CustomDrawingView

package it.test.ui.component;

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.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;

    public class DrawingView extends View
    {
        private Path mDrawPath;
        private Paint mBackgroundPaint;
        private Paint mDrawPaint;
        private Canvas mDrawCanvas;
        private Bitmap mCanvasBitmap;
        private boolean mDisegnoAbilitato;
        private boolean drawMode;
        private boolean mTestoAbilitato;
        private float x, y;

        private String testoDaDisegnare = "";

        private ArrayList<Path> mPaths = new ArrayList<>();
        private ArrayList<Paint> mPaints = new ArrayList<>();
        private ArrayList<Path> mUndonePaths = new ArrayList<>();
        private ArrayList<Paint> mUndonePaints = new ArrayList<>();

        // Set default values
        private int mBackgroundColor = 0x00FFFFFF;
        private int mPaintColor = 0x00660000;
        private int mStrokeWidth = 10;

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

        private void init()
        {
            mDrawPath = new Path();
            mBackgroundPaint = new Paint();
            initPaint();
        }

        private void initPaint()
        {
            mDrawPaint = new Paint();
            mDrawPaint.setColor(mPaintColor);
            mDrawPaint.setAntiAlias(true);
            mDrawPaint.setStrokeWidth(mStrokeWidth);
            mDrawPaint.setStyle(Paint.Style.STROKE);
            mDrawPaint.setStrokeJoin(Paint.Join.ROUND);
            mDrawPaint.setStrokeCap(Paint.Cap.ROUND);
        }

        private void drawBackground(Canvas canvas)
        {
            mBackgroundPaint.setColor(Color.TRANSPARENT);
            mBackgroundPaint.setAntiAlias(true);
            mBackgroundPaint.setAlpha(0);
            canvas.drawRect(0, 0, this.getWidth(), this.getHeight(), mBackgroundPaint);

        }

        private void drawPaths(Canvas canvas)
        {
            int i = 0;
            for (Path p : mPaths)
            {
                canvas.drawPath(p, mPaints.get(i));
                i++;
            }
        }

        @Override
        protected void onDraw(Canvas canvas)
        {
            drawBackground(canvas);
            drawPaths(canvas);

            canvas.drawPath(mDrawPath, mDrawPaint);
        }

        @Override
        protected void onSizeChanged(int w, int h, int oldw, int oldh)
        {
            super.onSizeChanged(w, h, oldw, oldh);

            mCanvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);

            mDrawCanvas = new Canvas(mCanvasBitmap);
        }


        public void setTestoDaDisegnare(String testo)
        {
            testoDaDisegnare = testo;
        }


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

            if(mDisegnoAbilitato) {

                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        if(mTestoAbilitato)
                        {
                            mDrawPaint.getTextPath(testoDaDisegnare, 0, testoDaDisegnare.length(), touchX, touchY, mDrawPath);
                            mDrawPath.close();
                            invalidate();
                            return true;
                        }
                        else {
                            Log.d("Debug", "TOUCH EVENT: ACTION_DOWN");
                            mDrawPath.moveTo(touchX, touchY);
                        }
                        break;
                    case MotionEvent.ACTION_MOVE:
                        Log.d("Debug", "TOUCH EVENT: ACTION_DOWN");
                        mDrawPath.lineTo(touchX, touchY);
                        break;
                    case MotionEvent.ACTION_UP:
                        Log.d("Debug", "TOUCH EVENT: ACTION_DOWN");
                        mDrawPath.lineTo(touchX, touchY);
                        mPaths.add(mDrawPath);
                        mPaints.add(mDrawPaint);
                        mDrawPath = new Path();
                        initPaint();
                        break;
                    default:
                        return false;
                }

            }

            invalidate();
            return true;
        }

        public void clearCanvas()
        {
            mPaths.clear();
            mPaints.clear();
            mUndonePaths.clear();
            mUndonePaints.clear();
            mDrawCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
            invalidate();
        }

        public void startEraser()
        {
            Log.d("Drawingview", "StartEraser");
            mDrawPaint.setXfermode(null);
            mDrawPaint.setAlpha(0xFF);
            mDrawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));

        }

        public void setPaintColor(int color)
        {
            mPaintColor = color;
            mDrawPaint.setColor(mPaintColor);
        }

        public void setDisegnoAbilitato(boolean abilitato)
        {
            mDisegnoAbilitato = abilitato;
        }

        public void setmTestoAbilitato(boolean abilitato) { mTestoAbilitato = abilitato; }

        public void setPaintStrokeWidth(int strokeWidth)
        {
            mStrokeWidth = strokeWidth;
            mDrawPaint.setStrokeWidth(mStrokeWidth);
        }

        public void setBackgroundColor(int color)
        {
            mBackgroundColor = color;
            mBackgroundPaint.setColor(mBackgroundColor);
            invalidate();
        }

        public void drawText(String testo)
        {
            Paint paintText = new Paint(Paint.ANTI_ALIAS_FLAG);
            mDrawPaint.setColor(Color.BLUE);
            mDrawPaint.setTextSize(200);

            Rect rectText = new Rect();
            paintText.getTextBounds(testo, 0, testo.length(), rectText);

            mDrawCanvas.drawText(testo, 10, 25, mDrawPaint);
        //  invalidate();
        }



        public Bitmap getBitmap()
        {
            drawBackground(mDrawCanvas);
            drawPaths(mDrawCanvas);
            return mCanvasBitmap;
        }

        public void undo()
        {
            if (mPaths.size() > 0)
            {
                mUndonePaths.add(mPaths.remove(mPaths.size() - 1));
                mUndonePaints.add(mPaints.remove(mPaints.size() - 1));
                invalidate();
            }
        }


        public void redo()
        {
            if (mUndonePaths.size() > 0)
            {
                mPaths.add(mUndonePaths.remove(mUndonePaths.size() - 1));
                mPaints.add(mUndonePaints.remove(mUndonePaints.size() - 1));
                invalidate();
            }
        }
    }