We Keep Coding

Hide/Show an image drawn with Graphics

I have multiple images drawn with Graphics. How can I make them appear and disappear using a JCheckBox ?
private void drawImages(int index) {
Graphics g = mNew.getGraphics();
int x = index % this.width;
int y = index / this.width;
g.drawImage(imageLabelPixel.get(idImage-1), x, y, 100, 100, null);
}

You wouldn't use graphics to draw something on the screen you want to remove. Graphics just renders it on the screen along with all the other graphics you have drawn, It doesn't keep track of components
Your options are to add an action event to your checkbox and repaint the screen from scratch not drawing the image, or to just use a Label to draw the image and set it to invisible when the box is checked

I would do it like that:
JCheckBox cb = new JCheckBox();
ImgPanel p = new ImgPanel();
cb.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent evt){
if(cb.isSelected){
p.set(0);
} else {
p.set(-1);
}
}
});
.
public class ImgPanel extends JPanel {
private int i = 0;
private List<BufferedImage> imgs;
public ImgPanel(){
//init imgs
}
public void set(){
i = 0;
repaint();
}
#Override
public void paintComponent (Graphics g){
super.paintComponent(g);
if(i >= 0){
Image img = imgs.get(i-1);
Image img1 = img.getScaledInstance(100, 100, null);
}
g.drawImage(img1, 0, 0, null);
}
}
You can't simply draw on a graphic and then hand it to a compoennt or so (I don't really understand what your given code should have done). Instead you have to overwrite the paintComponent method of a Component and put your custom drawing code in there.

Java draw component on java.awtGraphics

I have a method that creates a buffered image and I want to be able to create a progress bar and then paint that onto the buffered image. Any idea how I can achieve this please?
public void paint() {
BufferedImage img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB);
Graphics g = img.getGraphics();
JProgressBar pb = new JProgressBar();
//Draw the progress bar on Graphics g ???
}

Yours appears to be an xy problem in that you really don't want to add or remove components inside of any painting method. I'm going to assume that you want to place a JProgressBar onto a component that shows an image, and to do this best, create a class that extends JPanel, override its paintComponent method, draw your image in that method override, and add your JProgressBar to that JPanel (but not within its paint or paintComponent method).
e.g.
public class MyPanel extends JPanel {
private BufferedImage image;
private JProgressBar progressBar = new JProgressBar();
public MyPanel() {
// get your image here
add(progressBar);
}
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();;
if (image == null) {
return size;
} else {
int w = Math.max(image.getWidth(), size.width);
int h = Math.max(image.getHeight(), size.height);
return new Dimension(w, h);
}
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null) {
g.drawImage(image, 0, 0, null);
}
}
}

How to set Background image in JDesktopPane

I want to set the background of the JDesktopPane (I add this JDesktopPane directly from the palette into the JFrame)
I try to override the method public void paintComponent (Graphics g) but it's not working
Here is the code:
JDesktop p = new JDesktop();
ImageIcon icon = new ImageIcon("images/Nénuphars6892.jpg");
final Image img = icon.getImage();
img.getScaledInstance(159, 207, Image.SCALE_SMOOTH);
p.principal = new JDesktopPane() {
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(img, 0, 0, getSize().width, getSize().height, this);
}
};
p.setVisible(true);

I resolve this problem by adding that on the creation of the JDesktopPane choosing customize code (variable principal) :
principal = new javax.swing.JDesktopPane()
{
ImageIcon icon = new ImageIcon("images/blue_digital_waves_abstract.jpg");
Image image = icon.getImage();
Image newimage = image.getScaledInstance(1500, 1000, Image.SCALE_SMOOTH);
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(newimage, 0, 0, this);
}
}
;

JDesktopPane desktopPane = new JDesktopPane() {
private final ImageIcon image = new ImageIcon("sample.jpg");;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int x = (desktopPane.getWidth() - image.getIconWidth()) / 2;
int y = (desktopPane.getHeight() - image.getIconHeight()) / 2;
g.drawImage(image.getImage(), x, y, this);
}
};

How to make the Panels on JLayeredPane transparent?

