How to make the JFrame contentPane transparent but the JFrame visible? - java

I wanted to know how to make the JFrame's contentPane transparent but the JFrame visible. I saw many pages but all showed on how to make the JFrame border visible but the contentPane visible.
I tried using setOpacity() but that requires the JFrame to be undecorated.
Are there any methods that I can achieve this?

Swing was not designed to paint with transparent backgrounds. You cannot create a transparent contentPane. However, you can fake a transparent background.
Here's a screenshot showing a fake transparent background. I cropped and reduced the image by 50% to get it to display in this answer.
So, how did I do this?
I took a snapshot of the background and painted the background on the JPanel.
This only works if you do not change the background while you're displaying your JFrame. If you change the background by opening or closing any other applications, this fake will not work.
You can move the JFrame around. Do not move the JFrame close to the edge of the screen, or you'll ruin the illusion.
Iconifying and deiconifying the JFrame works, but the illusion becomes obvious.
You can resize, maximize, and restore the JFrame.
It requires a lot of code to make this fake work properly.
Here's the complete runnable code. I made all the additional classes inner classes so I could post this code as one block.
import java.awt.AWTException;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TransparentJPanelView implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new TransparentJPanelView());
}
private DrawingPanel drawingPanel;
private JFrame frame;
private TransparentJPanelModel model;
public TransparentJPanelView() {
this.model = new TransparentJPanelModel();
this.drawingPanel = new DrawingPanel(model);
}
#Override
public void run() {
this.frame = new JFrame("Fake Transparent JPanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.addComponentListener(new FrameComponentListener(this, model));
FrameListener listener = new FrameListener(this, model);
frame.addWindowListener(listener);
frame.addWindowFocusListener(listener);
frame.addWindowStateListener(listener);
frame.add(drawingPanel, BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public void repaint() {
drawingPanel.repaint();
}
public JFrame getFrame() {
return frame;
}
public class DrawingPanel extends JPanel {
private static final long serialVersionUID = 1L;
private TransparentJPanelModel model;
public DrawingPanel(TransparentJPanelModel model) {
this.model = model;
this.setLayout(new FlowLayout());
this.setPreferredSize(new Dimension(600, 300));
JButton button = new JButton("Click me");
this.add(button);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Point point = new Point(this.getLocation());
SwingUtilities.convertPointToScreen(point, this);
Image image = model.getSubImage(point.x, point.y, getWidth(), getHeight());
g.drawImage(image, 0, 0, this);
}
}
public class FrameComponentListener extends ComponentAdapter {
private final TransparentJPanelView view;
private final TransparentJPanelModel model;
public FrameComponentListener(TransparentJPanelView view,
TransparentJPanelModel model) {
this.view = view;
this.model = model;
}
#Override
public void componentResized(ComponentEvent event) {
view.repaint();
}
#Override
public void componentMoved(ComponentEvent event) {
view.repaint();
}
}
public class FrameListener extends WindowAdapter {
private final TransparentJPanelView view;
private final TransparentJPanelModel model;
public FrameListener(TransparentJPanelView view,
TransparentJPanelModel model) {
this.view = view;
this.model = model;
}
#Override
public void windowDeiconified(WindowEvent event) {
model.setBackground();
view.repaint();
}
}
public class TransparentJPanelModel {
private BufferedImage background;
private final Rectangle screenRect;
private final Robot robot;
public TransparentJPanelModel() {
this.robot = createRobot();
this.screenRect = new Rectangle(
Toolkit.getDefaultToolkit().getScreenSize());
setBackground();
}
private Robot createRobot() {
Robot robot = null;
try {
robot = new Robot();
} catch (AWTException e) {
e.printStackTrace();
}
return robot;
}
public void setBackground() {
this.background = robot.createScreenCapture(screenRect);
}
public Image getSubImage(int x, int y, int width, int height) {
if (x < 0) {
x = 0;
width = Math.min(width, screenRect.width);
}
if (y < 0) {
y = 0;
height = Math.min(height, screenRect.height);
}
if (x + width > screenRect.width) {
width = screenRect.width - x;
}
if (y + height > screenRect.height) {
height = screenRect.height - y;
}
return background.getSubimage(x, y, width, height);
}
}
}

You can use setVisible(false) method for each element that is inside that JFrame. You use this in the intialize() method. Once you want them to be shown (for example after some button is clicked) than you will use the same method setVisible(true).

