CODEWITHSUNDEEP
javaswinggraphicsappletawt
badProgrammer
badProgrammer

Reputation: 27

Shape increases in size instead of moving - Java (GUI applet)

I am trying to change the y position of the rectangle, however, whenever I try to, it expands/gets bigger vertically. 

public class PlayerPaddle implements Paddle {

    double yVelocity;
    final double GRAVITY = 0.94;

    //move up/down faster (if not accelerating = slow down)
    boolean upAccel, downAccel;

    //determines if player 1 or player 2 (on left or on right)
    int player;

    //position of actual paddle
    int x;
    double y;


    Rectangle panel;

    public PlayerPaddle(int player) {

        upAccel = false;
        downAccel = false;

        y = 210; //not moving initially
        yVelocity = 0;

        if (player == 1) {
            //left side
            x = 20;
        } else {
            //right side
            x = 660;
        }
    }


    @Override
    public void draw(Graphics g) {

        //draw paddle
        g.setColor(Color.WHITE);
        g.fillRect(x, (int) y, 20, 80);
    }


    @Override
    public void move() {

        if (upAccel) {
            yVelocity -= 2;
        } else if (downAccel) {
            yVelocity += 2;
        } else if ((!upAccel) && (!downAccel)) {
            yVelocity *= GRAVITY;
        }
        y += yVelocity; //changes y position of paddle
    }

    public void setUpAccel(boolean input) {
        upAccel = input;
    }

    public void setDownAccel(boolean input) {
        downAccel = input;
    }

    @Override
    public int getY() {
        return (int) y;
    }
}

I want to know how to make the rectangle move up and down vertically. A similar question had only one answer which said that the previously painted rectangle was not being cleared and as a result is expanding. But even when I say g.clearRect(...) it still expands and does not move.

I am new to Swing and Awt but I am really committed to learning. Thanks for the help.

Upvotes: 0

Views: 52

Answers (1)

camickr
camickr

Reputation: 324118

A similar question had only one answer which said that the previously painted rectangle was not being cleared and as a result is expanding

And that is still probably the problem here.

Somewhere, not in the code presented here, you need to invoke the draw(...) method of this class.

So in that code you need to make sure the background of the component is cleared before you draw the paddle. Since you should be overriding the paintComponent(...) method of a panel to do custom painting your code should look something like:

@Override
protected void paintComponent(Graphics g)
{
    super.paintComponent(g);
    // draw the paddle
}

Read the section from the Swing tutorial on Custom Painting for more information and working examples.

I am new to Swing and Awt but I am really committed to learning.

Then keep a link to the tutorial handy for all Swing basics.

Upvotes: 1

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