Drawing rectangles on a JPanel
Solution 1
still no idea,
for example
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
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() {
add(new CustomComponents());
pack();
// enforces the minimum size of both frame and component
setMinimumSize(getSize());
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 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);
}
}
Solution 2
instead of adding
contentPane.add(new DrawRectPanel());
you should do
contentPane.add(panel1);
Because you already have new DrawRectPanel
in panel1. But in your code you are adding another instance of DrawRectPanel
in contentPane
. And never added panel1
in none of your container
.
infoSyStem
Updated on June 04, 2022Comments
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infoSyStem almost 2 years
I have a JScrollPane and on top of it I have a JPanel named 'panel1'. I want some rectangles to be drawn on this JPanel.
I have a class named DrawRectPanel which extends JPanel and does all the drawing stuff. The problem is that, I tried to draw the rectangles on panel1 by writing the following code :
panel1.add(new DrawRectPanel());
but nothing appeared on panel1 then I tried, just as a test to the class DrawRectPanel :
JFrame frame = new JFrame(); frame.setSize(1000, 500); Container contentPane = frame.getContentPane(); contentPane.add(new DrawRectPanel()); frame.show();
This worked, and produced the drawings but on a separate JFrame How can I draw the rectangles on panel1 ? Thanks in advance.
EDIT : code for DrawRectPanel
public class DrawRectPanel extends JPanel { DrawRectPanel() { Dimension g = new Dimension(400,400); this.setPreferredSize(g); System.out.println("label 1"); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); System.out.println("label 2"); g.setColor(Color.red); g.fillRect(20, 10, 80, 30); } }
only label 1 is printed on the screen
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infoSyStem over 12 yearsfirst, i should add panel1 (which overrides paintcomponent function) on a scrollpane, so i should write scrollpane.add(panel1) , if i do this, only the constructor of panel1 is called and not the paintcomponent function itself, do you know why ?
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gtiwari333 over 12 yearsyou can manually call paintcomponent by panel1.repaint();panel1.validate();
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camickr over 12 years+1, the key is that you need to provide a preferred size for the layout managers.