CODEWITHSUNDEEP
androidkotlinandroid-recyclerview
milancodes
milancodes

Reputation: 173

Changing RecyclerView item's width makes the view disappear

I have the following code:

(setViewHolder is called in Adapter's OnCreateViewHolder)

override fun setViewHolder(parent: ViewGroup): BaseViewHolder<Task> {
        return if (isHorizontal) {
            val view =
                LayoutInflater.from(parent.context)
                    .inflate(R.layout.horizontal_recycler_item, parent, false)

            // Overriding default width
            val params = view.layoutParams as ViewGroup.MarginLayoutParams
            params.width = ((parent.width / 2.15) - params.marginStart - params.marginEnd).toInt()
            view.layoutParams = params

            TaskViewHolder(view)
        } else {
            val view =
                LayoutInflater.from(parent.context)
                    .inflate(R.layout.details_list_item, parent, false)
            TaskViewHolder(view)
        }
    }

And everything works fine until I refresh the fragment. And that's when the RecyclerView just becomes invisible. However, removing the line, where I set the width, from setViewHolder solves my issue.

What causes this?

Upvotes: 1

Views: 192

Answers (1)

Hababa
Hababa

Reputation: 571

The reason it becomes invisible is because you set width with parent.width directly,

We can not get the true value from parent.width when it is not measured.

Here provides two ways you can achieve for your requirement.

1. Calculate a View's dimension in layout after measure

   view.measure(View.MeasureSpec, View.MeasureSpec)

After view.measure, we can call view.measuredWidth or view.measuredHeight to get the true value and calculate the size you want.

   (view.measuredWidth / 3).toInt()

You just only need to find out what MeasureSpec you need to calculate.

But note that measure will caused a heavy-weight in loading, you need to use it carefully.

2. Set value by the screen size

We can get screen resolution in DisplayMetric by context.resources.displayMetric, so you can calculate the size you want

    (context.resources.displayMetric.width / 3).toInt()

Upvotes: 1

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