/*

* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

* Base class for tree view elements

*

*/

package com.nokia.tracebuilder.view;

import java.util.Iterator;

import org.eclipse.jface.viewers.AbstractTreeViewer;

import org.eclipse.jface.viewers.TreeViewer;

import com.nokia.tracebuilder.engine.TraceBuilderConfiguration;

/**

 * Base class for tree view elements

 * 

 */

abstract class WrapperBase {

	/**

	 * Parent wrapper

	 */

	private WrapperBase parent;

	/**

	 * Visibility flag, used to optimize view updates

	 */

	private boolean isInView;

	/**

	 * Restore visibility flag. When a tree element is expanded, the children of

	 * children that have this flag are marked as visible

	 */

	private boolean restoreIntoView;

	/**

	 * View updater

	 */

	private WrapperUpdater updater;

	/**

	 * Constructor

	 * 

	 * @param parent

	 *            the parent wrapper

	 * @param updater

	 *            the wrapper updater

	 */

	WrapperBase(WrapperBase parent, WrapperUpdater updater) {

		this.parent = parent;

		this.updater = updater;

	}

	/**

	 * Gets the children

	 * 

	 * @return the children of this wrapper

	 */

	abstract Object[] getChildren();

	/**

	 * Checks if this wrapper has children

	 * 

	 * @return true if there are children

	 */

	abstract boolean hasChildren();

	/**

	 * Gets the parent

	 * 

	 * @return parent wrapper

	 */

	WrapperBase getParent() {

		return parent;

	}

	/**

	 * Clears the contents of this wrapper. Wrapper cannot be used after delete

	 */

	void delete() {

		parent = null;

	}

	/**

	 * Sets the shown in view flag

	 * 

	 * @param isInView

	 *            the new flag value

	 */

	void setInView(boolean isInView) {

		this.isInView = isInView;

		if (parent != null && isInView) {

			parent.setChildInView();

		}

	}

	/**

	 * Returns true if this wrapper is shown in the view

	 * 

	 * @return the shown in view flag

	 */

	boolean isInView() {

		return isInView;

	}

	/**

	 * Collapses the sibling wrappers of this wrapper

	 * 

	 * @param viewer

	 *            the tree viewer

	 */

	void collapseSiblings(TreeViewer viewer) {

		Iterator<WrapperBase> itr = ((ListWrapper) getParent())

				.getVisibleWrappers();

		while (itr.hasNext()) {

			WrapperBase child = itr.next();

			// The siblings are shown in view

			child.setInView(true);

			if (child != this && child instanceof ListWrapper) {

				collapseSiblings(viewer, (ListWrapper) child);

			}

		}

	}

	/**

	 * Collapses the sibling wrappers of this wrapper

	 * 

	 * @param viewer

	 *            the viewer

	 * @param child

	 *            the child

	 */

	private void collapseSiblings(TreeViewer viewer, ListWrapper child) {

		// The collapsed wrapper is shown in view, but it

		// children are hidden

		// If a sibling is shown, it is collapsed

		boolean needsCollapse = child.hasChildren()

				&& child.getVisibleWrappers().next().isInView();

		if (needsCollapse) {

			child.setChildrenInView(false);

			viewer.collapseToLevel(child, AbstractTreeViewer.ALL_LEVELS);

		}

	}

	/**

	 * Dumps this object to System.out

	 * 

	 * @param indentLevel

	 *            the indent level

	 * @param provider

	 *            the label provider

	 */

	void dumpToSystemOut(int indentLevel, TraceLabelProvider provider) {

		if (TraceBuilderConfiguration.TRACE_VIEW_STATE) {

			StringBuffer sb = new StringBuffer();

			for (int i = 0; i < indentLevel; i++) {

				sb.append("  "); //$NON-NLS-1$

			}

			sb.append(provider.getText(this));

			System.out.println(sb);

		}

	}

	/**

	 * Gets the view update notifier

	 * 

	 * @return the update notifier

	 */

	WrapperUpdater getUpdater() {

		return updater;

	}

	/**

	 * Recursively flags the parents as in view

	 */

	private void setChildInView() {

		isInView = true;

		if (parent != null) {

			parent.setChildInView();

		}

	}

	/**

	 * Sets restore into view flag. When a tree element is expanded, the child

	 * elements that have this flag are marked as "in view"

	 * 

	 * @param flag

	 *            the new flag value. This changes to true only if this wrapper

	 *            is already visible

	 */

	void setRestoreIntoView(boolean flag) {

		if (flag && isInView()) {

			restoreIntoView = true;

		} else {

			restoreIntoView = false;

		}

	}

	/**

	 * Gets the restore into view flag

	 * 

	 * @return the flag

	 */

	boolean isRestoredIntoView() {

		return restoreIntoView;

	}

}