The document discusses the key components of a ListView in Android, including the ListView itself, list items, and data for each item. It explains that list items can contain simple or complex layouts. The data comes from adapters that act as intermediaries between the data source and ListView. Adapters fetch data, create layouts for each item, and return items to the ListView. Common data sources are arrays, content providers, and database cursors. The main adapter types are ArrayAdapter for arrays and SimpleCursorAdapter for content providers and cursors.

1. Prof. Neeraj Bhargava
Vishal Dutt
Department of Computer Science, School of
Engineering & System Sciences
MDS University, Ajmer

2. What is a list view?
 A ViewGroup that displays scrollable items.

3. 3 Parts of a ListView
 The ListView itself
 aka a ViewGroup
 List items
 Each row/item in the list. Each item is a layout
consisting of a View or ViewGroup.
 Data for each item

4. ListItem
 Since the ListItem can be a ViewGroup, we have the
power to display very simple or extremely complex
layouts for each item.
 A TextView
 A TextView and ImageView
 A TextView and CheckBox
 A TextView and Button
 A TextView, ImageView, CheckBox, Button, and
RatingBar, etc

5. Where does the data come from?
 ListViews receive data via Adapters.
 The Adapter behaves as the middleman between the
data source and the ListView.

6. The job of an Adapter
 The Adapter fetches data from the source.
 Creates the layout that represents each list item.
 Takes the data fetched from the source places it into
the list item layout.
 Returns a list item to the ListView.

7. How an Adapter Works
Array<String> mMovies = { "Bill and Ted's Excellent Adventures", "Teen
Wolf", "Honey I shrunk the kids", "Texas Chainsaw Massacre",
"Puppet Master" }
Adapter
Bill and Ted’s
Excellent…
Teen Wolf
Honey I shrunk…
Texas Chainsaw
Mas…
Pupper Master
Bill and Ted…
ListView

8. Data source for Adapters
1. Arrays
2. Content Provider
 Used to get Calendar and Contact info from phone.
3. Database Cursor

9. Types of Adapters
 ArrayAdapter
 Works with Arrays
 Can handle any Java Object as input
 Uses the .toString() method of the JavaObject to obtain
text for list item.
 SimpleCursorAdapter
 Works with a Content Provider and Database Cursor