
import org.eclipse.jface.preference.PreferencePage;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog;
import org.eclipse.ui.internal.dialogs.PropertyDialog;
import org.eclipse.ui.internal.dialogs.PropertyPageContributorManager;
import org.eclipse.ui.internal.dialogs.PropertyPageManager;
import org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog;

/**
 * The PreferencesUtil class is the class that opens a properties or preference
 * dialog on a set of ids.
 * 
 * @since 3.1
 */
public final class PreferencesUtil {

	
	/**
	 * Apply the data to the first page if there is any.
	 * 
	 * @param data
	 *            The data to be applied
	 * @param displayedIds
	 *            The ids to filter to.
	 * @param dialog
	 *            The dialog to apply to.
	 */
	private static void applyOptions(Object data, String[] displayedIds,
			FilteredPreferenceDialog dialog) {
		if (data != null) {
			dialog.setPageData(data);
			IPreferencePage page = dialog.getCurrentPage();
			if (page instanceof PreferencePage) {
				((PreferencePage) page).applyData(data);
			}
		}

		if (displayedIds != null) {
			dialog.showOnly(displayedIds);
		}
	}

	/**
	 * Creates a workbench preference dialog and selects particular preference
	 * page. If there is already a preference dialog open this dialog is used
	 * and its selection is set to the page with id preferencePageId. Show the
	 * other pages as filtered results using whatever filtering criteria the
	 * search uses. It is the responsibility of the caller to then call
	 * <code>open(). The call to open() will not return
	 * until the dialog closes, so this is the last chance to manipulate the
	 * dialog.
	 * 
	 * @param shell
	 *            The Shell to parent the dialog off of if it is not already
	 *            created. May be <code>null in which case the active
	 *            workbench window will be used if available.
	 * @param preferencePageId
	 *            The identifier of the preference page to open; may be
	 *            <code>null. If it is null, then the
	 *            preference page is not selected or modified in any way.
	 * @param displayedIds
	 *            The ids of the other pages to be displayed using the same
	 *            filtering criterea as search. If this is <code>null,
	 *            then the all preference pages are shown.
	 * @param data
	 *            Data that will be passed to all of the preference pages to be
	 *            applied as specified within the page as they are created. If
	 *            the data is <code>null nothing will be called.
	 * 
	 * @return a preference dialog.
	 * @since 3.1
	 * @see PreferenceDialog#PreferenceDialog(Shell, PreferenceManager)
	 */
	public static final PreferenceDialog createPreferenceDialogOn(Shell shell,
			String preferencePageId, String[] displayedIds, Object data) {
		FilteredPreferenceDialog dialog = WorkbenchPreferenceDialog
				.createDialogOn(shell, preferencePageId);

		applyOptions(data, displayedIds, dialog);

		return dialog;
	}

	/**
	 * Creates a workbench preference dialog to a particular preference page.
	 * Show the other pages as filtered results using whatever filtering
	 * criteria the search uses. It is the responsibility of the caller to then
	 * call <code>open(). The call to open() will not
	 * return until the dialog closes, so this is the last chance to manipulate
	 * the dialog.
	 * 
	 * @param shell
	 *            The shell to use to parent the dialog if required.
	 * @param propertyPageId
	 *            The identifier of the preference page to open; may be
	 *            <code>null. If it is null, then the
	 *            dialog is opened with no selected page.
	 * @param element
	 *            IAdaptable An adaptable element to open the dialog on.
	 * @param displayedIds
	 *            The ids of the other pages to be displayed using the same
	 *            filtering criterea as search. If this is <code>null,
	 *            then the all preference pages are shown.
	 * @param data
	 *            Data that will be passed to all of the preference pages to be
	 *            applied as specified within the page as they are created. If
	 *            the data is <code>null nothing will be called.
	 * 
	 * @return A preference dialog showing properties for the selection or
	 *         <code>null if it could not be created.
	 * @since 3.1
	 */
	public static final PreferenceDialog createPropertyDialogOn(Shell shell,
			final IAdaptable element, String propertyPageId,
			String[] displayedIds, Object data) {

		FilteredPreferenceDialog dialog = PropertyDialog.createDialogOn(shell,
				propertyPageId, element);

		if (dialog == null) {
			return null;
		}

		applyOptions(data, displayedIds, dialog);

		return dialog;

	}

	/**
	 * Indicates whether the specified element has at least one property page
	 * contributor.
	 * 
	 * @param element
	 *            an adapter element of a property page
	 * @return true for having at least one contributor; false otherwise
	 * @since 3.4
	 */
	public static boolean hasPropertiesContributors(Object element) {
		if (element == null || !(element instanceof IAdaptable))
			return false;
		Collection contributors = PropertyPageContributorManager.getManager()
				.getApplicableContributors(element);
		return contributors != null && contributors.size() > 0;
	}

	/**
	 * Return all of the properties page contributors for an element.
	 * @param element
	 * @return {@link IPreferenceNode}[]
	 * @since 3.4
	 */
	public static IPreferenceNode[] propertiesContributorsFor(Object element) {
		PropertyPageManager pageManager = new PropertyPageManager();
			if (element == null) {
			return null;
		}
		// load pages for the selection
		// fill the manager with contributions from the matching contributors
		PropertyPageContributorManager.getManager().contribute(pageManager,
				element);
		// testing if there are pages in the manager
		List pages =  pageManager.getElements(PreferenceManager.PRE_ORDER);
		IPreferenceNode[] nodes = new IPreferenceNode[pages.size()];
		pages.toArray(nodes);
		return nodes;
	}

}