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So i just learnt about affine transformation in java 2D and how each transformation behaves.So what i tried as a side project was to create a circle rotating around it's axis program,i tried translating first to the (0,0) then rotating by a degree then translating back to initial position,did that through 360 iterations with 1 degree increment but the circle still rotates out of that center points(although it goes back to its original point at last iteration).
here's what have done so far:
public void paint(Graphics g)
{
Graphics2D g2d = (Graphics2D) g;
//Use of antialiasing to have nicer lines.
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
//The lines should have a thickness of 3.0 instead of 1.0.
BasicStroke bs = new BasicStroke(3.0f);
g2d.setStroke(bs);
//The GeneralPath to decribe the car.
//GeneralPath gp = new GeneralPath();
//Start at the lower front of the car.
g2d.setPaint(new Color(110, 100, 0));
RenderingHints rh = new RenderingHints(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
//Draw the car.
//g2d.fillOval(215, 135, 50, 50);
Shape s = new Ellipse2D.Double(160,160,40,40);
sustain(1000);
for(int i=0;i<360;i++) {
AffineTransform rotation = new AffineTransform();
rotation.setToRotation(Math.PI/180+i);
AffineTransform translate = new AffineTransform();
translate.setToTranslation(-160, -160);
AffineTransform translate2 = new AffineTransform();
translate2.setToTranslation(160, 160);
rotation.concatenate(translate);
translate2.concatenate(rotation);
clearWindow(g2d);
g2d.setPaint(new Color(110, 100, 0));
g2d.fill(translate2.createTransformedShape(s));
}
I've spent some time re-reading your question and looking over you code and I'm still unclear on
What it is you want to do and
What your problem is
But when has that ever stopped me from having a play 😉
Okay, so this has two circles (same shape) circling around a central point (translated) point.
Something to keep in mind is, transforms are accumulative, so you can see, between the second and third circle, I reset the transform (dispose of the graphics and take another snapshot) so my poor challenged brain doesn't get completely screwed up
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private int angle = 0;
public TestPane() {
Timer timer = new Timer(5, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
angle += 1;
repaint();
}
});
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(120, 120);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
//Use of antialiasing to have nicer lines.
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.drawLine(getWidth() / 2, 0, getWidth() / 2, getHeight());
g2d.drawLine(0, getHeight() / 2, getWidth(), getHeight() / 2);
RenderingHints rh = new RenderingHints(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
Shape s = new Ellipse2D.Double(0, 0, 40, 40);
g2d.transform(AffineTransform.getTranslateInstance(40, 40));
g2d.setPaint(Color.RED);
g2d.draw(s);
g2d.transform(AffineTransform.getTranslateInstance(-30, -30));
g2d.transform(AffineTransform.getRotateInstance(Math.toRadians(angle), 50, 50));
g2d.setPaint(new Color(110, 100, 0));
g2d.drawRect(0, 0, 40, 40);
g2d.draw(s);
g2d.dispose();
g2d = (Graphics2D) g.create();
g2d.transform(AffineTransform.getTranslateInstance(40, 40));
g2d.transform(AffineTransform.getTranslateInstance(-20, -20));
g2d.transform(AffineTransform.getRotateInstance(Math.toRadians(angle / 2), 40, 40));
g2d.setPaint(Color.BLUE);
g2d.drawRect(0, 0, 40, 40);
g2d.draw(s);
}
}
}
I need it to rotate around its axis(have a circular motion in respect to its own center with out changing positions)
Okay, still not clear. If you want to rotate the object around it's centre point, but have it moving at the same time, then the order in which you apply your transformations is important.
For example, I'd translate it's position first, then rotate it, as it's easier to rotate about it's centre point without needing to calculate additional offsets
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Path2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private int angle = 0;
private Path2D path;
public TestPane() {
path = new Path2D.Double();
path.moveTo(20, 20);
path.lineTo(0, 20);
path.append(new Ellipse2D.Double(0, 0, 40, 40), false);
Timer timer = new Timer(5, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
angle += 1;
repaint();
}
});
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(120, 120);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
//Use of antialiasing to have nicer lines.
