I'm testing a program that uses a JSlider to adjust the width of a circle, and the value of the slider is working, but its not actually changing the 'width' variable. Please help!!! Here is what I have so far:
public class SliderTest extends JFrame{
private static DrawShape circle = new DrawShape();
JSlider slider;
JLabel label;
public SliderTest() {
setLayout(new FlowLayout());
slider = new JSlider(JSlider.HORIZONTAL, 150, 450, 300);//orientation, min val, max value, starting val
slider.setMajorTickSpacing(50);//every 5 integers will be a new tick position
slider.setPaintTicks(true);
add(slider);
label = new JLabel("Current value 300");
add(label);
event e = new event();
slider.addChangeListener(e);;
}//end cons
public class event implements ChangeListener{
public void stateChanged(ChangeEvent e) {
JSlider slider = (JSlider)e.getSource();
int value = slider.getValue();
label.setText("Current Value " + value);
circle.setWidth(value);
repaint();
}//end stateChanged
}//end class event
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("Circle");
frame.add(circle);
frame.setSize(500,400);
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
JFrame frame1 = new SliderTest ();
frame1.setTitle("Toolbar");
frame1.setSize(300,200);
frame1.setLocation(200,100);
frame1.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame1.setVisible(true);
}
}
The other class:
public class DrawShape extends JPanel{
private float width = 300;
private Ellipse2D circle = new Ellipse2D.Float(100, 20, 300, 300);
public DrawShape() {
}
public DrawShape(float width) {
circle.setFrame(100, 20, width, 300);
}
public void setWidth(int w) {
this.width = w;
circle.setFrame(100, 20, w, 300);
revalidate();
}
#Override
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
size.width = circle.getBounds().width;
return size;
}
public void paintComponent (Graphics g) {
super.paintComponents(g);
Graphics2D graphics = (Graphics2D)g;
graphics.setColor(Color.black);
graphics.fill(circle);
}//end paintComponent
}//end class
Two (major) issues popup.
Firstly, in your event handler, you're repainting the slider frame, which isn't going to help, so it your setWidth you should add a repaint request, for example.
public void setWidth(int w) {
System.out.println("setWidth " + w);
this.width = w;
circle.setFrame(100, 20, w, 300);
revalidate();
repaint();
}
Secondly, you all calling super.paintComponents (note the s at the end) instead of super.paintComponent, for example...
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.black);
g2d.fill(circle);
}//end paintComponent
This will cause you a significant amount of grieve with strange paint artifacts...
Related
This question already has answers here:
paintComponent not painting onto JPanel
(2 answers)
Closed 5 years ago.
I'm making a game in Java and first I didn't use a JPanel which caused flickering on repaint() and so I decided to use it. I'm not sure how to implement it in my current code. When I tried to do so all I got was a window that was as small as it gets. My original Window class code:
public class Window extends JFrame {
private double stepLen;
public Window(double stepLen) {
this.stepLen = stepLen;
this.setSize(800, 600);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setResizable(false);
this.setTitle("Frogger");
this.setLayout(null);
getContentPane().setBackground(Color.black);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
int x = (dim.width - this.getSize().width)/2;
int y = (dim.height - this.getSize().height)/2;
this.setLocation(x, y);
JLabel goal = new JLabel();
goal.setText("|=========|");
goal.setForeground(Color.WHITE);
goal.setFont(new Font("Seif", Font.PLAIN, 20));
add(goal);
goal.setBounds(325, -10, 600, 50);
setFocusable(true);
requestFocusInWindow();
this.setVisible(true);
}
This code works and it creates a window.
Main class:
Window window = new Window(50);
And then I tried to do it this way:
I have separate GameFrame (JFrame) and GameCanvas (JPanel) classes.
