I've created a custom control which is a subclass of LinearLayout. I have also created a layout file on which this control is based. Finally I have defined attributes which I parse in the constructor to set my custom properties on. As an example, one of those properties is called 'text'.
Here's a simplified version of my code (I've stripped out a lot of the other properties and such so we can just focus on the one property 'text'):
First, the class (our custom version of a RadioButton)...
public class RadioButton extends LinearLayout
{
private TextView textView;
public RadioButton(Context context, AttributeSet attrs)
{
super(context, attrs);
initAttributes(attrs, 0);
}
private void initAttributes(AttributeSet attrs, int defStyle)
{
final TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.CheckBoxView, defStyle, 0);
text = a.getString(R.styleable.RadioButton_text);
if(text == null)
text = "Not set";
a.recycle();
}
#Override
protected void onFinishInflate()
{
super.onFinishInflate();
textView = (TextView)findViewById(R.id.textView);
textView.setText(text);
}
private String text;
public String getText() { return text; }
public void setText(String newValue)
{
text = newValue;
if(textView != null)
textView.setText(text);
}
}
Here's the attrs.xml file...
<resources>
<attr name="text" format="string" />
<declare-styleable name="RadioButton">
<attr name="text" />
</declare-styleable>
</resources>
And here's the 'reusable_radiobutton.xml' layout file (Note: the internal RadioButtonView is a custom-rendered View and works fine):
<?xml version="1.0" encoding="utf-8"?>
<com.somedomain.reusable.ui.RadioButton
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical">
<com.somedomain.reusable.ui.RadioButtonView
android:id="#+id/radioButtonView"
style="#style/DefaultRadioButtonView" />
<TextView
android:id="#+id/textView"
style="#style/DefaultRadioButtonText" />
</com.somedomain.reusable.ui.RadioButton>
With the above, users of my control can simply include it in their own layout files, like so...
<include android:id="#+id/someRadioButton"
layout="#layout/reusable_radiobutton" />
The in their code, using the following, they can get that instance and do with it what they wish, like so...
RadioButton someRadioButton = (RadioButton)findViewById(R.id.someRadioButton);
someRadioButton.text = "Woot!";
This works as expected.
However, this doesn't...
<include android:id="#+id/someRadioButton"
layout="#layout/reusable_radiobutton"
app:text="Hello World!" />
It gives me a warning, but otherwise ignores it.
I then tried this...
<com.somedomain.reusable.ui.RadioButton
app:text="Hello World!" />
While this does instantiate my control and does pass 'Hello World!' to my property via the attributes, nothing actually loads or even associates the layout file to my class so nothing appears on the screen!
So how can I create a custom view, based on a layout, which other developers can simply reference in their own layout files while also allowing them to set custom attributes?
Hope that all made sense! :)
Note: The Android documentation talks about exactly what I'm after, 'Compound Controls' as referenced here, but they don't give an example of using a layout to define the compounded control. However, I feel that was pretty close.
Found it here on SO. I didn't realize you could inflate something into yourself. That and using the Merge tag took care of it for me.
I have a EdidText and a Button in a Fragment. When I click the Button i want to checks whether the EditText is empty or not. If is empty I want to return an error message, If notEmpty means move to other fragments or something further process.
I previously search the solution for my problem, but mostly I found the solution like ,
if(textView.getText().toString().trim().equals("")) {
textView.setError("something");
} else {
//do something;
}
The above code worked correctly, but what I ask, how to do this in a layout not programmatically.
I want to know is this is achieved through the layout xml file or not. If possible means please give me an example.
Thank you in advance.
You can't set an error in with XML.
you need to set it in the onCreate of your fragment. This way you won't see the difference if it is set in xml or in code.
You could write your own EditText and add an extra style attribute "error". After that you need to use your own EditText and again set the error in the onCreate.
