Create a text list that can be filtered

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Create a text list that can be filtered

You can create an application that uses the KeywordFilterField class, included in the net.rim.device.api.ui.component package, to provide a UI field that consists of a single text input field and a list of selectable elements. A word that a BlackBerry® device user enters into the text input field filters the elements in the list. For more information about using the KeywordFilterField class, see the KeywordFilterFieldDemo sample, included with the BlackBerry® Java® Development Environment version 4.3.1.

Import the following classes:
- net.rim.device.api.ui.component.KeywordFilterField
- net.rim.device.api.collection.util.SortedReadableList
- net.rim.device.api.collection.util.SortedReadableList
- java.util.Vector
- java.io.InputStream
- net.rim.device.api.io.LineReader
- java.lang.String
Import the net.rim.device.api.ui.component.KeywordProvider interface.
Create variables. In the following code sample, CountryList extends the SortedReadableList class and implements the KeywordProvider interface.
```
private KeywordFilterField _keywordField;    
private CountryList _CountryList;  
private Vector _countries;
```
To create a list of selectable text items, populate a vector with data from a text file.
```
_countries = getDataFromFile();
```

Create an instance of a class that extends the SortedReadableList class.

_CountryList = new CountryList(StringComparator.getInstance(true),_countries);

To specify the elements of the list, create a new instance of a KeywordFilterField object.
```
_keywordField = new KeywordFilterField();
```

Invoke KeywordFilterField.setList().

_keywordField.setList(_CountryList, _CountryList);

Set a label for the input field of the KeywordFilterFIeld.
```
_keywordField.setLabel("Search: ");
```

Create the main screen of the application and add a KeywordFilterField to the main screen.

KeywordFilterDemoScreen screen = new KeywordFilterDemoScreen(this,_keywordField);
screen.add(_keywordField.getKeywordField());
screen.add(_keywordField);
pushScreen(screen);

To create a method that populates and returns a vector of Country objects containing data from text file, In the method signature, specify Vector as the return type.
```
public Vector getDataFromFile()
    {
```
Create and store a reference to a new Vector object.
```
Vector countries = new Vector();
```

Create an input stream to the text file.

InputStream stream = getClass().getResourceAsStream("/Data/CountryData.txt");

Read CRLF delimited lines from the input stream.

LineReader lineReader = new LineReader(stream);

Read data from the input stream one line at a time until you reach the end of file flag. Each line is parsed to extract data that is used to construct Country objects.

for(;;)
{   //Obtain a line of text from the text file
String line = new String(lineReader.readLine());
//If we are not at the end of the file, parse the line of text
 if(!line.equals("EOF")) 
 {int space1 = line.indexOf(" ");
  String country = line.substring(0,space1);                        
  int space2 = line.indexOf(" ",space1+1);
  String population = line.substring(space1+1,space2);                       
  String capital = line.substring(space2+1,line.length());
  // Create a new Country object.                        
  countries.addElement(new Country(country,population,capital));                                        
  }
  else
  {
   break;
   }
 }  // end the for loop
 return countries;    
}

To add a keyword to the list of selectable text items, invoke SortedReadableList.doAdd(element).
```
SortedReadableList.doAdd(((Country)countries.elementAt(i)).getCountryName()) ;
```
To update the list of selectable text items, invoke KeywordFilterField.updateList().
```
_keywordField.updateList();
```
To obtain the key word that a BlackBerry device user typed into the KeywordFilterField, invoke KeywordFilterField.getKeyword().
```
String userTypedWord = _keywordField.getKeyword();
```

Parent topic: UI components

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Create a text list that can be filtered