So, part of the problem, as I see it, is some the components don't want to render until they are attached to a native peer (or realised window).
There are two choices, you could simply print the live component which is already on the screen. This is a problem, because the ComponentPrintable will change the size of the component, which will affect the live component, making it somewhat unpleasant to the user.
The second option is to create a new instance of the component and place it on another JFrame. The tricky part is getting the frame to realise it self and create a native peer.
Luckily, there are a couple of methods which we know can do this, pack been one of them.
The following example is taken from the Using Text Components example, as it's a realitvly complex component.
When you click print, it makes a new instance of this component, add's it to a JFrame, packs the frame and then prints the component.
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import static java.awt.print.Printable.PAGE_EXISTS;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.IOException;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.JTextPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.text.BadLocationException;
import javax.swing.text.Style;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyleContext;
import javax.swing.text.StyledDocument;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JButton print = new JButton("Print");
print.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
TextSamplerDemo demo = new TextSamplerDemo();
JFrame test = new JFrame();
test.add(demo);
test.pack();
ComponentPrintable printable = new ComponentPrintable(demo);
PrinterJob printerJob = PrinterJob.getPrinterJob();
PageFormat pf = printerJob.pageDialog(printerJob.defaultPage());
printerJob.setPrintable(printable, pf);
if (printerJob.printDialog()) {
try {
printerJob.print();
} catch (PrinterException e1) {
JOptionPane.showMessageDialog(null, "Printing failed", "Print", JOptionPane.OK_OPTION);
}
}
}
});
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
TextSamplerDemo demo = new TextSamplerDemo();
frame.add(demo);
frame.add(print, BorderLayout.SOUTH);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ComponentPrintable extends JPanel implements Printable {
private Component comp;
public ComponentPrintable(Component comp) {
this.comp = comp;
}
@Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
if (pageIndex > 0) {
return Printable.NO_SUCH_PAGE;
}
Dimension componentSize = comp.getPreferredSize();
comp.setSize(componentSize);
Dimension printSize = new Dimension();
printSize.setSize(pageFormat.getImageableWidth(), pageFormat.getImageableHeight());
double scaleFactor = getScaleFactorToFit(componentSize, printSize);
if (scaleFactor > 1d) {
scaleFactor = 1d;
}
double scaleWidth = componentSize.width * scaleFactor;
double scaleHeight = componentSize.height * scaleFactor;
Graphics2D g2 = (Graphics2D) graphics;
double x = ((pageFormat.getImageableWidth() - scaleWidth) / 2d) + pageFormat.getImageableX();
double y = ((pageFormat.getImageableHeight() - scaleHeight) / 2d) + pageFormat.getImageableY();
AffineTransform at = new AffineTransform();
at.translate(x, y);
at.scale(scaleFactor, scaleFactor);
g2.transform(at);
comp.printAll(g2);
g2.dispose();
comp.revalidate();
return PAGE_EXISTS;
}
private double getScaleFactorToFit(Dimension original, Dimension toFit) {
double dScale = 1d;
if (original != null && toFit != null) {
double dScaleWidth = getScaleFactor(original.width, toFit.width);
double dScaleHeight = getScaleFactor(original.height, toFit.height);
dScale = Math.min(dScaleHeight, dScaleWidth);
}
return dScale;
}
private double getScaleFactor(int iMasterSize, int iTargetSize) {
double dScale = 1;
if (iMasterSize > iTargetSize) {
dScale = (double) iTargetSize / (double) iMasterSize;
} else {
dScale = (double) iTargetSize / (double) iMasterSize;
}
return dScale;
}
}
public class TextSamplerDemo extends JPanel
implements ActionListener {
private String newline = "\n";
protected static final String textFieldString = "JTextField";
protected static final String passwordFieldString = "JPasswordField";
protected static final String ftfString = "JFormattedTextField";
protected static final String buttonString = "JButton";
protected JLabel actionLabel;
public TextSamplerDemo() {
setLayout(new BorderLayout());
//Create a regular text field.
JTextField textField = new JTextField(10);
textField.setActionCommand(textFieldString);
textField.addActionListener(this);
//Create a password field.
