onDraw

package com.example.testapp;

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.Menu;

import android.view.MenuItem;

import android.view.MotionEvent;

import android.view.View;

public class MainActivity extends Activity {

final static int LINE =1, CIRCLE=2, Rac=3;

static int curShape=LINE;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(new MyView(this));

        setTitle("break");

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu)

    {

    super.onCreateOptionsMenu(menu);

    menu.add(0,1,0,"선 그리기");

    menu.add(0,2,0,"원 그리기");

    menu.add(0,3,0,"사각형 그리기");

    return true;

    }

    

    @Override

    public boolean onOptionsItemSelected(MenuItem item){

    switch(item.getItemId()) {

    case 1:

    curShape = LINE;

    return true;

    case 2:

    curShape = CIRCLE;

    return true;

    case 3:

    curShape = Rac;

    }

    return super.onOptionsItemSelected(item);

    }

    

    private static class MyView extends View{

    int startX=-1, startY=-1, stopX=-1, stopY=-1;

    public MyView(Context context){

    super(context);

    }

   

    @Override

    public boolean onTouchEvent(MotionEvent event){

    switch (event.getAction()){

    case MotionEvent.ACTION_DOWN:

    startX=(int)event.getX();

    startY=(int)event.getY();

    break;

    case MotionEvent.ACTION_MOVE:

    case MotionEvent.ACTION_UP:

    stopX=(int)event.getX();

    stopY=(int)event.getY();

    this.invalidate();

    break;

    }

    return true;

    }

   

    @Override

    protected void onDraw(Canvas canvas){

    super.onDraw(canvas);

    Paint paint=new Paint();

    paint.setAntiAlias(true);

    paint.setStrokeWidth(5);

    paint.setStyle(Paint.Style.STROKE);

    paint.setColor(Color.RED);

   

    switch (curShape){

    case LINE:

    canvas.drawLine(startX,startY,stopX,stopY,paint);

    break;

    case CIRCLE:

    int radius = (int) Math.sqrt(Math.pow(stopX - startX, 2) 

    + Math.pow(stopY - startY,2));

    canvas.drawCircle(startX, startY, radius, paint);

    break;

    case Rac:

    canvas.drawRect(startX, startY, stopX, stopY, paint);

   

    }

    }

    }

}