Custom BindingAdapter with 2 parameteres and requireAll throws KaptExecution

Question

This is the error I got:

> Task :app:kaptDevDebugKotlin FAILED
  location: package ...app.databinding
FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:kaptDevDebugKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.gradle.internal.KaptExecution
   > java.lang.reflect.InvocationTargetException (no error message)

This is my custom BindingAdapter:

@Suppress("unused")
object BindingAdapters {

    @JvmStatic
    @BindingAdapter(value = ["isVisible", "hide"], requireAll = false)
    fun setVisible(view: View, show: Boolean?, hide: Boolean?) {
        view.visibility = if (show != false) View.VISIBLE else if (hide != false) View.INVISIBLE else View.GONE
    }
...
}

Usage in layout:

<include
    layout="@layout/view_loading_small"
    isVisible="@{viewModel.isLoading()}" ... />

Where:

private val _isLoading = MutableLiveData<Boolean>(false)
val isLoading: LiveData<Boolean> = _isLoading

I don't know what's happening, I've always used this method without problem. Today I've added the "hide" parameter and BAM KaptExecution InvocationTargetException.
The only workaround is changing my BindingAdapter object to:

    @JvmStatic
    @BindingAdapter(value = ["isVisible", "hide"], requireAll = false)
    fun setVisible(view: View, show: Boolean?, hide: Boolean?) {
        view.visibility = if (show != false) View.VISIBLE else if (hide != false) View.INVISIBLE else View.GONE
    }

    @JvmStatic
    @BindingAdapter(value = ["isVisible"])
    fun setVisible(view: View, show: Boolean) {
        setVisible(view, show, false)
    }

But this makes no sense, isn't the requireAll = false supposed to solve this? What am I missing here?

Answer 1

When you include a layout and want to change it visibility, you should do it via parameters. Following your example, your layout view_loading_small should have this:

<data>
        <variable
            name="visible"
            type="boolean" />
    </data>

Note: Add isVisible="@{visible}" on the view that you want to change visibility

And your include:

<include
    layout="@layout/view_loading_small"
    app:visible="@{viewModel.isLoading()}" ... />

With this you should have no problems anymore. Also you can remove this:

 @JvmStatic
    @BindingAdapter(value = ["isVisible"])
    fun setVisible(view: View, show: Boolean) {
        setVisible(view, show, false)
    }

One last thing, there’s a core-ktx extension function called isVisible:

inline var View.isVisible: Boolean
    get() = visibility == View.VISIBLE
    set(value) {
        visibility = if (value) View.VISIBLE else View.GONE
    }

So to be 100% safe, I think its probably a good idea to name your custom function with something else.

Hope it helps! Regards!