Related

Clicking a button within a JFrame passes an data to a JPanel

I have a Jframe with two buttons: '1' and '2'. Clicking the button '1' should display the capital letter A in the JPanel.
Code fore my JFrame:
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DrawFrame extends JFrame{
private final int WIDTH = 500;
private final int HEIGHT = 300;
private JButton number1;
private JButton number2;
private JPanel numberPanel;
private DrawPanel graphicsPanel;
public DrawFrame()
{
createSelectionPanel();
createGraphicsPanel();
this.setSize(WIDTH, HEIGHT);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
private void createSelectionPanel()
{
numberPanel = new JPanel();
number1 = new JButton("1");
number2 = new JButton("2");
numberPanel.setLayout(new GridLayout(2,2));
numberPanel.add(number1);
numberPanel.add(number2);
this.add(numberPanel, BorderLayout.WEST);
}
private void createGraphicsPanel()
{
//instantiate drawing panel
graphicsPanel = new DrawPanel();
//add drawing panel to right
add(graphicsPanel);
}
private class Number1ButtonListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
Number number = new Number();
number.setNumber('A');
}
}
//creates a drawing frame
public static void main(String[] args)
{
DrawFrame draw = new DrawFrame();
}
}
Code for my JPanel
import javax.swing.JPanel;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
public class DrawPanel extends JPanel{
public Coordinates current;
public DrawPanel(){
//nothing drawn initially
current = null;
//set white background for drawing panel
setBackground(Color.WHITE);
//add mouse listeners
MouseHandler mouseHandler = new MouseHandler();
this.addMouseListener(mouseHandler);
this.addMouseMotionListener(mouseHandler);
}
public void paint(Graphics g){
super.paint(g);
if(current!=null){
I want to replace "A" with number.getNumber()
g.drawString("A", current.getX(), current.getY());
}
}
//class to handle all mouse events
private class MouseHandler extends MouseAdapter implements MouseMotionListener
{
public void mousePressed(MouseEvent event)
{
current = new Coordinates(event.getX(), event.getY());
}
public void mouseReleased(MouseEvent event)
{
repaint();
}
}
}
I'm not sure if this is possible. So sorry if I am mistaken in my logic. Please provide an alternate way for me to approach this problem. Appreciate any guidance.
Thanks!
The Coordinates and Number classes weren't included, so I had to modify the code somewhat.
Here's the GUI I created.
The first thing I did was create a model class for the GUI. By creating a model class, I could make the display string and the drawing coordinate available to the view and the controller classes. This is a simple example of the model / view / controller pattern.
package com.ggl.drawing;
import java.awt.Point;
public class GUIModel {
private String displayString;
private Point coordinate;
public GUIModel(String displayString) {
this.displayString = displayString;
}
public Point getCoordinate() {
return coordinate;
}
public void setCoordinate(int x, int y) {
this.coordinate = new Point(x, y);
}
public void setCoordinate(Point coordinate) {
this.coordinate = coordinate;
}
public void setDisplayString(String displayString) {
this.displayString = displayString;
}
public String getDisplayString() {
return displayString;
}
}
Now that we have a model, lets look at the DrawFrame class.
package com.ggl.drawing;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class DrawFrame implements Runnable {
private final int WIDTH = 500;
private final int HEIGHT = 300;
private JFrame frame;
private GUIModel model;
public DrawFrame() {
this.model = new GUIModel("A");
}
#Override
public void run() {
frame = new JFrame("Draw Letters");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createSelectionPanel(), BorderLayout.WEST);
frame.add(new DrawPanel(WIDTH, HEIGHT, model), BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
private JPanel createSelectionPanel() {
JPanel numberPanel = new JPanel();
ButtonListener listener = new ButtonListener();
JButton number1 = new JButton("A");
number1.addActionListener(listener);
JButton number2 = new JButton("B");
number2.addActionListener(listener);
numberPanel.setLayout(new GridLayout(0, 2));
numberPanel.add(number1);
numberPanel.add(number2);
return numberPanel;
}
private class ButtonListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent event) {
model.setDisplayString(event.getActionCommand());
