I've been using the new com.sun.awt.AWTUtilities class and am intrigued. I got com.sun.awt.AWTUtilities/setWindowOpacity(java.awt.Window window, float f) to work perfectly, but am now wondering if there is any way to change the opacity of an individual component, such as a javax.swing.JInternalFrame or javax.swing.JButton.
Try this:
class TransparentButton extends JButton {
public TransparentButton(String text) {
super(text);
setOpaque(false);
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
super.paint(g2);
g2.dispose();
}
}
Related
I'm writing paint on screen program using Java Swing. It working on ubuntu linux. But windows shows black screen instead of transparent panel. I included similar example code. What is wrong in my code?
import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class Example {
public static final Color COLOR_TRANSPARENT = new Color(0,0,0,0);
public Example() {
Canvas drawArea = new Canvas();
drawArea.setBackground(COLOR_TRANSPARENT);
drawArea.setOpaque(true);
JWindow drawingFrame = new JWindow();
drawingFrame.setBackground(COLOR_TRANSPARENT);
drawingFrame.setContentPane(drawArea);
drawingFrame.pack();
drawingFrame.setSize(640, 460);
drawingFrame.setVisible(true);
drawingFrame.setLocationRelativeTo(null);
drawingFrame.setAlwaysOnTop(true);
}
public static void main(String[] args){
SwingUtilities.invokeLater(Example::new);
}
class Canvas extends JPanel{
private Image image;
private Graphics2D g2;
public Canvas() {
super();
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
int x = e.getX();
int y = e.getY();
g2.setPaint(Color.RED);
g2.fillOval(x-10, y-10, 20, 20);
repaint(x-10, y-10, 20, 20);
}
});
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image == null){
image = createImage(getWidth(), getHeight());
g2 = (Graphics2D) image.getGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setBackground(COLOR_TRANSPARENT);
clear();
}
Graphics2D g2 = (Graphics2D) g;
g2.drawImage(image, 0,0, null);
}
public void clear(){
System.out.println("clearing canvas ");
g2.setComposite(AlphaComposite.Clear);
g2.setBackground(COLOR_TRANSPARENT);
g2.setColor(COLOR_TRANSPARENT);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.clearRect(0, 0, getWidth(), getHeight());
g2.setPaint(Color.RED);
g2.setComposite(AlphaComposite.SrcOver);
repaint();
}
}
}
Here is screenshot what I wanted.
Example code updated. Now code should work without any other additional code.
For windows I made a couple of changes:
image = createImage(getWidth(), getHeight());
image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
I used a BufferedImage to you can set the alpha values of the image to be transparent.
//public static final Color COLOR_TRANSPARENT = new Color(0,0,0,0);
public static final Color COLOR_TRANSPARENT = new Color(0,0,0,1);
I made the alpha value non-zero, because a value of zero means the Java application won't receive the MouseEvent because it is passed to the application under the window.
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
I've been trying to make a shop for my game.
This has been unsuccessful.
I've tried drawComponent, didn't work.
No errors, code executed, but didn't work.
Now i'm trying to do:
private void render() {
Graphics2D g = (Graphics2D) graphics.getGraphics();
/////////////////////
g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
/////////////////////
g.dispose();
Graphics2D g2d = (Graphics2D) getGraphics();
g2d.drawImage(img, 0, 0, null);
g2d.dispose();
}
Now i get a NullPointerException on g2d.
I've tried everything.
`Exception in thread "game" java.lang.NullPointerException
at com.johnythecarrot.game.Shop$DrawPane.access$2(Shop.java:123)
at com.johnythecarrot.game.Shop.render(Shop.java:154)
at com.johnythecarrot.game.Game.render(Game.java:75)
at com.johnythecarrot.game.Game.run(Game.java:112)
at java.lang.Thread.run(Unknown Source)`
My goals are to be able to have clickable buttons.
It DID work. But i had to restart almost everytime. Because mostly of the time to code wasn't even executed. So i tried to fix it. Now it's all messed up.
This is the code to it.
