Question

I have one three rectangles in my canvas. I wanted to change the colours of three rectangles
in a slow manner one by one.
For example: When starting the application, user should be able to see three rectangles with the same colour (blue).
After 2 secons that rectangles colour should change to red.
Again after 2 secons the next rectangles colour should get changed.
The last one is also done the same way, that means after 2 seconds of the 2nd rectangle.

I wrote in my own way. But it is not working. All the rectanlges are changed together. I want one by one.

Could anyone give me the logic.

final Runnable timer = new Runnable() {

        public void run() {


            //list of rectangles size =3; each contain Rectangle.
            for(int i = 0 ; i < rectangleList.size();i++){

                if(rectangleListt.get(i).getBackgroundColor().equals(ColorConstants.blue)){
                    try {

                        rectangleList.get(i).setBackgroundColor(ColorConstants.yellow);
                        Thread.sleep(1500);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

                    //rectSubFigureList.get(i).setBorder(null);
                }/*else{
                    rectSubFigureList.get(i).setBackgroundColor(ColorConstants.blue);
                }*/


            }

Answer 1

You can set a Timer:

    // declaration: 
    static int changed = 0;

    // the timer:     
    Timer t = new Timer(2000, new ActionListener() {
         @Override
         public void actionPerformed(ActionEvent e) {
                // Change the colour here:
                if (changed == 0) {
                  // change the first one
                } else if (changed == 1) {
                  // change the second one
                } else if (changed == 2) {
                  // change the last one
                } else {
                  ((Timer) e.getSource()).stop();
                }
                changed ++;

          }
     });
     t.start();