So guys I want to use the code I have to set the background of the jFrame without adding anything from another class (like using this code in a jPanel then adding that panel to a jFrame). I wanna do everything in this class. I really have no idea what to do, so I tried this out but this code is not displaying the image!
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
public class panel extends JFrame{
Image img;
public void paintComponent(Graphics g){
super.paintComponents(g);
g.drawImage(img, 0, 0, getWidth(), getHeight(), null);
g.dispose();
}
public panel(){
img=new ImageIcon(getClass().getResource("bg_login.jpg")).getImage();
setExtendedState(JFrame.MAXIMIZED_BOTH);
pack();
setVisible(true);
}
public static void main(String[] args){
new panel();
}
}
there is no paintcomponent() method for jframe as it's not a jcomponent but a container .you can make a panel and overide paintcomponent method then setcontentpane of jframe to that panel
example
public class panel extends JPanel {
Image img;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
g.drawImage(img, 0, 0, getWidth(), getHeight(), null);
}
// g.dispose();
}
public panel() {
img=new ImageIcon(getClass().getResource("bg_login.jpg")).getImage();
}
public static void main(String[] args) {
JFrame jFrame = new JFrame();
jFrame.setExtendedState(JFrame.MAXIMIZED_BOTH);
panel panel = new panel();
jFrame.setContentPane(panel);
jFrame.pack();
jFrame.setVisible(true);
}
}
Related
public class Rec extends JFrame {
public Rec (){
JFrame jframe = new JFrame();
jframe.setSize(500, 500);
jframe.setVisible(true);
}
public void render (Graphics g){
g.setColor(Color.red);
g.fillRect(0,0,50,50);
}
public static void main(String[] args) {
Rec frame = new Rec();
frame.render(g);
}
}
Why does this not work? I am aware I may need a paintComponent, if so how would I go about doing this? Any help would be great, Thank You!
The thing is that painting in a JFrame is not what you should be doing. It is better (in this instance) to set the contentpane as a JPanel, and paint inside the JPanel.
Take this short snippet as an example:
import java.awt.*;
import javax.swing.*;
public class Rec {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame rec = new JFrame();
rec.setSize(50, 150);
rec.setContentPane(new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(0, 0, 50, 50);
}
});
rec.setVisible(true);
}
});
}
}
Result:
//May be this is what you are looking for.
public void paintComponent(Graphics g) {
// Create a copy of the passed in Graphics object
Graphics gCopy = g.create();
// Change the properties of gCopy and use it for drawing here
// Dispose the copy of the Graphics object
gCopy.dispose();
}
//or might be this
import javax.swing.JPanel;
import java.awt.Graphics;
import java.awt.Dimension;
import javax.swing.JFrame;
public class DrawingCanvas extends JPanel {
public DrawingCanvas() {
this.setPreferredSize(new Dimension(600, 75));
}
#Override
public void paintComponent(Graphics g) {
// Draw a rectangle
g.fillRect(100, 100, 100, 100);
}
public static void main(String[] args) {
JFrame frame =new JFrame("Drawing");
frame.getContentPane().add(new DrawingCanvas());
frame.pack();
frame.setVisible(true);
}
}
I am using the same numbers to set the size of my frame as I am to paint the rectangle, yet the graphics are larger than my JFrame. Why is this?
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test {
public static void main(String[] arguments) {
Test test = new Test();
JFrame frame = new JFrame();
DrawPane contentPane = test.new DrawPane();
frame.setContentPane(contentPane);
frame.setSize(300, 400);
frame.setVisible(true);
}
private class DrawPane extends JPanel {
#Override
protected void paintComponent(Graphics g) {
g.setColor(Color.YELLOW);
g.fillRect(0, 0, 300, 400);
}
}
}
It's because of border. And it's a good example why you shouldn't explicitly determine size for your JFrame. Instead calling setSize override getPreferredSize method from your JPanel:
private class DrawPane extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.YELLOW);
g.fillRect(0, 0, 300, 400);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 400);
}
}
Then call pack for your JFrame instead setSize and your JFrame will adjust it's size according to its content.
I am trying to create a simple drawing program which contains a toolbar and a drawing area. The program's main window is a JFrame. I have added a JToolBar and a JPanel (drawingPanel) on which to draw. However, the line is not drawn on drawingPanel but behind it (I can see the line when I remove drawingPanel - just comment out CreateDrawingPanel();). How can I draw the line on drawingPanel?
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.SwingUtilities;
public class UserInterface extends JPanel
{
static JFrame frame;
static JPanel drawingPanel;
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
CreateFrame();
}
});
}
private static void CreateFrame()
{
frame = new JFrame("Interface");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500,500);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
frame.setExtendedState(Frame.MAXIMIZED_BOTH);
frame.add(new UserInterface());
}
public UserInterface()
{
setLayout(new BorderLayout());
CreateToolBar();
CreateDrawingPanel();
repaint();
}
private void CreateToolBar()
{
JToolBar toolbar = new JToolBar(JToolBar.VERTICAL);
JButton button = new JButton("Some button");
toolbar.add(button);
add(toolbar, BorderLayout.WEST);
toolbar.setBackground(Color.black);
toolbar.setFloatable(false);
}
private void CreateDrawingPanel()
{
drawingPanel = new JPanel();
add(drawingPanel, BorderLayout.CENTER);
drawingPanel.setBackground(Color.white);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.drawLine(100, 100, 120, 500);
}
}
All your drawing is on the UserInterface object, as this is where you override paintComponent().
