How do you scale an ImageView like centerCrop, but from top?

Question

Let's say I'm getting some image from an API. I have no idea what the image's dimensions will be ahead of time, but I know that I want that image to become the src of an ImageView I have set to some specific size. I want whatever image I get from the API to fill the entire ImageView, I want to preserve aspect ratio, and I don't care if one dimension (width or height) becomes too big for the set size of the view—so I use centerCrop.

<ImageView
  android:layout_width="400px"
  android:layout_height="300px"
  android:scaleType="centerCrop" />

If the image that comes back from the API is this:

When it gets set as the ImageView's src, the result will be something akin to this (shaded parts are cropped off):

However, I get a request that we should always show the top of the image and crop from the bottom up. So the desired result is something like this:

I'm sure this is possible, but I'm a web guy operating out of his league here. Will it be better to extend ImageView somehow, or to try scaleType="matrix" and setImageMatrix(), or some third, unmentioned option?

Answer 1

If you are using Glide, you can use a custom transformation. Feel free to use mine (which is an almost exact copy of the CenterCrop Class by Glide), which takes percentages:

https://gist.github.com/bjornson/3ff8888c09908d5c6cc345d0a8e1f6a7

Use it just like any other bitmap transformation:

Glide.with(getContext())
    .load(imagePath)
    .transform(new PositionedCropTransformation(getContext(), 1, 0))
    .into(imageView);

Commonly needed values: top-left: 0, 0 top-right: 0, 1 bottom-left: 1, 0 bottom-right: 1, 1

Use 0.5f for center