Set text color using data binding on Android

Question

I'm trying to set TextView text color using data binding library

android:textColor="@{holder.getTitleColor(context, item)}"

where the method in Holder class is defined like below

public int getTitleColor(Context context, Item item) {
   ...
}

No matter if I return color int (@ColorInt) or color resource (@ColorRes) it paints the text solid white. What am I doing wrong?

Answer 1

I seems the int you are providing is interpreted as a hex color, even though it seem intuitive that this setter should be expecting a resource ID.

use the Context reference generated for each bindable view, and use it to convert the resource ID to the color you are pointing to, as described in the DataBinding Dev Guide:

A special variable named context is generated for use in binding expressions as needed. The value for context is the Context from the root View's getContext().

use it to set color like this:

 <TextView             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@{data.text}"             android:textColor="@{context.getColor(data.colorRes)}"             /> 

Edit

for backwards compatibility you can use ContextCompat. Import needed:

<layout>     <data>         <import type="android.support.v4.content.ContextCompat"/>         <variable name="data" type="com.whatever.myapp.MyModel"/>         ...     </data>     ...      <TextView             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@{data.text}"             android:textColor="@{ContextCompat.getColor(context, data.colorRes)}"             /> </layout> 

Answer 2

create method by using BindingAdapter

@BindingAdapter({"bind:color"}) public static void setColor(TextView textView, Item item) {     textView.setTextColor(<set color of your choice>); } 

and to call it from xml

app:color="@{item}" 

Answer 3

In addition to the solution of @Mardann, here is an updated solution that also works on API lower than 23 by using ContextCompat.getColor():

<layout>

    <data>
        <import type="androidx.core.content.ContextCompat" />
        <variable
            name="data"
            type="com.example.myapp.MyDataObject" />
    </data>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@{data.text}"
        android:textColor="@{ContextCompat.getColor(context, data.colorRes)}"/>
    </layout>

• Make sure to import ContextCompat as shown above.
• You can automagically 'context' as method parameter for ContextCompat.getColor() because it will be automatically resolved to the view's context.