Data Binding Compiler cannot find custom binding adapter provided

Question

I have made a binding adapter available statically inside my Fragment which basically change my button appearance from "Stop" to "Play" and vice-versa.

companion object {
        @BindingAdapter("playState")
        fun Button.setPlayState(item: UIState) {
            item.let {
                if (it.isPlaying) {
                    setText("Stop")
                    setBackgroundColor(ContextCompat.getColor(context, R.color.colorStop))
                } else {
                    setText("Play")
                    setBackgroundColor(ContextCompat.getColor(context, R.color.colorPlay))
                }
            }
        }
    }

Here is my layout file. I have provided a data class for it.

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">
    <data>
        <!-- stuff here -->
        <variable
            name="viewmodel"
            type="com.mypackage.ui.ViewModel"/>
        <variable
            name="uistate"
            type="com.mypackage.ui.UIState" />
    </data>
    <!-- layout, buttons, and more stuff here. Just pay attention to this following button -->
     <Button
            android:id="@+id/play_button"
            android:layout_width="150sp"
            android:layout_height="75sp"
            android:layout_marginTop="20sp"
            android:onClick="@{() -> viewmodel.onPlayClicked()}"
            android:text="@string/play_button"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.498"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/minus_layout"
            app:layout_constraintVertical_bias="0.026"
            app:playState="@{uistate}"/>


</layout>

UIState itself is pretty self-explanatory.

data class UIState(var isPlaying: Boolean)

and the () -> viewmodel.onPlayClicked() flips the Boolean at UIState.

After compiling, Data Binding Compiler throws this error:

Cannot find a setter for <android.widget.Button app:playState> 
that accepts parameter type 'com.mypackage.ui.UIState'

I have tried:

Rebuilding the project by removing .gradle folder
Looking for answer here and here.
Removed @JvmStatic annotation at the extension function
Moved the extension function to top level instead of Fragment's companion object.

score 0 · Answer 1 · answered Nov 12 '19 at 06:59

0

You don't have to use @JvmStatic because you are using Kotlin extension feature.

answered Nov 12 '19 at 06:59

Amjad Alwareh

2,926
22
27

score 0 · Answer 2 · answered Nov 12 '19 at 07:27

0

You need to add the view reference as a paramater to your BindingAdapter method.

 @BindingAdapter("playState")
    fun setPlayState(button:Button,item: UIState) {
        //do your work here
    }

answered Nov 12 '19 at 07:27

Gautam

3,252
3
23
32

This is same as what he used. He just used Extension function way. What is the difference? – Mohanakrrishna Nov 12 '19 at 07:29

Nik · Accepted Answer · 2019-11-12T08:22:26.633

0

I think you missed to add kotlin plugin in your gradle

apply plugin: 'kotlin-kapt'

edited Nov 12 '19 at 08:22

answered Nov 12 '19 at 07:50

Nik

1,991
2
13
30

score -1 · Answer 4 · answered Nov 12 '19 at 07:34

-1

Your namespace

xmlns:app="http://schemas.android.com/apk/res-auto"

is wrong for custom binding adapters. Please use the namespace

xmlns:app="http://schemas.android.com/tools"

since app:playState is not in the namespace you have given its not working properly

answered Nov 12 '19 at 07:34

Mohanakrrishna

148
3
13

i have used "http://schemas.android.com/tools" at `tools` namespace. I have tried your solution as well but no change. – Barjuan Davis Nov 12 '19 at 08:05

Data Binding Compiler cannot find custom binding adapter provided

4 Answers4