import objectdraw.*;

import java.awt.*;

 

    // A program that produces an animation of the sun rising and setting.

    // The animation is driven by dragging the mouse.

public class ScrollingSun extends WindowController {

 

    private FilledOval sun;     // Circle that represents the sun

    private Text instructions;  // Display of instructions

 

        // Place the sun and some brief instructions on the screen

    public void begin() {

        sun = new FilledOval( canvas.getWidth()/4,

                              canvas.getHeight() - canvas.getWidth()/4,

                              canvas.getWidth()/2,

                              canvas.getWidth()/2, canvas);

 

        instructions = new Text("Drag the mouse up or down",

                                                0, 0, canvas);

        instructions.moveTo((canvas.getWidth()-instructions.getWidth() )/2, 20);

    }

 

        // Move the sun to follow the mouse's vertical motion

    public void onMouseDrag( Location mousePosition ) {

        sun.moveTo(canvas.getWidth()/4, mousePosition.getY());

        instructions.hide();

    }

   

        // Move the sun back to its starting position and redisplay

        // the instructions

    public void onMouseExit( Location point ) {

        sun.moveTo(canvas.getWidth()/4, canvas.getHeight() - canvas.getWidth()/4);

        instructions.show();

    }