Develop Reference

java - Put JComponent in front of graphics in NullLayoutManager?

I have a JButton in a JPanel that has graphics, but the button won't show as it is in the layer BELOW the graphics.
I've already read this : Put JLabel in front of Graphics 2D Rectangle in JPanel
But the answers tell me not to use the NullLayoutManager.
Is there any way to do it with the NullLayoutManager, because I need to specifically position my JButton in my JPanel?
If this is not possible, are there any other ways I can position a JComponent at a position x, y? I've also googled that and NullLayoutManager is what the world wide web gives me.
Code:
JPanel p = new JPanel(){
#Override
public void paintComponent(Graphics gr){
Graphics2D g = (Graphics2D) gr;
g.setColor(Color.BLACK);
g.fillRect(0, 0, 800, 800);
g.setFont(titlefont);
g.setColor(Color.WHITE);
g.drawString("dont steal my game idea plz", 25, 100);
g.drawImage(bi, 138, 70, null);
repaint();
}
};
p.setLayout(null);
JButton b = new JButton("PLAY");
b.setLocation(100, 200);
b.setFont(ufont);
f.add(p);
p.add(b);

Is there any way to do it with the NullLayoutManager, because I need to specifically position my JButton in my JPanel?
The answer is "yes", but do you understand what the layout managers actually do? How they work and the role they fill in order to replace them and take over the requirements of their functionality?
null layouts are just a bad idea, there are so many things that can wrong with them it's mind numbing just trying to think about it. If none of the stock layout managers do what you want, maybe consider using MigLayout or some other layout manager, possibly even writing your own, at least this way, you will still be able to work within the API, which has been designed to work around layout managers.
There are a couple of other issues, first, you're painting your image AFTER the paint the text, this could cause some issues if the two overlap. Second, you're breaking the paint chain by not calling super.paintComponent, this could result in some unexpected and unwanted results. Third, you don't need to fill the component, use setBackground and let the super.paintComponent deal with it.
import java.awt.Color;
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.Insets;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DownWithNullLayouts {
public static void main(String[] args) {
new DownWithNullLayouts();
}
public DownWithNullLayouts() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private Font titlefont;
private BufferedImage bi;
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(30, 0, 0, 0);
add(new JButton("Play"), gbc);
try {
bi = ImageIO.read(...);
} catch (IOException ex) {
ex.printStackTrace();
}
titlefont = UIManager.getFont("Label.font");
setBackground(Color.BLACK);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - bi.getWidth()) / 2;
int y = (getHeight()- bi.getHeight()) / 2;
g2d.drawImage(bi, x, y, this);
g2d.setFont(titlefont);
g2d.setColor(Color.WHITE);
g2d.drawString("dont steal my game idea plz", 25, 100);
g2d.dispose();
}
}
}
Take a closer look at Painting in AWT and Swing and Performing Custom Painting for more details

java custom shaped frame using image [duplicate]

This question already has answers here:
Image/Graphic into a Shape
(3 answers)
Closed 8 years ago.
i like to create a java jframe look like this image.i have already crated jframes with different shapes like triangles ,circles ,polygons and some crazy shapes .but the problem it's too hard[99% impossible ] to create shape like this image.so how can i make a jframe like this.i used this code for create shaped window..
setUndecorated(true);
Polygon polygon = new Polygon();
polygon.addPoint(0, 0);
polygon.addPoint(100,100);
GeneralPath path = new GeneralPath();
path.append(polygon, true);
setShape(path);
now can i convert this image to a shape .then set setshapes.any idea?
or is there anyway to make jframe's fully transperent and jlable which hold image completely visible?

