Java

Blank JFrame

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•

Join Date: Oct 2009

Posts: 15

Reputation: babylonlion is an unknown quantity at this point

Solved Threads: 0

babylonlion babylonlion is offline

Offline

Newbie Poster

Blank JFrame

Nov 7th, 2009

Hi guys,
The following program works the way I want it to but there's one small problem; when it loads, it doesn't give a blank frame. It want it to show the output after I click on the blank area. Help me please.

 Help with Code Tags 
 Java Syntax (Toggle Plain Text) 
import java.awt.*;
import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
 
public class TrackMouseMovementTest{
 
	public static void main(String[] args){
 
		EventQueue.invokeLater(new Runnable(){
			public void run(){
				MouseFrame frame = new MouseFrame();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setVisible(true);
			}
		});
	}
}
 
class MouseFrame extends JFrame
{
	public MouseFrame(){
	setTitle("Mouse Movement Tracker");
	setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
 
	MouseComponent component = new MouseComponent();
	add(component);
	}
	public static final int DEFAULT_WIDTH = 500;
	public static final int DEFAULT_HEIGHT = 500;
}
 
class MouseComponent extends JComponent{
	public MouseComponent(){
	    addMouseListener(new MouseHandler());
	}
 
	private class MouseHandler extends MouseAdapter{
		public void mousePressed(MouseEvent event){	
		  x = event.getX();
		  y = event.getY();
	      repaint();
		}
	}
		public void paintComponent(Graphics g){
	        g.drawString("X: " + x + ",Y: " + y + "",x,y);
	        g.drawString("Click #: " + counter ++ ,x , y + 16);
    } 
	int x;
	int y;  
	private static int counter=-1;
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class TrackMouseMovementTest{
	
	public static void main(String[] args){
		
		EventQueue.invokeLater(new Runnable(){
			public void run(){
				MouseFrame frame = new MouseFrame();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setVisible(true);
			}
		});
	}
}

class MouseFrame extends JFrame
{
	public MouseFrame(){
	setTitle("Mouse Movement Tracker");
	setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
	
	MouseComponent component = new MouseComponent();
	add(component);
	}
	public static final int DEFAULT_WIDTH = 500;
	public static final int DEFAULT_HEIGHT = 500;
}

class MouseComponent extends JComponent{
	public MouseComponent(){
	    addMouseListener(new MouseHandler());
	}
	
	private class MouseHandler extends MouseAdapter{
		public void mousePressed(MouseEvent event){	
		  x = event.getX();
		  y = event.getY();
	      repaint();
		}
	}
		public void paintComponent(Graphics g){
	        g.drawString("X: " + x + ",Y: " + y + "",x,y);
	        g.drawString("Click #: " + counter ++ ,x , y + 16);
    } 
	int x;
	int y;  
	private static int counter=-1;
}

•

Join Date: Nov 2008

Posts: 332

Reputation: quuba is on a distinguished road

Solved Threads: 54

quuba

Offline

Posting Whiz

Nov 7th, 2009

Introduce own boolean flag 'pressed' and use it to switch needed behavior

•

Join Date: Oct 2008

Posts: 2,721

Reputation: adatapost has much to be proud of

Solved Threads: 498

adatapost

Offline

Posting Maven

Nov 7th, 2009

Don't paint when value of x & y variable is zero.

 Help with Code Tags 
 Java Syntax (Toggle Plain Text) 
public void paintComponent(Graphics g){
  if(x>0 &&  y>0) {
     g.drawString("X: " + x + ",Y: " + y + "",x,y);
     g.drawString("Click #: " + counter ++ ,x , y + 16);
  }
}
public void paintComponent(Graphics g){
  if(x>0 &&  y>0) {
     g.drawString("X: " + x + ",Y: " + y + "",x,y);
     g.drawString("Click #: " + counter ++ ,x , y + 16);
  }
}

•

Join Date: May 2008

Posts: 54

Reputation: gangsta1903 is an unknown quantity at this point

Solved Threads: 1

gangsta1903 gangsta1903 is offline

Offline

Junior Poster in Training

Nov 7th, 2009

As the previous poster said, use a boolean for first click, also increment your counter in mousePressed. If you increment it in paintComonent, counter will be incremented everytime the frame is repainted. For example when you resize your frame, your counter dramatically changes. This is the fixed code.

 Help with Code Tags 
 java Syntax (Toggle Plain Text) 
import java.awt.*;
import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
 
public class TrackMouseMovementTest {
 
	public static void main(String[] args) {
 
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				MouseFrame frame = new MouseFrame();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setVisible(true);
			}
		});
	}
}
 
class MouseFrame extends JFrame {
	public MouseFrame() {
		setTitle("Mouse Movement Tracker");
		setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
 
		MouseComponent component = new MouseComponent();
		add(component);
	}
 
	public static final int DEFAULT_WIDTH = 500;
	public static final int DEFAULT_HEIGHT = 500;
}
 
class MouseComponent extends JComponent {
	public MouseComponent() {
		firstClick = false;
		addMouseListener(new MouseHandler());
	}
 
	private boolean firstClick;
 
	private class MouseHandler extends MouseAdapter {
		public void mousePressed(MouseEvent event) {
			x = event.getX();
			y = event.getY();
			counter++;
			firstClick = true;
			repaint();
		}
	}
 
	public void paintComponent(Graphics g) {
		if (firstClick) {
			g.drawString("X: " + x + ",Y: " + y + "", x, y);
			g.drawString("Click #: " + counter, x, y + 16);
		}
	}
 
	int x;
	int y;
	private static int counter = 0;
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class TrackMouseMovementTest {

	public static void main(String[] args) {

		EventQueue.invokeLater(new Runnable() {
			public void run() {
				MouseFrame frame = new MouseFrame();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setVisible(true);
			}
		});
	}
}

class MouseFrame extends JFrame {
	public MouseFrame() {
		setTitle("Mouse Movement Tracker");
		setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

		MouseComponent component = new MouseComponent();
		add(component);
	}

	public static final int DEFAULT_WIDTH = 500;
	public static final int DEFAULT_HEIGHT = 500;
}

class MouseComponent extends JComponent {
	public MouseComponent() {
		firstClick = false;
		addMouseListener(new MouseHandler());
	}

	private boolean firstClick;

	private class MouseHandler extends MouseAdapter {
		public void mousePressed(MouseEvent event) {
			x = event.getX();
			y = event.getY();
			counter++;
			firstClick = true;
			repaint();
		}
	}

	public void paintComponent(Graphics g) {
		if (firstClick) {
			g.drawString("X: " + x + ",Y: " + y + "", x, y);
			g.drawString("Click #: " + counter, x, y + 16);
		}
	}

	int x;
	int y;
	private static int counter = 0;
}