(DoubleInt is a part of my library it's nothing more than just x and y. )
public class Shop {
public BuildWindow window;
public static JWindow w;
private int WIDTH = 860, HEIGHT = 440;
private BufferedImage graphics = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
public DrawPane drawPane;
public Shop() {
//window = new BuildWindow().setSize(new DoubleInt(100, 100)).at(wi, he).setTitle("Shop").setOpacity(1).setDragable(false).showEmpty(true);
w = new JWindow();
w.setOpacity(1);
w.setSize(WIDTH, HEIGHT);
w.setLocation(800, 800);
w.setVisible(false);
w.setAlwaysOnTop(true);
//graphics = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
}
private void createShop() {
/***Graphics2D g = (Graphics2D) graphics.getGraphics();
g.setColor(Color.blue);
g.drawString("hey", WIDTH-50, HEIGHT-50);
g.fillRect(0, 0, WIDTH, HEIGHT);*/
}
public class DrawPane extends JPanel {
int width = WIDTH;
int height = HEIGHT;
private ArrayList<Shape> buttons;
private Shape btn1 = new Rectangle2D.Double(20, 60, width/2, height-20);
private Shape btnClose = new Rectangle2D.Double(width-25, 5, 20, 20);
Point wCoords;
Point mCoords;
public DrawPane() {
buttons = new ArrayList<>();
buttons.add(btn1);
buttons.add(btnClose);
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
super.mouseClicked(e);
for(Shape s : buttons) {
if(s.contains(e.getPoint())) {
System.out.println("Clicked " + s.getBounds());
if(s == btnClose) {
w.dispose();
}
}
}
}
#Override
public void mousePressed(MouseEvent e) {
mCoords = e.getPoint();
}
#Override
public void mouseReleased(MouseEvent arg0) {
mCoords = null;
}
});
addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
wCoords = e.getLocationOnScreen();
w.setLocation(wCoords.x - mCoords.x, wCoords.y - mCoords.y);
}
});
}
void repaintThis() {
repaint();
}
BufferedImage img = loadImageFrom.LoadImageFrom(Shop.class, "bar.png");
Graphics gb;
/**
* super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g.setColor(Color.red);
//g.fillRect(0, 0, width, 50);
g.drawImage(img, 0, 0, width, 50, null);
g.setColor(Color.WHITE);
g.drawString("SHOP", 15, 30);
g.drawString("X", width-20, 20);
for(Shape b : buttons) {
g2d.draw(b);
}
System.out.println("Built");
gb = g;
*/
private void render() {
Graphics2D g = (Graphics2D) graphics.getGraphics();
/////////////////////
g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
/////////////////////
g.dispose();
Graphics2D g2d = (Graphics2D) getGraphics();
g2d.drawImage(img, 0, 0, null);
g2d.dispose();
}
public void Build() {
Graphics g = gb;
Graphics2D g2d = (Graphics2D) g;
g.setColor(Color.red);
//g.fillRect(0, 0, width, 50);
g.drawImage(img, 0, 0, width, 50, null);
g.setColor(Color.WHITE);
g.drawString("SHOP", 15, 30);
g.drawString("X", width-20, 20);
for(Shape b : buttons) {
g2d.draw(b);
}
System.out.println("Built");
}
}
public void render(Graphics2D g) {
drawPane.render();
}
public void addDrawPane() {
drawPane = new DrawPane();
w.add(drawPane);
}
}
If you need access to more code, just ask me.
You should override the paintComponent method like this:
public class DrawPane extends JPanel {
// all your variables and other things
#Override
paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
// Your code goes here, use the g2d
}
}
then if you need to repaint your component, simply call repaint() on it.
What's the easiest way in Java SE 7 to obtain an instance just to plot a few points for debugging? Desktop environment.
You could use a BufferedImage:
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D graphics2D = image.createGraphics();
The easiest and safest way is to use to cast the Graphics reference in paintComponent and cast it as needed. That way the Object is correctly initialized. This reference can be passed to other custom painting methods as required.
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
...
}
You should probably just create a JPanel and paint on it.
public class MyPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
.... // my painting
}
}
My code:
public class YesOrNo{
Graphics g;
public void createAndShowGui() {
JPanel x=new JPanel(){
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
}
}
public void drawARectangle(){
g.drawRect(10, 10, 50, 50);
}
}
I know I can call a method inside paintComponent and pass g to it as parameter, but can you do it without calling that method inside paintComponent?
Is it possible to apply transformations to custom or premade controls in Swing? By one hand transformations are allowed, by other hand there are probably some gaps in implementation with this.
