I've created a JFrame.
Inside this JFrame, I've created a JPanel.
Inside this JPanel I've created another JPanel (lets call it "A").
I've drawn in "A" a rectangle, and wanted to create buttons using graphics.
There is no rectangle in my gui. I could see that the paintComponent() method inside "A" is not being invoked.
Code:
The JPanels: (the child JPanel is inner class)
public class MemoryPanel extends JPanel {
public MemoryPanel(){
setPreferredSize(new Dimension(350,448));
}
#Override
public void paintComponent(Graphics g) {
//POSITIONING
setLayout(new BorderLayout());
//CREATE MEMORY BUTTONS
MemButton a=new MemButton();
//Drawing Rectangles for Memory
add(a,BorderLayout.CENTER);
}
private class MemoryButton extends JPanel{
public MemoryButton(){
setLayout(null);
setPreferredSize(new Dimension(87,40));
}
#Override
public void paintComponent(Graphics g){
Graphics2D td= (Graphics2D)g;
td.drawRect(0, 0, 20, 20);
}
}
}
You should program the JButtons first in order for your graphics to work as buttons. I belive this post will help you with that:
Creating a custom button in Java
I you want a rectangle to be the background for your buttons you can draw it in your main panel and add the buttons on it. Try using different Layouts to mantain some order.
I've made a simple GUI to test your code and the rectangle appears correctly.
I made no relevant changes in the code that you posted.
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class SimpleJFrameProgram extends JFrame {
private static final long serialVersionUID = 1L;
public SimpleJFrameProgram() {
super("TEST");
initComponents();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.pack();
this.setLocationRelativeTo(null);
this.setVisible(true);
}
private void initComponents() {
MemoryPanel memoryPanel = new MemoryPanel();
this.add(memoryPanel);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
new SimpleJFrameProgram();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
I've applyed minor changes to your MemoryPanel: replaced MemButton by your MemoryButton and fill the rectangle in red to improve its visibility for the test. Without this last change, the rectangle appears too.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;
public class MemoryPanel extends JPanel {
public MemoryPanel(){
setPreferredSize(new Dimension(350,448));
}
#Override
public void paintComponent(Graphics g) {
// POSITIONING
setLayout(new BorderLayout());
// CREATE MEMORY BUTTONS
MemoryButton a = new MemoryButton();
// Drawing Rectangles for Memory
add(a,BorderLayout.CENTER);
}
private class MemoryButton extends JPanel{
public MemoryButton(){
setLayout(null);
setPreferredSize(new Dimension(87,40));
}
#Override
public void paintComponent(Graphics g) {
Graphics2D td = (Graphics2D) g;
td.setColor(Color.red);
td.fillRect(0, 0, 20, 20);
}
}
}
This is the obtained result:
Maybe your problem is located on initializing the parent JFrame.
Changing the class name of MemoryButton fixed it.
I had another package with the same class name.
Related
I was trying to dysplay an object line by line where each line is an object. Then I use a box Layout but when I do so only the top layer (which is the last object called) is drawed how can I fiw this ?
here is a minimal exemple :
import javax.swing.*;
import java.awt.*;
public class Main {
public static void main(String[] args) {
MainFrame frame = new MainFrame();
}
}
private class MainFrame extends JFrame {
public MainFrame(){
setSize(600,400);
setLocationRelativeTo(null);
setVisible(true);
setContentPane(new Container());
}
}
private class Container extends JPanel {
public Container(){
setLayout(new BoxLayout(this,BoxLayout.Y_AXIS));
for(int i =0;i<10;i++){
add(new Line());
}
}
}
private class Line extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.green);
g.fillRect(getX(),getY(),getWidth(),getHeight());
}
}
here is what I've got :
and what I've expected :
Some test (the blue rectangle in the paint method of the JBackPannel class) showed me that somewhere something is drawing a white canvas, but I don't know where and why ...
here is a link to a minimal exemple
Custom painting is always done relative to the component, not the components location in the parent panel.
So:
g.fillRect(getX(),getY(),getWidth(),getHeight());
should be:
g.fillRect(0, 0, getWidth(), getHeight());
I searched all over the Internet but could not find out why the circle is appears to be distorted beyond the middle of the JFrame(sorry,no image because i needed 10 reputation to post images).
I checked my code but found no errors.I'm a newbie to java GUI programming .
This is my code so far:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class test1 extends JPanel implements MouseMotionListener
{
private static final long serialVersionUID = -2068330714634802982L;
public int Mousex,Mousey;
public void init()
{
addMouseMotionListener(this);
}
public void mouseMoved(MouseEvent e)
{
Mousex=e.getX();
Mousey=e.getY();
repaint();
}
public void mouseDragged(MouseEvent e){}
public void paintComponent(Graphics g)
{
Graphics2D g2=(Graphics2D)g;
g2.setColor(Color.GREEN);
g2.fillOval(Mousex,Mousey,50,50);
}
public static void main(String[] args)
{
test1 t=new test1();
JFrame frame=new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(1305,650);
frame.setLocationRelativeTo(null);
frame.getContentPane().add(t);
frame.setResizable(true);
frame.setVisible(true);
}
}
You need to call
t.init();
to register the MouseMotionListener. Also super.paintComponent(g); in the needs to be invoked in the paintComponent method to repaint the parent container otherwise the last rectangle wont be clearly visible.
