Develop Reference

About java swing Linked label [duplicate]

I want to learn how to write an ActionListener for JLabel. I want to make a label that open a new frame for user when user clicks the label. Maybe MouseListener can work but I do not know how to make it.

I recommend using a JTextField rather than a JLabel for this use.
Being based on a component designed to be focusable, it allows an ActionListener and looks and feels more like an HTML link.
E.G.
That is how it appears when the mouse is hovering over the first link.
LinkLabel
/* License - LGPL
LinkLabel Using the Desktop Class
There are a lot of link labels. This one uses the Java 1.6+
Desktop class for its functionality, and is thereby suitable
for applets, applications launched using JWS, and 'standard'
(non-JWS) desktop applications.
Note that the Desktop class can be used with pre 1.6 JREs. It
is available through JDIC.
https://jdic.dev.java.net/nonav/documentation/javadoc/jdic/org/jdesktop/jdic/desktop/Desktop.html
*/
import java.awt.Desktop;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.JTextField;
import javax.swing.JPanel;
import javax.swing.JOptionPane;
import javax.swing.border.MatteBorder;
import javax.swing.border.Border;
import java.net.URI;
import java.io.File;
/**
A Java 1.6+ LinkLabel that uses the Desktop class for opening
the document of interest.
The Desktop.browse(URI) method can be invoked from applications,
applets and apps. launched using Java Webstart. In the latter
two cases, the usual fall-back methods are used for sandboxed apps
(see the JavaDocs for further details).
While called a 'label', this class actually extends JTextField,
to easily allow the component to become focusable using keyboard
navigation.
To successfully browse to a URI for a local File, the file name
must be constructed using a canonical path.
#author Andrew Thompson
#version 2008/08/23
*/
public class LinkLabel
// we extend a JTextField, to get a focusable component
extends JTextField
implements MouseListener, FocusListener, ActionListener {
/** The target or href of this link. */
private URI target;
public Color standardColor = new Color(0,0,255);
public Color hoverColor = new Color(255,0,0);
public Color activeColor = new Color(128,0,128);
public Color transparent = new Color(0,0,0,0);
public boolean underlineVisible = true;
private Border activeBorder;
private Border hoverBorder;
private Border standardBorder;
/** Construct a LinkLabel that points to the given target.
The URI will be used as the link text.*/
public LinkLabel(URI target) {
this( target, target.toString() );
}
/** Construct a LinkLabel that points to the given target,
and displays the text to the user. */
public LinkLabel(URI target, String text) {
super(text);
this.target = target;
}
/* Set the active color for this link (default is purple). */
public void setActiveColor(Color active) {
activeColor = active;
}
/* Set the hover/focused color for this link (default is red). */
public void setHoverColor(Color hover) {
hoverColor = hover;
}
/* Set the standard (non-focused, non-active) color for this
link (default is blue). */
public void setStandardColor(Color standard) {
standardColor = standard;
}
/** Determines whether the */
public void setUnderlineVisible(boolean underlineVisible) {
this.underlineVisible = underlineVisible;
}
/* Add the listeners, configure the field to look and act
like a link. */
public void init() {
this.addMouseListener(this);
this.addFocusListener(this);
this.addActionListener(this);
setToolTipText(target.toString());
if (underlineVisible) {
activeBorder = new MatteBorder(0,0,1,0,activeColor);
hoverBorder = new MatteBorder(0,0,1,0,hoverColor);
standardBorder = new MatteBorder(0,0,1,0,transparent);
} else {
activeBorder = new MatteBorder(0,0,0,0,activeColor);
hoverBorder = new MatteBorder(0,0,0,0,hoverColor);
standardBorder = new MatteBorder(0,0,0,0,transparent);
}
// make it appear like a label/link
setEditable(false);
setForeground(standardColor);
setBorder(standardBorder);
setCursor( new Cursor(Cursor.HAND_CURSOR) );
}
/** Browse to the target URI using the Desktop.browse(URI)
method. For visual indication, change to the active color
at method start, and return to the standard color once complete.
This is usually so fast that the active color does not appear,
but it will take longer if there is a problem finding/loading
the browser or URI (e.g. for a File). */
public void browse() {
setForeground(activeColor);
setBorder(activeBorder);
try {
Desktop.getDesktop().browse(target);
} catch(Exception e) {
e.printStackTrace();
}
setForeground(standardColor);
setBorder(standardBorder);
}
/** Browse to the target. */
public void actionPerformed(ActionEvent ae) {
browse();
}
/** Browse to the target. */
public void mouseClicked(MouseEvent me) {
browse();
}
/** Set the color to the hover color. */
public void mouseEntered(MouseEvent me) {
setForeground(hoverColor);
setBorder(hoverBorder);
}
/** Set the color to the standard color. */
public void mouseExited(MouseEvent me) {
setForeground(standardColor);
setBorder(standardBorder);
}
public void mouseReleased(MouseEvent me) {}
public void mousePressed(MouseEvent me) {}
/** Set the color to the standard color. */
public void focusLost(FocusEvent fe) {
setForeground(standardColor);
setBorder(standardBorder);
}
/** Set the color to the hover color. */
public void focusGained(FocusEvent fe) {
setForeground(hoverColor);
setBorder(hoverBorder);
}
public static void main(String[] args) throws Exception {
JPanel p = new JPanel(new GridLayout(0,1));
File f = new File(".","LinkLabel.java");
/* Filename must be constructed with a canonical path in
order to successfully use Desktop.browse(URI)! */
f = new File(f.getCanonicalPath());
URI uriFile = f.toURI();
LinkLabel linkLabelFile = new LinkLabel(uriFile);
linkLabelFile.init();
p.add(linkLabelFile);
LinkLabel linkLabelWeb = new LinkLabel(
new URI("http://sscce.org/"),
"SSCCE");
linkLabelWeb.setStandardColor(new Color(0,128,0));
linkLabelWeb.setHoverColor(new Color(222,128,0));
linkLabelWeb.init();
/* This shows a quirk of the LinkLabel class, the
size of the text field needs to be constrained to
get the underline to appear properly. */
p.add(linkLabelWeb);
LinkLabel linkLabelConstrain = new LinkLabel(
new URI("http://sdnshare.sun.com/"),
"SDN Share");
linkLabelConstrain.init();
/* ..and this shows one way to constrain the size
(appropriate for this layout).
Similar tricks can be used to ensure the underline does
not drop too far *below* the link (think BorderLayout
NORTH/SOUTH).
The same technique can also be nested further to produce
a NORTH+EAST packing (for example). */
JPanel labelConstrain = new JPanel(new BorderLayout());
labelConstrain.add( linkLabelConstrain, BorderLayout.EAST );
p.add(labelConstrain);
LinkLabel linkLabelNoUnderline = new LinkLabel(
new URI("http://java.net/"),
"java.net");
// another way to deal with the underline is to remove it
linkLabelNoUnderline.setUnderlineVisible(false);
// we can use the methods inherited from JTextField
linkLabelNoUnderline.
setHorizontalAlignment(JTextField.CENTER);
linkLabelNoUnderline.init();
p.add(linkLabelNoUnderline);
JOptionPane.showMessageDialog( null, p );
}
}

