Android Paint 안드로이드 그림판 만들기

Android Paint 안드로이드 그림판 만들기

 

activity_main.xml layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <Button
            android:id="@+id/draw_red_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="red" />

        <Button
            android:id="@+id/draw_blue_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="blue" />

        <Button
            android:id="@+id/draw_black_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="black" />

        <Button
            android:id="@+id/clear_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="clear" />




    </LinearLayout>

    <LinearLayout
        android:id="@+id/draw_linear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"/>



</LinearLayout>

 

MainActivity.java

package com.example.paint1;

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;
import android.widget.Button;
import android.widget.LinearLayout;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    class Point{
        float x;
        float y;
        boolean check;
        int color;

        public Point(float x, float y, boolean check,int color)
        {
            this.x = x;
            this.y = y;
            this.check = check;
            this.color = color;
        }
    }

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

        @Override
        protected void onDraw(Canvas canvas) {
            Paint p = new Paint();
            p.setStrokeWidth(15);
            for(int i=1 ; i<points.size() ; i++)
            {
                p.setColor(points.get(i).color);
                if(!points.get(i).check)
                    continue;
                canvas.drawLine(points.get(i-1).x,points.get(i-1).y,points.get(i).x,points.get(i).y,p);
            }
        }
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float x = event.getX();
            float y = event.getY();

            switch (event.getAction())
            {
                case MotionEvent.ACTION_DOWN:
                    points.add(new Point(x,y,false , color));
                case MotionEvent.ACTION_MOVE :
                    points.add(new Point(x,y,true , color));
                    break;
                case MotionEvent.ACTION_UP :
                    break;
            }
            invalidate();
            return true;
        }
    }

    ArrayList<Point> points = new ArrayList<Point>();
    Button draw_red_btn,draw_blue_btn,draw_black_btn,clearbtn;
    LinearLayout drawlinear;
    int color = Color.BLACK;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final MyView m = new MyView(this);
        /* ----- 색 변경 ------ */
        findViewById(R.id.draw_red_btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                color = Color.RED ;
            }
        });
        findViewById(R.id.draw_blue_btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                color = Color.BLUE ;
            }
        });
        findViewById(R.id.draw_black_btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                color = Color.BLACK ;
            }
        });

        clearbtn = findViewById(R.id.clear_btn);
        drawlinear = findViewById(R.id.draw_linear);
        clearbtn.setOnClickListener(new View.OnClickListener() { //지우기 버튼 눌렸을때
            @Override
            public void onClick(View v){
                points.clear();
                m.invalidate();
            }
        });
        drawlinear.addView(m);
    }
}

 

youtu.be/nWrZLYm_Ioc