Weird problem in Windows 7 and Ubuntu 10.10 in a java application

[Jeferson Siqueira]

Hi.

I'm dealing with a really weird problem with an project that I've started to work on at work, a kind of a 'Paint' in java; until now, I've just implemented the single lines and rectangles tools.. and it works fine at my Ubuntu 10.10 but, when i try to run the project in windows 7, happens a kind of 'recursion' in my JPanel that shows the draws.. does someone knows why it happens ?,, here comes the screenshot

[James Sabre]

You have a bug in your code but how can anyone help without seeing the code?

[Luigi Plinge]

You need to call super.paintComponent() in your paintComponent() method. It's not a bug - you just haven't coded your method as per guidelines.

[James Sabre]

Luigi Plinge wrote:You need to call super.paintComponent() in your paintComponent() method. It's not a bug - you just haven't coded your method as per guidelines.

If that is the cause of the problem, and I am not convinced, how is that "not a bug" ?

[Campbell Ritchie]

Welcome to the Ranch, anyway bug or no bug

[Luigi Plinge]

I just meant it's not a bug in Swing, since the behaviour is unspecified if you don't call super.paintComponent().

[Jeferson Siqueira]

yes, I'm not calling the super.paintComponent(g); but i guess it's not the cause of the problem; because it runs fine both Ubuntu 10.10 and Windows XP, the problem its just happening in the Windows 7 Ultimate; what is the problem with the seven?

[Luigi Plinge]

There is no problem with Windows 7 - you're just doing it wrong.

[Rob Spoor]

Jeferson Siqueira wrote:yes, I'm not calling the super.paintComponent(g); but i guess it's not the cause of the problem; because it runs fine both Ubuntu 10.10 and Windows XP, the problem its just happening in the Windows 7 Ultimate; what is the problem with the seven?

I still say it's the absent super.paintComponent. In most cases of painting issues when paintComponent is overridden, an absent super.paintComponent is the reason.

Moving to our GUI forum.

[Luigi Plinge]

If you google "java override paintcomponent" the top result is the Sun documentation which says:

subclasses of Swing components which have a UI delegate (vs. direct subclasses of JComponent), should invoke super.paintComponent() within their paintComponent override
...
If for some reason the component extension does not want to allow the UI delegate to paint (if, for example, it is completely replacing the component's visuals), it may skip calling super.paintComponent(), but it must be responsible for filling in its own background if the opaque property is true, as discussed in the section on the opaque property.

[James Sabre]

Luigi Plinge wrote:If you google "java override paintcomponent" the top result is the Sun documentation which says:

subclasses of Swing components which have a UI delegate (vs. direct subclasses of JComponent), should invoke super.paintComponent() within their paintComponent override
...
If for some reason the component extension does not want to allow the UI delegate to paint (if, for example, it is completely replacing the component's visuals), it may skip calling super.paintComponent(), but it must be responsible for filling in its own background if the opaque property is true, as discussed in the section on the opaque property.

But this says nothing to indicate that failure to call super.paintComponent() may produce the recursive look experienced by the OP.

I have never had that recursive look. I write cross platform Swing programs which draw in the paintComponent() method and some of them do not call super.paintComponent(); I then paint the background.

Until either you or the OP produce code to show it does I will not be convinced that a failure to call super.paintComponent() can cause the recursive look. Start coding!

[Stephan van Hulst]

It can, but it's only the illusion of a recursive look. The issue is usually caused when you drag a window which has "opaque" components that do not paint all the pixels within their bounds.

When you drag the window, artifacts from the last time the window was painted will remain in the 'unpainted' pixels, giving it the appearance of a window in a window.

In this case it looks like the window was dragged very quickly. However, these artifacts may be caused by other things as well, maybe data remaining in the GPU's memory?

I also suspect the problem is caused by failing to call super.paintComponent(). If this is not the problem, then I would be *very* curious to learn what else it might be.

Waiting for the original poster to post an SSCCE.

[Luigi Plinge]

If you want a short example see my thread https://coderanch.com/t/526505/GUI/java/Why-getting-copy-button-JPanel

Stick in a super.paintComponent and it works fine.

