Question

I have a List<Size> list1 which is from parameters.getSupportedPreviewSizes()
I would like to sort it in ascending order (width * height).
I have tried Collection.sort, but seems not work.
What is the best way to sort the list? Thanks.

Answer 1

Use a custom Comparator.

A Comparator is used to compare two objects to determine their ordering with respect to each other. On a given Collection, a Comparator can be used to obtain a sorted Collection which is totally ordered.

final Camera camera = ...;
final List<Camera.Size> sizes = camera.getParameters().getSupportedPreviewSizes();
Collections.sort(sizes, new Comparator<Camera.Size>() {

  public int compare(final Camera.Size a, final Camera.Size b) {
    return a.width * a.height - b.width * b.height;
  }
});