Swing Graphics and JPanel setPrefrerredSize

[Ron Summer]

Hi all,
I hope I can get some help with this question concerning the following code.

 
public class TestScreen extends AAAFrame implements Common, ActionListener {
	private static final long serialVersionUID = 1L;
	private PicturesArea  pic = null;
	Color panelColor = new Color (40, 189, 171);
	JScrollPane scrollPane = new JScrollPane();
	Graphics2D g2 = null;

	public TestScreen(PicturesArea pic){
		super("Title Report");
		this.pic = pic;
		DrawingPanel panel = new DrawingPanel();
		panel.setBackground(panelColor);

		Container c = getContentPane();
		c.setLayout (new PercentLayout());  
		c.setBackground(panelColor);

		scrollPane = new JScrollPane(panel);
		JPanel buttonPanel = new JPanel();
		buttonPanel.setLayout (new FlowLayout(FlowLayout.CENTER, 15, 8));

		NoFocusButton b = new NoFocusButton ("Cancel", new ImageIcon(Utility.getImage(getClass().getResourceAsStream("return.gif"))));
		b.setToolTipText("Return to Previous Screen");
		b.addActionListener (this);
		buttonPanel.add(b);
		
		scrollPane.revalidate();
		buttonPanel.setBackground(panelColor);
		scrollPane.paint(g2);
		c.add("1 1 100 90",scrollPane);
		c.add("1 91 100 100", buttonPanel);
		setSize(SCREENWIDTH, SCREENLENGTH);
	}

	public void actionPerformed(ActionEvent e) {
		if (e.getSource() instanceof JButton) {
			String label = ((JButton)e.getSource()).getText();
			if (label.equals("Cancel")) {
				setVisible(false);
				dispose();
			}
		}
	}

	public class DrawingPanel extends JPanel {
		private static final long serialVersionUID = 3402498689136443092L;
		int res = Toolkit.getDefaultToolkit().getScreenResolution();

		DrawingPanel () {
			setBackground (panelColor);
		} 

		public void paintComponent(Graphics g)   {
			super.paintComponent(g);
			g2 = (Graphics2D) g;
			g2.setTransform(AffineTransform.getScaleInstance((double)res/72,(double)res/72));
			pic.ViewNewPicturesReport(g2);
		}
	}
}

The problem I am having is the setPreferredSize on the DrawingPanel. When the DrawingPanel object is created pictures (image) are loaded along with a description (text) of each one using Graphics2D commands in pic.ViewNewPicturesReport(g2). The scrollPanel does not scroll to the bottom of the report but only shows what one screen would look like. When I set the panel.setPreferredSize to some large dimension like (1500, 3500), then the scrollPanel will scroll to the end of the report. If I have a short amount of pictures the end of the scroll area could be way down, likewise if I have a large number of pictures and text then the scroll would stop before the end of the report. i have tried letting the DrawingPanel set the preferred size using getPreferredSize but didn't even have a scrolling area.

I couple of other items, I have tried using pack, validate, and revalidate after returning from the new DrawingPanel. All those methods doesn't seem to have any positive effect on the proper scrolling range.

How can I get the scrollPane to correctly determine what the end of the DrawingPanel's view and scroll correctly?

Everything I've seen on setPreferredSize seems to preset the Dimension in code. Can this be done using a method of Graphics2D? some other method? or maybe some formula?

Thanks for any and all help.

[Ron Summer]

I'm new to posting on this forum, so I not sure if I did everything correctly.

But I've had several viewers but no help.
Is what I'm asking doable? Is their enough information given to receive an answer?
Thanks.

[Rob Camick]

i have tried letting the DrawingPanel set the preferred size using getPreferredSize

That is the proper approach.

Can this be done using a method of Graphics2D?

Not that I know of.

some other method? or maybe some formula?

What have you tried? I would guess that you multiply the width/height of your original image by the scaling factor.

I'm new to posting on this forum, so I not sure if I did everything correctly

A SSCCE always provides more information. You never know someone may use the SSCCE as a starting point to determine the forumula for you to use.

[Ron Summer]

Thanks for the post.
The location of the images are stored in a database, their may be none or many pictures. The size of the image can varying depending upon the resolution that the picture was taken in, we don't scale them.

In the DrawingPanel, I have tried setPreferredSize(getPreferredSize()) upon returning from the pic.ViewNewPicturesReport method. Which return (10,10 being returned and no scrollbars. Which is way to small, my main Frame is set to (853, 1450).

I have tired the setPreferredSize(getPreferredSize()) after adding the panel to the JScrollBar in the ctor of ConditionViewPrintFrame with the same value of (10,10) being returned and again scrollbars.

Thanks,

[Rob Camick]

we don't scale them.

Your posted code uses the getScaledImage() method.

Which return (10,10

Yes, that is the size of the panel

I have tried setPreferredSize(getPreferredSize())

That is not what was suggested. You need to override the getPreferredSize() method to return the size of the image that you want to paint on the panel.

You haven't posted a SSCCE so I can't help anymore.

[Ron Summer]

Your posted code uses the getScaledImage() method.

I think you must be confusing my code with another you are helping. I don't use that method.

That is not what was suggested. You need to override the getPreferredSize() method to return the size of the image that you want to paint on the panel.

Again I think you must be confusing my code with another you are helping. You never made that suggestion concerning this thread.

Also I'm not always dealing with a single image, sometimes their maybe none others it could be as many as 15 - 20 or more.

But thanks for the effort.

[Rob Spoor]

Ron Summer wrote:

			g2.setTransform(AffineTransform.getScaleInstance((double)res/72,(double)res/72));

Looks like scaling to me.

[Rob Camick]

Add the images to a JLabel and add the labels to a panel using a layout manager and you won't have to worry about this.

[Ron Summer]

Rob Prime you are correct, what I should have said is that the images are not scaled using the getScaledImage() method that Rob Camick was referencing.

Rob Carmick I don't have access to the image(s) just the method that fetches, writes some descriptive line(s) of text, and renders them. So a label is not an option.

Thanks all.

[Darryl Burke]

If the PicturesArea class doesn't expose an API to determine directly or indirectly the dimensions of the area it paints to, then there's no way you can achieve your goal. Or at least, not without a totally hackish and inefficient approach like painting to a BufferedImage sized larger than the maximum possible size and scanning the pixels to find the highest-value column and row with non-default color.

db