JFrame, JPanel, paintComponent how to

JFrame, JPanel, paintComponent how to - java

Hi I have following classes, I want display content
(paintComponentor that panel with this rectangle from paint class)
inside my JFrame. I try already find out how to achieve this by
looking at different examples posted on this forum however this
doesn't help me I need simple example like panel inside frame with
paint component or something similar to understand how should work!
ps. don't hang me on tree because I am newbie jut ask question!!!
[I want something like this][1]
package scp;
import java.awt.*;
import javax.swing.*;
public class Panel extends JPanel {
public Panel() {
//this.setPreferredSize(new Dimension(200,200));
//panel = new Panel();
setVisible(true);
setLayout(new FlowLayout());
setSize(200, 300);
getRootPane();
}
#Override
public void paintComponent(Graphics g){
g.drawString("HEY",20,20);
g.drawRect(200, 200, 200, 200);
}
}
and
package scp;
import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.beans.EventHandler;
public class Frame extends JFrame {
JButton redButton;
JButton blueButton;
public Frame()
{
super("EventHandling");
setLayout(new FlowLayout());
redButton = new JButton("Red");
add(redButton);
blueButton = new JButton("Blue");
add(blueButton);
EventHandler h = new EventHandler();
redButton.addActionListener(h);
blueButton.addActionListener(h);
}
private class EventHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if (e.getSource()==redButton)
getContentPane().setBackground(Color.RED);
else if(e.getSource()==blueButton)
getContentPane().setBackground(Color.BLUE);
}
}
}
and
package scp;
import javax.swing.JFrame;
public class EventHandling {
public static void main(String[] args) {
Frame f = new Frame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(800,600);
f.setVisible(true);
f.getContentPane().add(new Panel());
}
}
[1]: http://i.stack.imgur.com/OJTrq.png

Start by taking a look at:
Painting in AWT and Swing
Performing Custom Painting
2D Graphics
This is probably the simplest I can make it...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
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 {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int width = getWidth() - 100;
int height = getHeight() - 100;
int x = (getWidth() - width) / 2;
int y = (getHeight() - height) / 2;
g2d.setColor(Color.RED);
g2d.drawRect(x, y, width, height);
g2d.dispose();
}
}
}
Compound Example
This example uses an outer panel, which has an empty border applied to it, this pushes the content of the edges of the outer panel.
The inner panel (which is unchanged from the last example), as a light gray border applied to it so you can see it, the red rectangle is still been painted by the panels paintComponent method.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JPanel outer = new JPanel(new BorderLayout()) {
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
};
outer.setBorder(new EmptyBorder(50, 50, 50, 50));
TestPane tp = new TestPane();
tp.setBorder(new LineBorder(Color.LIGHT_GRAY));
outter.add(tp);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(outer);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int width = getWidth() - 100;
int height = getHeight() - 100;
int x = (getWidth() - width) / 2;
int y = (getHeight() - height) / 2;
g2d.setColor(Color.RED);
g2d.drawRect(x, y, width, height);
g2d.dispose();
}
}
}

Related

trying to display timer count, drawString method not working properly

I am trying to display a timer count, but it is not being displayed, but everything else works fine. Thank you for helping btw.
import javax.swing.*;
import java.util.*;
import javax.swing.Timer;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Tester {
static Timer timer;
static JFrame frame;
static JPanel panel;
public static void init(){
frame = new JFrame();
panel = new JPanel();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setSize(500, 500);
frame.add(panel);
}
The method above is just to make code cleaner.
public static void main(String[] args) {
init();
class Clicker extends JPanel{
int timesClicked;
public Clicker(){
timesClicked = 0;
}
void updateClicks(){
timesClicked++;
repaint();
}
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
System.out.println("Called!!!");
g2.drawString("Half Seconds: "+timesClicked, 100, 100);
}
} //end of Clicker
drawString method not working is above.
final Clicker c = new Clicker();
panel.add(c);
class TimeChecker implements ActionListener{
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Clicked!");
c.updateClicks();
}
}// end of TimeChecker
ActionListener listener = new TimeChecker();
timer = new Timer(500,listener);
timer.start();
}
}

