bundles/common/org.eclipse.apogy.common.widgets.ui/src/org/eclipse/apogy/common/widgets/ui/ProgressBarComposite.java

/*******************************************************************************
 * Copyright (c) 2018 Agence spatiale canadienne / Canadian Space Agency 
 * 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:
 *     Pierre Allard,
 *     Regent L'Archeveque,  
 *     Sebastien Gemme - initial API and implementation
 *
 * SPDX-License-Identifier: EPL-1.0
 *     
 *******************************************************************************/
package org.eclipse.apogy.common.widgets.ui;

import java.net.URL;
import java.text.DecimalFormat;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ProgressBarComposite extends Composite {

	private static final Logger Logger = LoggerFactory.getLogger(ProgressBarComposite.class);

	private static final String IMAGES_FOLDER = "platform:/plugin/org.eclipse.apogy.common.widgets.ui/images/"; // Images
																												// path
	private static final int MAX_VALUE = 100;
	private static final int MIN_VALUE = 0;

	private Image background;
	private int actualValue; // Actual value of the progress bar in percent.

	/**
	 * Constructor parameter information:
	 * 
	 * @param initialValue The initial value of the progress bar.
	 */
	public ProgressBarComposite(Composite parent, int style, int initialValue) {
		super(parent, style | SWT.DOUBLE_BUFFERED);

		setActualValue(initialValue);

		initImages();

		createPaintListener();
		createDisposeListener();
	}

	public synchronized int getActualValue() {
		return this.actualValue;
	}

	public synchronized void setActualValue(int actualValue) {
		if (actualValue > MAX_VALUE)
			this.actualValue = MAX_VALUE;
		else if (actualValue < MIN_VALUE)
			this.actualValue = MIN_VALUE;
		else
			this.actualValue = actualValue;
		redraw();
	}

	public synchronized void increaseValue() {
		setActualValue(this.actualValue + 1);
	}

	public synchronized void decreaseValue() {
		setActualValue(this.actualValue - 1);
	}

	private void initImages() {
		try {
			Device device = Display.getCurrent();
			URL url = new URL(IMAGES_FOLDER + "gadgeCenter.png");
			this.background = new Image(device, url.openStream());
		} catch (Exception e) {
			Logger.error(e.getMessage(), e);
		}
	}

	private void paintMeter(GC gc) {

		int centerXMeter = getBounds().width / 2;
		int centerYMeter = getBounds().height / 2;

		float XScaleFactor = 0f;
		float YScaleFactor = 0f;

		// Draw image
		if (this.background != null) {
			XScaleFactor = (((float) getBounds().width) / ((float) this.background.getBounds().width));
			YScaleFactor = (((float) getBounds().height) / ((float) this.background.getBounds().height));
			gc.drawImage(this.background, 0, 0, this.background.getBounds().width, this.background.getBounds().height,
					0, 0, getBounds().width, getBounds().height);
		} else {
			Color color = new Color(getDisplay(), 0, 0, 0);
			gc.setForeground(color);
			gc.setLineWidth(4);
			gc.drawRectangle(2, 2, getBounds().width - 4, getBounds().height - 4);
			color.dispose();
		}
		// Draw gadge state
		double gadgeWidth = getBounds().width - 2;
		int value = (int) Math.round(gadgeWidth * (this.actualValue / 100.0));

		gc.setAlpha(100);

		Color c = new Color(Display.getCurrent(), 0, 255, 0);

		gc.setBackground(c);

		gc.fillRectangle(1, 1, value, getBounds().height - 2);

		c.dispose();

		// draw number on gadge
		int size = 0;
		if (XScaleFactor > YScaleFactor)
			size = Math.round(7f * YScaleFactor);
		else
			size = Math.round(7f * XScaleFactor);
		DecimalFormat df = new DecimalFormat("0");
		Font font = new Font(getDisplay(), "Tahoma", size, SWT.BOLD);
		gc.setFont(font);
		gc.setAlpha(255);
		String numberPercent = df.format(this.actualValue) + "%";
		int widthOfNumber = 0;
		for (int i = 0; i < numberPercent.length(); i++)
			widthOfNumber += gc.getAdvanceWidth(numberPercent.charAt(i));
		int heightOfNumber = gc.getFontMetrics().getHeight();
		c = new Color(Display.getCurrent(), 0, 0, 0);
		gc.setForeground(c);
		gc.drawString(numberPercent, centerXMeter - (widthOfNumber / 2) + 1, centerYMeter - (heightOfNumber / 2) + 1,
				true);
		c.dispose();
		c = new Color(Display.getCurrent(), 255, 255, 255);
		gc.setForeground(c);
		gc.drawString(numberPercent, centerXMeter - (widthOfNumber / 2), centerYMeter - (heightOfNumber / 2), true);
		c.dispose();
		font.dispose();

	}

	private void createDisposeListener() {
		addDisposeListener(new DisposeListener() {
			@Override
			public void widgetDisposed(DisposeEvent e) {
				if (ProgressBarComposite.this.background != null)
					ProgressBarComposite.this.background.dispose();
			}
		});
	}

	private void createPaintListener() {
		addPaintListener(new PaintListener() {
			@Override
			public void paintControl(PaintEvent e) {
				paintMeter(e.gc);
			}
		});
	}
}