/*******************************************************************************

 * Copyright (c) 2004, 2009 Tasktop Technologies 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:

 *     Benjamin Pasero - initial API and implementation

 *     Tasktop Technologies - improvements

 *******************************************************************************/

package com.nokia.carbide.remoteconnections.internal.ui.mylyn;

import org.eclipse.jface.resource.DeviceResourceException;

import org.eclipse.jface.resource.ResourceManager;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Color;

import org.eclipse.swt.graphics.RGB;

import org.eclipse.swt.widgets.Display;

/**

 * Helper Class to create the colors for the {@link AbstractNotificationPopup}.

 * <p>

 * Note: Copied from FormColors of UI Forms.

 * </p>

 * 

 * @author Benjamin Pasero (initial contribution from RSSOwl, see bug 177974)

 * @author Mik Kersten

 */

public class NotificationPopupColors {

	private final Display display;

	private Color titleText;

	private Color gradientBegin;

	private Color gradientEnd;

	private Color border;

	private final ResourceManager resourceManager;

	public NotificationPopupColors(Display display, ResourceManager resourceManager) {

		this.display = display;

		this.resourceManager = resourceManager;

		createColors();

	}

	private void createColors() {

		createBorderColor();

		createGradientColors();

		// previously used SWT.COLOR_TITLE_INACTIVE_FOREGROUND, but too light on Windows XP

		titleText = getColor(resourceManager, getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW));

	}

	public Color getGradientBegin() {

		return gradientBegin;

	}

	public Color getGradientEnd() {

		return gradientEnd;

	}

	public Color getBorder() {

		return border;

	}

	public Color getTitleText() {

		return titleText;

	}

	private void createBorderColor() {

		RGB tbBorder = getSystemColor(SWT.COLOR_TITLE_BACKGROUND);

		RGB bg = getImpliedBackground().getRGB();

		// Group 1

		// Rule: If at least 2 of the RGB values are equal to or between 180 and

		// 255, then apply specified opacity for Group 1

		// Examples: Vista, XP Silver, Wn High Con #2

		// Keyline = TITLE_BACKGROUND @ 70% Opacity over LIST_BACKGROUND

		if (testTwoPrimaryColors(tbBorder, 179, 256)) {

			tbBorder = blend(tbBorder, bg, 70);

		} else if (testTwoPrimaryColors(tbBorder, 120, 180)) {

			tbBorder = blend(tbBorder, bg, 50);

		} else {

			tbBorder = blend(tbBorder, bg, 30);

		}

		border = getColor(resourceManager, tbBorder);

	}

	private void createGradientColors() {

		RGB titleBg = getSystemColor(SWT.COLOR_TITLE_BACKGROUND);

		Color bgColor = getImpliedBackground();

		RGB bg = bgColor.getRGB();

		RGB bottom, top;

		// Group 1

		// Rule: If at least 2 of the RGB values are equal to or between 180 and

		// 255, then apply specified opacity for Group 1

		// Examples: Vista, XP Silver, Wn High Con #2

		// Gradient Bottom = TITLE_BACKGROUND @ 30% Opacity over LIST_BACKGROUND

		// Gradient Top = TITLE BACKGROUND @ 0% Opacity over LIST_BACKGROUND

		if (testTwoPrimaryColors(titleBg, 179, 256)) {

			bottom = blend(titleBg, bg, 30);

			top = bg;

		}

		// Group 2

		// Rule: If at least 2 of the RGB values are equal to or between 121 and

		// 179, then apply specified opacity for Group 2

		// Examples: XP Olive, OSX Graphite, Linux GTK, Wn High Con Black

		// Gradient Bottom = TITLE_BACKGROUND @ 20% Opacity over LIST_BACKGROUND

		// Gradient Top = TITLE BACKGROUND @ 0% Opacity over LIST_BACKGROUND

		else if (testTwoPrimaryColors(titleBg, 120, 180)) {

			bottom = blend(titleBg, bg, 20);

			top = bg;

		}

		// Group 3

		// Rule: If at least 2 of the RGB values are equal to or between 0 and

		// 120, then apply specified opacity for Group 3

		// Examples: XP Default, Wn Classic Standard, Wn Marine, Wn Plum, OSX

		// Aqua, Wn High Con White, Wn High Con #1

		// Gradient Bottom = TITLE_BACKGROUND @ 10% Opacity over LIST_BACKGROUND

		// Gradient Top = TITLE BACKGROUND @ 0% Opacity over LIST_BACKGROUND

		else {

			bottom = blend(titleBg, bg, 10);

			top = bg;

		}

		gradientBegin = getColor(resourceManager, top);

		gradientEnd = getColor(resourceManager, bottom);

	}

	private RGB blend(RGB c1, RGB c2, int ratio) {

		int r = blend(c1.red, c2.red, ratio);

		int g = blend(c1.green, c2.green, ratio);

		int b = blend(c1.blue, c2.blue, ratio);

		return new RGB(r, g, b);

	}

	private int blend(int v1, int v2, int ratio) {

		int b = (ratio * v1 + (100 - ratio) * v2) / 100;

		return Math.min(255, b);

	}

	private boolean testTwoPrimaryColors(RGB rgb, int from, int to) {

		int total = 0;

		if (testPrimaryColor(rgb.red, from, to)) {

			total++;

		}

		if (testPrimaryColor(rgb.green, from, to)) {

			total++;

		}

		if (testPrimaryColor(rgb.blue, from, to)) {

			total++;

		}

		return total >= 2;

	}

	private boolean testPrimaryColor(int value, int from, int to) {

		return value > from && value < to;

	}

	private RGB getSystemColor(int code) {

		return getDisplay().getSystemColor(code).getRGB();

	}

	private Color getImpliedBackground() {

		return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND);

	}

	private Display getDisplay() {

		return display;

	}

	private Color getColor(ResourceManager manager, RGB rgb) {

		try {

			return manager.createColor(rgb);

		} catch (DeviceResourceException e) {

			return manager.getDevice().getSystemColor(SWT.COLOR_BLACK);

		}

	}

}