Android-Invalidate()

package com.high_guy.tut;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;
import java.lang.Math;

public class MainActivity extends Activity {
    private int wy,t;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyView(this));
    }

    public class MyView extends View {
        public MyView(Context context) {
            super(context);
            // TODO Auto-generated constructor stub
        }

        @Override
        protected void onDraw(Canvas canvas) {
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
            // TODO Auto-generated method stub
            super.onDraw(canvas);
            int x = getWidth();
            int y = getHeight();
            int radius;
            radius = 10;
            Paint paint = new Paint();
            paint.setStyle(Paint.Style.FILL);
            paint.setColor(Color.WHITE);
            canvas.drawPaint(paint);
            // Use Color.parseColor to define HTML colors
            //paint.setColor(Color.parseColor("#CD5C5C"));
            paint.setColor(Color.BLUE);
            for(int i=0;i<y-20;i++) {
                t++;
                wy = (int)Math.sin(t)*20;
                canvas.drawCircle(x/2+wy, 10+i*20, radius, paint);
            }
            invalidate();
        }
    }
}

package com.high_guy.tut;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import java.lang.Math;

public class MainActivity extends Activity {
    private int wy,t,x,y,radius,i;
    private Paint paintC;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // requesting to turn the title OFF
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        // full screen
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        // set layout
        setContentView(new MyView(this));
    }

    public class MyView extends View {
        public MyView(Context context) {
            super(context);
            init();
        }

        private void init() {
            radius = 10;
            
            paintC = new Paint();
            paintC.setStyle(Paint.Style.FILL);
            paintC.setColor(Color.BLUE);
	}

	@Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            // draw background
            canvas.drawColor(Color.WHITE);
            
            // set width and height
            x = getWidth();
            y = getHeight();

            // change circle
            if(i<y-20){
                t++;
                wy = (int)Math.sin(t)*20;
                canvas.drawCircle(x/2+wy, 10+i*20, radius, paintC);
                i++;
            }
            
            // refresh view
            invalidate();
        }
    }
}

package com.guy.high.first;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import java.lang.Math;

public class MainActivity extends Activity {
    private int t,x,y,radius,sin,cos;
    private Paint paintC;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // requesting to turn the title OFF
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        // full screen
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        // set layout
        setContentView(new MyView(this));
    }

    public class MyView extends View {
        public MyView(Context context) {
            super(context);
            init();
        }

        private void init() {
            radius = 10;

            paintC = new Paint();
            paintC.setStyle(Paint.Style.FILL);
            paintC.setColor(Color.BLUE);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            // draw background
            canvas.drawColor(Color.WHITE);

            // set width and height
            x = getWidth();
            y = getHeight();

            // change circle
            canvas.drawCircle(x/2+sin, y/2+cos, radius, paintC);

            t++;
            sin = (int)Math.sin(t)*50;
            cos = (int)Math.cos(t)*50;

            // refresh view
            invalidate();
        }
    }
}

package com.guy.high.first;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends Activity {
    private int x,y,radius;
    private double t;
    private float sin, cos;
    private Paint paintC;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // requesting to turn the title OFF
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        // full screen
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        // set layout
        setContentView(new MyView(this));
    }

    public class MyView extends View {
        public MyView(Context context) {
            super(context);
            init();
        }

        private void init() {
            radius = 10;

            paintC = new Paint();
            paintC.setStyle(Paint.Style.FILL);
            paintC.setColor(Color.BLUE);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            // draw background
            canvas.drawColor(Color.WHITE);

            // set width and height
            x = getWidth();
            y = getHeight();

            // draw circle
            canvas.drawCircle(x/2+sin, y/2+cos, radius, paintC);

            // math
            t+=0.1;
            sin = (float)Math.sin(t)*50;
            cos = (float)Math.cos(t)*50;

            // check values for sin/cos in logcat
            Log.d("MainActivity", sin + " " + cos);
            
            // refresh view
            invalidate();
        }
    }
}