How to rename Java's thread

Here is an example created from http://www.java2s.com/Code/Java/SWT-JFace-Eclipse/SWTandThread.htm
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
public class MultiThread extends Shell {
Button btnNewButton = new Button(this, SWT.NONE);
/**
* Launch the application.
* #param args
*/
public static void main(String args[]) {
try {
Display display = Display.getDefault();
MultiThread shell = new MultiThread(display);
shell.open();
shell.layout();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Create the shell.
* #param display
*/
public MultiThread(Display display) {
super(display, SWT.SHELL_TRIM);
btnNewButton.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
applicationThread.start();
}
});
btnNewButton.setBounds(86, 47, 68, 23);
btnNewButton.setText("New Button");
createContents();
}
/**
* Create contents of the shell.
*/
protected void createContents() {
setText("SWT Application");
setSize(450, 300);
}
#Override
protected void checkSubclass() {
// Disable the check that prevents subclassing of SWT components
}
final Runnable print = new Runnable() {
public void run() {
System.out.println("Print from thread: \t" + Thread.currentThread().getName());
}
};
final Thread applicationThread = new Thread("currentThread") {
public void run() {
System.out.println("Hello from thread: \t" + Thread.currentThread().getName());
getDisplay().syncExec(print);
System.out.println("Bye from thread: \t" + Thread.currentThread().getName());
}
};
}
My question is: why IllegalThreadStateException occur on second click on button? Is it because second click creates a thread with same name as previous? How can I avoid that?
Thank you in advance!