ATTENTION the question is about how to apply transfomations from control's parent, not about how to use transformations at all. I.e. transformation must be issued by the parent, while child should just obey it. So, please hint how to transform standard Swing controls or how to write custom controls which obey PARENT transformation.
Simple example which applies transform to Graphics before drawing childs and which doesn't work:
public class Tester_TransformDuringPaint_01 {
private static Logger log = LoggerFactory.getLogger(Tester_TransformDuringPaint_01.class);
private static class JPanelEx extends JPanel {
private AffineTransform transform = new AffineTransform();
public AffineTransform getTransform() {
return transform;
}
public void setTransform(AffineTransform transform) {
this.transform = transform;
}
#Override
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
AffineTransform savedTransform = g2.getTransform();
g2.transform(transform);
super.paintComponent(g);
g2.drawOval(0, 0, 100, 100);
g2.setTransform(savedTransform);
}
#Override
protected void paintChildren(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
AffineTransform savedTransform = g2.getTransform();
g2.transform(transform);
super.paintChildren(g);
g2.setTransform(savedTransform);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JButton button = new JButton("Button");
button.setBounds(0,20,100,60);
JPanelEx panel = new JPanelEx();
panel.setLayout(null);
panel.setBounds(10, 10, 640, 480);
panel.setBackground(Color.PINK);
panel.setTransform(AffineTransform.getScaleInstance(2, 1));
panel.add(button);
JFrameEx frame = new JFrameEx();
frame.setLayout(null);
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(0.5);
frame.center();
frame.setVisible(true);
}
});
}
}
draws the following:
while left half of the button looks alive, and bigger part looks dead.
This is because different pars of API draws button with different approach.
Modified O'Reilly hack 51
Below is the code based on #lbalazscs's example, which shows that transformations don't work even if they are "in bounds"
public class BackwardsJButton extends JButton {
public BackwardsJButton(String text) {
super(text);
}
public void paint(Graphics g) {
if (g instanceof Graphics2D) {
Graphics2D g2 = (Graphics2D) g;
AffineTransform savedTransform = g2.getTransform();
AffineTransform flipTrans = new AffineTransform();
double widthD = (double) getWidth();
//flipTrans.setToTranslation(widthD, 0);
//flipTrans.scale(-2.0, 1);
flipTrans.scale(0.5, 1);
g2.transform(flipTrans);
super.paint(g);
g2.setTransform(savedTransform);
} else {
super.paint(g);
}
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
buildFrame();
}
});
}
private static void buildFrame() {
JFrame f = new JFrame("Test");
f.setLayout(new FlowLayout());
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.add(new BackwardsJButton("BackwardsJLabel"));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}
output follows (you may need to resize window and move mouse to see it, because Swing bug is located inside mouse hover code:
You have some innovative ideas how to abuse Swing :)
It is possible to apply affine transform while drawing components, but only if you are happy within the bounds of the component(for example you could mirror the text). If you override paint, you change how the component is drawn, but this will not change its size because the size depends on completely other variables, and you still cannot draw reliably outside its bounds.
I think it is not a good idea to transform the painting of premade components, because even if you succeed graphically, mouse clicks will be expected in the original places.
Note that you need to reset the transformation after you are done, because the same Graphics object will be used to paint other components.
AffineTransform savedTransform = g.getTransform();
g.setTransform(specialTransform);
... your drawing here
g.setTransform(savedTransform);
EDIT: here is a complete running example of a transformed component
import javax.swing.*;
import javax.swing.plaf.metal.MetalButtonUI;
import java.awt.*;
import java.awt.geom.AffineTransform;
public class ScaledButton extends JButton {
public ScaledButton(String text) {
super(text);
}
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
Color savedColor = g2.getColor();
g2.setColor(getBackground());
g2.fill(new Rectangle(0, 0, getWidth(), getHeight()));
g2.setColor(savedColor);
AffineTransform backup = g2.getTransform();
g2.scale(0.5, 1);
super.paintComponent(g);
g2.setTransform(backup);
}
#Override
protected void paintBorder(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
AffineTransform backup = g2.getTransform();
g2.scale(0.5, 1);
super.paintBorder(g);
g2.setTransform(backup);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
buildFrame();
}
});
}
private static void buildFrame() {
JFrame f = new JFrame("Test");
f.setLayout(new FlowLayout());
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.add(new ScaledButton("ScaledButton"));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}