PhotoView adjust image size to better fit bounds of ImageView

I think that this feature is very useful for PhotoView.

When I set an image/drawable/bitmap in ImageView and I would like the PhotoView automatically adjust the image size to fit the bounds of ImageView (without empty space).

I think this is very simple, when I set an image we can compute the scale to fit in the ImageView:

```

int width = drawable.getWidth();
int height = drawable.getHeight();

int ivWidth = imageView.getWidth();
int ivHeight = imageView.getHeight();

float xScale = ((float) ivWidth) / width;
float yScale = ((float) ivHeight) / height;

float scale = (xScale > yScale) ? xScale : yScale;

```

So, scale can be used to fit the image in the ImageView size.

I looked this feature in PhotoView but I didn't find.

[Example](http://imgur.com/GCgmhkw)