}
}
// creates a drawing frame
public static void main(String[] args) {
SwingUtilities.invokeLater(new DrawFrame());
}
}
I started the Java Swing application on the Event Dispatch thread with the call to the SwingUtilities invokeLater method.
I separated the JFrame construction from the 2 JPanels construction. I used a JFrame, rather than extend a JFrame. The only time you should extend any Java class is if you want to override one or more of the class methods.
I used the same ButtonListener for both JButtons. I'm guessing what you want, but I drew either an "A" or a "B", depending on which button you left clicked.
Let's look at the DrawPanel class.
package com.ggl.drawing;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JPanel;
public class DrawPanel extends JPanel {
private static final long serialVersionUID = 3443814601865936618L;
private GUIModel model;
public DrawPanel(int width, int height, GUIModel model) {
this.setPreferredSize(new Dimension(width, height));
this.model = model;
// add mouse listeners
MouseHandler mouseHandler = new MouseHandler();
this.addMouseListener(mouseHandler);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (model.getCoordinate() != null) {
Point p = model.getCoordinate();
Font font = g.getFont().deriveFont(48F);
g.setFont(font);
g.drawString(model.getDisplayString(), p.x, p.y);
}
}
// class to handle all mouse events
private class MouseHandler extends MouseAdapter {
#Override
public void mousePressed(MouseEvent event) {
model.setCoordinate(event.getPoint());
}
#Override
public void mouseReleased(MouseEvent event) {
DrawPanel.this.repaint();
}
}
}
The major change I made in this class was to use the paintComponent method, rather than the paint method. The paintComponent method is the correct method to override.
I set the size of the drawing panel in the DrawPanel constructor. It's much better to let Swing figure out the size of the JFrame. That's what the pack method in the DrawFrame run method does.
I increased the font size so you can see the drawn letter better.
I removed the mouse motion listener code, as it wasn't needed.
I hope this was helpful to you.
OK, all I know so far is that you want the text displayed in a JPanel to change if a button is pressed. If so, then your code looks to be way too complex for the job. Suggestions include:
Give the DrawingPanel a setter method, say, setText(String text), that allows outside classes to change the text that it displays.
Within that method, set a field of DrawingPanel, say called text, and call repaint().
Override DrawingPanel's paintComponent not its paint method, and call the super's method within your override.
Within the paintComponent method, call drawString to draw the String held by the text field, if the field is not null.
Give your buttons ActionListeners or AbstractActions that call the DrawingPanel's setText(...) method, setting the text to be displayed.
For example:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class DrawAorB extends JPanel {
private DrawingPanel drawingPanel = new DrawingPanel();
public DrawAorB() {
JPanel btnPanel = new JPanel(new GridLayout(1, 0, 5, 5));
btnPanel.add(new JButton(new ButtonAction("A")));
btnPanel.add(new JButton(new ButtonAction("B")));
setLayout(new BorderLayout());
add(drawingPanel, BorderLayout.CENTER);
add(btnPanel, BorderLayout.PAGE_END);
}
private class ButtonAction extends AbstractAction {
public ButtonAction(String name) {
super(name);
}
#Override
public void actionPerformed(ActionEvent e) {
String text = e.getActionCommand();
drawingPanel.setText(text);
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("DrawAorB");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new DrawAorB());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class DrawingPanel extends JPanel {
private static final int PREF_W = 200;
private static final int PREF_H = PREF_W;
private String text = null;
public void setText(String text) {
this.text = text; // set the JPanel's text
repaint(); // and draw it
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (text != null) {
int x = getWidth() / 2;
int y = getHeight() / 2;
// use FontMetrics if you want to center text better
g.drawString(text, x, y);
}
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
}
Even simpler, easier, and probably better would be to display the text within a JLabel as it's much easier to center this text.