Create a new class and extend it from EditText like this:
public class MyEditText extends EditText {
public MyEditText(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyEditText);
String error = a.getString(R.styleable.MyEditText_error);
a.recycle();
setError(error);
}
}
In Attr add this:
<declare-styleable name="MyEditText">
<attr name="error" format="reference|string" />
</declare-styleable>
After that you will need to always use MyEditText
Check it with this code
editText.getText().toString().isEmpty()
I want to create a custom Android View (MyCustomView). In this View I want to have a property of a custom Type (MyCustomType). Similar to this:
MyCustomView extends LinearLayout {
private MyCustomType prop1;
public MyCustomType getProp1()
{
return this.prop1;
}
public void setProp1(MyCustomType value)
{
this.prop1 = value;}
}
}
So far so good. But now I want to be able to set the value of this property from XML. I can create a custom attribute with string, int, reference format, but I do not see how to define this attribute to be of MyCustomType format. I image something similar to this:
<declare-styleable name="MyCustomView">
<attr name="prop1" format="MyCustomType"/>
</declare-styleable>
Is this possible somehow? Or custom type attributes are possible to be set only from code behind?
Thank you!
I don`t really understand why you need this. but you can use format="String" and write full class name in property field in your layout. For example:
custom:prop1="com.example.MyCustomType"
then in constructor of your View:
TypedArray a = context.getTheme().obtainStyledAttributes(
attrs,
R.styleable.MyCustomView,
0, 0);
String className = a.getString(R.id.prop1);
Class<MySustomType> c = Class.forName(className);
MySustomType prop = c.newInstance();
setProp1(prop);
You cannot use own property types with android framework. You can come with own proprties based on available types but that's it. Not sure what type you got in mind in your case, but in most cases whatever that custom thing is, it could be solved by available primitives.
Other questions say that the style cannot be set programmatically, but a View can be initialised with a style such as when it is loaded from XML.
How can I initialise a View with a particular style programmaticly (not in XML)? I tried using View(Context context, AttributeSet attrs, int defStyle), but I don't know what to parse in for the second argument. Passing in null results in the View not being displayed
I'm having the same problem, but haven't found any practical way to directly set a style programmatically, so far. I would like to populate my screen with a lot of widgets, of a given type, let's say buttons. It is impractical to define them all in the layout file. I would like to create them programmatically, but I would also like to define their style in a style xml file.
The solution I have devised consists in defining just one of those widgets in the layout file, create all the others programmatically, and clone the style info from the first one to the other ones.
An example follows.
In the style file, define the style for your buttons. For example:
<style name="niceButton">
<item name="android:layout_width">160dip</item>
<item name="android:layout_height">60dip</item>
<item name="android:gravity">center</item>
<item name="android:textSize">18dip</item>
<item name="android:textColor">#000000</item>
</style>
Then subclass class "Button", by deriving a class "NiceButton". Define the constructor that will be needed by the inflater:
public NiceButton(Context context, AttributeSet attrs) {
super(context, attrs);
}
Then define another constructor, which purpose is to clone an existing button:
public NiceButton(int id, NiceButton origButton) {
super(origButton.getContext());
setId(id);
setLayoutParams(origButton.getLayoutParams());
setGravity(origButton.getGravity());
setPadding(origButton.getPaddingLeft(),
origButton.getPaddingTop(),
origButton.getPaddingRight(),
origButton.getPaddingBottom());
setTextSize(TypedValue.COMPLEX_UNIT_PX, origButton.getTextSize());
setTextColor(origButton.getTextColors());
// ... also copy whatever other attributes you care about
}
In your layout file, define just the first one of your buttons. Suppose for example that you want to put your buttons in a table:
<TableLayout android:id="#+id/button_table"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TableRow android:id="#+id/button_row_0">
<com.mydomain.mypackage.NiceButton
style="#style/niceButton" android:id="#+id/button_0" />
<!-- More rows/buttons created programmatically -->
</TableRow>
</TableLayout>
Notice that the full qualified name of the widget class is used; obviously, you will have to replace com.mydomain.mypackage with the actual package name.
In your activity, you may want to define an array which is going to hold a reference to all of the buttons, and a common listener to be called when any of the buttons is pressed:
NiceButton[] mButtonViews = new NiceButton[10];
private View.OnClickListener mNiceButtonClickListener = new View.OnClickListener() {
public void onClick(View view) {
int i = view.getId();
mButtonViews[i].setText("PRESSED!");
}
};
Notice how the view id is used as an index in the array of buttons. So you will need your buttons to have an id from 0 to n-1.
