/*******************************************************************************
 * Copyright (c) 2001, 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.internal.views.properties.tabbed.view;

import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FormAttachment;
import org.eclipse.swt.layout.FormData;
import org.eclipse.swt.layout.FormLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.forms.IFormColors;
import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetWidgetFactory;


/**
 * The title in the tabbed property sheet page.
 * 
 * @author Anthony Hunter
 */
public class TabbedPropertyTitle
	extends Composite {

	private CLabel label;

	private Image image = null;

	private String text = null;
	
	private static final String BLANK = ""; //$NON-NLS-1$

	private static final String TITLE_FONT = "org.eclipse.ui.internal.views.properties.tabbed.view.TabbedPropertyTitle"; //$NON-NLS-1$
	
	private TabbedPropertySheetWidgetFactory factory;

	/**
	 * Constructor for TabbedPropertyTitle.
	 * 
	 * @param parent
	 *            the parent composite.
	 * @param factory
	 *            the widget factory for the tabbed property sheet
	 */
	public TabbedPropertyTitle(Composite parent,
			TabbedPropertySheetWidgetFactory factory) {
		super(parent, SWT.NO_FOCUS);
		this.factory = factory;

		this.addPaintListener(new PaintListener() {

			public void paintControl(PaintEvent e) {
				if (image == null && (text == null || text.equals(BLANK))) {
					label.setVisible(false);
				} else {
					label.setVisible(true);
					drawTitleBackground(e);
				}
			}
		});

		factory.getColors().initializeSectionToolBarColors();
		setBackground(factory.getColors().getBackground());
		setForeground(factory.getColors().getForeground());

		FormLayout layout = new FormLayout();
		layout.marginWidth = 1;
		layout.marginHeight = 2;
		setLayout(layout);

		Font font;
		if (! JFaceResources.getFontRegistry().hasValueFor(TITLE_FONT)) {
			FontData[] fontData = JFaceResources.getFontRegistry().getBold(
					JFaceResources.DEFAULT_FONT).getFontData();
			/* title font is 2pt larger than that used in the tabs. */  
			fontData[0].setHeight(fontData[0].getHeight() + 2);
			JFaceResources.getFontRegistry().put(TITLE_FONT, fontData);
		}
		font = JFaceResources.getFont(TITLE_FONT);
		
		label = factory.createCLabel(this, BLANK);
		label.setBackground(new Color[] {
				factory.getColors().getColor(IFormColors.H_GRADIENT_END),
				factory.getColors().getColor(IFormColors.H_GRADIENT_START) },
				new int[] { 100 }, true);
		label.setFont(font);
		label.setForeground(factory.getColors().getColor(IFormColors.TITLE));
		FormData data = new FormData();
		data.left = new FormAttachment(0, 0);
		data.top = new FormAttachment(0, 0);
		data.right = new FormAttachment(100, 0);
		data.bottom = new FormAttachment(100, 0);
		label.setLayoutData(data);

		/*
		 * setImage(PlatformUI.getWorkbench().getSharedImages().getImage(
		 * ISharedImages.IMG_OBJ_ELEMENT));
		 */
	}

	/**
	 * @param e
	 */
	protected void drawTitleBackground(PaintEvent e) {
		Rectangle bounds = getClientArea();
		label.setBackground(new Color[] {
				factory.getColors().getColor(IFormColors.H_GRADIENT_END),
				factory.getColors().getColor(IFormColors.H_GRADIENT_START) },
				new int[] { 100 }, true);
		Color bg = factory.getColors().getColor(IFormColors.H_GRADIENT_END);
		Color gbg = factory.getColors().getColor(IFormColors.H_GRADIENT_START);
		GC gc = e.gc;
		gc.setForeground(bg);
		gc.setBackground(gbg);
		gc.fillGradientRectangle(bounds.x, bounds.y, bounds.width,
				bounds.height, true);
		// background bottom separator
		gc.setForeground(factory.getColors().getColor(
				IFormColors.H_BOTTOM_KEYLINE1));
		gc.drawLine(bounds.x, bounds.height - 2, bounds.x + bounds.width - 1,
				bounds.height - 2);
		gc.setForeground(factory.getColors().getColor(
				IFormColors.H_BOTTOM_KEYLINE2));
		gc.drawLine(bounds.x, bounds.height - 1, bounds.x + bounds.width - 1,
				bounds.height - 1);
	}

	/**
	 * Set the text label.
	 * 
	 * @param text
	 *            the text label.
	 * @param image
	 *            the image for the label.
	 */
	public void setTitle(String text, Image image) {
		this.text = text;
		this.image = image;
		if (text != null) {
			label.setText(text);
		} else {
			label.setText(BLANK); 
		}
		label.setImage(image);
		redraw();
	}
}