I have a JLayeredPane with 4 layers added to it. 1 base layer, which is opaque and three 'transparent' layers (setOpaque(false)).
The problem is that although the panels are drawn onto, with every refresh a gray color is shown. The same thing happens if there is no refresh happening. In other words, instead of showing whatever was drawn onto the base layer, a gray color is shown, I assume this is from one of the layers above.
Here is a SSCCE - I'm not sure if this is short enough but it shows my problem.
public class SSCCE extends JLayeredPane{
public static void main(String[] args){
JFrame frame = new JFrame();
frame.setSize(950, 600);
frame.add(new SSCCE());
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
// private fields
private boolean drawInitial = true;
private boolean drawn = false;
private JPanel overlay, base, iconPanel, middle;
private BufferedImage baseBuffer, midBuffer, overlayBuffer, iconBuffer;
private boolean updateInit = true;
private Rectangle2D stored = new Rectangle2D.Double(60, 60, 40, 100);
public SSCCE() {
setBorder(new LineBorder(Color.BLACK));
setDoubleBuffered(false);
setOpaque(true);
setSize(new Dimension(950, 600));
setPreferredSize(new Dimension(950, 600));
base = new JPanel();
base.setBackground(new Color(0,0,0,0));
base.setSize(new Dimension(getWidth(), getHeight()));
this.add(base, new Integer(0));
middle = new JPanel();
middle.setSize(new Dimension(getWidth(), getHeight()));
middle.setBackground(new Color(0,0,0,0));
middle.setOpaque(false);
this.add(middle, new Integer(1));
overlay = new JPanel();
overlay.setBackground(new Color(0,0,0,0));
overlay.setOpaque(false);
overlay.setSize(new Dimension(getWidth(), getHeight()));
this.add(overlay, new Integer(2));
iconPanel = new JPanel();
iconPanel.setBackground(new Color(0,0,0,0));
iconPanel.setSize(getWidth(), getHeight());
iconPanel.setOpaque(false);
this.add(iconPanel, new Integer(3));
}
public void update() {
if(updateInit){
checkBuffer();
updateInit = false;
}
drawInfoRect();
drawIcon();
highlightPath(stored);
}
public void render() {
if (drawInitial) {
Graphics2D baseGraphics = (Graphics2D) base.getGraphics();
baseGraphics.drawImage(baseBuffer, 0, 0, null);
}
setResistanceColor((Graphics2D)baseBuffer.getGraphics());
middle.getGraphics().drawImage(midBuffer, 0, 0, null);
iconPanel.getGraphics().drawImage(iconBuffer, 0, 0, null);
drawInfoRect();
base.getGraphics().drawImage(baseBuffer, 0, 0, null);
if (drawn) {
overlay.getGraphics().drawImage(overlayBuffer, 0, 0, null);
}
repaint();
}
// /**
// * draws the appropriate colour
// */
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
update();
render();
}
/**
* sets the appropriate colours according to the resistance
* #param g2
*/
private void setResistanceColor(Graphics2D g2) {
Rectangle2D sp = new Rectangle2D.Double(50,50, 50, 50);
g2.setColor(Color.GREEN);
g2.fill(sp);
g2.setColor(Color.BLACK);
}
/**
* checks if there already exists an image to buffer with
*/
private void checkBuffer() {
if (baseBuffer == null) {
baseBuffer = (new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB));
// background color
Graphics2D g2 = (Graphics2D) baseBuffer.getGraphics();
g2.setColor(Color.decode("#729fcf"));
Rectangle2D rect = new Rectangle2D.Double(0, 0, baseBuffer.getWidth(), baseBuffer.getHeight());
g2.fill(rect);
}
if (midBuffer == null) {
midBuffer = (new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB));
// background color
Graphics2D g2 = (Graphics2D) midBuffer.getGraphics();
g2.setColor(Color.RED);
Rectangle2D rect = new Rectangle2D.Double(0, 0, midBuffer.getWidth(), midBuffer.getHeight());
g2.fill(rect);
}
if (overlayBuffer == null) {
overlayBuffer = (new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB));
}
if (iconBuffer == null) {
iconBuffer = (new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB));
}
}
public void highlightPath(Shape enlighten) {
Area area = new Area();
area.add(new Area(enlighten));
// clearing image before drawing
Graphics2D midBufferG = (Graphics2D) midBuffer.getGraphics();
clearImage(midBufferG);
midBufferG.setColor(Color.white);
// adds a transparent overlay
midBufferG.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.50f));
midBufferG.fill(area);
}
public void drawIcon() {
Graphics2D iconG = (Graphics2D) iconBuffer.getGraphics();
clearImage(iconG);
}
public void drawInfoRect() {
Graphics2D graph = (Graphics2D) overlayBuffer.getGraphics();
Rectangle2D visible = getVisibleRect();
int boxX = (int) (visible.getX() + 50);
int boxY = (int) (visible.getY() + 450);
RoundRectangle2D rect = new RoundRectangle2D.Double(boxX, boxY, 200, 150, 25, 25);
graph.setColor(Color.decode("#729fcf").darker());
graph.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.4f));
graph.fill(rect);
graph.setColor(Color.BLACK);
drawn = true;
}
private void clearImage(Graphics2D graph){
graph.setComposite(AlphaComposite.Clear);
graph.fillRect(0, 0, overlayBuffer.getWidth(), overlayBuffer.getHeight());
graph.setComposite(AlphaComposite.SrcOver);
}
}
It might be some basic mistake I made. Thanks for your help!