Finally, here is the way you can create your buttons in the onCreate method:
// Retrieve some elements from the layout
TableLayout table = (TableLayout)findViewById(R.id.button_table);
TableRow row = (TableRow)findViewById(R.id.button_row_0);
NiceButton origButton = (NiceButton)findViewById(R.id.button_0);
// Prepare button 0
origButton.setId(0);
origButton.setText("Button 0");
origButton.setOnClickListener(mNiceButtonClickListener);
mButtonViews[0] = origButton;
// Create buttons 1 to 10
for (int i = 1; i < 10; i++) {
if (i % 2 == 0) {
row = new TableRow(this);
table.addView(row);
}
NiceButton button = new NiceButton(i, origButton);
button.setText("Button " + i);
button.setOnClickListener(mNiceButtonClickListener);
mButtonViews[i] = button;
row.addView(button);
}
Here's how the screen appears after you have pressed some buttons:
Well, there's some code involved, but in the end you can create as many widgets you want programmatically, and still have their attributes defined as a style.
If you want to style a view you have 2 choices: the simplest one is to just specify all the elements in code:
button.setTextColor(Color.RED);
button.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);
The other option is to define the style in XML, and apply it to the view. In the general case, you can use a ContextThemeWrapper for this:
ContextThemeWrapper newContext = new ContextThemeWrapper(baseContext, R.style.MyStyle);
button = new Button(newContext);
To change the text-related attributes on a TextView (or its subclasses like Button) there is a special method:
button.setTextAppearance(context, R.style.MyTextStyle);
This last one cannot be used to change all attributes; for example to change padding you need to use a ContextThemeWrapper. But for text color, size, etc. you can use setTextAppearance.
AttributeSet contains the list of attributes specified in xml (ex. layout_width, layout_height etc).
If you are passing it as null, then you should explicitly set the height/width of view.
How can I define underlined text in an Android layout xml file?
It can be achieved if you are using a string resource xml file, which supports HTML tags like <b></b>, <i></i> and <u></u>.
<resources>
<string name="your_string_here"><![CDATA[This is an <u>underline</u>.]]></string>
</resources>
If you want to underline something from code use:
TextView textView = (TextView) view.findViewById(R.id.textview);
SpannableString content = new SpannableString("Content");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
textView.setText(content);
You can try with
textview.setPaintFlags(textview.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);
Strings.xml file content:
<resource>
<string name="my_text">This is an <u>underline</u>.</string>
</resources>
Layout xml file shold use the above string resource with below properties of textview, as shown below:
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="#string/my_text"
android:selectAllOnFocus="false"
android:linksClickable="false"
android:autoLink="all"
/>
The "accepted" answer above does NOT work (when you try to use the string like textView.setText(Html.fromHtml(String.format(getString(...), ...))).
As stated in the documentations you must escape (html entity encoded) opening bracket of the inner tags with <, e.g. result should look like:
<resource>
<string name="your_string_here">This is an <u>underline</u>.</string>
</resources>
Then in your code you can set the text with:
TextView textView = (TextView) view.findViewById(R.id.textview);
textView.setText(Html.fromHtml(String.format(getString(R.string.my_string), ...)));
For Button and TextView this is the easiest way:
Button:
Button button = (Button) findViewById(R.id.btton1);
button.setPaintFlags(button.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);
Textview:
TextView textView = (TextView) findViewById(R.id.textview1);
textView.setPaintFlags(textView.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);
In Kotlin extension function can be used. This can only be used from code, not xml.
fun TextView.underline() {
paintFlags = paintFlags or Paint.UNDERLINE_TEXT_FLAG
}
Usage:
tv_change_number.underline()
tv_resend_otp.underline()
To do that in Kotlin:
yourTextView.paint?.isUnderlineText = true
One line solution
myTextView.setText(Html.fromHtml("<p><u>I am Underlined text</u></p>"));
It is bit late but could be useful for someone.
