MessageRenderer.java

/****************************************************************************
 * Copyright (c) 2007 Composent, Inc. 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:
 *    Jacek Pospychala <jacek.pospychala@pl.ibm.com> - bug 197329, 190851
 *****************************************************************************/
package org.eclipse.ecf.presence.ui.chatroom;

import java.text.SimpleDateFormat;
import java.util.*;
import org.eclipse.core.runtime.Assert;
import org.eclipse.ecf.internal.presence.ui.Messages;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.themes.ITheme;

/**
 * Default implementation of {@link IMessageRenderer}.
 *
 */
public class MessageRenderer implements IMessageRenderer {

	/**
	 * Messages sent by local user
	 */
	protected static final String SENT_COLOR = "org.eclipse.ecf.presence.ui.sentColor"; //$NON-NLS-1$
	protected static final String SENT_FONT = "org.eclipse.ecf.presence.ui.sentFont"; //$NON-NLS-1$

	/**
	 * Any received messages
	 */
	protected static final String RECEIVED_COLOR = "org.eclipse.ecf.presence.ui.receivedColor"; //$NON-NLS-1$
	protected static final String RECEIVED_FONT = "org.eclipse.ecf.presence.ui.receivedFont"; //$NON-NLS-1$

	/**
	 * System messages, eg. server notifications
	 */
	protected static final String SYSTEM_COLOR = "org.eclipse.ecf.presence.ui.systemColor"; //$NON-NLS-1$
	protected static final String SYSTEM_FONT = "org.eclipse.ecf.presence.ui.systemFont"; //$NON-NLS-1$

	/**
	 * The default color used to highlight message when the user's
	 * name is referred to in the chatroom. The default color is red.
	 */
	protected static final String RECEIVEDHIGHLIGHT_COLOR = "org.eclipse.ecf.presence.ui.receivedHighlightColor"; //$NON-NLS-1$
	protected static final String RECEIVEDHIGHLIGHT_FONT = "org.eclipse.ecf.presence.ui.receivedHighlightFont"; //$NON-NLS-1$

	/**
	 * Date stamp in message window
	 */
	protected static final String DATE_COLOR = "org.eclipse.ecf.presence.ui.dateColor"; //$NON-NLS-1$
	protected static final String DATE_FONT = "org.eclipse.ecf.presence.ui.dateFont"; //$NON-NLS-1$

	protected static final String DEFAULT_TIME_FORMAT = Messages.MessageRenderer_DEFAULT_TIME_FORMAT;

	protected static final String DEFAULT_DATE_FORMAT = Messages.MessageRenderer_DEFAULT_DATE_FORMAT;

	private StringBuffer buffer;

	private List styleRanges = new ArrayList();

	protected boolean nickContained;
	protected boolean isSent;
	protected String message;
	protected String originator;

	private String font;
	private String color;

	public StyleRange[] getStyleRanges() {
		return (StyleRange[]) styleRanges.toArray(new StyleRange[styleRanges.size()]);
	}

	public String render(String msg, String orig, String localUserName) {
		Assert.isNotNull(localUserName);

		styleRanges.clear();

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

		buffer = new StringBuffer();

		this.message = msg;
		this.originator = orig;

		// check to see if the message has the user's name contained within
		// and make sure that the person referring to the user's name
		// is not the user himself, no highlighting is required in this case
		// as the user is already aware that his name is being referenced
		nickContained = (msg.indexOf(localUserName) != -1) && (!localUserName.equals(orig));
		isSent = (orig != null) && (orig.equals(localUserName));

		if (orig == null) {
			color = SYSTEM_COLOR;
			font = SYSTEM_FONT;
		} else if (isSent) {
			color = SENT_COLOR;
			font = SENT_FONT;
		} else if (nickContained) {
			color = RECEIVEDHIGHLIGHT_COLOR;
			font = RECEIVEDHIGHLIGHT_FONT;
		} else {
			color = RECEIVED_COLOR;
			font = RECEIVED_FONT;
		}

		doRender();

		return buffer.toString();
	}

	protected void doRender() {

		appendDateTime();
		if (originator != null) {
			appendNickname();
		}
		appendMessage();
	}

	protected void appendDateTime() {
		String msg = NLS.bind(Messages.MessageRenderer_DEFAULT_DATETIME_FORMAT, getCurrentDate(DEFAULT_TIME_FORMAT)) + " "; //$NON-NLS-1$
		append(msg, DATE_COLOR, null, DATE_FONT);
	}

	protected void appendNickname() {
		String msg = originator + ": "; //$NON-NLS-1$
		append(msg, color, null, font);
	}

	protected void appendMessage() {
		append(message, color, null, font);
	}

	protected void append(String msg, String foreground, String background, String font1) {
		if (msg == null) {
			return;
		}

		int start = buffer.length();

		buffer.append(msg);

		if (foreground == null && background == null && font1 == null) {
			return;
		}

		StyleRange styleRange = new StyleRange(start, msg.length(), getColor(foreground), getColor(background));
		styleRange.font = getFont(font1);
		styleRanges.add(styleRange);
	}

	private Color getColor(String name) {
		if (name == null) {
			return null;
		}

		ITheme theme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();
		Color c = theme.getColorRegistry().get(name);

		if (c == null) {
			return Display.getDefault().getSystemColor(SWT.COLOR_BLACK);
		}

		return c;
	}

	private Font getFont(String name) {
		if (name == null) {
			return null;
		}

		ITheme theme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();
		Font f = theme.getFontRegistry().get(name);

		if (f == null) {
			return Display.getDefault().getSystemFont();
		}

		return f;
	}

	protected String getCurrentDate(String format) {
		SimpleDateFormat sdf = new SimpleDateFormat(format);
		String res = sdf.format(new Date());
		return res;
	}

	protected String getDateTime() {
		StringBuffer buf = new StringBuffer();
		buf.append(getCurrentDate(DEFAULT_DATE_FORMAT)).append(" ").append( //$NON-NLS-1$
				getCurrentDate(DEFAULT_TIME_FORMAT));
		return buf.toString();
	}
}