2019.9.25

MainActivity.java

package edu.byuh.cis.cs203.hellocs203.sys;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LetiView lv = new LetiView(this);
        setContentView(lv);
    }
}

LetiView.java

package edu.byuh.cis.cs203.hellocs203.sys;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Toast;

import edu.byuh.cis.cs203.hellocs203.graphics.Duck;

public class LetiView extends View {

    private Duck donald;
    private boolean init;

    public /*static*/ class Timer extends Handler {

        public Timer() {
            sendMessageDelayed(obtainMessage(), 0);
        }

        @Override
        public void handleMessage(Message m) {
            //Log.d("CS203", "Hello, Altair!");
            donald.dance();
            invalidate();
            sendMessageDelayed(obtainMessage(), 100);
        }
    }


    public LetiView(Context c) {
        super(c);
        init = false;
        donald = new Duck(getResources());
        Toast t = Toast.makeText(c, "This is another factory example!", Toast.LENGTH_LONG);
        t.show();
        Timer tim = new Timer();
}

    @Override
    public void onDraw(Canvas c) {
        float w = c.getWidth();
        float h = c.getHeight();
        if (init == false) {
            donald.resize(w);
            donald.setPosition(w-donald.width(), 0);
            init = true;
        }
        c.drawColor(Color.GREEN);
        donald.draw(c);
    }

}

Duck.java

package edu.byuh.cis.cs203.hellocs203.graphics;

import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.RectF;

import edu.byuh.cis.cs203.hellocs203.R;

public class Duck {
    private Bitmap image;
    private RectF bounds;

    /**
     * Create a new duck
     * @param res the Android resources object
     */
    public Duck(Resources res) {
        bounds = new RectF();
        image = BitmapFactory.decodeResource(res, R.drawable.duck);
    }

    /**
     * scale the duck to its correct on-screen size
     * @param screenWidth the width of the screen in pixels
     */
    public void resize(float screenWidth) {
        float duckSize = screenWidth * 0.2f;
        image = Bitmap.createScaledBitmap(image,
                (int)duckSize, (int)duckSize, true);
        bounds.set(0,0,duckSize, duckSize);
    }

    /**
     * Draw the duck at its predefined location
     * @param c the Android canvas object
     */
    public void draw(Canvas c) {
        c.drawBitmap(image, bounds.left, bounds.top, null);
    }

    /**
     * Sets the center of the duck to (x,y)
     * @param x the new center x coordinate
     * @param y the new center y coordinate
     */
    public void setPosition(float x, float y) {
        bounds.offsetTo(x,y);
    }

    public float width() {
        return bounds.width();
    }

    public void dance() {
        float dx = 5-(float)(Math.random() * 10);
        float dy = 5-(float)(Math.random() * 10);
        bounds.offset(dx,dy);
    }
}