Thread: Simple GUI/Animation question...

I am currently trying to build a very basic animation program. I want to draw an arc, or bending line, based off input from the GUI.

I'm very new to Java, with some experience in other languages.

I have the basic code working kind of. My GUI pops up and I can redraw new lines when the user hits the buttons, but the two aren't properly related. I just want my line to be drawn in a box on the same GUI screen as the buttons.

I'm sure you pros can solve this in a heartbeat. I've been trying to do this by scrapping together other examples I've found online.

my Main code that starts the GUI:

package animation;
 
import javax.swing.*;
 
public class Main extends JApplet {
 
	public Main() {
		add(new Main());
	}
 
	public static void main(String[] args) {
		JFrame win = new JFrame("Strain Gauge Simulation");
		win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		win.setContentPane(new BBPanel());
		win.pack();
		win.setVisible(true); 
	}
}

My code that builds the GUI panel:

package animation;
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
 
 
class BBPanel extends JPanel {
 
    private int forces;
    Arc1 m_cc;
 
    BBPanel() {
    	forces = 0;      
        m_cc = new Arc1();
 
        m_cc.init(forces);
 
        m_cc.setPreferredSize(new Dimension(500, 500));
 
        JButton forcedButton = new JButton("Force Down");
        JButton forceuButton = new JButton("Force Up");
 
        forceuButton.addActionListener(new ForceuAction());
        forcedButton.addActionListener(new ForcedAction());
 
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout());
 
        buttonPanel.add(forceuButton);
        buttonPanel.add(forcedButton);
 
        this.setLayout(new BorderLayout());
        this.add(buttonPanel, BorderLayout.NORTH);
        this.add(m_cc       , BorderLayout.CENTER);
    }
 
    class ForceuAction implements ActionListener {
    	public void actionPerformed(ActionEvent e) {
    		forces = forces + 1;
    		JFrame f = new JFrame();
    	      Arc1 curve = new Arc1();
    	      f.setLocation(150+forces*10, 150+forces*10);
    	      f.setSize(500,500);
    	      curve.init(forces);
    	      f.getContentPane().add(curve);
    	      f.setDefaultCloseOperation(1);
    	      f.setVisible(true);
 
    		System.out.println(forces);
    	}
    }
 
    class ForcedAction implements ActionListener {
    	public void actionPerformed(ActionEvent e){
 
    		forces = forces - 1;
    		m_cc.init(forces);
    		JFrame f = new JFrame();
    	     Arc1 curve = new Arc1();
    	      f.setLocation(150+forces*10, 150+forces*10);
    	      f.setSize(500,500);
    	      curve.init(forces);
    	      f.getContentPane().add(curve);
    	      f.setDefaultCloseOperation(1);
    	      f.setVisible(true);
 
    		System.out.println(forces);
    	}
    }  
}

And the code I have that draws the line:

package animation;
 
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.QuadCurve2D;
import java.awt.geom.Rectangle2D;
import java.util.Vector;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
 
import javax.swing.JApplet;
 
public class Arc1 extends JApplet{
  DrawingCanvas canvas;
 
 
  public static void main(String[] a){
 
      /*JFrame f = new JFrame();
      Arc1 curve = new Arc1();
      f.setSize(1000,1000);
      curve.init();
      f.getContentPane().add(curve);
      f.setDefaultCloseOperation(1);
      f.setVisible(true);*/
  }
 
  public void init(int forces) {
 
    Container container = getContentPane();
    canvas = new DrawingCanvas(forces);
    container.add(canvas);
  }
 
  class DrawingCanvas extends Canvas {
 
    Vector quadCurves;
    QuadCurve2D selectedCurve = null;
    Rectangle2D boundingRec = null;
 
    public DrawingCanvas(int forces){
 
      quadCurves = new Vector();
      quadCurves.addElement(new QuadCurve2D.Float(1, 100, 301, 100, 401, 100+forces*5));     
    }
 
    public void paint(Graphics g) {
      Graphics2D g2D = (Graphics2D) g;
 
      for (int i = 0; i < quadCurves.size(); i++) {
        g2D.draw((QuadCurve2D) quadCurves.elementAt(i));
      }
 
    }
  }
}

Any help would be great, I would really love have that line embedded below the buttons. The example code I'm building off of can be found here

And I know that I shouldn't rebuild a new frame each time the force is changed by hitting the button, but I added it in so you can see what I would like to appear on the GUI, instead of a new window.

Thanks so much for the advice. I've read through a lot of that, but again, its mostly above my head still because I'm so new to Java. Regardless, I made some changes based on what you provided.

And yes I am coding an application, running in Eclipse.

It works.... better. Now its a matter of refreshing the newly drawn image. If I resize the window it refreshes, but I can click the 'up/down' buttons all I want and it wont change until I do so.

Here is the new code per your advice:

package animation;
 
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.QuadCurve2D;
import java.awt.geom.QuadCurve2D.Float;
import java.util.Vector;
import javax.swing.*;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
 
 
class BBPanel extends JPanel {
    private int forces;
 
    BBPanel() {     
 
        JButton forcedButton = new JButton("Force Down");
        JButton forceuButton = new JButton("Force Up");
 
        forceuButton.addActionListener(new ForceuAction());
        forcedButton.addActionListener(new ForcedAction());
 
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout());
 
        JPanel drawpanel = new JPanel();
        drawpanel.setLayout(new FlowLayout());
        drawpanel.setVisible(true);
        drawpanel.setBorder(BorderFactory.createLineBorder(Color.black));
        drawpanel.setPreferredSize(new Dimension(450,300));
 
        JPanel southpanel = new JPanel();
        southpanel.setLayout(new FlowLayout());
        southpanel.setVisible(true);
        southpanel.setBorder(BorderFactory.createLineBorder(Color.black));
 
        ImageIcon icon = new ImageIcon("C:\\Users\\bmj119\\Pictures\\wsb.jpg"); 
        JLabel label = new JLabel(icon);
        southpanel.add(label);
 
        buttonPanel.add(forceuButton);
        buttonPanel.add(forcedButton);
 
        this.setLayout(new BorderLayout());
        this.add(buttonPanel, BorderLayout.NORTH);
        this.add(drawpanel, BorderLayout.CENTER);
        this.add(southpanel, BorderLayout.SOUTH);
    }
 
    class ForceuAction implements ActionListener {
    	public void actionPerformed(ActionEvent e) {
 
    	    forces = forces + 1; 
 
    		System.out.println(forces);
 
    	}
    }
 
    class ForcedAction implements ActionListener {
    	public void actionPerformed(ActionEvent e){
 
    		forces = forces - 1;
 
    		System.out.println(forces);
 
    	}
    }
 
 
    public void paint(Graphics g) {
    	super.paintComponents(g);
 
        Graphics2D g2D = (Graphics2D) g;
        Vector<Float> quadCurves;
		quadCurves = new Vector<Float>();
	    quadCurves.addElement(new QuadCurve2D.Float(1, 100, 301, 100, 401, 100+forces*5));
 
        for (int i = 0; i < quadCurves.size(); i++) {
          g2D.draw((QuadCurve2D) quadCurves.elementAt(i));
        }      
    }
 
}

Thanks again, I feel I'm really close.

Ok, maybe Its not working as well as I thought, if I resize too much it distorts everything. If I can get it to auto-refresh this won't be a problem, but I would like to know why.

I feel like the drawing is just 'landing' in the intended panel, as opposed to being embedded at the desired position.