You have a combination of issues
Clicker was never actually added to anything
panel uses a FlowLayout by default, but Clicker provides no sizing hints, so it's sized to 0x0
You code generally is setup a little weird. I would learn to do without static very, very quickly.
Quick and fast solution...
Change the layout manager for panel to BorderLayout...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Test {
static Timer timer;
static JFrame frame;
static JPanel panel;
public static void init() {
frame = new JFrame();
panel = new JPanel(new BorderLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setSize(500, 500);
frame.add(panel);
}
public static void main(String[] args) {
init();
class Clicker extends JPanel {
int timesClicked;
public Clicker() {
timesClicked = 0;
}
void updateClicks() {
timesClicked++;
repaint();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
System.out.println("Called!!!");
g2.setColor(Color.BLACK);
g2.drawString("Half Seconds: " + timesClicked, 100, 100);
}
} //end of Clicker
final Clicker c = new Clicker();
panel.add(c);
panel.revalidate();
panel.repaint();
class TimeChecker implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Clicked!");
c.updateClicks();
}
}// end of TimeChecker
ActionListener listener = new TimeChecker();
timer = new Timer(500, listener);
timer.start();
}
}
A slightly different approach (with out static)
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
Clicker clicker = new Clicker();
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(clicker);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
class TimeChecker implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Clicked!");
clicker.updateClicks();
}
}// end of TimeChecker
ActionListener listener = new TimeChecker();
Timer timer = new Timer(500, listener);
timer.start();
}
});
}
public class Clicker extends JPanel {
private int timesClicked;
public Clicker() {
timesClicked = 0;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 200);
}
void updateClicks() {
timesClicked++;
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
System.out.println("Called!!!");
g2.setColor(Color.BLACK);
g2.drawString("Half Seconds: " + timesClicked, 100, 100);
}
}
}

Brightness implementation for JPanel in Swing

I want to create brightness functionality in Swing. JPanel and its component's brightness level will be adjust in this functionality.
To achieve this I used JLayeredPane and added JPanel as BrightNessPanel on the top of my JPanel called MainPanel. I am giving brightness effect by changing the opacity of BrightNessPanel. This will simulate Brightness effect for my MainPanel.
Now problem is that, I am not able to click the buttons present on MainPanel because of layer of BrightNessPanel.
How do I pass through clicks from BrightNessPanel to the buttons present on MainPanel??

You might be able to make use the JLayer API which allows you to perform painting operations ontop of other components.
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLayer;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.LayerUI;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
TestPane testPane = new TestPane();
BrightnessLayerUI layerUI = new BrightnessLayerUI();
JLayer<JComponent> layer = new JLayer<>(testPane, layerUI);
JSlider slider = new JSlider(0, 100);
slider.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
int value = slider.getValue();
float brightness = (100 - value) / 100f;
layerUI.setBrightness(brightness);
testPane.repaint();
}
});
slider.setValue(100);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(layer);
frame.add(slider, BorderLayout.SOUTH);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
add(new JTextField(10), gbc);
add(new JButton("Hello"), gbc);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.dispose();
}
}
public class BrightnessLayerUI extends LayerUI<JComponent> {
private float brightness = 0f;
public void setBrightness(float brightness) {
this.brightness = brightness;
}
public float getBrightness() {
return brightness;
}
#Override
public void paint(Graphics g, JComponent c) {
super.paint(g, c);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(c.getBackground());
g2d.setComposite(AlphaComposite.SrcOver.derive(getBrightness()));
g2d.fillRect(0, 0, c.getWidth(), c.getHeight());
g2d.dispose();
}
}
}
One of the advantages of this is you could actually introduce a "brightness" algorithm, rather than faking it, by using a backing buffer, which is demonstrated the link above (this use to to blur the UI)

