/*******************************************************************************
 * Copyright (c) 2004 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
 *     Vlad Dumitrescu
 *******************************************************************************/
package org.erlide.ui.util;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Display;

/**
 * The color manager for the system (very simple implementation)
 *
 *
 * @author Eric Merritt [cyberlync at gmail dot com]
 */
public class ColorManager implements IColorManager {

    protected Map<String, RGB> fKeyTable = new HashMap<>(10);

    protected Map<Display, Map<RGB, Color>> fDisplayTable = new HashMap<>(
            2);

    /**
     * Flag which tells if the colors are automatically disposed when the
     * current display gets disposed.
     */
    private final boolean fAutoDisposeOnDisplayDispose;

    /**
     * Creates a new Erlang color manager which automatically disposes the
     * allocated colors when the current display gets disposed.
     */
    public ColorManager() {
        this(true);
    }

    /**
     * Creates a new Erlang color manager.
     *
     * @param autoDisposeOnDisplayDispose
     *            if <code>true</code> the color manager automatically disposes
     *            all managed colors when the current display gets disposed and
     *            all calls to
     *            {@link org.eclipse.jface.text.source.ISharedTextColors#dispose()}
     *            are ignored.
     *
     */
    public ColorManager(final boolean autoDisposeOnDisplayDispose) {
        fAutoDisposeOnDisplayDispose = autoDisposeOnDisplayDispose;
    }

    public void dispose(final Display display) {
        final Map<RGB, Color> colorTable = fDisplayTable.get(display);
        if (colorTable != null) {
            final Iterator<Color> e = colorTable.values().iterator();
            while (e.hasNext()) {
                final Color color = e.next();
                if (color != null && !color.isDisposed()) {
                    color.dispose();
                }
            }
        }
    }

    /*
     * @see IColorManager#getColor(RGB)
     */
    @Override
    public Color getColor(final RGB rgb) {

        if (rgb == null) {
            return null;
        }

        final Display display = Display.getCurrent();
        Map<RGB, Color> colorTable = fDisplayTable.get(display);
        if (colorTable == null) {
            colorTable = new HashMap<>(10);
            fDisplayTable.put(display, colorTable);
            if (fAutoDisposeOnDisplayDispose) {
                display.disposeExec(new Runnable() {

                    @Override
                    public void run() {
                        dispose(display);
                    }
                });
            }
        }

        Color color = colorTable.get(rgb);
        if (color == null) {
            color = new Color(Display.getCurrent(), rgb);
            colorTable.put(rgb, color);
        }

        return color;
    }

    /*
     * @see IColorManager#dispose
     */
    @Override
    public void dispose() {
        if (!fAutoDisposeOnDisplayDispose) {
            dispose(Display.getCurrent());
        }
    }

    /*
     * @see IColorManager#getColor(String)
     */
    @Override
    public Color getColor(final String key) {

        if (key == null) {
            return null;
        }

        final RGB rgb = fKeyTable.get(key);
        return getColor(rgb);
    }

}