Android, Checkbox listener in XML?

Question

It's possible, to do things like this

XML:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
    <Button android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:id="@+id/addContactButton"
              android:text="@string/addContactButtonLabel"  
              android:onClick="launchContactAdder"/><!-- here --> 

</LinearLayout>

Java:

public void launchContactAdder(View v)
{
    Intent i = new Intent(this, ContactAdder.class);
    startActivity(i);
}

but there is a requirement, that the method must be public, void and the most important take View as an argument.

Now i'd like to do exactly the same thing but with Checkbox button. Checkbox has android:onclick attribute, but in Android tutorial (http://developer.android.com/resources/samples/ContactManager/index.html) I can see this code

showInvisibleControl.setOnCheckedChangeListener(new OnCheckedChangeListener()
{
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
    {
        Log.d(TAG, "mShowInvisibleControl changed: " + isChecked);
        showInvisible = isChecked;
        populateContactList();
    }
});

So there is a onCheckedChanged(CompoundButton buttonView, boolean isChecked) method. Is there any way to do this by XML? There's no android:onCheckedChange attribute, only android:onClick attribute, but as I wrote above, name of that attribute must have corresponding method name, which takes View as an argument, but from the code above I understand that i must have a method with CompoundButton and boolean arguments.

Any way to do that in "XML way"?

TLPNull · Accepted Answer · 2013-04-26 18:42:49Z

6

Official documentation: https://developer.android.com/guide/topics/ui/controls/checkbox.html

<CheckBox android:id="@+id/checkbox_meat"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/meat"
    android:onClick="onCheckboxClicked"/>
<CheckBox android:id="@+id/checkbox_cheese"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/cheese"
    android:onClick="onCheckboxClicked"/>

answered Apr 26, 2013 at 18:42

TLPNull

4954 silver badges12 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

atjua · Accepted Answer · 2016-05-18 07:02:43Z

3

It is now possible to do this with the use of data binding library. First you need to create a handler class (in this example, I call it MainActivityHandlers). Inside this handler class, define a method (for example the name is method1) with the corresponding implementation Then in your layout file, you just need to implement :

  ...
 <data>
    <variable
        name="handler"
        type="com.test.android.testapp.MainActivityHandlers" />
</data>
...
         <RadioGroup
        ...
        android:onCheckedChanged="@{handler.method1}"
        ...
        >

and you're good to go. More info : https://developer.android.com/topic/libraries/data-binding/index.html

answered May 18, 2016 at 7:02

atjua

5391 gold badge9 silver badges18 bronze badges

Comments

Sir Codesalot · Accepted Answer · 2018-05-07 08:57:39Z

1

I believe using a lambda is more convenient:

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/firstName"
    android:text="@={user.firstName}" />
<CheckBox
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:onCheckedChanged="@{()->handler.checked(firstName)}" />

For more details see this.

Also, I find the use of two way binding very useful for checkboxes:

<CheckBox
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked='@={user.isChecked}'/>

Note that onCheckedChanged is called before the two way binding sets the value.

edited May 7, 2018 at 8:57

answered May 7, 2018 at 8:45

Sir Codesalot

7,3712 gold badges54 silver badges61 bronze badges

Collectives™ on Stack Overflow

Android, Checkbox listener in XML?

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related