Android - 在数据绑定适配器中传递视图

Question

I've a image view with a checkbox on top of it, something similar to what you'd have on a multi-selection image gallery.

<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>
        <variable
            name="entity"
            type="a.l.s.v.entity.Image" />
        <variable
            name="viewModel"
            type="a.l.s.v.image.ImageViewModel" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout>
        <ImageView
            android:id="@+id/image"
            ...
            app:loadImage="@{entity.uri}"/>
        <CheckBox
            android:id="@+id/imageCheckbox"
            ...
            app:visibleIf="@{viewModel.showCheckbox}"
            app:depressViewOnSelect="what goes here?"/> <!-- Can we pass views here? -->

    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

Goal: I'm trying to depress the image (add some view padding) when long pressed as a means of UX acknowledgment.

Issue: One of the ideas that came across my mind was to do a data binding on checkbox via an adapter app:depressViewOnSelect and pass in the ImageView from the above layout. What I fail to understand is what should I write in XML if I were to pass in the view parameter? Is it possible at all with data binding?

@JvmStatic
@BindingAdapter("app:depressViewOnSelect")
fun depressViewOnSelect(checkbox: CheckBox, view: View) {
    checkbox.setOnCheckedChangeListener { _, isChecked ->
        if(isChecked)
            view.setPadding(dpToPx(view.context, padding))
        else
            view.setPadding(0)
    }
}

Edit: Currently I've added the listener within onLongClick() method of my RecyclerView.ViewHolder , which implements the OnLongClickListener . The problem with that approach comes when implementing a drag-select for images when the long press happens only for a single view holder, which means the listener is not installed on other view holders.

Answer 1

I added a view variable to access it from layout and bound it as binding.view = imageView within ViewHolder implementation.

<data>
    <variable
        name="entity"
        type="app.lanet.sails.home.image.model.Image" />
    <variable
        name="view"
        type="android.widget.ImageView" />
    <variable
        name="counter"
        type="app.lanet.sails.home.common.media.selection.SelectionCounter" />
</data>

Finally, pass the view as any other data binding parameter app:depressViewOnSelect="@{view}" in the XML.