check out the underscored clickable button style:
<TextView
android:id="#+id/btn_some_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/btn_add_contact"
android:textAllCaps="false"
android:textColor="#57a0d4"
style="#style/Widget.AppCompat.Button.Borderless.Colored" />
strings.xml:
<string name="btn_add_contact"><u>Add new contact</u></string>
Result:
A cleaner way instead of the
textView.setPaintFlags(textView.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);
method is to use
textView.getPaint().setUnderlineText(true);
And if you need to later turn off underlining for that view, such as in a reused view in a RecyclerView, textView.getPaint().setUnderlineText(false);
If you want to achieve this in XML, declare your string in resource and put that resource value into underline tag (<u></u>) of HTML.
in TextView, add
android:text="#string/your_text_reference"
And in string resource value,
<string name="your_text_reference"><u>Underline me</u></string>
If you want to achieve this programmatically, for Kotlin use
textView.paintFlags = textView.paintFlags or Paint.UNDERLINE_TEXT_FLAG
or,
textView.text = Html.fromHtml("<p><u>Underline me</u></p>")
I know this is a late answer, but I came up with a solution that works pretty well... I took the answer from Anthony Forloney for underlining text in code and created a subclass of TextView that handles that for you. Then you can just use the subclass in XML whenever you want to have an underlined TextView.
Here is the class I created:
import android.content.Context;
import android.text.Editable;
import android.text.SpannableString;
import android.text.TextWatcher;
import android.text.style.UnderlineSpan;
import android.util.AttributeSet;
import android.widget.TextView;
/**
* Created with IntelliJ IDEA.
* User: Justin
* Date: 9/11/13
* Time: 1:10 AM
*/
public class UnderlineTextView extends TextView
{
private boolean m_modifyingText = false;
public UnderlineTextView(Context context)
{
super(context);
init();
}
public UnderlineTextView(Context context, AttributeSet attrs)
{
super(context, attrs);
init();
}
public UnderlineTextView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
init();
}
private void init()
{
addTextChangedListener(new TextWatcher()
{
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after)
{
//Do nothing here... we don't care
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count)
{
//Do nothing here... we don't care
}
#Override
public void afterTextChanged(Editable s)
{
if (m_modifyingText)
return;
underlineText();
}
});
underlineText();
}
private void underlineText()
{
if (m_modifyingText)
return;
m_modifyingText = true;
SpannableString content = new SpannableString(getText());
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
setText(content);
m_modifyingText = false;
}
}
Now... whenever you want to create an underlined textview in XML, you just do the following:
<com.your.package.name.UnderlineTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:gravity="center"
android:text="This text is underlined"
android:textColor="#color/blue_light"
android:textSize="12sp"
android:textStyle="italic"/>
I have added additional options in this XML snippet to show that my example works with changing the text color, size, and style...
Hope this helps!
The most recent approach of drawing underlined text is described by Romain Guy on medium with available source code on GitHub.
This sample application exposes two possible implementations:
A Path-based implementation that requires API level 19
A Region-based implementation that requires API level 1
Just use the attribute in string resource file e.g.
<string name="example"><u>Example</u></string>
I used this xml drawable to create a bottom-border and applied the drawable as the background to my textview
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape android:shape="rectangle" >
<solid android:color="#android:color/transparent" />
</shape>
</item>
<item android:top="-5dp" android:right="-5dp" android:left="-5dp">
<shape>
<solid android:color="#android:color/transparent" />
<stroke
android:width="1.5dp"
android:color="#color/pure_white" />
</shape>
</item>
</layer-list>
Most Easy Way
TextView tv = findViewById(R.id.tv);
tv.setText("some text");
setUnderLineText(tv, "some");
Also support TextView childs like EditText, Button, Checkbox
public void setUnderLineText(TextView tv, String textToUnderLine) {
String tvt = tv.getText().toString();
int ofe = tvt.indexOf(textToUnderLine, 0);
UnderlineSpan underlineSpan = new UnderlineSpan();
SpannableString wordToSpan = new SpannableString(tv.getText());
for (int ofs = 0; ofs < tvt.length() && ofe != -1; ofs = ofe + 1) {
ofe = tvt.indexOf(textToUnderLine, ofs);
if (ofe == -1)
break;
else {
wordToSpan.setSpan(underlineSpan, ofe, ofe + textToUnderLine.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
tv.setText(wordToSpan, TextView.BufferType.SPANNABLE);
}
}
}
If you want
- Clickable underline text?