JPasswordField passwordField = new JPasswordField(10);
passwordField.setActionCommand(passwordFieldString);
passwordField.addActionListener(this);
//Create a formatted text field.
JFormattedTextField ftf = new JFormattedTextField(
java.util.Calendar.getInstance().getTime());
ftf.setActionCommand(textFieldString);
ftf.addActionListener(this);
//Create some labels for the fields.
JLabel textFieldLabel = new JLabel(textFieldString + ": ");
textFieldLabel.setLabelFor(textField);
JLabel passwordFieldLabel = new JLabel(passwordFieldString + ": ");
passwordFieldLabel.setLabelFor(passwordField);
JLabel ftfLabel = new JLabel(ftfString + ": ");
ftfLabel.setLabelFor(ftf);
//Create a label to put messages during an action event.
actionLabel = new JLabel("Type text in a field and press Enter.");
actionLabel.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));
//Lay out the text controls and the labels.
JPanel textControlsPane = new JPanel();
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints c = new GridBagConstraints();
textControlsPane.setLayout(gridbag);
JLabel[] labels = {textFieldLabel, passwordFieldLabel, ftfLabel};
JTextField[] textFields = {textField, passwordField, ftf};
addLabelTextRows(labels, textFields, gridbag, textControlsPane);
c.gridwidth = GridBagConstraints.REMAINDER; //last
c.anchor = GridBagConstraints.WEST;
c.weightx = 1.0;
textControlsPane.add(actionLabel, c);
textControlsPane.setBorder(
BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Text Fields"),
BorderFactory.createEmptyBorder(5, 5, 5, 5)));
//Create a text area.
JTextArea textArea = new JTextArea(
"This is an editable JTextArea. "
+ "A text area is a \"plain\" text component, "
+ "which means that although it can display text "
+ "in any font, all of the text is in the same font."
);
textArea.setFont(new Font("Serif", Font.ITALIC, 16));
textArea.setLineWrap(true);
textArea.setWrapStyleWord(true);
JScrollPane areaScrollPane = new JScrollPane(textArea);
areaScrollPane.setVerticalScrollBarPolicy(
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
areaScrollPane.setPreferredSize(new Dimension(250, 250));
areaScrollPane.setBorder(
BorderFactory.createCompoundBorder(
BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Plain Text"),
BorderFactory.createEmptyBorder(5, 5, 5, 5)),
areaScrollPane.getBorder()));
//Create an editor pane.
JEditorPane editorPane = createEditorPane();
JScrollPane editorScrollPane = new JScrollPane(editorPane);
editorScrollPane.setVerticalScrollBarPolicy(
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
editorScrollPane.setPreferredSize(new Dimension(250, 145));
editorScrollPane.setMinimumSize(new Dimension(10, 10));
//Create a text pane.
JTextPane textPane = createTextPane();
JScrollPane paneScrollPane = new JScrollPane(textPane);
paneScrollPane.setVerticalScrollBarPolicy(
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
paneScrollPane.setPreferredSize(new Dimension(250, 155));
paneScrollPane.setMinimumSize(new Dimension(10, 10));
//Put the editor pane and the text pane in a split pane.
JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,
editorScrollPane,
paneScrollPane);
splitPane.setOneTouchExpandable(true);
splitPane.setResizeWeight(0.5);
JPanel rightPane = new JPanel(new GridLayout(1, 0));
rightPane.add(splitPane);
rightPane.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Styled Text"),
BorderFactory.createEmptyBorder(5, 5, 5, 5)));
//Put everything together.