Use Below code to set threads Name
Thread.currentThread().setName("Hello");

I hope you are starting a thread again without instantiating an object of thread which will result an java.lang.IllegalThreadStateException..
for e.g if you start an thread by instantiating and call start to start executing a thread. Again if you call thread.start will leads to java.lang.IllegalThreadStateException..
The same thing you are trying to achieve in your code.
once your button is clicked you are executing an thread and starting the thread again by calling thread.start()..
For every button click you should start a new thread() by instantiating object of thread.

From the documentation of Thread.start:
throws
IllegalThreadStateException - if the thread was already started.
You are not creating a new thread with the same name, you are calling start() on the same thread again and get what the documentation promised you.
It seems, whoever made that example did not consider the possibility that a user clicks a button more than once…

The problem is that you can't start same thread twice: check javadoc
It is never legal to start a thread more than once. In particular, a
thread may not be restarted once it has completed execution.

ActionListener for JLabel

I want to learn how to write an ActionListener for JLabel. I want to make a label that open a new frame for user when user clicks the label. Maybe MouseListener can work but I do not know how to make it.

I recommend using a JTextField rather than a JLabel for this use.
Being based on a component designed to be focusable, it allows an ActionListener and looks and feels more like an HTML link.
E.G.
That is how it appears when the mouse is hovering over the first link.
LinkLabel
/* License - LGPL
LinkLabel Using the Desktop Class
There are a lot of link labels. This one uses the Java 1.6+
Desktop class for its functionality, and is thereby suitable
for applets, applications launched using JWS, and 'standard'
(non-JWS) desktop applications.
Note that the Desktop class can be used with pre 1.6 JREs. It
is available through JDIC.
https://jdic.dev.java.net/nonav/documentation/javadoc/jdic/org/jdesktop/jdic/desktop/Desktop.html
*/
import java.awt.Desktop;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.JTextField;
import javax.swing.JPanel;
import javax.swing.JOptionPane;
import javax.swing.border.MatteBorder;
import javax.swing.border.Border;
import java.net.URI;
import java.io.File;
/**
A Java 1.6+ LinkLabel that uses the Desktop class for opening
the document of interest.
The Desktop.browse(URI) method can be invoked from applications,
applets and apps. launched using Java Webstart. In the latter
two cases, the usual fall-back methods are used for sandboxed apps
(see the JavaDocs for further details).
While called a 'label', this class actually extends JTextField,
to easily allow the component to become focusable using keyboard
navigation.
To successfully browse to a URI for a local File, the file name
must be constructed using a canonical path.
#author Andrew Thompson
#version 2008/08/23
*/
public class LinkLabel
// we extend a JTextField, to get a focusable component
extends JTextField
implements MouseListener, FocusListener, ActionListener {
/** The target or href of this link. */
private URI target;
public Color standardColor = new Color(0,0,255);
public Color hoverColor = new Color(255,0,0);
public Color activeColor = new Color(128,0,128);
public Color transparent = new Color(0,0,0,0);
public boolean underlineVisible = true;
private Border activeBorder;
private Border hoverBorder;
private Border standardBorder;
/** Construct a LinkLabel that points to the given target.
The URI will be used as the link text.*/
public LinkLabel(URI target) {
this( target, target.toString() );
}
/** Construct a LinkLabel that points to the given target,
and displays the text to the user. */
public LinkLabel(URI target, String text) {
super(text);
this.target = target;
}
/* Set the active color for this link (default is purple). */
public void setActiveColor(Color active) {
activeColor = active;
}
/* Set the hover/focused color for this link (default is red). */
public void setHoverColor(Color hover) {
