[코틀린코드연습장] 아무 기능도 없는 그림판

그림판에는 광고가 있으니, 그냥 그림판을 만들어볼까 했는데, 

쉽지 않고만... 인터넷을 뒤져서 한번 해본다.

그림판 지우기는 편의상 옵션메뉴로 처리(배운걸 써먹는구만 ㅋ)

[메인.xml]

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    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:background="#FFFFFF"
    android:padding="0dp"
    tools:context="com.tistory.sunnybong.pic.MainActivity">

    <com.tistory.sunnybong.pic.CanvasView
        android:id = "@+id/canvas"
        android:layout_width="match_parent"
        android:layout_height="match_parent"        
        android:layout_centerHorizontal="true"
        android:layout_alignParentTop="true"
        />


</RelativeLayout>

[메인.kt]

class MainActivity : AppCompatActivity() {

    lateinit var canvasView: CanvasView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        canvasView = findViewById(R.id.canvas)

//        clearCanvas.setOnClickListener(ClearCanvas(canvasView) as View.OnClickListener)

    }

//    fun ClearCanvas(view: View) {
//        canvasView.ClearCanvas()
//    }

    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
        menuInflater.inflate(R.menu.menu, menu)
        return super.onCreateOptionsMenu(menu)
    }

    override fun onOptionsItemSelected(item: MenuItem?): Boolean {

        when(item?.itemId) {
            R.id.erase -> canvasView.ClearCanvas()
        }

        return super.onOptionsItemSelected(item)

    }

}

[캔버스 만들기 클래스.kt]

class CanvasView(internal var context: Context, attrs : AttributeSet?) : View(context, attrs) {

    private var mbitmap : Bitmap? = null
    private var mCanvas : Canvas? = null
    private var mPath : Path = Path()
    private var mPaint: Paint = Paint()
    private var mX : Float = 0.toFloat()
    private var mY : Float = 0.toFloat()

    init {
        mPaint.isAntiAlias = true
        mPaint.color = Color.rgb(255,0,216)
        mPaint.style = Paint.Style.STROKE
        mPaint.strokeJoin = Paint.Join.ROUND
        mPaint.strokeWidth = 4f
    }

    override fun onDraw(canvas: Canvas?) {
        super.onDraw(canvas)
        canvas!!.drawPath(mPath, mPaint)
    }

    override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
        super.onSizeChanged(w, h, oldw, oldh)

        mbitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)
        mCanvas = Canvas(mbitmap)

    }

    private fun onStartTouchEvent(x:Float, y:Float) {
        mPath.moveTo(x,y)
        mX = x
        mY = y
    }

    private fun onMoveTouchEvent(x:Float, y:Float) {
        val dx = Math.abs(x - mX)
        val dy = Math.abs(y - mY)
        if(dx >= TOLERANCE || dy >= TOLERANCE) {
            mPath.quadTo(mX,mY,(x+mX)/2,(y+mY)/2)
            mX = x
            mY = y
        }

    }

    private fun upTouchEvent(){
        mPath.lineTo(mX,mY)
    }

    fun ClearCanvas(){
        mPath.reset()
        invalidate()
    }



    override fun onTouchEvent(event: MotionEvent): Boolean {
        val x = event.x
        val y = event.y

        when(event.action) {
            MotionEvent.ACTION_DOWN -> {
                onStartTouchEvent(x,y)
                invalidate()
            }
            MotionEvent.ACTION_MOVE -> {
                onMoveTouchEvent(x,y)
                invalidate()
            }
            MotionEvent.ACTION_UP -> {
                upTouchEvent()
                invalidate()
            }
        }
        return true
    }

    companion object {
        private val TOLERANCE = 5f
    }

}

[옵션메뉴.xml]

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/erase"
        android:icon="@android:drawable/checkbox_off_background"
        android:title="Erase"
        app:showAsAction="always" />
</menu>

음... 별거 아닌것 같지만 좀 복잡하니.. 공부 열심히 혀야겠다.