JPanel leftPane = new JPanel(new BorderLayout());
leftPane.add(textControlsPane,
BorderLayout.PAGE_START);
leftPane.add(areaScrollPane,
BorderLayout.CENTER);
add(leftPane, BorderLayout.LINE_START);
add(rightPane, BorderLayout.LINE_END);
}
private void addLabelTextRows(JLabel[] labels,
JTextField[] textFields,
GridBagLayout gridbag,
Container container) {
GridBagConstraints c = new GridBagConstraints();
c.anchor = GridBagConstraints.EAST;
int numLabels = labels.length;
for (int i = 0; i < numLabels; i++) {
c.gridwidth = GridBagConstraints.RELATIVE; //next-to-last
c.fill = GridBagConstraints.NONE; //reset to default
c.weightx = 0.0; //reset to default
container.add(labels[i], c);
c.gridwidth = GridBagConstraints.REMAINDER; //end row
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 1.0;
container.add(textFields[i], c);
}
}
public void actionPerformed(ActionEvent e) {
String prefix = "You typed \"";
if (textFieldString.equals(e.getActionCommand())) {
JTextField source = (JTextField) e.getSource();
actionLabel.setText(prefix + source.getText() + "\"");
} else if (passwordFieldString.equals(e.getActionCommand())) {
JPasswordField source = (JPasswordField) e.getSource();
actionLabel.setText(prefix + new String(source.getPassword())
+ "\"");
} else if (buttonString.equals(e.getActionCommand())) {
Toolkit.getDefaultToolkit().beep();
}
}
private JEditorPane createEditorPane() {
JEditorPane editorPane = new JEditorPane();
editorPane.setEditable(false);
java.net.URL helpURL = TextSamplerDemo.class.getResource(
"TextSamplerDemoHelp.html");
if (helpURL != null) {
try {
editorPane.setPage(helpURL);
} catch (IOException e) {
System.err.println("Attempted to read a bad URL: " + helpURL);
}
} else {
System.err.println("Couldn't find file: TextSampleDemoHelp.html");
}
return editorPane;
}
private JTextPane createTextPane() {
String[] initString
= {"This is an editable JTextPane, ", //regular
"another ", //italic
"styled ", //bold
"text ", //small
"component, ", //large
"which supports embedded components..." + newline,//regular
" " + newline, //button
"...and embedded icons..." + newline, //regular
" ", //icon
newline + "JTextPane is a subclass of JEditorPane that "
+ "uses a StyledEditorKit and StyledDocument, and provides "
+ "cover methods for interacting with those objects."
};
String[] initStyles
= {"regular", "italic", "bold", "small", "large",
"regular", "button", "regular", "icon",
"regular"
};
JTextPane textPane = new JTextPane();
StyledDocument doc = textPane.getStyledDocument();
addStylesToDocument(doc);
try {
for (int i = 0; i < initString.length; i++) {
doc.insertString(doc.getLength(), initString[i],
doc.getStyle(initStyles[i]));
}
} catch (BadLocationException ble) {
System.err.println("Couldn't insert initial text into text pane.");
}
return textPane;
}
protected void addStylesToDocument(StyledDocument doc) {
//Initialize some styles.
Style def = StyleContext.getDefaultStyleContext().
getStyle(StyleContext.DEFAULT_STYLE);
Style regular = doc.addStyle("regular", def);
StyleConstants.setFontFamily(def, "SansSerif");
Style s = doc.addStyle("italic", regular);
StyleConstants.setItalic(s, true);
s = doc.addStyle("bold", regular);
StyleConstants.setBold(s, true);
s = doc.addStyle("small", regular);
StyleConstants.setFontSize(s, 10);
s = doc.addStyle("large", regular);
StyleConstants.setFontSize(s, 16);
s = doc.addStyle("icon", regular);
StyleConstants.setAlignment(s, StyleConstants.ALIGN_CENTER);
ImageIcon pigIcon = createImageIcon("images/Pig.gif",
"a cute pig");
if (pigIcon != null) {
StyleConstants.setIcon(s, pigIcon);
}
s = doc.addStyle("button", regular);
StyleConstants.setAlignment(s, StyleConstants.ALIGN_CENTER);
ImageIcon soundIcon = createImageIcon("images/sound.gif",
"sound icon");
JButton button = new JButton();
if (soundIcon != null) {
button.setIcon(soundIcon);
} else {
button.setText("BEEP");
}
button.setCursor(Cursor.getDefaultCursor());
button.setMargin(new Insets(0, 0, 0, 0));
button.setActionCommand(buttonString);
button.addActionListener(this);
StyleConstants.setComponent(s, button);
}
protected ImageIcon createImageIcon(String path,
String description) {
java.net.URL imgURL = TextSamplerDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL, description);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
}
}
For this to work realistically, you would need to make a copy of all the data which the panel contained originally, otherwise it's kind of pointless