Adding Multiple Components In Seperate Classes to JFrame In Another Class

I have ran into a problem. The problem lies with adding multiple components to a JFrame, all within separate classes. I have to add the two components DrawBoard and QuestionBox into the JPanel 'panel' in the Board class. The DrawBoard and QuestionBox will both perform different functions.
The DrawBoard component should be 600x600 pixels, while the QuestionBox component should be 600x120 pixels. The DrawBoard is at the bottom and the QuestionBox sits at the top. I am not sure as to what layout to use.
When run I get this result.
Game class
package snake;
//This class is used to run the game.
public class Game {
/**
* #author HyperBlue
*/
public static Board board;
public static void main(String[] args) {
// TODO Auto-generated method stub
//Creates an object board from the Board() construct
board = new Board();
}
}
Board Class
public class Board implements ActionListener {
public DrawBoard drawBoard;
public QuestionBox questionBox;
public Timer ticker = new Timer(20, this);
public Board() {
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
JFrame frame = new JFrame("Snake");
frame.pack();
Insets insets = frame.getInsets();
JPanel container = new JPanel();
questionBox = new QuestionBox();
drawBoard = new DrawBoard();
container.setLayout(new BorderLayout());
container.add(questionBox, BorderLayout.NORTH);
container.add(drawBoard, BorderLayout.SOUTH);
frame.setMinimumSize(new Dimension(600+insets.left + insets.right, 720 +insets.bottom + insets.top));
frame.add(container);
//Sets the frame in middle of screen
frame.setLocation((dim.width / 2) - (frame.getWidth() / 2), (dim.height / 2) - (frame.getHeight() / 2));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
DrawBoard Class
package snake;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
//Warnings will not be thrown (are suppressed).
#SuppressWarnings("serial")
public class DrawBoard extends JPanel{
public static Color yellow = new Color(13816442);
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(yellow);
g.fillRect(0, 0, 600, 600);
}
}
QuestionBox Class
package snake;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class QuestionBox extends JPanel{
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, 600, 120);
}
}

Each component should be responsible for managing it's own size, you should start by overriding getPreferredSize of the panels and returning the size you would like to use.
You should also not rely on magic numbers, but instead should use actual physical values, for example, instead of
g.fillRect(0, 0, 600, 120);
You should use...
g.fillRect(0, 0, getWidth(), getHeight());
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test1 {
public static void main(String[] args) {
new Test1();
}
public Test1() {
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 static class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
add(new DrawBoard());
add(new QuestionBox(), BorderLayout.SOUTH);
}
}
public static class DrawBoard extends JPanel {
public static Color yellow = new Color(13816442);
#Override
public Dimension getPreferredSize() {
return new Dimension(600, 600);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(yellow);
g.fillRect(0, 0, 600, 600);
}
}
public static class QuestionBox extends JPanel {
#Override
public Dimension getPreferredSize() {
return new Dimension(600, 120);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, 600, 120);
}
}
}
You should also know that Toolkit.getDefaultToolkit().getScreenSize(); is not the most reliable method for determining the visible screen area, as it does not take into account various OS elements, like the task bar or dock, which can take up screen space.

Painting issue in custom layered container?

So I am working on a project here that requires a custom JLayeredPane - like class.
It has two members 'ground' and 'foreground' that are JPanel and an background (Image) member.
The way it was supposed to show was that the background Image should have been drawn and then all the components of the ground on top of it and then foreground's components at the apex. So foreground covers up ground which covers up background. Background should be shown only at places that do not have a Component in ground and foreground or where there is transparency in the JPanels.
It's paint function goes like this:
#Override
public void paint(Graphics g){
g.drawImage(background, 0, 0, null);
ground.paint(g.create());
foreground.paint(g.create());
g.dispose();
}
But nothing like that happens. Just the background image gets painted and nothing else shows.
I have used System.out.println() function to check that ground and foreground actually hold components and they do. But they just don't show.
Can anyone help me here?

