I'm trying to code an Othello, and... I'm already stuck with a basic view.
My main class:
public class Othello extends JFrame {
private static final long serialVersionUID = 1L;
public static final int WIDTH = 800;
public static final int HEIGHT = 600;
private Grid grid;
public Othello() {
this.setSize(WIDTH, HEIGHT);
this.setTitle("Othello");
this.grid = new Grid();
this.setContentPane(this.grid);
this.grid.revalidate();
this.grid.repaint();
}
public void run() {
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setResizable(false);
this.setVisible(true);
}
public static void main(String[] args) {
new Othello().run();
}
}
And my JPanel class:
public class Grid extends JPanel {
private static final long serialVersionUID = 1L;
public Grid() {}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(new Color(0,128,0));
g.fillRect(0, 0, WIDTH, HEIGHT);
}
}
I don't understand why it doesn't show anything.
The paintComponent is called, but nothing happens, I tried to call revalidate() and repaint() almost everywhere and nothing works.
I've been looking for the solution in different topics for almost 1 hour, and none of the solution I've found worked.
This is your problem:
g.fillRect(0, 0, WIDTH, HEIGHT);
The WIDTH and HEIGHT values are not what you expect them to be, and in fact they are likely both 0. Instead for safest programming, you need to get the actual width and height via getWidth() and getHeight()
No need for those revalidate()s and repaint()s. For example:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.*;
public class GridTest {
private static final int WIDTH = 800;
private static final int HEIGHT = 600;
private static void createAndShowGui() {
Grid mainPanel = new Grid(WIDTH, HEIGHT);
JFrame frame = new JFrame("Grid Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class Grid extends JPanel {
private static final long serialVersionUID = 1L;
private int prefW;
private int prefH;
public Grid(int prefW, int prefH) {
this.prefW = prefW;
this.prefH = prefH;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(new Color(0,128,0));
g.fillRect(0, 0, getWidth(), getHeight());
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(prefW, prefH);
}
}
Also there really is no need to override paintComponent if all you're doing is filling the background. A call to setBackground(new Color(0, 128, 0)); within the Grid constructor will set it. Of course you might need the paintComponent if you're going to draw other things -- but if it's a grid, consider using a grid of JLabels and setting their icons.
Related
In my main class I have the following code to load an image from my machine and display it on the frame to draw things on it:
public class ShowMap extends JPanel {
private static final int WIDTH = 1340;
private static final int HEIGHT = 613;
public void main(String args[]) {
JFrame frame = new JFrame("MAP");
frame.setPreferredSize(new Dimension(WIDTH, HEIGHT));
frame.setMinimumSize(new Dimension(WIDTH, HEIGHT));
frame.setMaximumSize(new Dimension(WIDTH, HEIGHT));
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = (JPanel)frame.getContentPane();
JLabel label = new JLabel();
label.setIcon(new ImageIcon("map.png"));
panel.add(label);
}
}
The image I am loading is a map where I would like to indicate the position of some objects by drawing points in the right coordinates. So it is important here to dictate to the DrawPoint class (below) what coordinates should get the point.
Also, I would greatly appreciate an explanation of how to erase a point that has been drawn.
My search led me to the following, but as soon as I add int coordx, int coordy to the arguments of the method, it is no more highlighted, and I don't know how to call this method in ShowMap while passing the coordinates as arguments.
public class DrawPoint extends JPanel {
private int coordx;
private int coordy;
public void paintComponent(Graphics g, int coordx, int coordy){
g.setColor(Color.BLACK);
g.fillOval(coordx,coordy,8,8);
}
}
Here is a demonstration of what MadProgrammer wrote in his comment : "should be changing a state variable of the component and then calling repaint" :
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class SwingTest extends JFrame {
private static final int SIZE = 300;
private DrawPoint drawPoint;
public SwingTest() {
setDefaultCloseOperation(EXIT_ON_CLOSE);
drawPoint = new DrawPoint();
drawPoint.setPreferredSize(new Dimension(SIZE, SIZE));
add(drawPoint);
pack();
setVisible(true);
}
//demonstrate change in DrawPoint state
private void reDraw() {
Random rnd = new Random();
Timer timer = new Timer(1000, e -> { //periodically change coordinates and repaint
drawPoint.setCoordx(rnd.nextInt(SIZE));
drawPoint.setCoordy(rnd.nextInt(SIZE));
drawPoint.repaint();
});
timer.start();
}
public static void main(String[] args){
SwingUtilities.invokeLater(() -> new SwingTest().reDraw());
}
}
class DrawPoint extends JPanel {
private int coordx, coordy;
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillOval(coordx,coordy,8,8);
}
//use setters to change the state
void setCoordy(int coordy) { this.coordy = coordy; }
void setCoordx(int coordx) {this.coordx = coordx;}
}
Hi I need to display a large content(its graphical data) of data in single, so I tried following code.
