ErrorDialog.java

package edu.mbl.jif.gui.error;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import javax.swing.*;
import javax.swing.text.*;

/**
 * Usage:
 *    ErrorDialog.showError("This is an error message.", new Exception());
 * 
 * from http://www.nakov.com/blog/2008/11/30/java-swing-error-dialog-with-exception-details/
 * @author Svetlin Nakov
 */
@SuppressWarnings("serial")
public class ErrorDialog extends JDialog {

	private static final String SHOW_DETAILS_TEXT = "Show Details ...";
	private static final String HIDE_DETAILS_TEXT = "Hide Details";
	private JButton jButtonClose;
	private ImagePanel imagePanelErrorIcon;
	private JButton jButtonShowHideDetails;
	private JPanel jPanelBottom;
	private JPanel jPanelCenter;
	private JPanel jPanelTop;
	private JScrollPane jScrollPaneErrorMsg;
	private JTextPane jTextPaneErrorMsg;
	private JScrollPane jScrollPaneException;
	private JTextArea jTextAreaException;

	private static final String ERROR_ICON_RESOURCE_LOCATION = 
		"edu/mbl/jif/gui/error/Error-Icon.gif";

	public ErrorDialog(String errorMessage) {
		this(errorMessage, null);
	}
	
	public ErrorDialog(String errorMessage, Throwable exception) {
		this.setTitle("Error");
		this.setModal(true);
		this.setResizable(false);
		this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);

        jPanelTop = new JPanel();
        imagePanelErrorIcon = new ImagePanel(ERROR_ICON_RESOURCE_LOCATION);
        jPanelTop.setLayout(null);
        jPanelTop.setPreferredSize(new Dimension(480, 100));
        imagePanelErrorIcon.setLocation(new Point(20, 36));
        jPanelTop.add(imagePanelErrorIcon);

        jTextPaneErrorMsg = new JTextPane();
        jTextPaneErrorMsg.setFont(jTextPaneErrorMsg.getFont().deriveFont(
        	jTextPaneErrorMsg.getFont().getStyle() | Font.BOLD, 
        	jTextPaneErrorMsg.getFont().getSize()+1));
        jTextPaneErrorMsg.setBorder(null);
        jTextPaneErrorMsg.setEditable(false);
        jTextPaneErrorMsg.setBackground(null);
        jScrollPaneErrorMsg = new JScrollPane(jTextPaneErrorMsg);
        jScrollPaneErrorMsg.setBorder(null);
        jScrollPaneErrorMsg.setSize(new Dimension(405, 80));
        jScrollPaneErrorMsg.setLocation(new Point(71, 13));
        jPanelTop.add(jScrollPaneErrorMsg);

        jPanelCenter = new JPanel();
        jPanelCenter.setSize(new Dimension(420, 300));
        jTextAreaException = new JTextArea();
        jScrollPaneException = new JScrollPane(jTextAreaException);
        jScrollPaneException.setPreferredSize(new Dimension(470, 300));
        jPanelCenter.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));
        jPanelCenter.add(jScrollPaneException);

        jPanelBottom = new JPanel();
        jButtonShowHideDetails = new JButton();
        jButtonClose = new JButton();
        jPanelBottom.setLayout(new FlowLayout(FlowLayout.CENTER, 30, 15));

        jButtonShowHideDetails.setText(SHOW_DETAILS_TEXT);
        jButtonShowHideDetails.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                showHideExceptionDetails();
            }
        });
        jPanelBottom.add(jButtonShowHideDetails);

        jButtonClose.setText("Close");
        jButtonClose.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
            	dispose();
            }
        });
        jPanelBottom.add(jButtonClose);
  
        this.setLayout(new BorderLayout());
        this.add(jPanelTop, BorderLayout.NORTH);
        this.add(jPanelCenter, BorderLayout.CENTER);
        this.add(jPanelBottom, BorderLayout.SOUTH);

        this.jTextPaneErrorMsg.setEditorKit(new VerticalCenteredEditorKit());
        this.jTextPaneErrorMsg.setText(errorMessage);
        
        this.jPanelCenter.setVisible(false);
        
        if (exception != null) {
        	String exceptionText = getStackTraceAsString(exception);
        	jTextAreaException.setText(exceptionText);
        	jTextAreaException.setEditable(false);
        } else {
        	this.jButtonShowHideDetails.setVisible(false);
        }