To make a transparent window, you need to set the frames background color's alpha to 0. This is probably the most counter intuitive call I've seen in a while, as if you do this to any other Swing component, you will completely screw up the paint process.
You don't want to change the opacity of the window, as it effectives the entire window and it's contents equally.
For example...
JWindow frame = new JWindow();
frame.setBackground(new Color(0, 0, 0, 0));
You don't have to use a JWindow, but this means I don't need to undecorate it myself...
You also need to make sure that whatever content you add to the window is transparent (opaque = false), so that it doesn't "hide" what's underneath it...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JWindow;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.CompoundBorder;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
public class LeafWindow {
public static void main(String[] args) {
new LeafWindow();
}
public LeafWindow() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JWindow frame = new JWindow();
frame.setBackground(new Color(0, 0, 0, 0));
frame.setContentPane(new LeafPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
frame.setAlwaysOnTop(true);
}
});
}
public class LeafPane extends JPanel {
private BufferedImage leaf;
public LeafPane() {
setBorder(new CompoundBorder(
new LineBorder(Color.RED),
new EmptyBorder(0, 0, 250, 0)));
try {
leaf = ImageIO.read(getClass().getResource("/Leaf.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
setOpaque(false);
setLayout(new GridBagLayout());
JButton button = new JButton("Close");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
add(button);
}
#Override
public Dimension getPreferredSize() {
return leaf == null ? new Dimension(200, 200) : new Dimension(leaf.getWidth(), leaf.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (leaf != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(leaf, 0, 0, this);
g2d.dispose();
}
}
}
}
This example deliberate adds a line border to the content as you can see what the original window bounds would be. It also uses a EmptyBorder to force the JButton onto the graphics, but this is just an example...

You'll have to create a shape based on your image. There are different threads here on SO that provide some way how to do this. The best one (based on the description, I didn't try it myself) might be Java - Create a shape from border around image. Another option for more complex images could be Image/Graphic into a Shape.
Another solution might be to use an undecorated frame along with "per-pixel transparency", as explained by Oracle here: http://docs.oracle.com/javase/tutorial/uiswing/misc/trans_shaped_windows.html

How to make Java Glasspane sticks to a location even if GUI was resized?

Java Glass pane auto resize when I resize the whole interface,but I want to make it stick to a specific location, it will look like this:
Instead of moving around when I resize it.
Thanks

There's a number of ways this might be achieved, but the basic requirement will require some kind of reference to the component your glass pane content is trying to stick to. This means that when the components are updated and are required to be laid out, you can find the location of the sticky component and update the position of the content on the glass pane.
Remember, the glass pane is a container which occupies the entire content are of a window, it's what's contained within the glass pane that you need to update
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class StickyGlassPaneExample {
public static void main(String[] args) {
new StickyGlassPaneExample();
}
public StickyGlassPaneExample() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
StickyGlassPane stickyGlassPane = new StickyGlassPane();
TestPane testPane = new TestPane(stickyGlassPane);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(testPane);
frame.setSize(600, 500);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
frame.setGlassPane(stickyGlassPane);
stickyGlassPane.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private List<JTextField> fields;
public TestPane(StickyGlassPane stickyGlassPane) {
fields = new ArrayList<JTextField>(100);
for (int index = 0; index < 100; index++) {
JTextField field = new JTextField(10);
fields.add(field);
add(field);
}
int fieldIndex = (int)(Math.random() * (fields.size() - 1));
JTextField sticky = fields.get(fieldIndex);
sticky.setText("Sticky");
stickyGlassPane.setStickyComponent(sticky);
}
}
public class StickyGlassPane extends JPanel {
private Component component;
private JPanel overlay;
public StickyGlassPane() {
setOpaque(false);
overlay = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.RED);
g2d.drawRect(0, 0, getWidth(), getHeight());
g2d.setComposite(AlphaComposite.SrcOver.derive(0.5f));
g2d.fillRect(0, 0, getWidth(), getHeight());
}
};
overlay.setOpaque(false);
add(overlay);
}
#Override
public void doLayout() {
if (component != null) {
Point p = component.getLocation();
SwingUtilities.convertPoint(component, p, this);
overlay.setLocation(p);
overlay.setSize(component.getSize());
} else {
overlay.setBounds(0, 0, 0, 0);
}
}
public void setStickyComponent(Component component) {
this.component = component;
revalidate();
}
}
}