canvas.setPreferredSize(new Dimension(3000, 300));
canvas.setBackground(Color.blue);
JScrollPane jsp = new JScrollPane(canvas);
setPreferredSize(new Dimension(600, 500));
setLayout(new GridLayout(1, 0, 5, 0));
jsp.getHorizontalScrollBar().addAdjustmentListener(new AdjustmentListener() {
#Override
public void adjustmentValueChanged(AdjustmentEvent e) {
System.out.println(e.getValue());
repaint();
}
});
add(jsp);
this is my MyCanvas class
class MyCanvas extends Canvas {
#Override
public void paint(Graphics g) {
super.paint(g);
System.out.println("paint");
g.setColor(Color.YELLOW);
for (int i = 0; i < 100; i++) {
g.drawString(""+i, i*30, 100);
// g.drawLine(10, 10, 20, 20);
}
}
}
but problem is that when I am scrolling window I cannot see full content as I expected it should print 100 numbers but not printed actually, can any one correct me?
see the result here
I recommend that you avoid mixing AWT and Swing components together (or if you absolutely must do this, then you have to make sure you understand the pitfalls and fully jump through all the necessary hoops.
Myself, I'd extend JPanel, I'd be sure that its preferredSize was where I want it, since this will determine how big it will be within the JScrollPane.
For example:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyScrollExample extends JPanel {
private static final int MAX = 100;
private MyPanel myPanel = new MyPanel(MAX);
public MyScrollExample() {
JScrollPane scrollPane = new JScrollPane(myPanel);
scrollPane.getViewport().setPreferredSize(new Dimension(600, 200));
add(scrollPane);
}
private static void createAndShowGui() {
MyScrollExample mainPanel = new MyScrollExample();
JFrame frame = new JFrame("MyScrollExample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
#SuppressWarnings("serial")
class MyPanel extends JPanel {
private static final Color BG = Color.BLUE;
private static final Color FG = Color.YELLOW;
private static final int WIDTH_GAP = 30;
private static final int HEIGHT_GAP = 100;
private int max;
public MyPanel(int max) {
setBackground(BG);
this.max = max;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(FG);
for (int i = 0; i < max; i++) {
g.drawString("" + i, i * WIDTH_GAP, HEIGHT_GAP);
}
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
int w = (WIDTH_GAP + 1) * max;
int h = HEIGHT_GAP * 3;
return new Dimension(w, h);
}
}
So, I have this simple program that allows you to click a JMenu item "New Rectangle" and it adds a shape on the center of the screen. My question is: how can I click-and-drag this around the window? I know I will need some type of Mouse Listener but I'm not sure exactly how to implement it.
public class SimpleDraw {
public static void main(String[] args) {
JFrame frame = new UMLWindow();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(30, 30, 1000, 700);
frame.getContentPane().setBackground(Color.white);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
// Display the window.
frame.setVisible(true);
}
}
class UMLWindow extends JFrame {
Squares squares = new Squares();
private static final long serialVersionUID = 1L;
public UMLWindow() {
addMenus();
}
public void addMenus() {
getContentPane().add(squares);
JMenuBar menubar = new JMenuBar();
JMenu shapes = new JMenu("Shapes");
JMenuItem rectangleMenuItem = new JMenuItem("New Rectangle");
rectangleMenuItem.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
squares.addSquare(10, 10, 100, 100);
}
});
shapes.add(rectangleMenuItem);
menubar.add(shapes);
setJMenuBar(menubar);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
class Squares extends JPanel {
private static final long serialVersionUID = 1L;
private List<Rectangle> squares = new ArrayList<Rectangle>();
public void addSquare(int x, int y, int width, int height) {
Rectangle rect = new Rectangle(getWidth() / 2 - width / 2, getHeight()
/ 2 - height / 2, width, height);
squares.add(rect);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
this.setOpaque(true);
this.setBackground(Color.WHITE);
Graphics2D g2 = (Graphics2D) g;
for (Rectangle rect : squares) {
g2.draw(rect);
}
repaint();
}
}
Maybe it can help you :
http://zetcode.com/tutorials/javaswingtutorial/resizablecomponent/
Disadvantage of code
In this code we do not layout manager. So if we have a component in center of jframe when this jframe is re-sizing this component maybe display in corner of jframe. You can solve this problem but it is a little complex. We can talk about this problem if you want.