One of the previously suggested answers actually solved my question, but for some reason they deleted their answer.
Setting the Background of my panels to setBackground(new
Color(0,0,0,0)); solved my problems.
According to the person that suggested this, the cause of that is the fact that JComponent may or may not draw transparent if not explicitly specified.
Thanks again!

java resize image dynamically to fit grids in gridlayout

I want to make a chess type board using a custom subclass of JButton. My problem is that my images of the chess pieces are a bit too small. Is there a way I can get the image to scale to exactly the size of each grid in my gridlayout? If I resize the Jframe, the grids will change size as well. Is there a way to get the image to resize dynamically upon resizing of the whole frame?

You have 3 option for this
1) Resize the images themselves using Gimp, Photoshop, etc.
2) Create an icon dynamically
Image i = icon.getImage();
if(i != null){
int width = (int)(size * fraction);
int height =(int)(size*icon.getIconHeight()/icon.getIconWidth()*fraction);
miniature = new ImageIcon(i.getScaledInstance(width, height, Image.SCALE_SMOOTH));
}
3) on the paint of your frame you can use scale
private void scaledDrawing(Graphics g, float scale){
Graphics2D g2 = (Graphics2D) g;
AffineTransform at = new AffineTransform();
AffineTransform save = g2.getTransform();
at.setToIdentity();
at.scale(goa.getScale().x, goa.getScale().y);
g2.transform(at);
image.paintIcon(c, g2);
g2.setTransform(save);
}

You could apply some transformation to the images but it might look a little ugly. If the images are small enough, maybe you can just force a minimum size of the button so that a scrollbar will appear if the frame is sized really small. Another option might be to have two or three different sets of the images at nicely scaled sizes, and swap them out for different board sizes.

Another alternative will be to override the paint function to fill all the available place:
#Override
public final void paint(final Graphics g) {
super.paint(g);
g.drawImage(image, 0, 0, getWidth(), getHeight(), this);
}
Here is an example:
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Image;
public final class Tileset extends Component {
private Image image;
public Tileset(final Image image) {
this.image = image;
}
#Override
public final void paint(final Graphics g) {
super.paint(g);
g.drawImage(image, 0, 0, getWidth(), getHeight(), this);
}
public final Image getImage() {
return (image);
}
public final void setImage(final Image image) {
this.image = image;
}
}
With:
import javax.swing.JPanel;
import java.awt.GridLayout;
public final class Map extends JPanel {
public Map(final GridLayout layout) {
setLayout(layout);
}
public Map(final Integer width, final Integer height) {
this(new GridLayout(width, height));
}
}
And:
final Map map = new Map(13, 17);
final Image grass = new ImageIcon("src/main/res/tilesets/grass1.png").getImage();
final Image wood = new ImageIcon("src/main/res/tilesets/wood1.png").getImage();
final Image rock = new ImageIcon("src/main/res/tilesets/rock1.png").getImage();
for (int i = 0; i != 13; ++i) {
for (int j = 0; j != 17; ++j) {
if (i % 2 == 0) {
if (j % 2 == 0)
map.add(new Tileset(grass), i, j);
else
map.add(new Tileset(rock), i, j);
}
else
map.add(new Tileset(wood), i, j);
}
}
That will give you: