Android course Lesson2
- 1. Android course Lesson two By Callum Taylor with help from Tim Mathews and Matt Allen
- 2. Lesson 2 Introduction • All slides can be found over at slideshare.net/3sidedcube/android-course-lesson2-45477308 • Twitter/Github @scruffyfox / @3sidedcube • All code for this lesson can be found over at github.com/3sidedcube/Android-BBCNews/tree/Lesson-2
- 3. Lesson 2 What we're making
- 4. Lesson 2 What we're making • Fragments • List views (and recycler views) • ArrayAdapter/BaseAdapter • ViewHolder pattern • "Tablet" landscape handling
- 9. Lesson 2 How ListViews work
- 12. Lesson 2 Adapters are awesome • It's an interface • Standard, generic way to control a dataset and views (MVC) • Very customisable • You can write your own "adapters"
- 13. Lesson 2 What an adapter looks like Data Source ListView Adapter ArrayList SQL Array Map FragmentAdapter LinearLayout
- 14. Lesson 2 Adapter methods • getCount() • getItem(int pos) • getItemId(int pos) • getView(int pos, View convertView, ViewGroup parent)
- 15. Lesson 2 Title Text • getCount() Exactly what it says, returns the number of items in the data set
- 16. Lesson 2 Title Text • getItem(int position) Returns the item at the given position from the data set
- 17. Lesson 2 Title Text • getItemId(int position) Returns the an optional ID of the item at the given position. ID/Representation of the item to increase performance of the list view
- 18. Lesson 2 Title Text • getView(int position, View convertView, ViewGroup parent) Returns the view in the list. This is where we do all of our data/view inflation for the list to display on screen position is the position of the item in the data list convertView is the view that will be shown parent is the parent view of the view being shown (usually the list view)