How to Draw Portion of Bitmap via Canvas DrawBitmap

Question

I have an
:

1. FrameLayout(marked with red)
2. Source ImageView(black)
3. Object(imageview) with OnTouchListener (orange)

Via Object with OnTouchListener,i want to show a portion of bitmap,that are filled on imageview(source imageview).

So it's not a problem,i'm doing like this:
Bitmap bt = Bitmap.createBitmap(sourceBitmap,event.getX(),event.getY(),250,250);

where:

1. SourceBitmap - is an image that are added to source ImageView
2. event.getX() / event.getY() is an coord,where i start to draw portion of bitmap
3. 250,250 - its an size of portion bitmap(part).

and the result is:

So the problems occurs,when my object(with touchlistener),going to the border(i have made this possibility for orange object,to go out of border with Object.width()/2).

So in this case:

how can i achieve this result:

where result of portion will be:

1. Part of bitmap
2. second part is color of framelayout background.

What i tried at current moment:

public boolean onTouch(View view, MotionEvent event) {

    switch (event.getAction()) {
        case MotionEvent.ACTION_MOVE:

            //i want to draw bigger portion then corrds
            int CurrentX = (int)view.getX() - (view.getWidth());
            int CurrentY = (int)view.getY() - (view.getHeight());

            //case,when object is going out of border
            if(CurrentX <= 0)
            {
                Paint paint = new Paint();
                paint.setStyle( Style.FILL  );
                paint.setColor( Color.RED );

                mBitmap = Bitmap.CreateBitmap(sourceBitmap,(int)view.getX() + Math.abs(CurrentX),(int)view.getY(),250,250);
                Canvas canvas = new Canvas(mBitmap);
                canvas.drawBitmap(mBitmap,new Rect((int)view.getX()+Math.abs(CurrentX), (int)view.getY(),250-Math.abs(CurrentX),250),new RectF(Math.abs(CurrentX), 0, 250,250),paint);
            }
            break;
    }

    return true;
}
}

Any suggestions? Thanks!

Answer 1

Solved by myself!
It was complicated,but result is pretty nice.
Here we go:
So for my case(when object with OnTouchListener can go out of border On X and Y axes),i've made Post Conditions(some kind of regulations).

---

Conditions

Width = Width of imageView,where i want to show result.
Height = Height of imageView,where i want to show result;

LeftSide

1. X_Coord < 0 && Y_Coord - Height / 2 < 0 && Y_Coord < Bitmap.Height
   This is our Top Area.
2. X_Coord < 0 && Y_Coord - Height / 2 > 0 && Y_Coord < Bitmap.Height
   This is our Middle Area.
3. X_Coord < 0 && Y_Coord - Height / 2 > 0 && Y_Coord > Bitmap.Height
   This is our Bottom Area.

---

RightSide

1. X_Coord > Bitmap.Height && Y_Coord - Height / 2 > 0 && Y_Coord < Bitmap.Height
   This is our Middle Area.
2. X_Coord > Bitmap.Height && Y_Coord - Height / 2 < 0 && Y_Coord < Bitmap.Height
   This is our Top Area.
3. X_Coord > Bitmap.Height && Y_Coord - Height / 2 > 0 && Y_Coord > Bitmap.Height
   This is our Bottom Area.

---

Standart(Area of Middle,that are not going to Left or Right side)

1. X_Coord - Width / 2 > 0 && X_Coord < Bitmap.Width && Y_Coord - Height / 2 < 0 && Y_Coord < Bitmap.Height
   This is our Top Area.
2. X_Coord - Width / 2 > 0 && X_Coord < Bitmap.Width && Y_Coord - Height / 2 > 0 && Y_Coord > Bitmap.Height
   This is our Bottom Area.
3. X_Coord - Width / 2 > 0 && X_Coord < Bitmap.Width && Y_Coord - Height / 2 > 0 && Y_Coord < Bitmap.Height
   This is our Middle Area.

---

So via this "Conditions",i'm drawing portion of bitmap on my MotionEvent.ACTION_MOVE case.
Let's see some example:

public boolean onTouch(View view, MotionEvent event) {

    switch (event.getAction()) {
        case MotionEvent.ACTION_MOVE:

        int Width = ResultImgView.getWidth();
        int Height = ResultImgView.getHeight();
        //paint for our Red background
        Paint paint = new Paint();
        paint.setStyle( Style.FILL  );
        paint.setColor( Color.RED );
        Bitmap mBitmap = null;
        Canvas canvas = null;

        //Our Condition 
        if(view.getX() - Width / 2 >= SourceBitmap.getWidth() 
            && view.getY() - Height / 2 > 0 && view.getY() + Height / 2 <  SourceBitmap.getHeight())
        {
            //Nice,we entered here. Seems that we're now located at RightSide at Middle position
            //So let's draw part of bitmap.
            //our margin for X coords
            int Difference = (int)((view.getX() - Width / 2 ) - SourceBitmap.getWidth();
            //dont forget to put margin
            //BTW we're now took portion of bitmap
            mBitmap = Bitmap.createBitmap(SourceBitmap, ((int)view.getX() - Width / 2) - Difference, (int)view.getY() - Height / 2, Width,Height);
            canvas = new Canvas(mBitmap);
            //draw rect
            canvas.drawRect(0,0,mBitmap.getWidth(),mBitmap.getHeight(),paint);
            //draw portion of bitmap
            canvas.drawBitmap(mBitmap,new Rect(Difference, 0,mBitmap.getWidth(),mBitmap.getHeight()),new Rect(0,0,mBitmap.getWidth() - Difference,mBitmap.getHeight()),null);
            //and that's all!
        }

        //do the same for other  condition....etc
        break;
}



   return true;
}

Enjoy!

PS Sorry for my eng :).