You are never calling init() on your panel so you don't add the MouseMotionListener to the panel. Try adding
t.init();
after creating your panel object. Alternatively, add a constructor to your class that adds the MouseMotionListener instead, so it's adden right when you create an object of the class:
public test1 () {
addMouseMotionListener(this);
}
I've been struggling to get an image to show up for some time now. Ive read a few different things, and all of them seem to have different ways of showing images. Can someone tell me what I'm doing wrong? I'm trying to make a program that uses 2 classes to make a picture show up in a frame. I guess what I don't understand still is what a Graphics object is, what a Graphics2D object is and how its different, and what method from what class do I call in order to make an image show up. Here is my code:
public class Smiley {
private BufferedImage smileyFace;
private Graphics2D renderWindow;
private Dimension smileyPosition;
private File smileyFile;
public Smiley() {
try{
smileyFile = new File("C:\\Users\\MyName\\Desktop\\smiley.png");
smileyFace = ImageIO.read(smileyFile);
}
catch (Exception e){
System.out.println("There was an error finding or reading the file \" smiley.png.\"");
}
MainScreen.graphicPane.drawImage(smileyFace,50,50, null);
}
and the second class:
public class MainScreen extends JFrame{
public static MainScreen ms;
public static Graphics2D graphicPane;
public static void main (String[] args){
MainScreen ms = new MainScreen();
Smiley newSmiley = new Smiley();
}
public MainScreen(){
super("Main Screen Window");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setVisible(true);
this.setSize(500,800);
this.getContentPane().setBackground(Color.black);
graphicPane = (Graphics2D) this.getContentPane().getGraphics();
}
}
the program compiles with no errors and nothing is reported back to me about not finding the file.
Your going to need some sore of paint method. For that you will require a Component to paint on. You need to learn a GUI framework, like Swing. There are clear compoents you can paint on like a JPanel. With that panel you need to override its paintComponent method.
The Graphcics object is what the component uses to actually paint the graphic onto the component.
The Graphics2D object just extends the capabilities of the Graphics object.
You should take a look at the Swing tuorial and the **Graphics toturial
To get your program running though you would do something like this
public class DrawPanel extends JPanel {
BufferedImage smileyFace;
public DrawPanel() {
try{
smileyFile = new File("C:\\Users\\MyName\\Desktop\\smiley.png");
smileyFace = ImageIO.read(smileyFile);
}
catch (Exception e){
System.out.println("There was an error finding or reading the file \" smiley.png.\"");
}
}
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(smileyFace,50,50, this);
}
#Override
public Dimension getPreferredSize(){
return new Dimension(500, 500);
}
}
Then you can instantiate that panel in another class, adding it to a JFrame to run it
public class Main {
public static void main(String[] args) {
SwingUtiliites.invokeLater(new Runnable(){
public void run() {
JFrame frame = new JFrame();
frame.add(new DrawPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
});
}
}
You are calling this in your constructor for your Smiley class.
MainScreen.graphicPane.drawImage(smileyFace,50,50, null);
If you are going to paint the image yourself you need to override paintComponent() in a component that gets added to your main screen.
Or just add the image to a JLabel that you added to the main screen.
You draw image in wrong way.
For using drawImage() you need to use that in paintComponent() method of JComponent(for example JPanel), examine next code:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.beans.Transient;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Example extends JFrame {
public Example() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new Smiley());
frame.pack();
frame.setVisible(true);
}
public static void main(String args[]) {
new Example();
}
class Smiley extends JPanel{
private BufferedImage smileyFace;
Smiley(){
try {
File smileyFile = new File("C:\\Users\\MyName\\Desktop\\smiley.png");
smileyFace = ImageIO.read(smileyFile);
} catch (Exception e) {
System.out
.println("There was an error finding or reading the file \" smiley.png.\"");
}
}
#Override
#Transient
public Dimension getPreferredSize() {
return new Dimension(smileyFace.getWidth(),smileyFace.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(smileyFace, 0,0, this);
}
}
}
or you can add your image to JLabel and that do all for you, change Smile class like next:
class Smiley extends JPanel{
Smiley(){
ImageIcon icon = new ImageIcon("C:\\Users\\MyName\\Desktop\\smiley.png");
JLabel l = new JLabel(icon);
add(l);
}
}
ALso read more about customPaintings.