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
RenderingHints rh = new RenderingHints(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.transform(AffineTransform.getTranslateInstance(40, 40));
g2d.transform(AffineTransform.getRotateInstance(Math.toRadians(angle), 20, 20));
g2d.setPaint(Color.RED);
g2d.draw(path);
g2d.dispose();
}
}
}
And as an addition, you could also have a look at How to rotate an object around another moving object in java?
I am working on a class that can rotate a wheel around the center. The wheel is created using graphics2d, but I can not figure out exactly how to get the wheel to rotate around the center.
Currently, the wheel rotates, but not exactly about the origin.
My ultimate goal here is to create the wheel so that it is multicolored as well as a program around it, but my main concern here is getting the rotating wheel to work. If you could point me in the right direction I would be forever grateful!
Here is my current code:
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.*;
public class RotateApp {
private static final int N = 3;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame();
frame.setLayout(new GridLayout(N, N, N, N));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new RotatePanel());
frame.pack();
frame.setVisible(true);
System.out.println();
}
});
}
}
class RotatePanel extends JPanel implements ActionListener {
private static final int SIZE = 256;
private static double DELTA_THETA = Math.PI / 90;
private final Timer timer = new Timer(25, this);
private Image image = RotatableImage.getImage(SIZE);
private double dt = DELTA_THETA;
private double theta;
public RotatePanel() {
this.setBackground(Color.lightGray);
this.setPreferredSize(new Dimension(
image.getWidth(null), image.getHeight(null)));
this.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
image = RotatableImage.getImage(SIZE);
dt = -dt;
}
});
timer.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.translate(this.getWidth() / 2, this.getHeight() / 2);
g2d.rotate(theta);
g2d.translate(-image.getWidth(this) / 2, -image.getHeight(this) / 2);
g2d.drawImage(image, 0, 0, null);
}
public void actionPerformed(ActionEvent e) {
theta += dt;
repaint();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(SIZE, SIZE);
}
}
class RotatableImage {
private static final Random r = new Random();
static public Image getImage(int size) {
BufferedImage bi = new BufferedImage(
size, size, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = bi.createGraphics();
g2d.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setPaint(Color.getHSBColor(r.nextFloat(), 1, 1));
g2d.setStroke(new BasicStroke(10.0f));
g2d.draw(new Line2D.Double(0, 100, 100, 100));
g2d.draw(new Line2D.Double(100, 100, 200, 100));
g2d.draw(new Line2D.Double(100, 0, 100, 100));
g2d.draw(new Line2D.Double(100, 100, 100, 200));
g2d.draw(new Line2D.Double(25, 25, 100, 100));
g2d.draw(new Line2D.Double(100, 100, 175, 175));
g2d.draw(new Line2D.Double(175, 25, 100, 100));
g2d.draw(new Line2D.Double(100, 100, 25, 175));
g2d.draw(new Ellipse2D.Double(0, 0, 200, 200));
g2d.dispose();
return bi;
}
}
You can use the Rotated Icon class to do the rotation for you so you don't have to worry about all the rotation logic and the rotation logic is in a reusable class.