Component won't display unless window is resized - Java

I have problem with image visibility after click the button. I have the main class with frame:
package superworld;
import java.awt.*;
import javax.swing.*;
public class SuperWorld {
public static void main(String[] args) {
JFrame frame= new JFrame();
frame.setSize(1050,650);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new SuperPanel());
frame.setVisible(true);
// frame.setResizable(false);
}
}
Then I have class with Panel with all components:
package superworld;
import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.Timer;
public class SuperPanel extends JPanel implements ActionListener{
Timer mainTimer;
public static final int HEIGHT = 550;
public static final int WIDTH = 1050;
int i;
int w=-100;
int h=-50;
ArrayList<SuperMiasto> miasta = new ArrayList<SuperMiasto>();
private JButton heroButton;
private JButton cywilButton;
public SuperPanel() {
mainTimer = new Timer(10,this);
heroButton = new HeroButton(this);
cywilButton = new CywilButton(this);
setLayout(null);
setPreferredSize(new Dimension(WIDTH, HEIGHT));
setBackground(Color.GREEN);
for(i=0;i<10;i++)
{
miasta.add( new SuperMiasto() );
miasta.get(i).x=w;
miasta.get(i).y=h;
miasta.get(i).imagelabel = new JLabel(miasta.get(i).image);
miasta.get(i).imagelabel.setBounds(miasta.get(i).x,miasta.get(i).y,miasta.get(i).image.getIconWidth(),miasta.get(i).image.getIconHeight());
add(miasta.get(i).imagelabel);
w=w+200;
if (w > WIDTH-200)
{
h=h+200;
w=-100;
}
}
}
public void paint(Graphics g){
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
add(heroButton);
add(cywilButton);
}
public void actionPerformed(ActionEvent e) {
repaint();
}
}
And Class with button with add new object with image:
package superworld;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class HeroButton extends JButton implements ActionListener {
private JPanel buttonPanel;
HeroButton(JPanel buttonPanel) {
super("Dodaj hero");
this.buttonPanel = buttonPanel;
setBounds(0,500,150,50);
addActionListener(this);
}
#Override
public void actionPerformed(ActionEvent e) {
SuperLudzie batman = new SuperLudzie();
batman.imagelabel = new JLabel(batman.image);
batman.imagelabel.setBounds(50,50,batman.image.getIconWidth(),batman.image.getIconHeight());
buttonPanel.add(batman.imagelabel);
}
}
And class of this SuperLudzie:
package superworld;
import java.awt.*;
import javax.swing.*;
public class SuperLudzie {
private String imie;
private int zycie;
private int inteligencja;
private int wytrzymalosc;
private int sila;
private int umiejetnosci_walki;
private int x,y;
ImageIcon image = new ImageIcon("C:/Users/Zuzanna Sawala/Moje dokumenty/NetBeansProjects/SuperWorld/mysz.jpg");
JLabel imagelabel;
}
Everything work great. I have only problem with this object and image created by button it's not visible just after clicking but after i resize a window. I know that it have something to do with setVisibility(true); but i'm not sure where to use it.
Use SwingUtilities.invokeLater() or EventQueue.invokeLater() to make sure that EDT is initialized properly.
Use overridden paintComponent() method instead of paint()
class SuperPanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
...
}
#Override
public Dimension getPreferredSize() {
return new Dimension(..., ...);
}
}
Read more points...
Try to avoid null layout and use proper layout that suits as per our need.
Please have a look at How to Use Various Layout Managers that has sole responsibilities for positioning and sizing of the components.