hoverColor = hover;
}
/* Set the standard (non-focused, non-active) color for this
link (default is blue). */
public void setStandardColor(Color standard) {
standardColor = standard;
}
/** Determines whether the */
public void setUnderlineVisible(boolean underlineVisible) {
this.underlineVisible = underlineVisible;
}
/* Add the listeners, configure the field to look and act
like a link. */
public void init() {
this.addMouseListener(this);
this.addFocusListener(this);
this.addActionListener(this);
setToolTipText(target.toString());
if (underlineVisible) {
activeBorder = new MatteBorder(0,0,1,0,activeColor);
hoverBorder = new MatteBorder(0,0,1,0,hoverColor);
standardBorder = new MatteBorder(0,0,1,0,transparent);
} else {
activeBorder = new MatteBorder(0,0,0,0,activeColor);
hoverBorder = new MatteBorder(0,0,0,0,hoverColor);
standardBorder = new MatteBorder(0,0,0,0,transparent);
}
// make it appear like a label/link
setEditable(false);
setForeground(standardColor);
setBorder(standardBorder);
setCursor( new Cursor(Cursor.HAND_CURSOR) );
}
/** Browse to the target URI using the Desktop.browse(URI)
method. For visual indication, change to the active color
at method start, and return to the standard color once complete.
This is usually so fast that the active color does not appear,
but it will take longer if there is a problem finding/loading
the browser or URI (e.g. for a File). */
public void browse() {
setForeground(activeColor);
setBorder(activeBorder);
try {
Desktop.getDesktop().browse(target);
} catch(Exception e) {
e.printStackTrace();
}
setForeground(standardColor);
setBorder(standardBorder);
}
/** Browse to the target. */
public void actionPerformed(ActionEvent ae) {
browse();
}
/** Browse to the target. */
public void mouseClicked(MouseEvent me) {
browse();
}
/** Set the color to the hover color. */
public void mouseEntered(MouseEvent me) {
setForeground(hoverColor);
setBorder(hoverBorder);
}
/** Set the color to the standard color. */
public void mouseExited(MouseEvent me) {
setForeground(standardColor);
setBorder(standardBorder);
}
public void mouseReleased(MouseEvent me) {}
public void mousePressed(MouseEvent me) {}
/** Set the color to the standard color. */
public void focusLost(FocusEvent fe) {
setForeground(standardColor);
setBorder(standardBorder);
}
/** Set the color to the hover color. */
public void focusGained(FocusEvent fe) {
setForeground(hoverColor);
setBorder(hoverBorder);
}
public static void main(String[] args) throws Exception {
JPanel p = new JPanel(new GridLayout(0,1));
File f = new File(".","LinkLabel.java");
/* Filename must be constructed with a canonical path in
order to successfully use Desktop.browse(URI)! */
f = new File(f.getCanonicalPath());
URI uriFile = f.toURI();
LinkLabel linkLabelFile = new LinkLabel(uriFile);
linkLabelFile.init();
p.add(linkLabelFile);
LinkLabel linkLabelWeb = new LinkLabel(
new URI("http://sscce.org/"),
"SSCCE");
linkLabelWeb.setStandardColor(new Color(0,128,0));
linkLabelWeb.setHoverColor(new Color(222,128,0));
linkLabelWeb.init();
/* This shows a quirk of the LinkLabel class, the
size of the text field needs to be constrained to
get the underline to appear properly. */
p.add(linkLabelWeb);
LinkLabel linkLabelConstrain = new LinkLabel(
new URI("http://sdnshare.sun.com/"),
"SDN Share");
linkLabelConstrain.init();
/* ..and this shows one way to constrain the size
(appropriate for this layout).
Similar tricks can be used to ensure the underline does
not drop too far *below* the link (think BorderLayout
NORTH/SOUTH).
The same technique can also be nested further to produce
a NORTH+EAST packing (for example). */
JPanel labelConstrain = new JPanel(new BorderLayout());
labelConstrain.add( linkLabelConstrain, BorderLayout.EAST );
p.add(labelConstrain);
LinkLabel linkLabelNoUnderline = new LinkLabel(
new URI("http://java.net/"),
"java.net");
// another way to deal with the underline is to remove it
linkLabelNoUnderline.setUnderlineVisible(false);
// we can use the methods inherited from JTextField
linkLabelNoUnderline.
setHorizontalAlignment(JTextField.CENTER);
linkLabelNoUnderline.init();
p.add(linkLabelNoUnderline);
JOptionPane.showMessageDialog( null, p );
}
}

How to change JButton?

