Figure 1. The default {@code text} input type.
A text field allows the user to type text into your app. It can be either single line or multi-line. Touching a text field places the cursor and automatically displays the keyboard. In addition to typing, text fields allow for a variety of other activities, such as text selection (cut, copy, paste) and data look-up via auto-completion.
You can add a text field to you layout with the {@link android.widget.EditText} object. You should usually do so in your XML layout with a {@code <EditText>} element.
Figure 1. The default {@code text} input type.
Figure 2. The {@code textEmailAddress} input type.
Figure 3. The {@code phone} input type.
Text fields can have different input types, such as number, date, password, or email address. The type determines what kind of characters are allowed inside the field, and may prompt the virtual keyboard to optimize its layout for frequently used characters.
You can specify the type of keyboard you want for your {@link android.widget.EditText} object with the {@code android:inputType} attribute. For example, if you want the user to input an email address, you should use the {@code textEmailAddress} input type:
<EditText
android:id="@+id/email_address"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/email_hint"
android:inputType="textEmailAddress" />
There are several different input types available for different situations. Here are some of the more common values for {@code android:inputType}:
The {@code android:inputType} also allows you to specify certain keyboard behaviors, such as whether to capitalize all new words or use features like auto-complete and spelling suggestions.
The {@code android:inputType} attribute allows bitwise combinations so you can specify both a keyboard layout and one or more behaviors at once.
Here are some of the common input type values that define keyboard behaviors:
For example, here's how you can collect a postal address, capitalize each word, and disable text suggestions:
<EditText
android:id="@+id/postal_address"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/postal_address_hint"
android:inputType="textPostalAddress|
textCapWords|
textNoSuggestions" />
All behaviors are also listed with the {@code android:inputType} documentation.
Figure 4. If you declare {@code android:imeOptions="actionSend"}, the keyboard includes the Send action.
In addition to changing the keyboard's input type, Android allows you to specify an action to be made when users have completed their input. The action specifies the button that appears in place of the carriage return key and the action to be made, such as "Search" or "Send."
You can specify the action by setting the {@code android:imeOptions} attribute. For example, here's how you can specify the Send action:
<EditText
android:id="@+id/search"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/search_hint"
android:inputType="text"
android:imeOptions="actionSend" />
If you do not explicitly specify an input action then the system attempts to determine if there are any subsequent {@code android:focusable} fields. If any focusable fields are found following this one, the system applies the (@code actionNext} action to the current {@link android.widget.EditText} so the user can select Next to move to the next field. If there's no subsequent focusable field, the system applies the {@code "actionDone"} action. You can override this by setting the {@code android:imeOptions} attribute to any other value such as {@code "actionSend"} or {@code "actionSearch"} or suppress the default behavior by using the {@code "actionNone"} action.
If you have specified a keyboard action for the input method using {@code android:imeOptions} attribute (such as {@code "actionSend"}), you can listen for the specific action event using an {@link android.widget.TextView.OnEditorActionListener}. The {@link android.widget.TextView.OnEditorActionListener} interface provides a callback method called {@link android.widget.TextView.OnEditorActionListener#onEditorAction onEditorAction()} that indicates the action type invoked with an action ID such as {@link android.view.inputmethod.EditorInfo#IME_ACTION_SEND} or {@link android.view.inputmethod.EditorInfo#IME_ACTION_SEARCH}.
For example, here's how you can listen for when the user clicks the Send button on the keyboard:
EditText editText = (EditText) findViewById(R.id.search);
editText.setOnEditorActionListener(new OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_SEND) {
sendMessage();
handled = true;
}
return handled;
}
});
If the keyboard is too large to reasonably share space with the underlying application (such as when a handset device is in landscape orientation) then fullscreen ("extract mode") is triggered. In this mode, a labeled action button is displayed next to the input. You can customize the text of this button by setting the {@code android:imeActionLabel} attribute:
<EditText
android:id="@+id/launch_codes"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/enter_launch_codes"
android:inputType="number"
android:imeActionLabel="@string/launch" />
Figure 5. A custom action label with {@code android:imeActionLabel}.
In addition to the actions you can specify with the {@code android:imeOptions} attribute, you can add additional flags to specify other keyboard behaviors. All available flags are listed along with the actions in the {@code android:imeOptions} documentation.
For example, figure 5 shows how the system enables a fullscreen text field when a handset device is in landscape orientation (or the screen space is otherwise constrained for space). You can disable the fullscreen input mode with {@code flagNoExtractUi} in the {@code android:imeOptions} attribute, as shown in figure 6.
Figure 6. The fullscreen text field ("extract mode") is disabled with {@code android:imeOptions="flagNoExtractUi"}.
If you want to provide suggestions to users as they type, you can use a subclass of {@link android.widget.EditText} called {@link android.widget.AutoCompleteTextView}. To implement auto-complete, you must specify an (@link android.widget.Adapter) that provides the text suggestions. There are several kinds of adapters available, depending on where the data is coming from, such as from a database or an array.
Figure 7. Example of {@link android.widget.AutoCompleteTextView} with text suggestions.
The following procedure describes how to set up an {@link android.widget.AutoCompleteTextView} that provides suggestions from an array, using {@link android.widget.ArrayAdapter}:
<?xml version="1.0" encoding="utf-8"?>
<AutoCompleteTextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/autocomplete_country"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="countries_array">
<item>Afghanistan</item>
<item>Albania</item>
<item>Algeria</item>
<item>American Samoa</item>
<item>Andorra</item>
<item>Angola</item>
<item>Anguilla</item>
<item>Antarctica</item>
...
</string-array>
</resources>
// Get a reference to the AutoCompleteTextView in the layout
AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autocomplete_country);
// Get the string array
String[] countries = getResources().getStringArray(R.array.countries_array);
// Create the adapter and set it to the AutoCompleteTextView
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, countries);
textView.setAdapter(adapter);
Here, a new {@link
android.widget.ArrayAdapter} is initialized to bind each item in the COUNTRIES
string array to a {@link android.widget.TextView} that exists in the {@code simple_list_item_1}
layout (this is a layout provided by Android that provides a standard appearance for text in a
list).
Then assign the adapter to the {@link android.widget.AutoCompleteTextView} by calling {@link android.widget.AutoCompleteTextView#setAdapter setAdapter()}.