I wrote a solution for this in this package here. You can see that there is an AreaDragger class, which sounds like what you are looking for
So I am testing out a JSlider for a bigger project and can't get it to work. The slider is supposed to adjust the size of a circle, and it's not working. I thought I might have an issue with the creation of the circle, and I am trying to use setFrame, and it's giving an error saying it's "undefined." Can anyone see why? Since it should take in either float or double as parameters. Or if you can see why it's not adjusting the size of the shape that would help a lot too... Here's what I have:
public class DrawShape extends JPanel{
private float width = 300;
private Shape circle = new Ellipse2D.Float(100, 20, width, 300);
public DrawShape() {
}
public DrawShape(float width) {
this.width = width;
}
public void setWidth(int w) {
this.width = w;
circle.setFrame(100, 20, width, 300);//This is where the error is
}
public void paintComponent (Graphics g) {
super.paintComponents(g);
Graphics2D graphics = (Graphics2D)g;
graphics.setColor(Color.black);
graphics.fill(circle);
}//end paintComponent
}//end class
Class with main:
public class SliderTest extends JFrame{
private static DrawShape circle = new DrawShape();
JSlider slider;
JLabel label;
public SliderTest() {
setLayout(new FlowLayout());
slider = new JSlider(JSlider.HORIZONTAL, 150, 450, 300);//orientation, min val, max value, starting val
slider.setMajorTickSpacing(50);//every 5 integers will be a new tick position
slider.setPaintTicks(true);
add(slider);
label = new JLabel("Current value 300");
add(label);
event e = new event();
slider.addChangeListener(e);;
}//end cons
public class event implements ChangeListener{
public void stateChanged(ChangeEvent e) {
JSlider slider = (JSlider)e.getSource();
int value = slider.getValue();
label.setText("Current Value " + value);
circle.setWidth(value);
repaint();
}//end stateChanged
}//end class event
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("Circle");
frame.add(circle);
frame.setSize(500,400);
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
JFrame frame1 = new SliderTest ();
frame1.setTitle("Toolbar");
frame1.setSize(300,200);
frame1.setLocation(200,100);
frame1.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame1.setVisible(true);
}
}
Shape does not have a setFrame method. RectangularShape does...
Instead of
private Shape circle = new Ellipse2D.Float(100, 20, width, 300);
You might try using...
private Ellipse2D circle = new Ellipse2D.Float(100, 20, width, 300);
instead...
Your public DrawShape(float width) { constructor is also wrong, as it does not actually do anything.
You should also consider overriding the getPreferredSize method so it can return the width of the shape as a part of the preferred size.
I'm not sure you actually need to maintain the width reference as you can ascertain this from the circle directly...IMHO
For Example
I've not tested this...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
import javax.swing.JPanel;
public class DrawShape extends JPanel {
private final Ellipse2D circle = new Ellipse2D.Float(100, 20, 300, 300);
public DrawShape() {
}
public DrawShape(float width) {
circle.setFrame(100, 20, width, 300);
}
public void setWidth(int w) {
circle.setFrame(100, 20, w, 300);
revalidate();
}
#Override
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
size.width = circle.getBounds().width;
return size;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponents(g);
Graphics2D graphics = (Graphics2D) g;
graphics.setColor(Color.black);
graphics.fill(circle);
}//end paintComponent
}//end class
I have this inner class:
private class Plats extends JComponent{
private String namn;
Plats(int x, int y, String n){
namn=n;
setBounds(x-10, y-10, 150, 40);
setPreferredSize(new Dimension(20, 20));
setMinimumSize(new Dimension(20, 20));
setMaximumSize(new Dimension(20, 20));
}
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.BLUE);
g.fillOval(0, 0, 20, 20);
g.setColor(Color.BLACK);
g.setFont(font);
g.drawString(namn, 0, 34);
}
public boolean contains(int x, int y){
return x<20 && x>0 && y<20 && y>0;
}
}
I want to set the bounds of the component to the width of the string that the constructor gets, but I can only get it to work if I do it inside the paintComponent method since I need the graphics object. It feels wrong to do it in the paintComponent method since every time the component has to be repainted it will set the bounds again and I only want to do it once when it is created.
Suggestions how I can solve this? Or should I just do it in the paintComponent anyway?, it works but I doesnt feel like a nice solution :( ?
Please don't use AbsoluteLayout, only if is there really important reason, use proper LayoutManager,
your JComponent should be returns PreferredSize (notice PreferredSize isnot accepted by all of standard or custom LayoutManagers) to its parent or container, for example
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ComponentEvent;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class CustomComponent extends JFrame {
private static final long serialVersionUID = 1L;
public CustomComponent() {
setTitle("Custom Component Graphics2D");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void display() {
CustomComponents cc = new CustomComponents();
/*cc.addComponentListener(new java.awt.event.ComponentAdapter() {
#Override
public void componentResized(ComponentEvent event) {
setSize(Math.min(getPreferredSize().width, getWidth()),
Math.min(getPreferredSize().height, getHeight()));
}
});*/
add(cc, BorderLayout.CENTER);
CustomComponents cc1 = new CustomComponents();
add(cc1, BorderLayout.EAST);
pack();
// enforces the minimum size of both frame and component
setMinimumSize(getSize());
//setMaximumSize(getMaximumSize());
setVisible(true);
}
public static void main(String[] args) {
CustomComponent main = new CustomComponent();
main.display();
}
}
class CustomComponents extends JComponent {
private static final long serialVersionUID = 1L;
#Override
public Dimension getMinimumSize() {
return new Dimension(100, 100);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
#Override
public Dimension getMaximumSize() {
return new Dimension(800, 600);
}
#Override
public void paintComponent(Graphics g) {
int margin = 10;
Dimension dim = getSize();
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);
}
}
Even without a graphics context, you can use either TextLayout or FontRenderContext to find the bounds; the two are compared here. Because you extend JComponent, your component should override the getXxxSize() methods, as shown in mKorbel's answer.
You can use the Font#getStringBounds(String str, FontRenderContext frc) to get a bounding rectangle of the string in the form of the said Font. From there you can return the width and height.
Font Java 1.6 API