My pong paddle is not operating right

Question

I'm still fairly new to android and I'm currently trying to create pong.

At the moment I am trying to animate two images, one is pong's ball and the second is the paddle. Right now I have those two images and I've got them animating. The ball behaves like I want it to bouncing around the x and y axis and I have the paddle sliding back and forth across the x axis but for some reason the paddle behaves weirdly.

The paddle for some reason animates choppy, stopping and starting whenever it wants. But whenever I remove the ball animation from the code the paddle acts and behaves like I intended it to

If anyone has any suggestion for what I am doing wrong or overlooking, I am all ears, Thanks!

package com.example.pongtest;

import java.util.Timer;
import java.util.TimerTask;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.app.Activity;

public class MainActivity extends Activity {

LinearLayout lay1;
ImageView ballImg, paddleImg;
TimerTask thisTimerTask;
Timer thisTimer;
LinearLayout.LayoutParams params;

float ballPosX=10; 
float ballPosY=10;
float paddlePosX=200;
float paddlePosY=10;
float ballOnLeftWall=0;
float ballOnRightWall=270;
float ballOnBottomWall=400;
float ballOnTopWall=0;
float paddleOnLeftWall=0;
float paddleOnRightWall=200;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    lay1 = new LinearLayout(this);
    ballImg = new ImageView(this);
    ballImg.setBackgroundResource(R.drawable.circlewdot);       
    setPosition(0,0,50,50);
    ballImg.setLayoutParams(params);

    paddleImg=new ImageView(this);
    paddleImg.setBackgroundResource(R.drawable.paddle);
    setPosition(0,0,50,10);
    paddleImg.setLayoutParams(params);

    lay1.addView(ballImg);
    lay1.addView(paddleImg);

    setContentView(lay1);

    thisTimerTask = new ThisTimerClass();
    thisTimer = new Timer(); 

    //setup frame rate of timer
    thisTimer.scheduleAtFixedRate(thisTimerTask, 2000, 16);
}

public void setPosition(float x, float y, float width, float height) {
params = new LinearLayout.LayoutParams(0,0);
params.topMargin = (int)y;
params.leftMargin = (int)x;
params.width = (int)width;
params.height = (int)height;
}

class ThisTimerClass extends TimerTask {
boolean directionOfBall_isRight = true;
boolean directionOfBall_isDown = true;
boolean directionOfPaddle_isLeft = true;

@Override
public void run() {
    // Will be called each time the timer is fired.
    MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {

        setPosition(ballPosX,ballPosY,50,50);
        ballImg.setLayoutParams(params);

        setPosition(paddlePosX,paddlePosY,50,10);
        paddleImg.setLayoutParams(params);

        //animates ball across the screen
        if (directionOfBall_isRight == true) 
        {ballPosX = (ballPosX + 1);}

        else if (directionOfBall_isRight == false) 
        {ballPosX = (ballPosX - 1);}

        if (directionOfBall_isDown == true) 
        {ballPosY = (ballPosY + 1);}

        else if (directionOfBall_isDown == false) 
        {ballPosY = (ballPosY - 1);}

        //redirects ball
        if (ballPosX > ballOnRightWall) 
        {directionOfBall_isRight = false;}

        else if (ballPosX < ballOnLeftWall) 
        {directionOfBall_isRight = true;} 

        if (ballPosY > ballOnBottomWall) 
        {directionOfBall_isDown = false;}

        else if (ballPosY < ballOnTopWall) 
        {directionOfBall_isDown = true;}

        //animates paddle across the screen
        if (directionOfPaddle_isLeft == true) 
        {paddlePosX = (paddlePosX - 1);}

        else if (directionOfPaddle_isLeft == false) 
        {paddlePosX = (paddlePosX + 1);}

        //redirects paddle
        if (paddlePosX < paddleOnLeftWall) 
        {directionOfPaddle_isLeft = false;}

        else if (paddlePosX > paddleOnRightWall) 
        {directionOfPaddle_isLeft = true;}
    }

});
}    
}
}

Answer 1

this is possibly because you are controlling the ball and the paddle on the same thread. the system can't concurrently do two things from a single thread!