The most significant issue is you're not calling super.paint, which is preventing what ever was previously painted to the Graphics context from been cleared or any child components from been painted.
For painting the background, you should be using paintComponent, which is used to paint the background of the component.
If you need to paint under the child components, but above the background, you should still use paintComponent, but paint the background first and then the next layer. The components will be painted after paintComponent.
Painting over components is actually more complex
Take a closer look at Custom Painting and Painting in Swing and AWT
Updated based on code snippets
In Screen which extends from Container, you are doing...
#Override
public void paint(Graphics g) {
super.paint(g);
GraphicsUtilities.drawPictureTiled(background, g);
paintComponents(g);
g.dispose();
}
Don't call paintComponents, super.paint has already done this.
Don't call dispose on a Graphics context you don't create
Based on the rest of the example code I have, you should be extending from JPanel and overriding paintComponent instead. This will allow you to put under the component layer
Because GroundPanel and ForeGroundPanel are both JPanels, there's no need to ever paint them yourself. In fact, you could simply use OverlayLayout or even a GridBagLayout and add them directly to the NestedScreen which is itself a container...
So, I stripped down you example code so I could get it working with the missing code as an example. I got a little more fancy and simply made a JPanel to act as the pause screen
This is all done by simply overlaying the components on top of each other using a GridBagLayout
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test1001 {
public static void main(String[] args) {
new Test1001();
}
public Test1001() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
try {
NestedScreen screen = new NestedScreen();
screen.setBackgroundLayer(ImageIO.read(getClass().getResource("/Sky.png")));
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(screen);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (IOException exp) {
exp.printStackTrace();
}
}
});
}
public interface GraphicsEngineComponents {
}
public class NestedScreen extends Screen implements GraphicsEngineComponents {
GroundPanel ground;
ForeGroundPanel foreground;
private PausePane pausePane;
public NestedScreen() {
ground = new GroundPanel();
foreground = new ForeGroundPanel();
pausePane = new PausePane();
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1;
gbc.weighty = 1;
gbc.fill = GridBagConstraints.BOTH;
add(pausePane, gbc);
add(foreground, gbc);
add(ground, gbc);
MouseAdapter handler = new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
pausePane.setVisible(!pausePane.isVisible());
}
};
addMouseListener(handler);
foreground.addMouseListener(handler);
ground.addMouseListener(handler);
}
public GroundPanel getGroundLayer() {
return ground;
}
public ForeGroundPanel getForegroundLayer() {
return foreground;
}
public void setBackgroundLayer(BufferedImage background) {
super.setBackgroundLayer(background);
}
public class GroundPanel extends JPanel {
public GroundPanel() {
setOpaque(false);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.GREEN);
g.fillRect(0, getHeight() - 200, getWidth(), 200);
}
}
public class PausePane extends JPanel {
private JLabel label;
public PausePane() {
setVisible(false);
setOpaque(false);
setBackground(new Color(0, 0, 0, 128));
setLayout(new GridBagLayout());
label = new JLabel("Paused");
label.setHorizontalAlignment(JLabel.CENTER);
label.setVerticalAlignment(JLabel.CENTER);
Font font = label.getFont();
font = font.deriveFont(Font.BOLD, 48f);
label.setFont(font);
label.setForeground(Color.WHITE);
add(label);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(getBackground());
g.fillRect(0, 0, getWidth(), getHeight());
}
}
public class ForeGroundPanel extends JPanel {
private BufferedImage pony;
public ForeGroundPanel() {
setOpaque(false);
try {
pony = ImageIO.read(getClass().getResource("/Pony.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (pony != null) {
int x = (getWidth() - pony.getWidth()) / 2;
int y = getHeight() - 200 - (pony.getHeight() / 2);
g.drawImage(pony, x, y, this);
}
}
}
}
public class Screen extends JPanel implements GraphicsEngineComponents {
private BufferedImage background;
public Screen() {
}
#Override
public String toString() {
return "Screen{" + "background=" + background + '}';
}
public BufferedImage getBackgroundPicture() {
return background;
}
#Override
public Dimension getPreferredSize() {
return background == null ? super.getPreferredSize() : new Dimension(background.getWidth(), background.getHeight());
}
protected void setBackgroundLayer(BufferedImage background) {
if (background != null && background.getHeight() != 0 && background.getWidth() != 0) {
this.background = background;
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (background != null) {
g.drawImage(background, 0, 0, this);
}
}
}
}
Take a look at Painting in AWT and Swing and Performing Custom Painting to understand how painting works in Swing.
A basic idea would be to avoid using all these compound or nested components and instead, create an engine that can paint the layers directly onto a Graphics context, maybe even painting to a BufferedImage which you can the paint onto a single component...

