Understanding fragments
We have mentioned that the central part of our main screen will contain a list of filtered items. We want to have several pages with a different set of filters applied. A user will be able to swipe left or right to change the filtered content and navigate through the following pages:
- All displayed
- Items for
Today
- Items for
Next 7 Days
- Only
Notes
- Only
TODO
s
To achieve this functionality, we will need to define fragments. What are fragments and what is their purpose?
A fragment is a portion of the interface of an Activity
instance. You can use fragments to create multiplane screens or screens with view paging, like in our case.
Just like activities, fragments have their own lifecycle. Fragment lifecycle is presented in the following diagram:
There are some additional methods that activities do not have:
onAttach()
: This is executed when a fragment is associated to an activity.onCreateView()
: This instantiates and returns a fragment's view instance.onActivityCreated()
: This executes...