[Jeferson Siqueira]

oh.
yes, I'm calling the super.paintComponent(g); now, but only once, because i want to keep everything I've already draw in my jpanel, but the weirdest thing, is that, today's morning, the problem was 'apparently' solved, but now, its happening again; I'll post the code of my JPanel and JFrame, that I'm developing using windowBuilder in eclipse

package com.cad;

import java.awt.Color;

public class CadPanel extends JPanel {
	private static final long serialVersionUID = 1L;
	private Color lineColor;
	private Point markerPoint;
	private Queue<Line> lines;
	private boolean stopSuperPaintComponent = false;
	
	public CadPanel() {
		setBorder(new LineBorder(new Color(0, 0, 0)));
		setBackground(Color.WHITE);
		lines = new LinkedList<Line>();
		lines.add(new Line(new Point(0, 0), new Point(0, 0)));

		addMouseListener(new MouseAdapter() {
			@Override
			public void mousePressed(MouseEvent arg0) {
				lines.peek().setPoint1(markerPoint);
			}

			@Override
			public void mouseReleased(MouseEvent arg0) {
				lines.peek().setPoint2(new Point(arg0.getX(), arg0.getY()));
				repaint();
			}
		});

		addMouseMotionListener(new MouseMotionAdapter() {
			@Override
			public void mouseMoved(MouseEvent arg0) {
				markerPoint = new Point(arg0.getX(), arg0.getY());
			}
		});

	}

	@Override
	public void paintComponent(Graphics g) {
		if(stopSuperPaintComponent == false){
			super.paintComponent(g);
			stopSuperPaintComponent = true;
		}
		g.setColor(lineColor);
		try {
			if (Screen.d == (Draw.LINE)) {
				g.setColor(lineColor);
				g.drawLine(lines.peek().getPoint1().x, lines.peek().getPoint1().y, lines.peek().getPoint2().x,	lines.peek().getPoint2().y);
			} else if (Screen.d == Draw.RECTANGLE) {
				g.setColor(lineColor);
				Rectangle rectangle = new Rectangle(new Point(lines.peek().getPoint1().x, lines.peek().getPoint1().y), new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y));
				rectangle.draw();
				g.drawRect(rectangle.getPointx(), rectangle.getPointy(), rectangle.getWidth(), rectangle.getHeight());
			}
			markerPoint = new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y);
		} catch (NullPointerException e) {
			throw new RuntimeException(e);
		}
	}

	public void setLineColor(Color c) {
		this.lineColor = c;
	}
	
	public String getCordinatesAsString() {
		return markerPoint.x + ":" + markerPoint.y;
	}
}

package com.cad;

import java.awt.Color;

public class Screen {
	private JFrame frmMinicadMax;
	private JFileChooser fileChooser;
	private JColorChooser colorChooser;
	private JLabel cordinatesLabel;
	private CadPanel panel;
	public static Draw d;

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			@Override
			public void run() {
				try {
					Screen window = new Screen();
					window.frmMinicadMax.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	public Screen() {
		initialize();
	}

	private void initialize() {
		frmMinicadMax = new JFrame();
		frmMinicadMax.setIconImage(Toolkit.getDefaultToolkit().getImage(Screen.class.getResource("/icon.png")));
		frmMinicadMax.setTitle("Mini-Cad - Max Lider");
		frmMinicadMax.setBounds(100, 100, 800, 600);
		frmMinicadMax.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frmMinicadMax.getContentPane().setLayout(null);

		JPanel sideMenuPanel = new JPanel();
		sideMenuPanel.setBounds(12, 12, 120, 219);
		frmMinicadMax.getContentPane().add(sideMenuPanel);
		sideMenuPanel.setLayout(null);

		JButton jBLine = new JButton("");
		jBLine.setToolTipText("Line");
		jBLine.setIcon(new ImageIcon(Screen.class.getResource("/line.png")));
		jBLine.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent arg0) {
				d = Draw.LINE;
			}
		});
		jBLine.setBounds(14, 49, 94, 23);
		sideMenuPanel.add(jBLine);

