Thread: JButton on JPanel

Hi,

Here is my code on how I add a JButton onto a JPanel. However, the JButton completely takes over the whole JPanel, how do I set the size of the JButton so it doesn't take over the whole JPanel?

import java.awt.BorderLayout;
 
import javax.swing.*;
 
public class test extends JFrame {
 
	public test() {
		super("Title");
		JPanel panel = new JPanel();
		add(panel);
 
		JButton mybutton = new JButton("TEST BUTTON");
		getContentPane().add(mybutton);
	}
 
}

Here is what it looks like:



Any help is appreciated,

thanks

Originally Posted by Darryl.Burke

JFrame uses a BorderLayout by default. Link below:
Lesson: Laying Out Components Within a Container (The Java™ Tutorials > Creating a GUI With JFC/Swing)

db

Thanks, this is just what I was looking for, something that would explain everything to me.

Much appreciated

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;


public class Week1MouseEventsQ6 extends JFrame
{
DrawPanel canvas;

public static void main(String[] args)
{
Week1MouseEventsQ6 w = new Week1MouseEventsQ6();
w.setVisible(true);
}

public Week1MouseEventsQ6()
{
setTitle("Week2MouseEvents: starting code");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500,220);
setLocation(300,300);
canvas = new DrawPanel(7, 5);
add(canvas);
}

class DrawPanel extends JPanel implements MouseListener
{
int numCols;
int numRows;

int clickColumnIndex = -1;
int clickRowIndex = -1;

int buttonNumber = 0;

boolean clickControl = false;

public void mouseReleased(MouseEvent event)
{
System.out.println("Mouse Released");
System.out.println("X: " + event.getX() + "Y: " + event.getY());
}
public void mousePressed(MouseEvent event)
{
System.out.println("Mouse Pressed");
System.out.println("X: " + event.getX() + "Y: " + event.getY());
}
public void mouseClicked(MouseEvent event)
{
buttonNumber = event.getButton();

clickColumnIndex = (numCols) * (event.getX()) / (getWidth());
clickRowIndex = (numRows) * (event.getY()) / (getHeight());

clickControl = true;

System.out.println("Mouse Clicked");
System.out.println("X: " + event.getX() + "Y: " + event.getY());
System.out.println("Row " + clickRowIndex + "Column " + clickColumnIndex);

repaint();

}
public void mouseEntered(MouseEvent event)
{
System.out.println("Mouse Entered");
System.out.println("X: " + event.getX() + "Y: " + event.getY());
}
public void mouseExited(MouseEvent event)
{
System.out.println("Mouse Exited");
System.out.println("X: " + event.getX() + "Y: " + event.getY());
}


public DrawPanel(int nc, int nr)
{
numCols = nc;
numRows = nr;

addMouseListener(this);
}

Rectangle getRect(int thisCol, int thisRow)
{
// if input is out of range, return "null"
if(thisCol <0 || thisRow < 0)
return null;
if(thisCol>=numCols || thisRow>=numRows)
return null;

// otherwise, make and return the Rectangle
int w = getWidth()/numCols;
int h = getHeight()/numRows;

int x = thisCol*w;
int y = thisRow*h;

Rectangle myRect = new Rectangle(x,y,w,h);
return myRect;
}

public void paint(Graphics g)
{
g.setColor(Color.gray);
g.fillRect(0,0,getWidth(), getHeight());
g.setColor(Color.black);


Graphics2D g2 = (Graphics2D)g;
// we'll use Graphics2D for it's "draw" method -
// neater than the Graphics "drawRect" suppled
// (which you could also use)

for (int i = 0;i<numCols;i++)
for(int j = 0;j<numRows;j++)
g2.draw(getRect(i,j));

if (clickControl == true)
{
Rectangle r2 = getRect(clickColumnIndex,clickRowIndex);
g.setColor(Color.red);
g.fillOval(r2.x,r2.y,r2.width, r2.height);
}

if (buttonNumber == 3)
{
Rectangle r3 = getRect(clickColumnIndex,clickRowIndex);
g.setColor(Color.yellow);
g.fillOval(r3.x,r3.y,r3.width, r3.height);
}

}

}

}



could someone please help i need to understand why it is declarred a boolean and why it is firsty tru and then decl;ared false later on please help me .I need to understand this ......

I think you have used the MouseListener to draw the rectangle and circle on clicks is it? if so the clicks and release should be used.if you cick click control becomes true and the painting takes place else it will not.if it is not used u have used repaint() .It starts painting continuously so used false.