Remove the paintComponent() override, and change the createDrawingPanel():
private void CreateDrawingPanel()
{
drawingPanel = new JPanel(){
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.drawLine(100, 100, 120, 500);
}
};
add(drawingPanel, BorderLayout.CENTER);
drawingPanel.setBackground(Color.white);
}
You could either define your drawingPanel like this:
drawingPanel = new JPanel(){
protected void paintComponent(Graphics g){
//Your draw Code
}
};
or you could create a class that inherits from JPanel:
public class DrawingPanel extends JPanel{
public DrawingPanel(){
//...
}
protected void paintComponent(Graphics g){
//Your draw Code
}
}
and use it like this:
drawingPanel = new DrawingPanel();
I have ran into a problem. The problem lies with adding multiple components to a JFrame, all within separate classes. I have to add the two components DrawBoard and QuestionBox into the JPanel 'panel' in the Board class. The DrawBoard and QuestionBox will both perform different functions.
The DrawBoard component should be 600x600 pixels, while the QuestionBox component should be 600x120 pixels. The DrawBoard is at the bottom and the QuestionBox sits at the top. I am not sure as to what layout to use.
When run I get this result.
Game class
package snake;
//This class is used to run the game.
public class Game {
/**
* #author HyperBlue
*/
public static Board board;
public static void main(String[] args) {
// TODO Auto-generated method stub
//Creates an object board from the Board() construct
board = new Board();
}
}
Board Class
public class Board implements ActionListener {
public DrawBoard drawBoard;
public QuestionBox questionBox;
public Timer ticker = new Timer(20, this);
public Board() {
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
JFrame frame = new JFrame("Snake");
frame.pack();
Insets insets = frame.getInsets();
JPanel container = new JPanel();
questionBox = new QuestionBox();
drawBoard = new DrawBoard();
container.setLayout(new BorderLayout());
container.add(questionBox, BorderLayout.NORTH);
container.add(drawBoard, BorderLayout.SOUTH);
frame.setMinimumSize(new Dimension(600+insets.left + insets.right, 720 +insets.bottom + insets.top));
frame.add(container);
//Sets the frame in middle of screen
frame.setLocation((dim.width / 2) - (frame.getWidth() / 2), (dim.height / 2) - (frame.getHeight() / 2));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
DrawBoard Class
package snake;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
//Warnings will not be thrown (are suppressed).
#SuppressWarnings("serial")
public class DrawBoard extends JPanel{
public static Color yellow = new Color(13816442);
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(yellow);
g.fillRect(0, 0, 600, 600);
}
}
QuestionBox Class
package snake;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class QuestionBox extends JPanel{
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, 600, 120);
}
}
Each component should be responsible for managing it's own size, you should start by overriding getPreferredSize of the panels and returning the size you would like to use.
You should also not rely on magic numbers, but instead should use actual physical values, for example, instead of
g.fillRect(0, 0, 600, 120);
You should use...
g.fillRect(0, 0, getWidth(), getHeight());
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test1 {
public static void main(String[] args) {
new Test1();
}
public Test1() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
add(new DrawBoard());
add(new QuestionBox(), BorderLayout.SOUTH);
}
}
public static class DrawBoard extends JPanel {
public static Color yellow = new Color(13816442);
#Override
public Dimension getPreferredSize() {
return new Dimension(600, 600);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(yellow);
g.fillRect(0, 0, 600, 600);
}
}
public static class QuestionBox extends JPanel {
#Override
public Dimension getPreferredSize() {
return new Dimension(600, 120);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, 600, 120);
}
}
}
You should also know that Toolkit.getDefaultToolkit().getScreenSize(); is not the most reliable method for determining the visible screen area, as it does not take into account various OS elements, like the task bar or dock, which can take up screen space.
I have a JPanel inside the JScrollPane and it does that whenever I try to scroll. Please help! How do I fix this?
EDIT
JScrollPane pane;
....
pane = new JScrollPane(GC.createGraph());
pane.setPreferredSize(new Dimension(480,480*2/3));
Placing as an answer for others to see. If you don't call the super.paintComponent, you'll get those artifacts. e.g.,
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.*;
public class ScrollPaneArtifacts extends JPanel {
private static final int SPA_WIDTH = 600;
private static final int SPA_HEIGHT = SPA_WIDTH;
#Override
protected void paintComponent(Graphics g) {
//super.paintComponent(g);
g.setColor(Color.red);
g.drawLine(0, 0, getWidth(), getHeight());
g.drawLine(getWidth(), 0, 0, getHeight());
}
#Override
public Dimension getPreferredSize() {
return new Dimension(SPA_WIDTH, SPA_HEIGHT);
}
private static void createAndShowUI() {
JScrollPane scrollpane = new JScrollPane(new ScrollPaneArtifacts());
scrollpane.getViewport().setPreferredSize(new Dimension(400, 400));
JFrame frame = new JFrame("ScrollPaneArtifacts");
frame.getContentPane().add(scrollpane);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
You do not need to call super.paintComponent you can simply clear the area to ensure no artifacts are left on the panel from the previous render (which calling super.paintComponent will do).
#Override
protected void paintComponent(Graphics g) {
g.clearRect(0,0,getWidth(),getHeight());
g.setColor(Color.red);
g.drawLine(0, 0, getWidth(), getHeight());
g.drawLine(getWidth(), 0, 0, getHeight());
}
Try this in Hovercrafts code if you like.