Photo Gallery

Feature

PhotoViewController
- Use SegmentedControl to change photo view style to list or grid layout.
- Infinite scroll: Retrieve next page photos when scroll down to the end of view.(maximum page number is 5)
- Apply animation block to make transition effect between layouts.
- Show correct image on cells, prevent images changing suddenly, and even a few different cells from the same image.
PhotoViewModel
- Get cell size information according to list or grid layout.
- Search photos from https://api.imgur.com/.
ImageLoader
- Use NSCache to store downloaded image, and re-download them if no cache.
- When cell is used again, cancel the downloading operation.