The Frame looks like this:
public class GameFrame extends JFrame{
private double stepLen;
public GameFrame() {
this.stepLen = 50;
this.setSize(800, 600);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setResizable(false);
this.setTitle("Frogger");
this.setLayout(null);
this.setVisible(true);
this.getContentPane().setBackground(Color.black);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
int x = (dim.width - this.getSize().width)/2;
int y = (dim.height - this.getSize().height)/2;
GameCanvas gcanvas = new GameCanvas();
this.add(gcanvas);
this.pack();
this.setLocation(x, y);
}
}
}
And the GameCanvas class
public class GameCanvas extends JPanel {
public GameCanvas() {
setDoubleBuffered(true);
JLabel goal = new JLabel();
goal.setText("|=========|");
goal.setForeground(Color.WHITE);
goal.setFont(new Font("Seif", Font.PLAIN, 20));
this.add(goal);
goal.setBounds(325, -10, 600, 50);
this.getPreferredSize();
this.setVisible(true);
this.repaint();
}
Camickr is correct - go up vote and mark his answer as correct, this is only here to save him from pulling out what little hair he has remaining
You're using a null layout, without taking over its responsibility
Failed to provide sizing hints to for the component to allow the layout manager (which you're no longer using) to do it's job
This are all common mistakes, to which there are countless answers already provided
GameFrame
public class GameFrame extends JFrame {
private double stepLen;
public GameFrame() {
this.stepLen = 50;
this.setSize(800, 600);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setResizable(false);
this.setTitle("Frogger");
// Well, there's your problem...
//this.setLayout(null);
// Don't do this here...
this.setVisible(true);
this.getContentPane().setBackground(Color.black);
// Simpler way to achieve this
//Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
//int x = (dim.width - this.getSize().width) / 2;
//int y = (dim.height - this.getSize().height) / 2;
GameCanvas gcanvas = new GameCanvas();
this.add(gcanvas);
this.pack();
//this.setLocation(x, y);
setLocationRelativeTo(null);
setVisible(true);
}
}
GameCanvas
public class GameCanvas extends JPanel {
public GameCanvas() {
// Pointless
//setDoubleBuffered(true);
JLabel goal = new JLabel();
goal.setText("|=========|");
goal.setForeground(Color.WHITE);
goal.setFont(new Font("Seif", Font.PLAIN, 20));
this.add(goal);
// Pointless
//goal.setBounds(325, -10, 600, 50);
// Pointless
//this.getPreferredSize();
// Pointless
//this.setVisible(true);
// Pointless
//this.repaint();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
#Override
public void paintComponent(Graphics g) {
int firstRoad = 5;
int i = 0;
int max = 10;
Graphics2D g2 = (Graphics2D) g;
super.paintComponent(g2);
g2.setColor(Color.WHITE);
g2.drawRect(5, 30, 75, 40);
while (i < max) {
g2.setColor(Color.WHITE);
g2.setStroke(new BasicStroke(3));
if (i % 2 == 0) {
g.setColor(Color.WHITE);
g.drawRect(3, firstRoad + 50 * i, 793, 50);
//g.fillRect(3, firstRoad + 50 * i, 793, 50);
} else {
g2.setColor(Color.WHITE);
g2.drawRect(3, firstRoad + 50 * i, 793, 50);
}
i++;
}
}
}
So, the way I was taught in my AP Computer Science class is to set your frame size and other frame characteristics in your main. Here is an example:
import javax.swing.JFrame;
public class theSetupClass{
public static void main(String[] args){
JFrame theGUI = new JFrame();
theGUI.setSize(300,400); //Sets the frame size to 300 by 400
theGUI.setTitle("Example");
theGUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
theComponentClass component = new theComponentClass(); //Create new theComponentClass
frame.add(component);//Add theComponentClass to theGUI
frame.setVisible(true);
}
}
The code above creates the JFrame and adds the following class to it.
import java.awt.*;
import javax.swing.*;
public class theComponentClass extends JComponent{
public void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g;
Rectangle r = new Rectangle(10,10,this.getWidth()-10,this.getHeight()-10);
//Creates a rectangle that is 10 pixels away from all sides of the frame
g2.fill(r); //Draws and fills the rectangle
}
}
I hope that you find this helpful!