		JButton jBRect = new JButton("");
		jBRect.setToolTipText("Rectangle");
		jBRect.setIcon(new ImageIcon(Screen.class.getResource("/rectangle.png")));
		jBRect.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				d = Draw.RECTANGLE;
			}
		});
		jBRect.setBounds(14, 83, 94, 23);

		sideMenuPanel.add(jBRect);

		JButton jBArrow = new JButton("Arrow");
		jBArrow.setToolTipText("Arrow pointer");
		jBArrow.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {

			}
		});
		jBArrow.setBounds(14, 11, 94, 23);
		sideMenuPanel.add(jBArrow);

		cordinatesLabel = new JLabel("");
		cordinatesLabel.setBounds(709, 516, 65, 14);
		frmMinicadMax.getContentPane().add(cordinatesLabel);

		panel = new CadPanel();
		panel.setBackground(Color.WHITE);
		panel.addMouseMotionListener(new MouseMotionAdapter() {
			@Override
			public void mouseMoved(MouseEvent arg0) {
				cordinatesLabel.setText(panel.getCordinatesAsString());
			}
		});                 	
		panel.setBounds(183, 11, 578, 494);
		frmMinicadMax.getContentPane().add(panel);
		panel.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));

		JMenuBar menuBar = new JMenuBar();
		frmMinicadMax.setJMenuBar(menuBar);

		JMenu mnFile = new JMenu("File");
		menuBar.add(mnFile);

		JMenuItem mntmNew = new JMenuItem("New");
		mnFile.add(mntmNew);

		JMenuItem mntmOpen = new JMenuItem("Open");
		mntmOpen.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				fileChooser = new JFileChooser("C:");
				fileChooser.showDialog(frmMinicadMax, "Open");
				fileChooser.setVisible(true);
			}
		});
		mnFile.add(mntmOpen);

		JMenuItem mntmSave = new JMenuItem("Save");
		mnFile.add(mntmSave);

		JMenuItem mntmExit = new JMenuItem("Exit");
		mntmExit.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent arg0) {
				System.exit(0);
			}
		});
		mnFile.add(mntmExit);
		
		JMenu mnEdit = new JMenu("Edit");
		menuBar.add(mnEdit);
		
		JMenuItem mntmChangeStrokesColor = new JMenuItem("Change Strokes Color");
		mntmChangeStrokesColor.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				colorChooser = new JColorChooser();
				
				colorChooser.setVisible(true);
				JColorChooser.showDialog(null, "Choose Line's Color", Color.BLACK);
				panel.setLineColor(colorChooser.getColor());
				panel.repaint();
			}
		});
		mnEdit.add(mntmChangeStrokesColor);
		
		JMenu mnHelp = new JMenu("Help");
		menuBar.add(mnHelp);
		
		JMenuItem mntmAbout = new JMenuItem("About");
		mntmAbout.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				JOptionPane.showMessageDialog(null, "Mini-Cad\n");
			}
		});
		
		JMenuItem mntmContact = new JMenuItem("Contact");
		mntmContact.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
			
			}
		});
		mnHelp.add(mntmContact);
		mnHelp.add(mntmAbout);
	}
}

[James Sabre]

Luigi Plinge wrote:If you want a short example see my thread https://coderanch.com/t/526505/GUI/java/Why-getting-copy-button-JPanel

Stick in a super.paintComponent and it works fine.

Running your example in Ubuntu 11.04 with JDK1.6.0_26, Windows XP with JDK1.6.0_26 and Windows 7 with JDK1.6.0_25 (all 32 bit) I don't see this problem. Is it possible that it is a graphics card 'feature'?

[Luigi Plinge]

See Rob Camick's article here for how to keep the contents. Bascially, you have to either re-draw the entire contents, or keep a BufferedImage in memory that you copy in.

James Sabre wrote: Is it possible that it is a graphics card 'feature'?

I don't know. My machine has an nVidia GTX 260 card.

Edit: someone else with the same problem here: https://coderanch.com/t/538767/GUI/java/Weird-displaying-issues-between-computers. Looks like Vista there.