I want to make a JButton look like a link in HTML. It will still be a button and when I click on it it will open some new JFrame. But I want to change what it looks like. I tried this:
JButton button = new JButton();
button.setText("hi");
button.setContentAreaFilled(false);
button.setBorderPainted(false);
button.setOpaque(false);
button.setBackground(Color.WHITE);
button.setCursor(Cursor.getPredefinedCursor(12));
But there is still some border around the text of my button. How do we remove the border completely?

But there is still some border around the text of my button
button.setFocusPainted( false );

I recommend using a JTextField rather than a JButton for this use.
E.G.
That is how it appears when the mouse is hovering over the first link.
LinkLabel.java
/* License - LGPL
LinkLabel Using the Desktop Class
There are a lot of link labels. This one uses the Java 1.6+
Desktop class for its functionality, and is thereby suitable
for applets, applications launched using JWS, and 'standard'
(non-JWS) desktop applications.
Note that the Desktop class can be used with pre 1.6 JREs. It
is available through JDIC.
https://jdic.dev.java.net/nonav/documentation/javadoc/jdic/org/jdesktop/jdic/desktop/Desktop.html
*/
import java.awt.Desktop;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.JTextField;
import javax.swing.JPanel;
import javax.swing.JOptionPane;
import javax.swing.border.MatteBorder;
import javax.swing.border.Border;
import java.net.URI;
import java.io.File;
/**
A Java 1.6+ LinkLabel that uses the Desktop class for opening
the document of interest.
The Desktop.browse(URI) method can be invoked from applications,
applets and apps. launched using Java Webstart. In the latter
two cases, the usual fall-back methods are used for sandboxed apps
(see the JavaDocs for further details).
While called a 'label', this class actually extends JTextField,
to easily allow the component to become focusable using keyboard
navigation.
To successfully browse to a URI for a local File, the file name
must be constructed using a canonical path.
#author Andrew Thompson
#version 2008/08/23
*/
public class LinkLabel
// we extend a JTextField, to get a focusable component
extends JTextField
implements MouseListener, FocusListener, ActionListener {
/** The target or href of this link. */
private URI target;
public Color standardColor = new Color(0,0,255);
public Color hoverColor = new Color(255,0,0);
public Color activeColor = new Color(128,0,128);
public Color transparent = new Color(0,0,0,0);
public boolean underlineVisible = true;
private Border activeBorder;
private Border hoverBorder;
private Border standardBorder;
/** Construct a LinkLabel that points to the given target.
The URI will be used as the link text.*/
public LinkLabel(URI target) {
this( target, target.toString() );
}
/** Construct a LinkLabel that points to the given target,
and displays the text to the user. */
public LinkLabel(URI target, String text) {
super(text);
this.target = target;
}
/* Set the active color for this link (default is purple). */
public void setActiveColor(Color active) {
activeColor = active;
}
/* Set the hover/focused color for this link (default is red). */
public void setHoverColor(Color hover) {
hoverColor = hover;
}
/* Set the standard (non-focused, non-active) color for this
link (default is blue). */
public void setStandardColor(Color standard) {
standardColor = standard;
}
/** Determines whether the */
public void setUnderlineVisible(boolean underlineVisible) {
this.underlineVisible = underlineVisible;
}
/* Add the listeners, configure the field to look and act
like a link. */
public void init() {
this.addMouseListener(this);
this.addFocusListener(this);
this.addActionListener(this);
setToolTipText(target.toString());
if (underlineVisible) {
activeBorder = new MatteBorder(0,0,1,0,activeColor);
hoverBorder = new MatteBorder(0,0,1,0,hoverColor);
standardBorder = new MatteBorder(0,0,1,0,transparent);
} else {
activeBorder = new MatteBorder(0,0,0,0,activeColor);
hoverBorder = new MatteBorder(0,0,0,0,hoverColor);
standardBorder = new MatteBorder(0,0,0,0,transparent);
}
// make it appear like a label/link
setEditable(false);
setForeground(standardColor);
setBorder(standardBorder);
setCursor( new Cursor(Cursor.HAND_CURSOR) );
}
/** Browse to the target URI using the Desktop.browse(URI)
method. For visual indication, change to the active color
at method start, and return to the standard color once complete.
This is usually so fast that the active color does not appear,
but it will take longer if there is a problem finding/loading
the browser or URI (e.g. for a File). */
public void browse() {
setForeground(activeColor);
setBorder(activeBorder);
try {
Desktop.getDesktop().browse(target);
} catch(Exception e) {
e.printStackTrace();
}
setForeground(standardColor);
setBorder(standardBorder);
}
/** Browse to the target. */
public void actionPerformed(ActionEvent ae) {
browse();
}
/** Browse to the target. */
public void mouseClicked(MouseEvent me) {
browse();
}
/** Set the color to the hover color. */
public void mouseEntered(MouseEvent me) {
setForeground(hoverColor);
setBorder(hoverBorder);
}
/** Set the color to the standard color. */
public void mouseExited(MouseEvent me) {
setForeground(standardColor);
setBorder(standardBorder);
}
public void mouseReleased(MouseEvent me) {}
public void mousePressed(MouseEvent me) {}
/** Set the color to the standard color. */
public void focusLost(FocusEvent fe) {
setForeground(standardColor);
setBorder(standardBorder);
}
/** Set the color to the hover color. */
public void focusGained(FocusEvent fe) {
setForeground(hoverColor);
setBorder(hoverBorder);
}
public static void main(String[] args) throws Exception {
JPanel p = new JPanel(new GridLayout(0,1));
File f = new File(".","LinkLabel.java");
/* Filename must be constructed with a canonical path in
order to successfully use Desktop.browse(URI)! */
f = new File(f.getCanonicalPath());
URI uriFile = f.toURI();
LinkLabel linkLabelFile = new LinkLabel(uriFile);
linkLabelFile.init();
p.add(linkLabelFile);
LinkLabel linkLabelWeb = new LinkLabel(
new URI("http://pscode.org/sscce.html"),
"SSCCE");
linkLabelWeb.setStandardColor(new Color(0,128,0));
linkLabelWeb.setHoverColor(new Color(222,128,0));
linkLabelWeb.init();
/* This shows a quirk of the LinkLabel class, the
size of the text field needs to be constrained to
get the underline to appear properly. */
p.add(linkLabelWeb);
LinkLabel linkLabelConstrain = new LinkLabel(
new URI("http://sdnshare.sun.com/"),
"SDN Share");
linkLabelConstrain.init();
/* ..and this shows one way to constrain the size
(appropriate for this layout).
Similar tricks can be used to ensure the underline does
not drop too far *below* the link (think BorderLayout
NORTH/SOUTH).
The same technique can also be nested further to produce
a NORTH+EAST packing (for example). */
JPanel labelConstrain = new JPanel(new BorderLayout());
labelConstrain.add( linkLabelConstrain, BorderLayout.EAST );
p.add(labelConstrain);
LinkLabel linkLabelNoUnderline = new LinkLabel(
new URI("http://java.net/"),
"java.net");
// another way to deal with the underline is to remove it
linkLabelNoUnderline.setUnderlineVisible(false);
// we can use the methods inherited from JTextField
linkLabelNoUnderline.
setHorizontalAlignment(JTextField.CENTER);
linkLabelNoUnderline.init();
p.add(linkLabelNoUnderline);
JOptionPane.showMessageDialog( null, p );
}
}

try this, it should force it to set no border :
setBorder(BorderFactory.createEmptyBorder());

there are only one correct way, to change Look and Feel
or simple example for MetalButtonUI and Windows OS only

