Working with the EditText
The EditText is the standard text entry widget in Android apps. If the user needs to enter text into an app, this is the primary way for them to do that.
There are many important properties that can be set to customize the behavior of an EditText. Several of these are listed below. Check out the official text fields guide for even more input field details.
An EditText is added to a layout with all default behaviors with the following XML:
<EditText
android:id="@+id/et_simple"
android:layout_height="wrap_content"
android:layout_width="match_parent">
</EditText>Note that an EditText is simply a thin extension of the TextView and inherits all of the same properties.
Getting the value of the text entered into an EditText is as follows:
EditText simpleEditText = (EditText) findViewById(R.id.et_simple);
String strValue = simpleEditText.getText().toString();By default, any text contents within an EditText control is displayed as plain text. By setting inputType, we can facilitate input of different types of information, like phone numbers and passwords:
<EditText
...
android:inputType="phone">
</EditText>Most common input types include:
| Type | Description |
|---|---|
| textUri | Text that will be used as a URI |
| textEmailAddress | Text that will be used as an e-mail address |
| textPersonName | Text that is the name of a person |
| textPassword | Text that is a password that should be obscured |
| number | A numeric only field |
| phone | For entering a phone number |
| date | For entering a date |
| time | For entering a time |
| textMultiLine | Allow multiple lines of text in the field |
You can set multiple inputType attributes if needed (separated by '|')
<EditText
android:inputType="textCapSentences|textMultiline"
/>You can see a list of all available input types here.
We might want to limit the entry to a single-line of text (avoid newlines):
<EditText
android:singleLine="true"
android:lines="1"
/>You can limit the characters that can be entered into a field using the digits attribute:
<EditText
android:inputType="number"
android:digits="01"
/>This would restrict the digits entered to just "0" and "1". We might want to limit the total number of characters with:
<EditText
android:maxLength="5"
/>Using these properties we can define the expected input behavior for text fields.
You can adjust the highlight background color of selected text within an EditText with the android:textColorHighlight property:
<EditText
android:textColorHighlight="#7cff88"
/>with a result such as this:
You may want to set the hint for the EditText control to prompt a user for specific input with:
<EditText
...
android:hint="@string/my_hint">
</EditText>which results in:
Assuming you are using the AppCompat library, you can override the styles colorControlNormal, colorControlActivated, and colorControlHighlight:
<style name="Theme.App.Base" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorControlNormal">#d32f2f</item>
<item name="colorControlActivated">#ff5722</item>
<item name="colorControlHighlight">#f44336</item>
</style>If you do not see these styles applied within a DialogFragment, there is a known bug when using the LayoutInflater passed into the [onCreateView()](http://developer.android.com/reference/android/app/Fragment.html#onCreateView(android.view.LayoutInflater, android.view.ViewGroup, android.os.Bundle)) method.
The issue has already been fixed in the AppCompat v23 library. See this guide about how to upgrade. Another temporary workaround is to use the Activity's layout inflater instead of the one passed into the onCreateView() method:
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = getActivity().getLayoutInflater().inflate(R.layout.dialog_fragment, container);
}Check out the basic event listeners cliffnotes for a look at how to listen for changes to an EditText and perform an action when those changes occur.
Traditionally, the EditText hides the hint message (explained above) after the user starts typing. In addition, any validation error messages had to be managed manually by the developer.
Starting with Android M and the design support library, the TextInputLayout can be used to setup a floating label to display hints and error messages. First, wrap the EditText in a TextInputLayout:
<android.support.design.widget.TextInputLayout
android:id="@+id/username_text_input_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/etUsername"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:ems="10"
android:hint="Username" />
</android.support.design.widget.TextInputLayout>Now the hint will automatically begin to float once the EditText takes focus as shown below:
We can also use the TextInputLayout to display error messages using the setError and setErrorEnabled properties in the activity at runtime:
private void setupFloatingLabelError() {
final TextInputLayout floatingUsernameLabel = (TextInputLayout) findViewById(R.id.username_text_input_layout);
floatingUsernameLabel.getEditText().addTextChangedListener(new TextWatcher() {
// ...
@Override
public void onTextChanged(CharSequence text, int start, int count, int after) {
if (text.length() > 0 && text.length() <= 4) {
floatingUsernameLabel.setError(getString(R.string.username_required));
floatingUsernameLabel.setErrorEnabled(true);
} else {
floatingUsernameLabel.setErrorEnabled(false);
}
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
}
});
}Here we use the addTextChangedListener to watch as the value changes to determine when to display the error message or revert to the hint.
TextInputLayout since the announcement of support design library v23.1 also can expose a character counter for an EditText defined within it. The counter will be rendered below the EditText and can change colors of both the line and character counter if the maximum number of characters has been exceeded:
The TextInputLayout simply needs to define app:counterEnabled and app:CounterMaxLength in the XML attributes. These settings can also be defined dynamically through setCounterEnabled() and setCounterMaxLength():
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
app:counterEnabled="true"
app:counterMaxLength="10"
app:counterTextAppearance="@style/counterText"
app:counterOverflowTextAppearance="@style/counterOverride">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="Username"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:ems="10"
android:hint="Username" />
</android.support.design.widget.TextInputLayout>Make sure you have the app namespace (xmlns:app="http://schemas.android.com/apk/res-auto" defined in your outer layout. You can type appNS as a shortcut in Android Studio to be declared.
The hint text can be styled by defining app:hintTextAppearance, and the error text can be changed with app:errorTextAppearance. The counter text and overflow text can also have their own text styles by defining app:counterTextAppearance and app:counterOverflowTextAppearance. We can use textColor, textSize, and fontFamily to help change the color, size, or font:
<style name="counterText">
<item name="android:textColor">#aa5353cc</item>
</style>
<style name="counterOverride">
<item name="android:textColor">#ff0000</item>
</style>Check out the official text fields guide for a step-by-step on how to setup autocomplete for the entry.
- http://developer.android.com/guide/topics/ui/controls/text.html
- http://code.tutsplus.com/tutorials/android-user-interface-design-edittext-controls--mobile-7183
- http://www.codeofaninja.com/2012/01/android-edittext-example.html
- http://www.tutorialspoint.com/android/android_edittext_control.htm
- http://developer.android.com/reference/android/widget/EditText.html
- http://android-developers.blogspot.com/2015/10/android-support-library-231.html?linkId=17977963