Background image in java swing issue

I've made a Jpanel with a background image and a Jbutton also with its background. The problem is that background sometimes is loaded sometimes no.
public class Window extends JFrame {
public static JFrame createwindow() {//fare singleton
JFrame frame = new JFrame("Battaglia navale");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(740, 740);
frame.setVisible(true);
frame.setResizable( false );
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
frame.setLocation(((int)dim.getWidth()-(int)frame.getWidth())/2, ((int)dim.getHeight()-(int)frame.getHeight())/2);
return frame;
}
}
public class StartWindow {
JFrame frame;
private JButton button;
private JButton button2;
final String button_start = "img/start.png";
ImageIcon start = new ImageIcon(button_start);
public void CreateStartWindow() {
frame = Window.createwindow();
Container container = frame.getContentPane();
JpanelStart panel = new JpanelStart();
container.add(panel);
this.button = new JButton(start);
button.setActionCommand("start");
button.setHideActionText(true);
button.setOpaque(false);
button.setFocusPainted(false);
button.setBorderPainted(false);
button.setContentAreaFilled(false);
this.button2 = new JButton("Classifica");
panel.add(button);
panel.add(button2);
frame.setVisible(true);
}
public void addActionListener(ActionListener al) {
this.button.addActionListener(al);
this.button2.addActionListener(al);
}
public void chiudi() {
frame.dispose();
}
}
class JpanelStart extends JPanel {
private Image img;
private String path_img = "img/sfondo.jpg";
public JpanelStart() {
img = Toolkit.getDefaultToolkit().createImage(path_img);
loadImage(img);
}
private void loadImage(Image img) {
try {
MediaTracker track = new MediaTracker(this);
track.addImage(img, 0);
track.waitForID(0);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
#Override
protected void paintComponent(Graphics g) {
setOpaque(false);
g.drawImage(img, 0, 0, this);
super.paintComponent(g);
}
}
super.paintComponet should go right after the method signature.
you set the button opacity to false, so it won't be seen.
Run your program from the Event Dispatch Thread.
public static void main(String[] args){
SwingUtilities.invokeLater(new Runnable(){
public void run() {
new StartWindow().CreateStartWindow();
}
});
}
In your method, you're making the frame visible before adding anything. Leave that out in the method
Don't set the size of the frame. Instead override the getPrefereedSize() of the JPanel and call pack() on the frame.
IMO, I see no use at all for this so-called helper method. I would toss it out the window
You should load your image as an embedded resource, and not from the file system.
img = ImageIO.read(StartWindow.class.getResource(path_img));
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.event.ActionListener;
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.JPanel;
import javax.swing.SwingUtilities;
public class StartWindow {
JFrame frame;
private JButton button;
private JButton button2;
final String button_start = "img/start.png";
ImageIcon start = new ImageIcon(button_start);
public void CreateStartWindow() throws IOException {
frame = Window.createwindow();
Container container = frame.getContentPane();
JpanelStart panel = new JpanelStart();
container.add(panel);
this.button = new JButton(start);
button.setActionCommand("start");
button.setHideActionText(true);
button.setOpaque(false);
button.setFocusPainted(false);
button.setBorderPainted(false);
button.setContentAreaFilled(false);
this.button2 = new JButton("Classifica");
panel.add(button);
panel.add(button2);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args){
SwingUtilities.invokeLater(new Runnable(){
public void run() {
try {
new StartWindow().CreateStartWindow();
} catch (IOException ex) {
Logger.getLogger(StartWindow.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
}
public void addActionListener(ActionListener al) {
this.button.addActionListener(al);
this.button2.addActionListener(al);
}
public void chiudi() {
frame.dispose();
}
}
class Window {
public static JFrame createwindow() {//fare singleton
JFrame frame = new JFrame("Battaglia navale");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
return frame;
}
}
class JpanelStart extends JPanel {
private static final int D_W = 700;
private static final int D_H = 700;
private Image img;
private String path_img = "/images/logo.gif";
public JpanelStart() throws IOException {
img = ImageIO.read(StartWindow.class.getResource(path_img));
loadImage(img);
}
private void loadImage(Image img) {
try {
MediaTracker track = new MediaTracker(this);
track.addImage(img, 0);
track.waitForID(0);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, D_W, D_W, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(D_W, D_H);
}
}
**Shows Up Every time **
draw the image after super.paintComponent(g) (which draws the component that you want to draw on top of)
call repaint() in loadImage() after the image is set (so that it redraws it)
loadImage() doesn't seem to be setting the img variable does it need to?
(not essential but recommended) you should also move UI changes into the EDT (Event Dispatch Thread).
Example of running a UI task on EDT
This puts UI operations on a queue so that all UI changes are made from the same thread and avoid interference.
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
//UI Operations
}
} );