Windows 7 Seems to break SWT Control.print(GC)

A bug has been filed and fixed (super quickly) in SWT:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=305294
Just to preface this, my goal here is to print the two images into a canvas so that I can animate the canvas sliding across the screen (think iPhone), sliding the controls themselves was too CPU intensive, so this was a good alternative until I tested it on Win7. I'm open to anything that will help me solve my original problem, it doesn't have to be fixing the problem below.
Does anyone know how to get "Control.print(GC)" to work with Windows 7 Aero? I have code that works just fine in Windows XP and in Windows 7, when Aero is disabled, but the command:
control.print(GC) causes a non-top control to be effectively erased from the screen.
GC gc = new GC(image);
try {
// As soon as this code is called, calling "layout" on the controls
// causes them to disappear.
control.print(gc);
} finally {
gc.dispose();
}
I have stacked controls and would like to print the images from the current and next controls such that I can "slide" them off the screen. However, upon printing the non-top control, it is never redrawn again.
Here is some example code. (Interesting code bits are at the top and it will require pointing at SWT in order to work.)
Thanks for any and all help. As a work around, I'm thinking about swapping controls between prints to see if that helps, but I'd rather not.
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StackLayout;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
public class SWTImagePrintTest {
private Composite stack;
private StackLayout layout;
private Label lblFlip;
private Label lblFlop;
private boolean flip = true;
private Button buttonFlop;
private Button buttonPrint;
/**
* Prints the control into an image
*
* #param control
*/
protected void print(Control control) {
Image image = new Image(control.getDisplay(), control.getBounds());
GC gc = new GC(image);
try {
// As soon as this code is called, calling "layout" on the controls
// causes them to disappear.
control.print(gc);
} finally {
gc.dispose();
}
}
/**
* Swaps the controls in the stack
*/
private void flipFlop() {
if (flip) {
flip = false;
layout.topControl = lblFlop;
buttonFlop.setText("flop");
stack.layout();
} else {
flip = true;
layout.topControl = lblFlip;
buttonFlop.setText("flip");
stack.layout();
}
}
private void createContents(Shell shell) {
shell.setLayout(new GridLayout(2, true));
stack = new Composite(shell, SWT.NONE);
GridData gdStack = new GridData(GridData.FILL_BOTH);
gdStack.horizontalSpan = 2;
stack.setLayoutData(gdStack);
layout = new StackLayout();
stack.setLayout(layout);
lblFlip = new Label(stack, SWT.BOLD);
lblFlip.setBackground(Display.getCurrent().getSystemColor(
SWT.COLOR_CYAN));
lblFlip.setText("FlIp");
lblFlop = new Label(stack, SWT.NONE);
lblFlop.setBackground(Display.getCurrent().getSystemColor(
SWT.COLOR_BLUE));
lblFlop.setText("fLoP");
layout.topControl = lblFlip;
stack.layout();
buttonFlop = new Button(shell, SWT.FLAT);
buttonFlop.setText("Flip");
GridData gdFlip = new GridData();
gdFlip.horizontalAlignment = SWT.RIGHT;
buttonFlop.setLayoutData(gdFlip);
buttonFlop.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
flipFlop();
}
});
buttonPrint = new Button(shell, SWT.FLAT);
buttonPrint.setText("Print");
GridData gdPrint = new GridData();
gdPrint.horizontalAlignment = SWT.LEFT;
buttonPrint.setLayoutData(gdPrint);
buttonPrint.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
print(lblFlip);
print(lblFlop);
}
});
}
/**
* #param args
*/
public static void main(String[] args) {
Shell shell = new Shell();
shell.setText("Slider Test");
shell.setSize(new Point(800, 600));
shell.setLayout(new GridLayout());
SWTImagePrintTest tt = new SWTImagePrintTest();
tt.createContents(shell);
shell.open();
Display display = Display.getDefault();
while (shell.isDisposed() == false) {
if (display.readAndDispatch() == false) {
display.sleep();
}
}
display.dispose();
}
}

This was the result of a bug:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=305294
It's since been fixed. Hopefully a new packaged version of SWT will come out soon so we can officially use it.