There are a few ways you go about doing this. I'll just introduce one way.
Create a background panel where you paint the background image (in the example below, it is BackgroundPanel with the image only being the forresty background). Set that panel as the content pane to the frame.
Create another ground panel where you can also paint something (in the example below if it the GroundPanel with only the image of bugs bunny painted.
Create your foreground panel and add it to the ground panel. You can add your foreground components to it. (in the example below the foreground image is the grassy hill, and I also add a button to it
All the panels' opaque property should be set to false, as to allow the panel behind it to be shown under any transparency.
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;
public class ThreeTier {
public static final int DIM_WIDTH = 600;
public static final int DIM_HEIGHT = 400;
private BufferedImage backgroundImage;
private BufferedImage groundImage;
private BufferedImage foregroundImage;
public ThreeTier() {
initImages();
JFrame frame = new JFrame();
frame.setContentPane(new BackgroundPanel());
frame.add(new GroundPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private void initImages() {
try {
backgroundImage = ImageIO.read(getClass().getResource("/resources/background.png"));
foregroundImage = ImageIO.read(getClass().getResource("/resources/foreground.png"));
groundImage = ImageIO.read(getClass().getResource("/resources/bugsBunny.png"));
} catch (IOException ex) {
Logger.getLogger(ThreeTier.class.getName()).log(Level.SEVERE, null, ex);
}
}
class BackgroundPanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(backgroundImage, 0, 0, DIM_WIDTH, DIM_HEIGHT, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(ThreeTier.DIM_WIDTH, ThreeTier.DIM_HEIGHT);
}
}
class GroundPanel extends JPanel {
private static final String RIGHT_ACTION = "rightAction";
private int imageX = 50;
private int imageY = 140;
public GroundPanel() {
setOpaque(false);
add(new ForegroundPanel());
InputMap im = getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
im.put(KeyStroke.getKeyStroke("RIGHT"), RIGHT_ACTION);
getActionMap().put(RIGHT_ACTION, new AbstractAction() {
public void actionPerformed(ActionEvent e) {
if (imageX >= DIM_WIDTH) {
imageX = 0 - groundImage.getWidth();
repaint();
} else {
imageX += 10;
repaint();
}
}
});
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(groundImage, imageX, imageY, groundImage.getWidth(), groundImage.getHeight(), this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(ThreeTier.DIM_WIDTH, ThreeTier.DIM_HEIGHT);
}
}
class ForegroundPanel extends JPanel {
public ForegroundPanel() {
setOpaque(false);
setLayout(new FlowLayout(FlowLayout.TRAILING, 10, 0));
JButton button = new JButton("I'm in the Foreground!");
add(button);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(foregroundImage, 0, 0, DIM_WIDTH, DIM_HEIGHT, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(ThreeTier.DIM_WIDTH, ThreeTier.DIM_HEIGHT);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ThreeTier();
}
});
}
}
UPDATE
Of course you could always just use the JLayeredPane. That's what it's for. See this example
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.border.LineBorder;
public class LayeredPaneDemo {
public static final int DIM_WIDTH = 600;
public static final int DIM_HEIGHT = 400;
public LayeredPaneDemo() {
ContainerPanel container = new ContainerPanel();
JLabel title = new JLabel("Lame Google Map");
title.setFont(new Font("verdana", Font.BOLD, 36));
title.setHorizontalAlignment(JLabel.CENTER);
JPanel panel = new JPanel(new GridBagLayout());
panel.add(container);
JFrame frame = new JFrame();
frame.add(panel);
frame.add(title, BorderLayout.NORTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new LayeredPaneDemo();
}
});
}
public class ContainerPanel extends JPanel {
public ContainerPanel() {
JLayeredPane layeredPane = new JLayeredPane();
layeredPane.setPreferredSize(new Dimension(DIM_WIDTH, DIM_HEIGHT));
BackgroundPanel bg = new BackgroundPanel();
GroundPanel gg = new GroundPanel();
ForegroundPanel fg = new ForegroundPanel();
bg.setBounds(0, 0, DIM_WIDTH, DIM_HEIGHT);
layeredPane.add(bg, new Integer(1));
gg.setBounds(0, 0, DIM_WIDTH, DIM_HEIGHT);
layeredPane.add(gg, new Integer(2));
fg.setBounds(0, 0, DIM_WIDTH, DIM_HEIGHT);
layeredPane.add(fg, new Integer(3));
setLayout(new GridBagLayout());
add(layeredPane);
setBorder(new LineBorder(Color.BLUE, 10));
}
}
public class ForegroundPanel extends JPanel {
public ForegroundPanel() {
JPanel buttonPanel = new JPanel(new GridLayout(3, 3));
buttonPanel.setOpaque(false);
buttonPanel.add(new JLabel());
buttonPanel.add(new JButton("UP"));
buttonPanel.add(new JLabel());
buttonPanel.add(new JButton("Left"));
buttonPanel.add(new JLabel());
buttonPanel.add(new JButton("Right"));
buttonPanel.add(new JLabel());
buttonPanel.add(new JButton("Down"));
buttonPanel.add(new JLabel());
FlowLayout flow = (FlowLayout) getLayout();
flow.setAlignment(FlowLayout.TRAILING);
flow.setHgap(0);
flow.setVgap(0);
add(buttonPanel);
setOpaque(false);
}
}
public class GroundPanel extends JPanel {
Image image = null;
public GroundPanel() {
try {
image = ImageIO.read(getClass().getResource("/resources/california.png"));
} catch (IOException ex) {
Logger.getLogger(LayeredPaneDemo.class.getName()).log(Level.SEVERE, null, ex);
}
setOpaque(false);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, DIM_WIDTH, DIM_HEIGHT, this);
}
}
public class BackgroundPanel extends JPanel {
public BackgroundPanel() {
setLayout(new GridBagLayout());
setBackground(Color.WHITE);
try {
Image img = ImageIO.read(getClass().getResource("/resources/google.jpg"));
add(new JLabel(new ImageIcon(img)));
} catch (IOException ex) {
Logger.getLogger(LayeredPaneDemo.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}