[James Sabre]

Jeferson Siqueira wrote:oh.
yes, I'm calling the super.paintComponent(g); now, but only once, because i want to keep everything I've already draw in my jpanel,

You can't do that. You must completely draw all the lines, shapes etc every that would be inside any corrupted area within the visible rectangle every time the paintComponent() is called. This means that for simple systems it is normally best to draw everything whenever paintComonent() is called.

[Jeferson Siqueira]

so, now I'm calling the super.paintComponent(g); but the problem persists, but it just paint the last line that i draw, erasing all the old ones, so, I'm made an boolean variable for it be called only once, but, the problem of the recursive screen persists, even now that i thought that change the JRE the problem could be solved, now i changed the JRE to the 1.6.23, and the problem persisted, but in Ubuntu 10.10, 11.04, windows xp home edition, and professional it worked fine, so now, i bet, that the problem is not with my code, does someone mind what is happening ?

[Luigi Plinge]

Read Rob Camick's article that I linked to a couple of posts above. It deals with your problem exactly.

[Jeferson Siqueira]

alright, I'm reading an i will implement a buffered image for my draws, but i was wondering, i the future, in this project, i'm thinking to manage the images by the mouse, as it was at 'Paint' or something, the buffered image solution would get me in trouble, wouldn't be?

[Stephan van Hulst]

Please post your paintComponent method so we can have a look at what you're doing.

[Jeferson Siqueira]

	@Override

	protected void paintComponent(Graphics g) {
		g.setColor(lineColor);

		if (Screen.d == (Draw.LINE)) {

			g.drawLine(lines.peek().getPoint1().x, lines.peek().getPoint1().y, lines.peek().getPoint2().x, lines.peek().getPoint2().y);

		} else if (Screen.d == Draw.RECTANGLE) {

			Rectangle rectangle = new Rectangle(new Point(lines.peek().getPoint1().x, lines.peek().getPoint1().y), new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y));

			rectangle.drawCordinates();

			g.drawRect(rectangle.getPointx(), rectangle.getPointy(), rectangle.getWidth(), rectangle.getHeight());

		} else if (Screen.d == Draw.ELIPSE) {

			Elipse elipse = new Elipse(new Point(lines.peek().getPoint1().x, lines.peek().getPoint1().y), new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y));

			elipse.drawCordinates();

			g.drawArc(elipse.getPointx(), elipse.getPointy(), elipse.getWidth(), elipse.getHeight(), 0, 360);

		}

		markerPoint = new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y);

	}

[Paul Clapham]

Jeferson Siqueira wrote:so, now I'm calling the super.paintComponent(g)

Not in that code, you aren't.

[Jeferson Siqueira]

oh, I'm sorry, the code that was on my computer was different from the other one, so here goes the right;

	@Override
	public void paintComponent(Graphics g) {
		super.paintComponent(g);
	
		g.setColor(lineColor);
		try {
			if (Screen.d == (Draw.LINE)) {
				g.setColor(lineColor);
				g.drawLine(lines.peek().getPoint1().x, lines.peek().getPoint1().y, lines.peek().getPoint2().x,	lines.peek().getPoint2().y);
			} else if (Screen.d == Draw.RECTANGLE) {
				Rectangle rectangle = new Rectangle(new Point(lines.peek().getPoint1().x, lines.peek().getPoint1().y), new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y));
				rectangle.draw();
				g.drawRect(rectangle.getPointx(), rectangle.getPointy(), rectangle.getWidth(), rectangle.getHeight());
			}else if(Screen.d == Draw.ELIPSE){
				Elipse elipse = new Elipse(new Point(lines.peek().getPoint1().x, lines.peek().getPoint1().y), new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y));
				elipse.draw();
				g.drawArc(elipse.getPointx(), elipse.getPointy(), elipse.getWidth(), elipse.getHeight(), 0, 360);
			}
			markerPoint = new Point(lines.peek().getPoint2().x, lines.peek().getPoint2().y);
		} catch (NullPointerException e) {
			throw new RuntimeException(e);
		}
	}