/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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: 

*

*/

package com.nokia.carbide.cpp.internal.news.reader.ui;

import org.eclipse.jface.layout.GridDataFactory;

import org.eclipse.jface.layout.GridLayoutFactory;

import org.eclipse.jface.resource.JFaceResources;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Font;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Control;

import org.eclipse.swt.widgets.Label;

import org.eclipse.ui.IWorkbench;

import org.eclipse.ui.IWorkbenchWindow;

import org.eclipse.ui.PlatformUI;

import org.eclipse.ui.menus.WorkbenchWindowControlContribution;

import com.nokia.carbide.cpp.internal.news.reader.CarbideNewsReaderPlugin;

import com.nokia.carbide.cpp.internal.news.reader.gen.FeedCache.FeedCacheManager;

import com.nokia.carbide.cpp.internal.news.reader.gen.FeedCache.IFeedCacheChangedlistener;

/**

 * Control to launch Carbide.c++ news page in the workbench.

 *

 */

public class NewsControlContribution extends WorkbenchWindowControlContribution

		implements IFeedCacheChangedlistener {

	// private data

	private static NewsControlContribution sharedInstance;

	private Label label;

	private boolean alert;

	/**

	 * The constructor.

	 */

	public NewsControlContribution() {

		sharedInstance = this;

		alert = false;

		FeedCacheManager.addFeedCacheChangedListener(this);

	}

	/*

	 * (non-Javadoc)

	 * @see org.eclipse.jface.action.ControlContribution#createControl(org.eclipse.swt.widgets.Composite)

	 */

	@Override

	protected Control createControl(Composite parent) {

		GridLayoutFactory.fillDefaults().margins(2, 2).applyTo(container);

		// Create a label for the trim.

		String text = CarbideNewsReaderPlugin.getFeedManager().getUnreadEntriesCount() + " unread";

		label.setText(text);

		if (alert) {

			Font font = JFaceResources.getFontRegistry().getBold(JFaceResources.DEFAULT_FONT);

			label.setFont(font);

			alert = false;

		}

		PlatformUI.getWorkbench().getHelpSystem().setHelp(parent, NewsUIHelpIDs.NEWSREADER_TRIM_COMMAND);

		return container;

	}

	/*

	 * (non-Javadoc)

	 * @see org.eclipse.jface.action.ContributionItem#dispose()

	 */

	public void dispose() {

		FeedCacheManager.removeFeedCacheChangedListener(this);

		super.dispose();

	}

	/**

	 * Perform the necessary updates in response to local feed cache changes.

	 */

	public void feedCacheChanged(boolean alertUser) {

		setAlert(alertUser);

		// perform update in UI thread

		final IWorkbench workbench = PlatformUI.getWorkbench();

		workbench.getDisplay().asyncExec(new Runnable() {

			public void run() {

				IWorkbenchWindow window = workbench.getActiveWorkbenchWindow();

				if (window != null) {

					update();

				}

			}

		});

	}

	/*

	 * (non-Javadoc)

	 * @see org.eclipse.jface.action.ContributionItem#isDynamic()

	 */

	@Override

	public boolean isDynamic() {

		return true;

	}

	/**

	 * Returns the shared instance.

	 * @return the shared instance

	 */

	public static NewsControlContribution getDefault() {

		return sharedInstance;

	}

	/*

	 * (non-Javadoc)

	 * @see org.eclipse.jface.action.ContributionItem#update()

	 */

	@Override

	public void update() {

		getDefault().getParent().update(true);

	}

	/**

	 * Set the flag that controls whether to generate alerts for user.

	 * @param alertUser - boolean that controls whether to generate alerts for user

	 */

	public void setAlert(boolean alertUser) {

		alert = alertUser;

	}

}