Staggered Top Alignment JPanels

I am attempting to use a FlowLayout to get my panels to align vertically. I want the bottom right to align toward the bottom of the top right panel, not the bottom of that row.
Here is what I have done:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class BigPanel extends JPanel {
#Override
public Component.BaselineResizeBehavior getBaselineResizeBehavior() {
return Component.BaselineResizeBehavior.CONSTANT_ASCENT;
}
#Override
public int getBaseline(int width, int height) {
return 0;
}
public BigPanel() {
FlowLayout layout = new FlowLayout();
layout.setAlignOnBaseline(true);
this.setLayout(layout);
this.add(new Panel1()); // size: 340x, 160y
this.add(new Panel2()); // size: 340x, 120y
this.add(new Panel3()); // size: 340x, 160y
this.add(new Panel4()); // size: 340x, 300y
}
}
How can I simply anchor panels and components to a set of coordinates? I have run into this problem many times this last week and use ridiculous workarounds for my jlabels, etc.
How it looks now:

There are probably a few ways you can achieve this, but the simplest would be to use compound layouts.
Use two panels to act as the columns and then place these onto the main container. Into these you would then place you other components.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
public class CompundLayout {
public static void main(String[] args) {
new CompundLayout();
}
public CompundLayout() {
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 {
public TestPane() {
JPanel left = new JPanel();
JPanel right = new JPanel();
setLayout(new GridLayout(0, 2, 2, 2));
left.add(createPane(Color.RED));
left.add(createPane(Color.GREEN));
right.add(createPane(Color.BLUE));
right.add(createPane(Color.MAGENTA));
add(left);
add(right);
}
protected JPanel createPane(Color color) {
SimplePane pane = new SimplePane();
pane.setBorder(new LineBorder(color));
return pane;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.dispose();
}
}
public class SimplePane extends JPanel {
private int width;
private int height;
public SimplePane() {
width = 100;
height = 50 + (int) Math.round(Math.random() * 100);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
}
}

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