package tz.signaturecapture;

import java.io.OutputStream;

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.RectF;

import android.util.AttributeSet;

import android.util.Log;

import android.view.MotionEvent;

import android.view.View;

public class SignatureWidget extends View

{

    private static final float STROKE_WIDTH = 5f;

    private static final float HALF_STROKE_WIDTH = STROKE_WIDTH / 2;

    private Paint paint = new Paint();

    private Path path = new Path();

    private float lastTouchX;

    private float lastTouchY;

    private final RectF dirtyRect = new RectF();

    public SignatureWidget(Context context, AttributeSet attrs)

    {

        super(context, attrs);

        paint.setAntiAlias(true);

        paint.setColor(Color.BLACK);

        paint.setStyle(Paint.Style.STROKE);

        paint.setStrokeJoin(Paint.Join.ROUND);

        paint.setStrokeWidth(STROKE_WIDTH);

    }

    public void save(View parent, OutputStream os)

    {

        Log.v("log_tag", "Width: " + parent.getWidth());

        Log.v("log_tag", "Height: " + parent.getHeight());

        Canvas canvas = new Canvas(bm);

        parent.draw(canvas);

        bm.compress(Bitmap.CompressFormat.PNG, 90, os);

    }

    public void clear()

    {

        path.reset();

        invalidate();

    }

    @Override

    protected void onDraw(Canvas canvas)

    {

        canvas.drawPath(path, paint);

    }

    @Override

    public boolean onTouchEvent(MotionEvent event)

    {

        float eventX = event.getX();

        float eventY = event.getY();

        switch (event.getAction())

        {

        case MotionEvent.ACTION_DOWN:

            path.moveTo(eventX, eventY);

            lastTouchX = eventX;

            lastTouchY = eventY;

            return true;

        case MotionEvent.ACTION_MOVE:

        case MotionEvent.ACTION_UP:

            resetDirtyRect(eventX, eventY);

            int historySize = event.getHistorySize();

            for (int i = 0; i < historySize; i++)

            {

                float historicalX = event.getHistoricalX(i);

                float historicalY = event.getHistoricalY(i);

                expandDirtyRect(historicalX, historicalY);

                path.lineTo(historicalX, historicalY);

            }

            path.lineTo(eventX, eventY);

            break;

        default:

            debug("Ignored touch event: " + event.toString());

            return false;

        }

        invalidate((int) (dirtyRect.left - HALF_STROKE_WIDTH),

                (int) (dirtyRect.top - HALF_STROKE_WIDTH),

                (int) (dirtyRect.right + HALF_STROKE_WIDTH),

                (int) (dirtyRect.bottom + HALF_STROKE_WIDTH));

        lastTouchX = eventX;

        lastTouchY = eventY;

        return true;

    }

    private void debug(String string){

    }

    private void expandDirtyRect(float historicalX, float historicalY)

    {

        if (historicalX < dirtyRect.left)

        {

            dirtyRect.left = historicalX;

        }

        else if (historicalX > dirtyRect.right)

        {

            dirtyRect.right = historicalX;

        }

        if (historicalY < dirtyRect.top)

        {

            dirtyRect.top = historicalY;

        }

        else if (historicalY > dirtyRect.bottom)

        {

            dirtyRect.bottom = historicalY;

        }

    }

    private void resetDirtyRect(float eventX, float eventY)

    {

        dirtyRect.left = Math.min(lastTouchX, eventX);

        dirtyRect.right = Math.max(lastTouchX, eventX);

        dirtyRect.top = Math.min(lastTouchY, eventY);

        dirtyRect.bottom = Math.max(lastTouchY, eventY);

    }

}