An example of using this class would be:
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;
import java.util.*;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.event.*;
public class Rotation4 extends JPanel
{
private JLabel label;
private RotatedIcon rotated;
private int degrees;
public Rotation4(Image image)
{
setLayout( new GridBagLayout() );
Icon icon = new ImageIcon( image );
rotated = new RotatedIcon(icon, 0);
rotated.setCircularIcon(true);
label = new JLabel(rotated);
label.setOpaque(true);
label.setBackground(Color.RED);
add(label, new GridBagConstraints());
setDegrees( 0 );
}
public void setDegrees(int degrees)
{
this.degrees = degrees;
rotated.setDegrees( degrees );
label.revalidate();
label.repaint();
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
Image bi = RotatableImage.getImage(210);
final Rotation4 r = new Rotation4(bi);
final JSlider slider = new JSlider(JSlider.HORIZONTAL, 0, 360, 0);
slider.addChangeListener(new ChangeListener()
{
public void stateChanged(ChangeEvent e)
{
int value = slider.getValue();
r.setDegrees( value );
}
});
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new JScrollPane(r));
f.add(slider, BorderLayout.SOUTH);
f.setSize(400, 400);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
});
}
static class RotatableImage
{
private static final Random r = new Random();
static public Image getImage(int size)
{
BufferedImage bi = new BufferedImage(size, size, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = bi.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setPaint(Color.getHSBColor(r.nextFloat(), 1, 1));
g2d.setStroke(new BasicStroke(10.0f));
g2d.draw(new Line2D.Double(5, 105, 205, 105));
g2d.draw(new Line2D.Double(105, 5, 105, 205));
g2d.draw(new Line2D.Double(35, 35, 175, 175));
g2d.draw(new Line2D.Double(175, 35, 35, 175));
g2d.draw(new Ellipse2D.Double(5, 5, 199, 199));
g2d.setColor(Color.BLACK);
g2d.fillOval(100, 100, 10, 10);
g2d.dispose();
return bi;
}
}
}
Note I also had to make changes with your image and your painting. These changes will need to be made whether you use the RotatedIcon or do the rotation code yourself:
The image size was changed to 210. This is because your stroke size is 10, so you need to account for the extra pixels in the circle outline.
You need to change the original of the circle by half the stroke size. So in this case the origin becomes (5, 5).
The size of the oval needs to be changed to 199. This is because of the way the outline of the oval is painted. 1 extra pixel is needed for the outline. If you leave the size at 200 then 1 pixel of the outline will be lost. This is not very noticeable when using a stroke size of 10, but if you use a size of 1, then the outline will be missing at the right and bottom edges.
The locations of your lines needs to be changes. you don't want the line right to the edge of the circle because then you will get a flat line at the edge instead of the rounded line. So I started the line 5 pixels from the start and ended it 5 pixels from the end.
Ok, with little modification and fewer "spokes", I got your wheel rotate centric (1.) and multicolor (2.):
UPDATE on 1.) To make centric rotation in your (original) code just chage SIZEto 200!
import java.awt.BasicStroke;
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 java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.swing.*;
public class RotateApp {
private static final int N = 3;
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
JFrame frame = new JFrame();
frame.setLayout(new GridLayout(N, N, N, N));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new RotatePanel());
frame.pack();
frame.setVisible(true);
System.out.println();
});
}
}
class RotatePanel extends JPanel implements ActionListener {
private static final int SIZE = 256;
private static final double DELTA_THETA = Math.PI / 90;
private final Timer timer = new Timer(25, this);
private Image image = RotatableImage.getImage(SIZE);
private double dt = DELTA_THETA;
private double theta;
public RotatePanel() {
this.setBackground(Color.lightGray);
this.setPreferredSize(new Dimension(SIZE, SIZE));
this.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
dt = -dt;
image = RotatableImage.getImage(SIZE);
}
});
timer.start();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.rotate(theta,128,128);
g2d.drawImage(image, 0, 0, null);
}
#Override
public void actionPerformed(ActionEvent e) {
theta += dt;
repaint();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(SIZE, SIZE);
}
}
class RotatableImage {
private static final Random r = new Random();
static public Image getImage(int size) {
BufferedImage bi = new BufferedImage(
size, size, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = bi.createGraphics();
g2d.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
final Color c1 = Color.getHSBColor(r.nextFloat(), 1, 1);
final Color c2 = Color.getHSBColor(r.nextFloat(), 1, 1);
g2d.setPaint(c1);
g2d.setStroke(new BasicStroke(10.0f));
g2d.draw(new Line2D.Double(0, size/2, size, size/2));
g2d.setPaint(c2);
g2d.draw(new Line2D.Double(size/2, 0, size/2, size));
g2d.setPaint(c1);
g2d.draw(new Ellipse2D.Double(0, 0, size, size));
g2d.dispose();
return bi;
}
}
Explanation:
So the "wobble" in your solution came from the fact, that you sized the image and the container/panel 256x256, but "based" your wheel layout on 200x200 only. I fixed all dimensions, and drew a correct cross, the g2d.rotate(theta,128,128); (!) relates then to the center.
