javax.swing.JPanel#paint ( )源码实例Demo

/**
 * Returns button with resource amounts and given text. If resources is empty then returns button
 * with just the text.
 */
public JButton getResourcesButton(final ResourceCollection resources, final String text) {
  if (resources.isEmpty()) {
    return new JButton(text);
  }
  final JPanel panel = getResourcesPanel(resources);
  panel.setOpaque(false);
  panel.add(new JLabel(text));
  panel.setSize(panel.getPreferredSize());
  panel.doLayout();
  final BufferedImage image =
      new BufferedImage(panel.getWidth(), panel.getHeight(), BufferedImage.TYPE_INT_ARGB);
  final Graphics2D g = image.createGraphics();
  panel.paint(g);
  g.dispose();
  return new JButton(new ImageIcon(image));
}
 

private void takeSnapShot() {
   imgCount++;
   JPanel panel = drawCanvas;
   
   (new File("snapshots/")).mkdirs();
   BufferedImage bufImage = new BufferedImage(panel.getSize().width, panel.getSize().height,BufferedImage.TYPE_INT_RGB);
   panel.paint(bufImage.createGraphics());
   File imageFile = new File("snapshots/"+imgCount+".png");
   try {
       imageFile.createNewFile();
       ImageIO.write(bufImage, "png", imageFile);
       System.out.println("Snapshot " + imgCount);
   } catch(Exception ex) {
       System.out.println("Unable to take snapshot: " + ex.getMessage());
   }
   
}
 

/**
 * Create the application icon.
 * 
 * This should be called on the EDT, because it creates/renders JComponents.
 */
private static BufferedImage createAppImage() {
	BufferedImage bi = new BufferedImage(100, 100,
			BufferedImage.TYPE_INT_ARGB);
	Graphics2D g = bi.createGraphics();

	JPanel p = new JPanel();
	p.setOpaque(false);
	QPanelUI qui = new QPanelUI();
	qui.setCalloutSize(10);
	qui.setCornerSize(10);
	qui.setCalloutType(CalloutType.BOTTOM_CENTER);
	qui.setFillColor1(Color.white);
	qui.setFillColor2(new Color(0xececec));
	qui.setShadowSize(5);
	qui.setStrokeColor(new Color(0x787878));
	p.setUI(qui);
	JSwitchButton switchButton1 = new JSwitchButton(true);
	JSwitchButton switchButton2 = new JSwitchButton(false);
	p.setLayout(new GridBagLayout());
	GridBagConstraints c = new GridBagConstraints();
	c.gridx = 0;
	c.gridy = 0;
	c.weightx = 1;
	c.weighty = 1;
	c.fill = GridBagConstraints.BOTH;
	c.insets = new Insets(4, 4, 4, 4);
	p.add(switchButton1, c);
	c.gridy++;
	p.add(switchButton2, c);
	Dimension d = p.getPreferredSize();
	d.width = Math.max(d.width, d.height);
	d.height = Math.max(d.width, d.height);
	p.setSize(d);
	p.getLayout().layoutContainer(p);
	p.paint(g);
	g.dispose();
	return bi;
}
 

public void save(File file, JPanel panel) throws IOException {
    String extension;
    int i = file.getName().lastIndexOf('.');
    if (i > 0) {
        extension = file.getName().substring(i + 1).toLowerCase();
    } else {
        extension = "png";
    }

    switch (extension) {
        case "png":
        case "gif":
        case "jpg":
        case "bmp":
            BufferedImage bi = new BufferedImage(OkapiUI.symbol.getWidth(), OkapiUI.symbol.getHeight(), BufferedImage.TYPE_INT_ARGB);
            panel.paint(bi.getGraphics());
            ImageIO.write(bi, extension, file);
            break;
        case "svg":
            SvgRenderer svg = new SvgRenderer(new FileOutputStream(file), OkapiUI.factor, OkapiUI.paperColour, OkapiUI.inkColour);
            svg.render(OkapiUI.symbol);
            break;
        case "eps":
            PostScriptRenderer eps = new PostScriptRenderer(new FileOutputStream(file), OkapiUI.factor, OkapiUI.paperColour, OkapiUI.inkColour);
            eps.render(OkapiUI.symbol);
            break;
        default:
            System.out.println("Unsupported output format");
            break;
    }
}
 

private void exportSVG(final JPanel panel, String selectedFile)
{
    // Create an instance of org.w3c.dom.Document.
    DOMImplementation domImpl = SVGDOMImplementation.getDOMImplementation();
    Document document = domImpl.createDocument(SVGDOMImplementation.SVG_NAMESPACE_URI, "svg", null);

    // Create an instance of the SVG Generator.
    SVGGraphics2D svgGenerator = new SVGGraphics2D(document);

    // Ask to render into the SVG Graphics2D implementation.
    if (panel instanceof FlexWordlePanel)
        ((FlexWordlePanel)panel).draw(svgGenerator, panel.getWidth(), panel.getHeight());
    else
        panel.paint(svgGenerator);

    // Finally, stream out SVG to the standard output using
    // UTF-8 encoding.
    boolean useCSS = true; // we want to use CSS style attributes
    Writer out;
    try
    {
        out = new OutputStreamWriter(new FileOutputStream(selectedFile), "UTF-8");
        svgGenerator.stream(out, useCSS);
        out.close();
    }
    catch (Exception e)
    {
        throw new RuntimeException(e);
    }
}
 

static private BufferedImage getScreenShot(JPanel panel) {
    BufferedImage bi = new BufferedImage(
            panel.getWidth(), panel.getHeight(), BufferedImage.TYPE_INT_ARGB);
    panel.paint(bi.getGraphics());
    return bi;
}