ImageIcon click and drag around the window

I'm trying to make it so I can click and drag an ImageIcon (in this case a card image but I'd like to learn how to do it generally) around the window but I don't really know how. I would like to be able to click and hold the mouse botton, drag the ImageIcon, and have stay where it is whn I release the mouse botton.
This is the code I have so far:
import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class MyFirstClass
{
public static void main(String[] args)
{
//load the card image from the gif file.
final ImageIcon cardIcon = new ImageIcon("cardImages/tenClubs.gif");
JLabel lbl = new JLabel(cardIcon);
//create a panel displaying the card image
JPanel panel = new JPanel()
{
//paintComponent is called automatically by the JRE whenever
//the panel needs to be drawn or redrawn
public void paintComponent(Graphics g) {
super.paintComponent(g);
cardIcon.paintIcon(this, g, 20, 20);
}
};
lbl.setTransferHandler(null);
MouseListener listener = new MouseAdapter() {
public void mousePressed(MouseEvent me) {
JComponent comp = (JComponent) me.getSource();
TransferHandler handler = comp.getTransferHandler();
handler.exportAsDrag(comp, me, TransferHandler.COPY);
}
};
lbl.addMouseListener(listener);
//create & make visible a JFrame to contain the panel
JFrame window = new JFrame("Cards");
window.add(panel);
window.setPreferredSize(new Dimension(200,200));
window.pack();
window.setVisible(true);
}
}
Thank you.

The problem is you're mixing paradigms...not to mention you never seem to add lbl to anything, so it could never possible receive events and the fact that the panel is under the control of a layout manager, making moving a component very difficult...
In Swing there are at least three different ways to drag something, which you use comes down to what it is you want to achieve.
You can...
Use MouseListener and MouseMotitionListener to perform the actions manually. This is useful if you want to physical place an object somewhere within the container, like you are trying to do, for example...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DragMe {
public static void main(String[] args) {
new DragMe();
}
public DragMe() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage img;
private Point imgPoint = new Point(0, 0);
public TestPane() {
try {
img = ImageIO.read(new File("Computer.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
MouseAdapter ma = new MouseAdapter() {
private Point offset;
#Override
public void mousePressed(MouseEvent e) {
Rectangle bounds = getImageBounds();
Point mp = e.getPoint();
if (bounds.contains(mp)) {
offset = new Point();
offset.x = mp.x - bounds.x;
offset.y = mp.y - bounds.y;
}
}
#Override
public void mouseReleased(MouseEvent e) {
offset = null;
}
#Override
public void mouseDragged(MouseEvent e) {
if (offset != null) {
Point mp = e.getPoint();
imgPoint.x = mp.x - offset.x;
imgPoint.y = mp.y - offset.y;
repaint();
}
}
};
addMouseListener(ma);
addMouseMotionListener(ma);
}
protected Rectangle getImageBounds() {
Rectangle bounds = new Rectangle(0, 0, 0, 0);
if (img != null) {
bounds.setLocation(imgPoint);
bounds.setSize(img.getWidth(), img.getHeight());
}
return bounds;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(img, imgPoint.x, imgPoint.y, this);
g2d.dispose();
}
}
}
}
You can...
Use the core Drag-n-Drop APIs. This very low level and provides you are wide variety of flexibility. You can drag components, data or sorts of stuff based on your needs...
For example:
java drag and drop
How to drag and drop JPanel with its components
move component after drag and drop
And if you're really adventurous, you can take a look at these...
My Drag Image is Better than Yours
Drop Target Navigation, or You Drag Your Bags, Let the Doorman Get the Door
Smooth JList Drop Target Animation
You can..
Make use of the new transfer API. The intention of this API is to make it easier to transfer data around the application. While, technically, it would be possible to move a component this way, this is not it's intention.
Take a look at...
Drag and Drop and Data Transfer
Introduction to the DnD API
How to drag and drop with Java 2, Part 1
For more details...