Can not draw using paintComponent if added to Jpanel but works fine in JFrame

I want to paint simple oval. In the following code, if I add draw a oval on Jpanel then it doesn't work however it works fine if I draw on frame. Following is the code which works.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class Controller {
public Controller() {
View view = new View();
Model model = new Model(100, 100, 100, 100);
view.paintModel(model);
}
public static void main(String[] args) {
Controller c = new Controller();
}
public class View extends JFrame {
private JPanel jpanel;
public View() {
this.setBounds(0, 0, 500, 500);
this.setLayout(new BorderLayout());
jpanel = new JPanel();
jpanel.setBackground(Color.WHITE);
jpanel.setLayout(null);
this.add(jpanel, BorderLayout.CENTER);
this.setVisible(true);
this.validate();
}
public void paintModel(Model model) {
jpanel.add(new ModelView(model));
jpanel.validate();
jpanel.repaint();
}
}
public class Model {
public int xPos;
public int yPos;
public int height;
public int width;
public Model(int xPos, int yPos, int height, int width) {
super();
this.xPos = xPos;
this.yPos = yPos;
this.height = height;
this.width = width;
}
}
public class ModelView extends JComponent {
private Model model;
public ModelView(Model model) {
super();
setBorder(new LineBorder(Color.RED));
this.model = model;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(model.xPos + model.width, model.yPos
+ model.height);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.black);
g.fillOval(model.xPos, model.yPos, model.width, model.height);
}
}
}
First of all, you are not calling super.paintComponent in you ModelView class, this is incredibly important, especially when dealing with transparent components like JComponent
Secondly, you've provide no layout information of the ModelView, that is, the component has no preferred, minimum or maximum size hint, so many of the layout managers will consider it to have a size of 0x0, which is what is happening here.
JPanel by default uses FlowLayout which will use the components preferred size to lay it out.
Update the ModelView to provide some sizing hints (in most cases, overriding getPreferredSize should be sufficient) or use a different layout manager on the JPanel you are adding the ModelView to which doesn't care about such things (like BorderLayout for example)
Updated
Additionally, you "may" be painting beyond the visual bounds of the component, for example, you create a model using, Model model = new Model(100, 100, 100, 100) then you render that model using g.fillOval(model.xPos, model.yPos, model.width, model.height), but the preferredSize of your component is only new Dimension(model.width, model.height), you are actually painting your oval at the right, lower edge (outside) of the component
Unless you intend to write you own layout manager to manage this, you should be taking the x/y offset into account when calculating the preferred size of the component, for example, new Dimension(model.xPos + model.width, model.yPos + model.height)
For example...sorry, I butchered your code a little to seed the model...
The red line is just a LineBorder which shows the boundaries of the ModelView component
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
public class View extends JFrame {
private JPanel jpanel;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
new View();
}
});
}
public View() {
this.setBounds(0, 0, 500, 500);
this.setLayout(new BorderLayout());
jpanel = new JPanel();
jpanel.setBackground(Color.WHITE);
this.add(jpanel, BorderLayout.CENTER);
Model model = new Model(100, 100, 100, 100);
paintModel(model);
this.setVisible(true);
}
public void paintModel(Model model) {
jpanel.add(new ModelView(model));
jpanel.validate();
jpanel.repaint();
}
public class ModelView extends JComponent {
private Model model;
public ModelView(Model model) {
super();
setBorder(new LineBorder(Color.RED));
this.model = model;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(model.xPos + model.width, model.yPos + model.height);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.black);
g.fillOval(model.xPos, model.yPos, model.width, model.height);
}
}
public class Model {
public int xPos;
public int yPos;
public int height;
public int width;
public Model(int xPos, int yPos, int height, int width) {
super();
this.xPos = xPos;
this.yPos = yPos;
this.height = height;
this.width = width;
}
}
}

