This project mimicks the functionality of iOS where navigation can occur by swiping from left to right to move back in the navigation stack (the navigationController->interactivePopGestureRecognizer delegate). The difference in this code vs existing libraries like https://github.com/ikew0ng/SwipeBackLayout is the use of Fragments. So this project is an example of using multiple fragments inside a single Activity and allowing the user to swipe to navigate. It also maintains compatibility with hardware back button as well as toolbar / action bar home buttons.
- Smooth fragment transitions are provided by res/anim X, Y delta translations
- A NavigationController interface handles callbacks from fragment UI and controls the logic to push new fragments
- A GestureDetector is used on the Activity to detect fling velocity and scroll (scroll implementation TBD)
Yes you could achieve this out of the box with a FragmentPagerAdapter, however you have to do a lot of extra work to handle navigation logic to load and remove fragments based on user interaction.
- support onScroll event and provide a preview of the back stack fragment (just like FragmentPagerAdapter!?) as the user scrolls or flings