[안드로이드 스튜디오] canvas (그림판)

xml 파일은 필요하지 않음.

(1)MainActivity.java

package com.example.touchevent;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    protected class MyView extends View {
        int x = 100, y = 100;
        String str;
        public MyView(Context context) {
            super(context);
            setBackgroundColor(Color.YELLOW);
        }
        @Override
        protected void onDraw(Canvas canvas) {
            Paint paint = new Paint(); // paint.setColor(Color.BLUE);
            paint.setColor(Color.rgb(0,0,255));
            canvas.drawCircle(x, y, 50, paint);
            paint.setTextSize(50);
            canvas.drawText("액션의 종류: " + str, 0, 100, paint);
        }
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            x = (int) event.getX();
            y = (int) event.getY();
            if (event.getAction() == MotionEvent.ACTION_UP)
                str = "ACTION_UP";
            if (event.getAction() == MotionEvent.ACTION_DOWN)
                str = "ACTION_DOWN";
            if (event.getAction() == MotionEvent.ACTION_MOVE)
                str = "ACTION_MOVE";
            invalidate();
            return true;
        }
    }
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        MyView myView = new MyView(this);
        setContentView(myView);
    }
}

(2) 실행화면