I am using a RecyclerView in a Fragment to display a list of elements, each containing a checkbox, as shown below.

Upon clicking the START button, I want to disable all of the elements in the RecyclerView.

Here is my code to do so:

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    startButton = view.findViewById<Button>(R.id.start_button)
    startButton.setOnClickListener {
        // yes, recyclerView is defined
        setViewGroupEnabled(recyclerView, false)
    }
}

fun setViewGroupEnabled(view: ViewGroup, enabled: Boolean) {
    Log.d(TAG, "Numkids: ${view.childCount}")
    view.isEnabled = enabled
    for (v in view.children) {
        if (v is ViewGroup) setViewGroupEnabled(v, enabled)
        else v.isEnabled = enabled
    }
}

This code disables most of the elements in recyclerView, but for some reason it skips some, often multiple at a time. It also appears to skip subviews in a pattern that varies based on how far down the list I have scrolled.

Why is it behaving so strangely?

CodePudding user response：

A RecyclerView has an Adapter. Its job is to handle the layout of each item of the RecyclerView. This includes disabling an item.

Add a class parameter to your adapter:

private var disabled = false

Add a method to your Adapter:

fun setDisabled(disabled: Boolean) {
    this.disabled = disabled
    notifyDatasetChanged()
}

In your onBindViewHolder method, check for the disabled parameter and disable the view as you want to:

override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {

    if (this.disabled) {
        //disable you view, by disabling whichever subview you want
    } else {
        // The normal non disabled flow (what you have now)
    }
}

Now call setDisabled(true) on a button click:

startButton.setOnClickListener {
    // yes, recyclerView is defined
    adapter.setDisabled(true)
}

And call setDisabled(false) to enable the items back.