- Underline multiple parts of TextView?
Then Check This Answer
A simple and flexible solution in xml:
<View
android:layout_width="match_parent"
android:layout_height="3sp"
android:layout_alignLeft="#+id/your_text_view_need_underline"
android:layout_alignRight="#+id/your_text_view_need_underline"
android:layout_below="#+id/your_text_view_need_underline"
android:background="#color/your_color" />
another solution is to a create a custom view that extend TextView as shown below
public class UnderLineTextView extends TextView {
public UnderLineTextView(Context context) {
super(context);
this.setPaintFlags(Paint.UNDERLINE_TEXT_FLAG);
}
public UnderLineTextView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
this.setPaintFlags(Paint.UNDERLINE_TEXT_FLAG);
}
}
and just add to xml as shown below
<yourpackage.UnderLineTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="underline text"
/>
try with Class
for java
textview.setPaintFlags(textview.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);
for Kotlin
textview.setPaintFlags(textview.getPaintFlags() or Paint.UNDERLINE_TEXT_FLAG)
try this code
in XML
<resource>
<string name="my_text"><![CDATA[This is an <u>underline</u>]]></string>
</resources>
in Code
TextView textView = (TextView) view.findViewById(R.id.textview);
textView.setText(Html.fromHtml(getString(R.string.my_text)));
Good Luck!
I simplified Samuel's answer:
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<!--https://stackoverflow.com/a/40706098/4726718-->
<item
android:left="-5dp"
android:right="-5dp"
android:top="-5dp">
<shape>
<stroke
android:width="1.5dp"
android:color="#color/colorAccent" />
</shape>
</item>
</layer-list>
Very compact, kotlin version:
tvTitle.apply {
text = "foobar"
paint?.isUnderlineText = true
}
Go to strings.xml resource file
Add a string in the resource file with an HTML underline tag where necessary.
strings.xml HTML underline sample
Call the string resource ID in your Java code as following:
sampleTextView.setText(R.string.sample_string);
The output should have the word "Stackoverflow" underlined.
Furthermore, the following code will not print the underline:
String sampleString = getString(R.string.sample_string);
sampleTextView.setText(sampleString);
Instead, use the following code to retain rich text format:
CharSequence sampleString = getText(R.string.sample_string);
sampleTextView.setText(sampleString);
"You can use either getString(int) or getText(int) to retrieve a string. getText(int) retains any rich text styling applied to the string." Android documentation.
Refer to the documentation: https://developer.android.com/guide/topics/resources/string-resource.html
I hope this helps.
The top voted answer is right and simplest. However, sometimes you may find that not working for some font, but working for others.(Which problem I just came across when dealing with Chinese.)
Solution is do not use "WRAP_CONTENT" only for your TextView, cause there is no extra space for drawing the line. You may set fixed height to your TextView, or use android:paddingVertical with WRAP_CONTENT.
HtmlCompat.fromHtml(
String.format(context.getString(R.string.set_target_with_underline)),
HtmlCompat.FROM_HTML_MODE_LEGACY)
<string name="set_target_with_underline"><u>Set Target<u> </string>
Note the Escape symbol in xml file
Its quite late to answer this but suppose if anyone wants to get the text dynamically then they can use this simple one line in their java code which works:
textView.setText(Html.fromHtml("<p><u>" + get_name + "</u></p>"));
<com.google.android.material.textfield.TextInputEditText
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:backgroundTint="#android:color/transparent"
android:hint="#string/search_url"
android:textColor="#color/coffee_color"
android:textColorHint="#color/coffee_color"
/>
I had a problem where I'm using a custom font and the underline created with the resource file trick (<u>Underlined text</u>) did work but Android managed to transform the underline to a sort of strike trough.
I used this answer to draw a border below the textview myself: https://stackoverflow.com/a/10732993/664449. Obviously this doesn't work for partial underlined text or multilined text.