안드로이드 그림판 만드는데 질문점

Question

package com.example.chap9_6;

 

import java.util.ArrayList;

import java.util.List;

 

import android.app.Activity;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Rect;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.MotionEvent;

import android.view.SubMenu;

import android.view.View;

 

public class MainActivity extends Activity {

 

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

static int curShape = LINE;

static int curColor = Color.DKGRAY;

static List<MyShape> myshape = new ArrayList<MyShape>();

static List<Paint> mypaint = new ArrayList<Paint>();

 

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(new MyGraphicView(this));

setTitle("연습문제 9-6");

}

 

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// TODO Auto-generated method stub

super.onCreateOptionsMenu(menu);

menu.add(0, 1, 0, "선 그리기");

menu.add(0, 2, 0, "원 그리기");

menu.add(0, 3, 0, "사각형 그리기");

SubMenu sMenu = menu.addSubMenu("색상 변경 >>");

sMenu.add(0, 4, 0, "빨강");

sMenu.add(0, 5, 0, "초록");

sMenu.add(0, 6, 0, "파랑");

return true;

}

 

@Override

public boolean onOptionsItemSelected(MenuItem item) {

// TODO Auto-generated method stub

switch (item.getItemId()) {

case 1:

curShape = LINE; // 선

return true;

case 2:

curShape = CIRCLE; // 원

return true;

case 3:

curShape = RECTANGLE; // 사각형

return true;

case 4:

curColor = Color.RED;

return true;

case 5:

curColor = Color.GREEN;

return true;

case 6:

curColor = Color.BLUE;

return true;

}

return super.onOptionsItemSelected(item);

}

 

private static class MyShape {

int shapeType; // 도형 종류

int startX, startY, stopX, stopY; // 도형의 2점

int color; // 도형 색상

}

 

private static class MyGraphicView extends View {

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

 

public MyGraphicView(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:

break;

case MotionEvent.ACTION_UP:

stopX = (int) event.getX();

stopY = (int) event.getY();

this.invalidate();

break;

}

 

return true;

}

 

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

 

MyShape ms = new MyShape();

 

Paint paint = new Paint();

paint.setAntiAlias(true);

paint.setStrokeWidth(5);

paint.setStyle(Paint.Style.STROKE);

paint.setColor(curColor);

 

ms.startX = startX;

ms.startY = startY;

ms.stopX = stopX;

ms.stopY = stopY;

ms.shapeType = curShape;

ms.color = curColor;

 

mypaint.add(paint);

 

myshape.add(ms);

 

for(int i=0; i<myshape.size(); i++) {

switch (myshape.get(i).shapeType) {

case LINE:

canvas.drawLine(myshape.get(i).startX, myshape.get(i).startY, myshape.get(i).stopX, myshape.get(i).stopY, mypaint.get(i));

break;

case CIRCLE:

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

+ Math.pow(myshape.get(i).stopY - myshape.get(i).startY, 2));

canvas.drawCircle(myshape.get(i).startX, myshape.get(i).startY, radius, mypaint.get(i));

break;

case RECTANGLE:

Rect rect = new Rect(myshape.get(i).startX, myshape.get(i).startY, myshape.get(i).stopX, myshape.get(i).stopY);

canvas.drawRect(rect, mypaint.get(i));

break;

}

}

}

}

}

 

 

이런 코드로 짜보았는데 드래그 할때마다 흔적이 보이게 하려고 합니다.

 

그래서 case MotionEvent.ACTION_MOVE: 의 break를 지우고 하면

 

이상하게 그림이 출력되어버립니다.

 

원래 마우스를 땠을 떄만 그림이 그려져야는데 움직이는 동안에도 그림이 그려져 버리네요

 

어떻게 해결할까요??