How to fit ImageIcon within JButton borders

I want to color some JButtons, some other questions here showed me, that it would be easier
to paint a little image (did it with gimp) and set it as icon for the JButton.
The number and size of the buttons should be variable (they're in a grid), so I want a high res image that I can scale how i need it.
The problem now is, I don't know how to 'cut the edges' of the icon, because the buttons have rounded edges.
Here you can see that the image is not inside of the button border.
And here is my method in the class that extends JButton.
public void setYellow() {
URL u = getClass().getResource("/img/yellow.png");
ImageIcon i = new javax.swing.ImageIcon(u);
//Image img = i.getImage();
//img = img.getScaledInstance(size, size, java.awt.Image.SCALE_SMOOTH);
//i = new ImageIcon(img);
setIcon(i);
}
EDIT
package test;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.URL;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import control.Control;
import view.Field;
import view.View;
public class HelloWorldSwing {
/**
* #param args
*/
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
TestView.initialize();
}
});
}
}
class TestView {
private static TestView view = new TestView();
public static TestView getView() {
return view;
}
private TestView() {
JFrame frame = new JFrame("HelloWorldSwing");
frame.setLayout(new GridLayout(0,3));
int buttonSize = 40;
frame.getContentPane().add(new MyButton(buttonSize));
frame.getContentPane().add(new MyButton(buttonSize));
frame.getContentPane().add(new MyButton(buttonSize));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
public static void initialize() {
}
}
class MyButton extends JButton {
int size;
public MyButton(int size) {
this.size = size;
setPreferredSize(new Dimension(size, size));
this.addActionListener(new ButtonHandler());
setBorder(LineBorder.createGrayLineBorder());
setOpaque(true);
}
public void setYellow() {
//URL u = getClass().getResource("/img/test.png"); // 64x64 png pic
URL u1 = null;
try {
u1 = new URL("http://assets1.qypecdn.net/uploads/users/0195/7210"
+ "/calvin_yellow_original_thumb.jpg");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ImageIcon i = new javax.swing.ImageIcon(u1);
// Image img = i.getImage();
// img = img.getScaledInstance(size, size, java.awt.Image.SCALE_SMOOTH);
// i = new ImageIcon(img);
setIcon(i);
// setBorderPainted(false);
// setContentAreaFilled(false); did not help
}
}
class ButtonHandler implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
MyButton mb = (MyButton) e.getSource();
mb.setYellow();
}
}
EDIT 2
Here are the pictures where the lines in setYellow()
setBorderPainted(false);
setContentAreaFilled(false);
are not commented out (unfortunately there is no difference)
Before button is clicked:
After button is clicked:
UPDATE
I added Borders to the MyButton constructor
setBorder(LineBorder.createGrayLineBorder());
and now the icons are inside the button borders. I added pictures.
But as you can see, we don't have these rounded button edges anymore.
button.setBorderPainted(false);
button.setContentAreaFilled(false);
As seen in this answer.
Update
I do not quite get what you are trying to achieve if not this.
I made the rollover icon to be orange so that we could easily see the size of one button, but otherwise I put 4 in a row to ensure the minimum frame width did not insert extra space between the buttons in a row.
import java.awt.*;
import java.awt.Image;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class HelloWorldSwing {
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
TestView.getView();
}
});
}
}
class TestView {
private static TestView view = new TestView();
public static TestView getView() {
return view;
}
private TestView() {
JFrame frame = new JFrame("HelloWorldSwing");
frame.setLayout(new GridLayout(3,4));
int buttonSize = 40;
for (int i=0; i<12; i++) {
frame.getContentPane().add(new MyButton(buttonSize));
}
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
public static void initialize() {
}
}
class MyButton extends JButton {
int size;
public MyButton(int size) {
this.size = size;
setPreferredSize(new Dimension(size, size));
this.addActionListener(new ButtonHandler());
setOpaque(true);
setYellow();
}
public Image getImage(int sz, Color color) {
BufferedImage bi = new BufferedImage(sz,sz,BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
g.setColor(color);
g.fillRect(0, 0, sz, sz);
g.dispose();
return bi;
}
public void setYellow() {
Image img = getImage(64, Color.YELLOW).getScaledInstance(size, size, java.awt.Image.SCALE_SMOOTH);
setIcon(new ImageIcon(img));
Image rollover = getImage(64, Color.ORANGE).getScaledInstance(size, size, java.awt.Image.SCALE_SMOOTH);
setRolloverIcon(new ImageIcon(rollover));
setBorderPainted(false);
setContentAreaFilled(false);
}
}
class ButtonHandler implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
MyButton mb = (MyButton) e.getSource();
mb.setYellow();
}
}

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