JLabel text gets overwritten on transparent bg

Im a newbie to java, Im trying to create an application like a desktop widget for which i have made the JPanel transparent. I have two JLabels on top of it one for holding an image and other for displaying time. I had a timer to update the time displayed in the JLabel. But With a transparent JPanel behind the jlabel's text gets overwritten instead of replacement. After Googling and Looking up on stackoverflow i tried many methods to override the paintcomponent method of the JLabel. But it didnt affect anything. Later I manually called the paintcomponent method inside the timer which worked out. But I feel its just a workaround. I need to know why the paintcomponent didnt get invoked and when it usually gets invoked.
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.RepaintManager;
import javax.swing.SwingConstants;
import javax.swing.text.SimpleAttributeSet;
import java.awt.BorderLayout;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
public class WindowSample {
private JFrame frame;
MyLabel panel1;
// JLabel panel1;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
WindowSample window = new WindowSample();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public WindowSample() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
frame.setSize(dim);
frame.setBounds(0, 0, 500, 500);
frame.setBackground(new Color(0, 255, 0, 0));
frame.setUndecorated(true);
frame.setContentPane(new ContentPane());
frame.getContentPane().setBackground(Color.WHITE);
frame.getContentPane().setLayout(null);
// ImagePanel panel = new ImagePanel();
JLabel panel = new JLabel(
scale(new ImageIcon("Science Drops.png").getImage()));
panel.setBounds(0, 0, 200, 200);
panel1 = new MyLabel();
// panel1 = new JLabel();
panel1.setHorizontalAlignment(SwingConstants.CENTER);
panel1.setAlignmentX(SwingConstants.CENTER);
panel1.setFont(new Font("Calibiri",Font.BOLD,16));
panel1.setBounds(0, 205, 200, 50);
Timer n = new Timer();
panel1.setBackground(Color.white);
n.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
DateFormat df = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
// this manual call to paintComponent did the trick. If i remove this line the text gets overwritten over itself for every second.
panel1.paintComponents(panel1.getGraphics());
panel1.setText(df.format(new Date()));
}
}, 1000, 1000);
frame.getContentPane().add(panel1);
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
#SuppressWarnings("serial")
public class MyLabel extends JLabel {
MyLabel() {
setOpaque(false);
}
#Override
public void paintComponents(Graphics arg0) {
Graphics2D g2d = (Graphics2D) arg0.create();
g2d.clearRect(0, 0, getWidth(), getHeight());
g2d.dispose();
super.paintComponents(arg0);
}
}
public class ContentPane extends JPanel {
public ContentPane() {
setOpaque(false);
}
#Override
protected void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.0f));
g2d.setColor(getBackground());
g2d.fill(getBounds());
g2d.dispose();
super.paintComponent(g);
}
}
public ImageIcon scale(Image src) {
int w = 200;
int h = 200;
int type = BufferedImage.TYPE_INT_ARGB;
BufferedImage dst = new BufferedImage(w, h, type);
Graphics2D g2 = dst.createGraphics();
g2.drawImage(src, 0, 0, w, h, frame);
g2.dispose();
return new ImageIcon(dst);
}
}

Read Backgrounds With Transparency for information on how transparency works and for some possible solutions.
Also, some other comments with your code:
Don't use a null layout. Swing was designed to be used with layout managers for to many reasons to list here.
Custom painting is done by overriding paintComponent() (no "s"). However, in your case I don't see any reason to do custom painting if you follow the advice in the link I provided above. I also don't think you need to do custom painting in your panel, but I don't totally understand what you are attempting to do.

Use javax.swing.Timer instead of java.util.Timer. Have a look at this tutorial from oracle about timers and swing.

You seem to be going about it the hard way...
labels are transparent by default.
labels support icons out of the box (include animated gifs ;))
null layouts are never a good idea, they might seem like a good idea, but you will spend more time correcting for funny little inconsistencies which be resolved using an appropriate layout manager...
java.util.Timer is not a suitable timer for Swing, instead you want to use javax.swing.Timer instead. It will trigger it's updates within the context of the EDT.
Based off what I think you want to do...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MyClock {
public static void main(String[] args) {
new MyClock();
}
public MyClock() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
final DateFormat df = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
final JLabel label = new JLabel(df.format(new Date()));
label.setIcon(new ImageIcon("Clock.png"));
Timer timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
label.setText(df.format(new Date()));
}
});
timer.start();
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.setUndecorated(true);
frame.setBackground(new Color(0, 255, 0, 0));
frame.add(label);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
Take a look at How to use icons for more details about icon support in Swing.
You may also find Window#alwaysOnTop useful (remember, all frames lead to Window)

I can't believe there is still nobody who answered the right answer. Here's how you get away with this kind of problem :
Apply setOpaque(false) to your components, but also to all the parents.
It will prevent painting problems on your components with transparent backgrounds.