I'm trying to make a panel that contains a shape and a button. The issue is that when I add a button to the JPanel, the shape does not appear. It just shows the button on the top of my screen. The square only shows up when add the square to the frame instead of the panel, but the button will not appear.
public static void main(String[] args)
{
JFrame frame = new JFrame();
JPanel panel = new JPanel();
//Replace FRAME_WIDTH/HEIGHT with a number greater than 100
frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
frame.setTitle("Square Game");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Creates a Red Square from RedSquare
final RedSquare red = new RedSquare();
panel.add(red);
JButton button = new JButton();
button.setText("Red");
panel.add(button);
frame.add(panel);
frame.setVisible(true);
}
public class RedSquare extends JComponent
{
private Square sq;
private int x = 100;
private int y = 0;
private Graphics2D g2;
public RedSquare()
{
sq = new Square(x,y,Color.red);
}
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
sq.draw(g2);
}
public int getX()
{
return x;
}
public int getY()
{
return y;
}
public void moveBy()
{
y++;
sq = new Square(x,y,Color.red);
repaint();
}
}
public class Square
{
private int x;
private int y;
private Color color;
public Square(int x, int y, Color color)
{
this.x = x;
this.y = y;
this.color = color;
}
public void draw(Graphics2D g2)
{
Rectangle body = new Rectangle(x, y, 40, 40);
g2.draw(body);
g2.setPaint(color);
g2.fill(body);
g2.draw(body);
}
}
Do I need to do something else to make this work? Am I missing something? I am new to this and any help is greatly appreciated.
I think you have to set layout in panel using panel.setLayout(new FlowLayout()); before adding anything into panel, to make it show your both shapes. As it is overriding right now .
When adding components to a JFrame try using the setContentPane rather than add. So from your example above, remove the frame.add(panel); and use frame.setContentPane(panel);
It is unusual that you are extending JComponent which is abstract - though not prohibited.
One solution is to use JPanel instead of JComponent.
And also setting the x coordinate to x=0 will show you the square.
Beyond that you can use a layout etc:
panel.setLayout(new BorderLayout());
....
panel.add("Center", red);
.......
panel.add("South", button);
To create my first 2D game in Java, I thought of using the JFrame's getContentPane(), updating it with the new view every 50ms.
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// ...
frame.setVisible(true);
// ...
Container area = frame.getContentPane();
Graphics pen = area.getGraphics();
pen.clearRect(0, 0, area.getWidth(), area.getHeight()); // Remove previous drawing
pen.drawString("Text", 50, 50);
// ...
area.repaint();
But it doesn't work; the window doesn't change.
As kiheru already said, use paintComponent(Graphics g) for custom painting. Here is an example:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
public class Example {
int i = 0;
public Example() {
JFrame frame = new JFrame();
frame.getContentPane().add(new DrawingPanel());
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
ActionListener actionListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
frame.getContentPane().repaint();
}
};
Timer timer = new Timer(500, actionListener); //500 = Every 500 milliseconds
timer.start();
}
class DrawingPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g); // Removes previous graphics
Random r = new Random(); //Randomizer
//Random x- and y-coordinates
int x = r.nextInt(400);
int y = r.nextInt(400);
//Random rgb-values
int red = r.nextInt(255);
int green = r.nextInt(255);
int blue = r.nextInt(255);
//Random width and height
int width = r.nextInt(100);
int height = r.nextInt(100);
g.setColor(new Color(red, green, blue)); //Setting color of the graphics
g.fillRect(x, y, width, height); //Filling a rectangle
}
}
public static void main(String[] args) {
new Example();
}
}
research for double buffering or for fast image drawing using VolatileImage type for directly rending into graphics card. In your case if you use double buffering the code will be:
private static BufferedImage bufferedImage = new BufferedImage(500, 500, BufferedImage.TYPE_INT_ARGB);
private static Graphics2D gBuff = bufferedImage.createGraphics();
public static void main(String[] args)
{
JFrame frame = new JFrame()
{
#Override
public void paint(Graphics g)
{
g.drawImage(bufferedImage,0,0,this);
}
};
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
gBuff.setColor(Color.WHITE);
gBuff.fillRect(0, 0, frame.getWidth(), frame.getHeight()); // Remove previous drawing
gBuff.setColor(Color.BLACK);
gBuff.drawString("Text", 50, 50);
// ...
frame.setVisible(true);
// ...