I have just started working with Swing and am trying to draw a button with a custom shape, a triangle in this example. I called the JButton subclass 'ShiftingButton' in the following code because of its unusual behavior. When the mouse enters its region, it is repainted with an offset from its original position. Furthermore the shifted, offset version is drawn in addition to the original position so that both the original and shifted versions appear together. That is, when I run this code, the button is shown as a triangle along the left edge of the window. Then when I run the mouse over the button, a new triangle is drawn (in addition to the old one), shifted down and to the right by about 10 pixels. Resizing the window changes the offset of the phantom button from the original.
Experimenting with mouse clicks shows that only the original, correctly-positioned button is active. The region of the offset phantom button is not active.
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.awt.Polygon;
public class ShiftingButton extends JButton implements ActionListener {
private Polygon shape;
public ShiftingButton () {
initialize();
addActionListener(this);
}
protected void initialize() {
shape = new Polygon();
setSize(120, 120);
shape.addPoint(0, 0);
shape.addPoint(0, 60);
shape.addPoint(90, 0);
setMinimumSize(getSize());
setMaximumSize(getSize());
setPreferredSize(getSize());
}
// Hit detection
public boolean contains(int x, int y) {
return shape.contains(x, y);
}
#Override
public void paintComponent (Graphics g) {
System.err.println("paintComponent()");
g.fillPolygon(shape);
}
protected void paintBorder(Graphics g) {
}
#Override
public void actionPerformed (ActionEvent ev) {
System.out.println("ShiftingButton ActionEvent!");
}
public static void main (String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
ShiftingButton button = new ShiftingButton();
panel.add(button);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
}
You failed to call super.paintComponent(g) inside the overridden paintComponent(...) method. Moreover, while overriding a method of the Base class, always try to keep the access specifier of the methods, the same, as much as possible. In this case it's protected and not public :-) Now function should be like this :
#Override
protected void paintComponent (Graphics g) {
System.err.println("paintComponent()");
super.paintComponent(g);
g.fillPolygon(shape);
}
EDIT 1 :
Moreover, since you are using a custom shape to be drawn, hence you again failed to specify the ContentAreaFilled property for this JButton in question, hence inside your constructor, you should write setContentAreaFilled(false), for it to work nicely. Though if this doesn't works (for reasons specified in the Docs), then you have to use the plain old Opaque property and set it to false for this JButton using setOpaque(false) :-)
Here is your code with modified changes :
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.awt.Polygon;
public class ShiftingButton extends JButton implements ActionListener {
private Polygon shape;
public ShiftingButton () {
setContentAreaFilled(false);
initialize();
addActionListener(this);
}
protected void initialize() {
shape = new Polygon();
setSize(120, 120);
shape.addPoint(0, 0);
shape.addPoint(0, 60);
shape.addPoint(90, 0);
}
#Override
public Dimension getPreferredSize() {
return (new Dimension(120, 120));
}
// Hit detection
public boolean contains(int x, int y) {
return shape.contains(x, y);
}
#Override
protected void paintComponent(Graphics g) {
System.err.println("paintComponent()");
super.paintComponent(g);
g.fillPolygon(shape);
}
protected void paintBorder(Graphics g) {
}
#Override
public void actionPerformed (ActionEvent ev) {
System.out.println("ShiftingButton ActionEvent!");
}
public static void main (String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
ShiftingButton button = new ShiftingButton();
panel.add(button);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
}
Yes, I am mixing awt and swing components, but maybe there is an easy fix because I dont know Java all that well.
My canvas object overrides paint and update:
package demo;
import java.awt.*;
public class rectangle extends Canvas {
public rectangle() {
this.setSize(500,300);
this.setVisible(true);
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.YELLOW);
g2.fill3DRect(0, 0, 500, 300, true);
}
public void update(Graphics g) { paint(g); }
}
When my JComboBox opens over top of this it doesnt paint on top of it. As an example, here is a JFrame that demonstrates what i'm talking about:
package demo;
import javax.swing.*;
import java.util.*;
import java.awt.*;
public class ASframe extends JFrame {
public ASframe() {
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
ArrayList listNames = new ArrayList();
listNames.add("One");
listNames.add("Two");
listNames.add("Three");
listNames.add("Four");
rectangle r = new rectangle();
JComboBox listBox = new JComboBox(listNames.toArray());
listBox.setVisible(true);
JPanel listPane = new JPanel();
listPane.setLayout(new BoxLayout(listPane, BoxLayout.PAGE_AXIS));
listPane.add(listBox);
listPane.add(r);
this.setResizable(false);
this.add(listPane);
this.pack();
}
public static void main(String arg[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new ASframe().setVisible(true);
}
});
}
}
Whats really interesting is that if the rectangle is smaller then the JComboBox, no issues at all. So, change the rectangle to 300x20 and it works as expected.
Thanks in advance.
Try telling Swing use the heavyweight component and see if that works.
JComboBox listBox = new JComboBox(listNames.toArray());
listBox.setVisible(true);
// additional line below
listBox.setLightWeightPopupEnabled(false); // use heavyweight component