org.drools.examples.broker.ui.ScrollingBanner.java Source code

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Here is the source code for org.drools.examples.broker.ui.ScrollingBanner.java

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/**
 * Copyright 2010 JBoss Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.drools.examples.broker.ui;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicInteger;

import javax.swing.JComponent;

import org.drools.examples.broker.model.StockTick;

import com.jgoodies.looks.FontSets;

/**
 * A simple component to show the incoming stock ticks
 * 
 * @author etirelli
 */
public class ScrollingBanner extends JComponent implements Runnable {

    private static final long serialVersionUID = 510l;
    private static final long SPACE = 10;

    private Queue<StockTick> ticks;
    private volatile boolean shutdown = false;
    private AtomicInteger headOffset = new AtomicInteger(0);
    private StockTick headTick = null;

    public ScrollingBanner() {
        super();
        this.ticks = new ConcurrentLinkedQueue<StockTick>();
        this.setBackground(Color.black);
        this.setForeground(Color.GREEN);
        this.setFont(FontSets.getLogicalFontSet().getTitleFont());
    }

    public void run() {
        shutdown = false;
        while (!shutdown) {
            repaint();
            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                shutdown = true;
            }
        }
    }

    public void shutdown() {
        shutdown = true;
    }

    public void addTick(StockTick tick) {
        ticks.add(tick);
    }

    public void paint(Graphics g) {
        final Dimension dim = this.getSize();
        final int y = ((int) (dim.height - g.getFontMetrics().getHeight()) / 2) + g.getFontMetrics().getHeight()
                - 2;
        // erase previous
        g.setColor(Color.BLACK);
        g.fillRect(0, 0, dim.width, dim.height);
        // redraw
        int width = 10;
        if (headTick == null) {
            headTick = ticks.poll();
            headOffset.set(0);
        }
        if (headTick != null) {
            String toDraw = headTick.toString().substring(headOffset.get());
            width += SPACE + drawString(g, y, width, headTick, toDraw);
        }
        for (StockTick tick : ticks) {
            String toDraw = tick.toString();
            width += SPACE + drawString(g, y, width, tick, toDraw);
            if (width > dim.width) {
                if (headOffset.addAndGet(2) >= headTick.toString().length()) {
                    headTick = null;
                }
                break;
            }
        }
    }

    private int drawString(Graphics g, final int y, int width, StockTick tick, String toDraw) {
        int size = g.getFontMetrics().stringWidth(toDraw);
        if (tick.getDelta() < 0) {
            g.setColor(Color.red);
        } else {
            g.setColor(Color.green);
        }
        g.drawString(toDraw, width, y);
        return size;
    }
}