CODEWITHSUNDEEP
androidandroid-databinding
Konstantin Konopko
Konstantin Konopko

Reputation: 5418

Use data binding to set View visibility

Trying to set visibility of View using custom variable, but error occurs: Identifiers must have user defined types from the XML file. visible is missing it. Is it possible to set view visibility using data binding? Thanks.

<data>
    <variable
        name="sale"
        type="java.lang.Boolean"/>
</data>

<FrameLayout android:visibility="@{sale ? visible : gone}"/>

Upvotes: 144

Views: 115768

Answers (4)

CoolMind
CoolMind

Reputation: 28793

Similar to Kiskae solution. Put this method in a separate file, for instance, Bindings.kt:

@BindingAdapter("android:visibility")
fun View.bindVisibility(visible: Boolean?) {
    isVisible = visible == true
    // visibility = if (visible == true) View.VISIBLE else View.GONE
}

Then in layout XML:

<data>

    <variable
        name="viewModel"
        type="SomeViewModel" />
</data>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:visibility="@{viewModel.number == 1}" />

Upvotes: 5

David Artmann
David Artmann

Reputation: 4402

As stated in the Android Developer Guide, you need to do it like this:

<data>
    <import type="android.view.View"/>
    <variable
        name="sale"
        type="java.lang.Boolean"/>
</data>

<FrameLayout android:visibility="@{sale ? View.GONE : View.VISIBLE}"/>

Upvotes: 348

Lior
Lior

Reputation: 842

In your layout:

<data>
    <variable
        name="viewModel"
        type="...."/>
</data>


<View
 android:layout_width="10dp"
 android:layout_height="10dp"
 android:visibility="@{viewModel.saleVisibility, default=gone}"/>

In your ViewModel java code:

@Bindable
public int getSaleVisibility(){
 return mSaleIndecator ? VISIBLE : GONE;
}

Upvotes: 70

Kiskae
Kiskae

Reputation: 25573

The problem is that visibility is an Integer on the View class, this means you have two ways to make this work:

  1. Use the View.VISIBLE and View.GONE constants. https://developer.android.com/topic/libraries/data-binding/index.html#imports
  2. Define a custom setter for visibility that takes a Boolean. https://developer.android.com/topic/libraries/data-binding/index.html#custom_setters

Possible implementation:

@BindingAdapter("android:visibility")
public static void setVisibility(View view, Boolean value) {
    view.setVisibility(value ? View.VISIBLE : View.GONE);
}

Which will make <FrameLayout android:visibility="@{sale}"/> work.

Upvotes: 53

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