I'm testing a program that uses a JSlider to adjust the width of a circle, and the value of the slider is working, but its not actually changing the 'width' variable. Please help!!! Here is what I have so far:
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);
}
}
The other class:
public class DrawShape extends JPanel{
private float width = 300;
private 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) {
this.width = w;
circle.setFrame(100, 20, w, 300);
revalidate();
}
@Override
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
size.width = circle.getBounds().width;
return size;
}
public void paintComponent (Graphics g) {
super.paintComponents(g);
Graphics2D graphics = (Graphics2D)g;
graphics.setColor(Color.black);
graphics.fill(circle);
}//end paintComponent
}//end class
Two (major) issues popup.
Firstly, in your event handler, you're repainting the slider frame, which isn't going to help, so it your setWidth you should add a repaint request, for example.
public void setWidth(int w) {
System.out.println("setWidth " + w);
this.width = w;
circle.setFrame(100, 20, w, 300);
revalidate();
repaint();
}
Secondly, you all calling super.paintComponents (note the s at the end) instead of super.paintComponent, for example...
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.black);
g2d.fill(circle);
}//end paintComponent
This will cause you a significant amount of grieve with strange paint artifacts...