/*******************************************************************************
 * Copyright (c) 2007 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:
 *    Takashi ITOH - initial API and implementation
 *******************************************************************************/

package org.eclipse.actf.util.win32;

import org.eclipse.actf.util.internal.win32.AccessibleHilighter;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;

/**
 * HighlightComposite is used to highlight an object. The composite is used in
 * {@link OverlayWindow}.
 */
public class HighlightComposite extends Composite implements IIntervalExec {

	private static final int BORDER_WIDTH = 3;

	private static HighlightComposite instance;

	private StyledText text;

	private Display display;

	private int flashingIndex = -1;

	private static int suppressRefCount = 0;

	private static boolean needRedraw = true;

	private static final int[][] FLASHING_COLORS = { { SWT.COLOR_YELLOW, 250 },
			{ SWT.COLOR_GREEN, 250 }, { SWT.COLOR_YELLOW, 250 },
			{ SWT.COLOR_GREEN, 250 }, { SWT.COLOR_YELLOW, 250 },
			{ SWT.COLOR_GREEN, 250 }, { SWT.COLOR_YELLOW, 1000 } };

	private static final int MESSAGE_COLOR = SWT.COLOR_INFO_FOREGROUND;

	private static final int MESSAGE_BACK = SWT.COLOR_INFO_BACKGROUND;

	private HighlightComposite(Composite parent, int style) {
		super(parent, style);
		display = getDisplay();
		GridLayout layout = new GridLayout();
		layout.marginWidth = layout.marginHeight = BORDER_WIDTH;
		setLayout(layout);
		text = new StyledText(this, SWT.NONE);
		text.setLayoutData(new GridData(GridData.FILL_BOTH));
		text.setBackground(parent.getBackground());
	}

	private void show(Rectangle rect, String message) {
		if (-1 != flashingIndex) {
			needRedraw = true;
		}
		flashingIndex = 0;
		if (null != message) {
			text.setText(message);
			StyleRange range = new StyleRange();
			range.start = 0;
			range.length = text.getCharCount();
			range.foreground = display.getSystemColor(MESSAGE_COLOR);
			range.background = display.getSystemColor(MESSAGE_BACK);
			text.setStyleRange(range);
		}
		getOverlayWindow().getComposite().moveAbove(null);
		moveAbove(null);
		setBounds(rect.x, rect.y, Math.max(BORDER_WIDTH, rect.width), Math.max(
				BORDER_WIDTH, rect.height));
		setVisible(true);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.actf.util.win32.IIntervalExec#exec()
	 */
	public int exec() {
		if (-1 != flashingIndex) {
			if (flashingIndex < FLASHING_COLORS.length) {
				setBackground(display
						.getSystemColor(FLASHING_COLORS[flashingIndex][0]));
				return FLASHING_COLORS[flashingIndex++][1];
			} else {
				flashingIndex = -1;
				setVisible(false);
				if (needRedraw) {
					needRedraw = false;
					getOverlayWindow().getComposite().redraw(); // Clear black
					// block
				}
			}
		}
		return 0;
	}

	/**
	 * Flash rectangle
	 * 
	 * @param rect
	 *            the position to be highlighted.
	 */
	public static void flashRectangle(Rectangle rect) {
		if (null != rect && 0 == suppressRefCount) {
			if (OverlayWindow.getVisible()) {
				OverlayWindow window = getOverlayWindow();
				if (null == instance) {
					instance = new HighlightComposite(window.getComposite(),
							SWT.NONE);
				}
				instance.show(rect, ""); //$NON-NLS-1$
				window.run();
			} else {
				AccessibleHilighter.flashRectangle(rect);
			}
		}
	}

	/**
	 * This method is used to synchronize the view updating.
	 * 
	 * @param increment
	 *            the increment(+) / decrement(-) width.
	 * @return the current suppress count.
	 */
	public static int updateSuppressCount(int increment) {
		suppressRefCount += increment;
		return suppressRefCount;
	}

	/**
	 * Set the flag to determine whether the object for highlight is shown or
	 * not.
	 * 
	 * @param show
	 *            true to show highlight object.
	 */
	public static void show(boolean show) {
		if (null != instance) {
			instance.setVisible(show);
		}
	}

	/**
	 * @return the default overlay window.
	 */
	private static OverlayWindow getOverlayWindow() {
		return OverlayWindow.getInstance(OverlayWindow.INDEX_HIGHLIGHT, true);
	}

	/**
	 * Initialize default overlay window.
	 */
	public static void initOverlayWindow() {
		getOverlayWindow();
	}

}