}
This is my problem :
I have one JPanel and i paint in this panel one rectangle ex. 100x100.
In another JPanel I wouldlike show/paint fragments on first JPanel ex. 50x50, but if I change first JPanel, another JPanel change too (dont copy graphics or Panel)
What I can do this?
First Panel Second Panel
Public class Okienko extends JFrame {
Panel p = new Panel();
public Okienko(){
//setLayout(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(p);
pack();
setVisible(true);
}
private class Panel extends JPanel{
public Panel(){
setPreferredSize(new Dimension(300,400));
setBackground(Color.red);
setVisible(true);
}
#Override
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
super.paint(g2);
g2.setColor(Color.blue);
g2.fill(new Rectangle2D.Float(100,100,100,100));
g2.setColor(Color.green);
g2.fill(new Rectangle2D.Float(50,50,50,50));
}
}
private class Panel2 extends Panel{
#Override
public void paint(Graphics g) {
//I would like to show/paint only fragment painted Panel, ex. 50x50 (only show one rectangle)
}
}
public static void main(String[] args) {
Okienko o = new Okienko();
}
}
So this is what you need to do.
You need to save the first JPanel's Graphics context to a BufferedImage. Here is a helper method, I used in the example program below
BufferedImage bi;
....
private void setImage(JPanel panel) {
Dimension d = panel.getPreferredSize();
int w = (int)d.getWidth();
int h =(int)d.getHeight();
bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
panel.paint(g);
g.dispose();
}
This saves the entire JPanel to a BufferedImage.
Use that BufferedImage to paint on the second JPanel. Use whatever coordinates you want. Use this method from Graphics class
public abstract boolean drawImage(Image img,
int dx1,
int dy1,
int dx2,
int dy2,
int sx1,
int sy1,
int sx2,
int sy2,
ImageObserver observer)
img - the specified image to be drawn. This method does nothing if img is null.
dx1 - the x coordinate of the first corner of the destination rectangle.
dy1 - the y coordinate of the first corner of the destination rectangle.
dx2 - the x coordinate of the second corner of the destination rectangle.
dy2 - the y coordinate of the second corner of the destination rectangle.
sx1 - the x coordinate of the first corner of the source rectangle.
sy1 - the y coordinate of the first corner of the source rectangle.
sx2 - the x coordinate of the second corner of the source rectangle.
sy2 - the y coordinate of the second corner of the source rectangle.
observer - object to be notified as more of the image is scaled and converted.
g.drawImage(bi, 0, 0, 200, 200, 0, 0, 50, 50, this);
Here's the result
Here's the full code
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
import javax.swing.SwingUtilities;
public class TestTwoPanels {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JPanel panel = new JPanel();
PanelTwo panelTwo = new PanelTwo();
PanelOne panelOne = new PanelOne(panelTwo);
JSplitPane split = new JSplitPane(
JSplitPane.HORIZONTAL_SPLIT, panelOne, panelTwo);
panel.add(split);
JFrame frame = new JFrame("Test Graphics");
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
private static class PanelOne extends JPanel {
Dimension size;
BufferedImage image;
PanelTwo panelTwo;
public PanelOne(PanelTwo panelTwo) {
this.panelTwo = panelTwo;
try {
URL url = new URL("http://swoo.co.uk/content/images/icons/stackoverflow.png");
image = ImageIO.read(url);
} catch (MalformedURLException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
panelTwo.setImage(PanelOne.this);
panelTwo.repaint();
}
#Override
public void paint(Graphics g) {
super.paint(g);
g.drawImage(image, 0, 0, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 250);
}
}
private static class PanelTwo extends JPanel {
BufferedImage bi;
public PanelTwo() {
setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
}
public void setImage(BufferedImage image) {
this.bi = image;
}
private void setImage(JPanel panel) {
Dimension d = panel.getPreferredSize();
int w = (int)d.getWidth();
int h =(int)d.getHeight();
System.out.println(d);
bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
panel.paint(g);
g.dispose();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(bi, 25, 25, 225, 225, 50, 50, 175, 175, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 250);
}
}
}
private void setImage(JPanel panel) {
Dimension d = panel.getPreferredSize();
int w = (int)d.getWidth();
int h =(int)d.getHeight();
System.out.println(d);
bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
This code is clearify for me.