Multi-color(easy): You can invoke setPaint() between each shape! ;)
I am trying to create my own component for swing, but when i try to paint the border of it with drawRect, it only draws the left and top edges! Why is that, and how can it be fixed?
Here is my paintComponent method:
#Override
protected void paintComponent(Graphics g) {
g.setColor(Color.white);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(Color.red);
g.drawRect(0, 0, getWidth(), getHeight());
}
Screenshot:
I am trying to create my own component for swing, but when i try to paint the border of it with drawRect,
Why are you trying to draw a Border. Swing supports borders. if your component needs a border then you should be using:
setBorder( new LineBorder(Color.RED) );
and let swing draw the border for you.
it only draws the left and top edges!
I think you should be using:
g.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
Maybe this will help you as a starting point:
package de.professional_webworkx.graphics;
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class DrawFrame extends JFrame {
/**
*
*/
private static final long serialVersionUID = -1285962479945295143L;
private JPanel northPanel;
public DrawFrame() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Draw");
this.setLayout(new BorderLayout());
this.getContentPane().add(createNorthPanel(), BorderLayout.BEFORE_FIRST_LINE);
this.getContentPane().add(new DrawPanel(), BorderLayout.CENTER);
this.setSize(1024, 768);
this.setVisible(true);
}
public JPanel createNorthPanel() {
northPanel = new JPanel();
northPanel.setBackground(Color.MAGENTA);
JLabel jLabel = new JLabel("XXXXXXXXXXXX");
jLabel.setForeground(Color.WHITE);
northPanel.add(jLabel);
return northPanel;
}
public static void main(String[] args) {
new DrawFrame();
}
}
DrawPanel.class
package de.professional_webworkx.graphics;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
public class DrawPanel extends JPanel {
/**
*
*/
private static final long serialVersionUID = 4949248244138855737L;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.drawRect(10, 10, getWidth()/2, getHeight()/2);
g.setColor(Color.YELLOW);
g.fillRect(11, 11, getWidth()/2-1, getHeight()/2-1);
g.draw3DRect(10, getHeight()/2+20, 600, 280, true);
}
}
Patrick
UPDATE: Thanks to camickr.
I have serious problem when I add JPanel to Oracle Forms Container (based-on AWT Container).
I add JPanel first, after that I add some VTextFields (Oracle Forms text field).
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import oracle.ewt.scrolling.scrollBox.ScrollBox;
import oracle.forms.ui.DrawnPanel;
import oracle.forms.ui.FScrollBox;
import oracle.forms.ui.VTextField;
public class OverlapTest {
int w = 800;
int h= 700;
public OverlapTest() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(w, h);
DrawnPanel main = new DrawnPanel();
main.setLayout(null);
main.setBounds(0, 0, w, h);
main.setVisible(true);
VTextField t1 = new VTextField();
t1.setBounds(100, 100, 130, 22);
VTextField t2 = new VTextField();
t2.setBounds(100, 150, 130, 22);
VTextField t3 = new VTextField();
t3.setBounds(100, 200, 130, 22);
final JPanel draw = new JPanel(){
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.red);
g2.fillRect(0, 100, 130, 200);
g2.dispose();
}
#Override
public void update(Graphics g) {
paint(g);
}
};
draw.setOpaque(false);
draw.setBounds(0, 0, w, h);
main.add(draw);
main.add(t1);
main.add(t2);
main.add(t3);
ScrollBox sBox = new ScrollBox(main);
sBox.setBounds(0, 0, w, h);
sBox.setVScrollInsets(1, 100);
oracle.forms.ui.FScrollBox fBox = new FScrollBox(sBox, 0, 0);
fBox.setVisible(true);
fBox.setBounds(0, 0, w - 50, h - 50);
main.setComponentZOrder(draw, 3);
main.setComponentZOrder(t1, 0);
main.setComponentZOrder(t2, 1);
main.setComponentZOrder(t3, 2);
f.add(fBox);
f.setVisible(true);
}
public static void main(String[] args) {
OverlapTest test = new OverlapTest();
}
}
As you see, I add the JPanel first, after that I setComponentZorder, that is because my requirement and in my real application I cannot add JPanel at the end of all component, so I did it follow that way.
