DrawingView.java

package com.example.asamles.app.paint;


import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;

public class DrawingView extends View {
    public final int SMALL = 10;
    private int paintColor = 0xFF000000;
    private Path drawPath;
    private Paint drawPaint;
    private Paint canvasPaint;
    private Canvas drawCanvas;
    private Bitmap canvasBitmap;
    private float brushSize;
//    private float lastBrushSize;

    public DrawingView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setupDrawing();
    }

    private void setupDrawing() {
        brushSize = SMALL;
//        lastBrushSize = brushSize;
        drawPath = new Path();
        drawPaint = new Paint();
        drawPaint.setColor(paintColor);
        drawPaint.setAntiAlias(true);
        drawPaint.setStrokeWidth(brushSize);
        drawPaint.setStyle(Paint.Style.STROKE);
        drawPaint.setStrokeJoin(Paint.Join.ROUND);
        drawPaint.setStrokeCap(Paint.Cap.ROUND);
        canvasPaint = new Paint(Paint.DITHER_FLAG);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        drawCanvas = new Canvas(canvasBitmap);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
        canvas.drawPath(drawPath, drawPaint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float touchX = event.getX();
        float touchY = event.getY();

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                drawPath.moveTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_MOVE:
                drawPath.lineTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_UP:
                drawPath.lineTo(touchX, touchY);
                drawCanvas.drawPath(drawPath, drawPaint);
                drawPath.reset();
                break;
            default:
                return false;
        }

        invalidate();
        return true;

    }

    public void setColor(int paintColor) {
        invalidate();
        this.paintColor = paintColor;
        // paintColor = Color.parseColor(newColor);
        drawPaint.setColor(paintColor);
    }

    public void setBrushSize(float newSize) {
        DisplayMetrics displayMetrics = null;
        if(getResources() != null)
            displayMetrics = getResources().getDisplayMetrics();
        if (displayMetrics != null) {
            brushSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
                    newSize, displayMetrics);
        } else {
            brushSize = newSize;
        }
        drawPaint.setStrokeWidth(brushSize);
    }

//    public void setLastBrushSize(float lastSize) {
//        lastBrushSize = lastSize;
//    }
//
//    public float getLastBrushSize() {
//        return lastBrushSize;
//    }

    public void setErase(boolean isErase) {
        if (isErase) {
            drawPaint.setColor(Color.WHITE);
//			drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
        } else {
            drawPaint.setColor(paintColor);
//			drawPaint.setXfermode(null);
        }
    }

    public void clear() {
        drawCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
        invalidate();
    }
}