Graphics2D g = bi.createGraphics();
You create blank BufferedImage and init to Graphics2D?
panel.paint(g);
You paint graphics context on panel and copy to bi?
g.dispose();
You release g.
}
Right now I am making my jinternal frames transparent using this code:
double rgbConversionBackpack = Double.parseDouble(MyClient.configFile.getProperty("BACKPACK_FRAME_ALPHA"));
double tmp = (rgbConversionBackpack / 100.0) * 255.0;
this.getContentPane().setBackground(new Color(140, 0, 0, (int)tmp));
this.setOpaque(false);
I have code on the sliders to set the alpha which all works perfectly and saves it to a properties file, yada, yada, yada. The question is how do I make the entire JInternal Frame transparent.
Right now I have only be able to set the content pane, and any other panels (etc) that are in the jinternal frames transparent, but I want to make the entire JinternalFrame(borders and all) transparent.
Screenshot below shows how on the backpack the red tinted are is partially transparent and looks decent, but still want the border to be transparent also.
Is there a way to override the draw super method for each of my classes the extend JInternalFrame to have it draw semi transparent(depending on value obviously)?
You could do this by changing the AlphaComposite that the JInternalFrame's paint method uses. You have to be careful though to repaint the containing top level window at the location of the transparent component lest you have funny side effects. For example:
import java.awt.*;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
#SuppressWarnings("serial")
public class TransparentInternalFrame extends JDesktopPane {
private static final Color COLOR_1 = Color.red;
private static final Color COLOR_2 = Color.blue;
private static final float PT_2 = 30f;
private static final int PREF_W = 800;
private static final int PREF_H = 500;
public TransparentInternalFrame() {
add(new MyInternalFrame("Foo", 50, 50, 300, 300, 0.2f));
add(new MyInternalFrame("Foo", 400, 100, 300, 300, 0.4f));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(new GradientPaint(0, 0, COLOR_1, PT_2, PT_2, COLOR_2, true));
g2.fillRect(0, 0, getWidth(), getHeight());
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
TransparentInternalFrame mainPanel = new TransparentInternalFrame();
JFrame frame = new JFrame("TransparentInternalFrame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
#SuppressWarnings("serial")
class MyInternalFrame extends JInternalFrame {
private AlphaComposite comp = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f);
public MyInternalFrame(String title, int x, int y, int w, int h, final float alpha) {
super(title);
setClosable(true);
setBounds(x, y, w, h);
setVisible(true);
int sliderValue = (int) (alpha * 100);
comp = comp.derive(alpha);
final JSlider slider = new JSlider(0, 100, sliderValue);
slider.setMajorTickSpacing(20);
slider.setMinorTickSpacing(5);
slider.setPaintLabels(true);
slider.setPaintTicks(true);
slider.setBorder(BorderFactory.createTitledBorder("Alpha Value"));
slider.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent cEvt) {
float alpha = (float) slider.getValue() / 100f;
setAlpha(alpha);
MyInternalFrame.this.repaint();
Window win = SwingUtilities.getWindowAncestor(MyInternalFrame.this);
win.repaint();
}
});
add(new JLabel("My Label", SwingConstants.CENTER));
add(slider, BorderLayout.SOUTH);
}
#Override
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setComposite(comp);
super.paint(g);
}
public void setAlpha(float alpha) {
comp = comp.derive(alpha);
}
}
But note that this program is not fully fixed. You'll still see pixel errors if you drag one JInternalFrame over another. I still need to work the bugs out...