		// Make [Escape] key as close button
		this.registerEscapeKey();

        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        setModal(true);
		this.pack();
		centerDialogOnTheScreen();
	}

	private void centerDialogOnTheScreen() {
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		Dimension dialogSize = this.getSize();
		int centerPosX = (screenSize.width - dialogSize.width) / 2;
		int centerPosY = (screenSize.height - dialogSize.height) / 2;
		setLocation(centerPosX, centerPosY);
	}
	
	private void showHideExceptionDetails() {
        if (this.jPanelCenter.isVisible()) {
            // Hide the exception details
            this.jButtonShowHideDetails.setText(SHOW_DETAILS_TEXT);
            this.jPanelCenter.setVisible(false);
    		this.pack();
            centerDialogOnTheScreen();
        } else {
            // Show the exception details
            this.jButtonShowHideDetails.setText(HIDE_DETAILS_TEXT);
            this.jPanelCenter.setVisible(true);
    		this.pack();
            centerDialogOnTheScreen();
        }
	}

	private String getStackTraceAsString(Throwable exception) {
		Writer result = new StringWriter();
		PrintWriter printWriter = new PrintWriter(result);
		exception.printStackTrace(printWriter);
		return result.toString();
	}

	/**
	 * Make the [Escape] key to behave like the [Close] button.
	 */
	public void registerEscapeKey() {
		KeyStroke escapeKeyStroke = 
			KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0, false);
		Action escapeAction = new AbstractAction() {
			private static final long serialVersionUID = 1L;

			public void actionPerformed(ActionEvent e) {
				jButtonClose.doClick();
			}
		};

		this.rootPane.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
				escapeKeyStroke, "ESCAPE");
		this.rootPane.getActionMap().put("ESCAPE", escapeAction);
	}
	
	public void hideAndDisposeDialog() {
		this.setVisible(false);
		this.dispose();
	}

	public static void showError(String errorMessage, 
			Throwable throwable) {
		ErrorDialog errorDialog = 
			new ErrorDialog(errorMessage, throwable);
		errorDialog.setVisible(true);		
	}

	public static void showError(String errorMessage) {
		ErrorDialog.showError(errorMessage, null);	
	}
	
	public static void main(String[] args) {
		ErrorDialog.showError("This is an error message.", new Exception());
	}
}

@SuppressWarnings("serial")
class VerticalCenteredEditorKit extends StyledEditorKit {
	public ViewFactory getViewFactory() {
		return new StyledViewFactory();
	}

	static class StyledViewFactory implements ViewFactory {
		public View create(Element elem) {
			String kind = elem.getName();
			if (kind != null) {
				if (kind.equals(AbstractDocument.ContentElementName)) {
					return new LabelView(elem);
				} else if (kind.equals(AbstractDocument.ParagraphElementName)) {
					return new ParagraphView(elem);
				} else if (kind.equals(AbstractDocument.SectionElementName)) {
					return new CenteredBoxView(elem, View.Y_AXIS);
				} else if (kind.equals(StyleConstants.ComponentElementName)) {
					return new ComponentView(elem);
				} else if (kind.equals(StyleConstants.IconElementName)) {
					return new IconView(elem);
				}
			}

			// Default to text display
			return new LabelView(elem);
		}
	}
	
	static class CenteredBoxView extends BoxView {
		public CenteredBoxView(Element elem, int axis) {
			super(elem, axis);
		}

		protected void layoutMajorAxis(int targetSpan, int axis, int[] offsets,
				int[] spans) {
			super.layoutMajorAxis(targetSpan, axis, offsets, spans);
			int textBlockHeight = 0;
			int offset = 0;

			for (int i = 0; i < spans.length; i++) {
				textBlockHeight += spans[i];
			}
			offset = (targetSpan - textBlockHeight) / 2;
			for (int i = 0; i < offsets.length; i++) {
				offsets[i] += offset;
			}
		}
	}
}