java - XMotion dealing with JComponents -

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• how move image (animation)? 2 answers

i having trouble. want draw rect onto jpanel added jframe contentpane. want x @ set pos moving -x , restarting +x begins. i.e. if have jpanel 800 x 400, want rext take in parameters moving along xaxis (x - velx) repainting @ 800 , continuing in - x direction. know isn't sufficient info, none of books have touch base on trying lack proper terminology.

// here example of doing this

public class animatedboat {

public static void main(string[] args) {     new animatedboat(); }  public animatedboat() {     eventqueue.invokelater(new runnable() {         @override         public void run() {             try {                 uimanager.setlookandfeel(uimanager.getsystemlookandfeelclassname());             } catch (classnotfoundexception | instantiationexception | illegalaccessexception | unsupportedlookandfeelexception ex) {             }              jframe frame = new jframe("test");             frame.setdefaultcloseoperation(jframe.exit_on_close);             frame.setlayout(new borderlayout());             frame.add(new animationpane());             frame.pack();             frame.setlocationrelativeto(null);             frame.setvisible(true);         }      }); }  public class animationpane extends jpanel {      private bufferedimage boat;     private int xpos = 0;     private int direction = 1;      public animationpane() {         try {             boat = imageio.read(new file("boat.png"));             timer timer = new timer(40, new actionlistener() {                 @override                 public void actionperformed(actionevent e) {                     xpos += direction;                     // change directions off window width                     if (xpos + boat.getwidth() > getwidth()) {                          xpos = getwidth() - boat.getwidth();                         direction *= -1;                     } else if (xpos < 0) {                         xpos = 0;                         direction *= -1;                     }                     repaint();                 }              });             timer.setrepeats(true);             timer.setcoalesce(true);             timer.start();         } catch (ioexception ex) {             ex.printstacktrace();         }     }      @override     public dimension getpreferredsize() {         return boat == null ? super.getpreferredsize() : new dimension(boat.getwidth() * 4, boat.getheight());     }      @override     protected void paintcomponent(graphics g) {         super.paintcomponent(g);          int y = getheight() - boat.getheight();         g.drawimage(boat, xpos, y, this);      }  } 

}