But currently I have one problem, all other component overlap the JPanel but the background of JPanel (the red rectangle) always hide other components like that.
This is the image:
I don't know, but when I use JTextField, everything is OK.
I'm using components of Oracle Forms in frmall.jar
You can download frmall.jar from http://www.megafileupload.com/en/file/329640/frmall-jar.html
Do you have any solution to make the red rectangle is overlapped by other components?
Sorry for my terible English.
Thanks in Advance.
now I try to replace Jpanel by Forms DrawnPanel, but it still have the problem:
FormCanvas form = new FormCanvas(){
#Override
public void paint(Graphics g, Dimension paramDimension,
Rectangle paramRectangle) {
// TODO Auto-generated method stub
super.paint(g, paramDimension, paramRectangle);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.red);
g2.fillRect(0, 100, 200, 200);
g2.dispose();
}
};
DrawnPanel draw = new DrawnPanel();
draw.setPainter(form);
draw.setVisible(true);
So now, every my components are Forms Component, but I still get this problem
The first advice I would offer is don't mix Swing & AWT components. Try updating the 'Oracle forms' jar to a Swing version, or failing that, use only AWT components in your code.
I have a view object that is a jPanel and holds other jPanels which in turn hold jLabels. I'm wanting to paint a gradient overlay on the object to give it a nice sleek look rather than the boring plain look.
My attempt thus far is:
public class InfoDisplay extends javax.swing.JPanel {
#Override
public void paintComponent(Graphics g) {
UIDefaults uid = UIManager.getDefaults();
Graphics2D g2d = (Graphics2D)g;
int w = getWidth();
int h = getHeight();
Color lightBlue = new Color(41, 117, 200);
Color darkBlue = new Color(2, 47, 106);
if (!isOpaque()) {
super.paintComponent( g );
return;
}
GradientPaint gp = new GradientPaint(0, 0, lightBlue, 0, h, darkBlue );
g2d.setPaint(gp);
g2d.fillRect( 0, 0, w, h );
setOpaque( false );
super.paintComponent( g );
setOpaque( true );
}
}
This doesn't seem to change the objects background at all. I'm fairly new to messing with things that aren't related to the Gui defaults.
I used the Gui builder in Netbeans to create the object, so initComponents() is also in the class, but I posted only the source that is relevant to the question.
Perhaps someone can point me in the right direction?
If you want a background JPanel to use a gradient paint, then just use it. Don't do all that funny stuff in your code with setOpaque and super.paintComponent. e.g.,
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.*;
#SuppressWarnings("serial")
public class GradientPaintPanel extends JPanel {
private static final Color LIGHT_BLUE = new Color(41, 117, 200);
private static final Color DARK_BLUE = new Color(2, 47, 106);
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
GradientPaint gradPaint = new GradientPaint(0, 0, LIGHT_BLUE, 0, getHeight(), DARK_BLUE);
g2.setPaint(gradPaint);
g2.fillRect(0, 0, getWidth(), getHeight());
}
public GradientPaintPanel() {
}
private static void createAndShowUI() {
GradientPaintPanel gradPaintPanel = new GradientPaintPanel();
gradPaintPanel.setPreferredSize(new Dimension(400, 300));
JFrame frame = new JFrame("GradientPaintEg");
frame.getContentPane().add(gradPaintPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}