How to update individual image of RecyclerView in android

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I have number of images in ViewPager (similar to A Gallery) . I want to edit the images that are present in the viewpager . There is no way I found, wherein I could get to the image or get the bitmap from that ViewPager .

The Ui looks somewhat like this

enter image description here

There is a bottom app bar . Wherein on click i get the current uri of the image succesfully .For eg, if I want to increase the brightness of the image ,I am able to do that successfully . But how do , make this changes to the image inside the viewpager , how can i access that bitmap and post accessing how do i stick it back to its original postion .

I want to know:

  1. How can I access to the bitmap present currently .
  2. How do I stick it back to the same location after making changes ?
android-recyclerview android
1 Answers

You have to iterate throughout the ViewGroup and get the ImageView based on ViewPager's current Item .

Your ViewHolder should look like this (This consist of DataBinding) . Here tags are set in the init block and pageNum of the currentItem is set as a global variable which will be used for getting the ImageView . The pageNumber function returns the pageNumber of the current item and imageView function returns the ImageView.

class EditViewHolder(val binding: RecyclerViewEditLayoutBinding) :
    RecyclerView.ViewHolder(binding.root) {

    private var pageNum: Int = -1


    init {

        binding.root.tag = this
    }


    fun bind(item: DataModel, pageNum: Int) {
        this.pageNum = pageNum
        Glide.with(binding.editImageView)
            .load(item.uri)
            .into(binding.editImageView)
    }

    fun getImageView(): ImageView {
        return binding.editImageView
    }

    fun getPageNum(): Int {
        return this.pageNum
    }

}

Now in your Fragment / Activity , you need to create two functions which are getViewHolderForItem() and getViewForItem() , these functions are as follows .

This function which is getViewHolderForItem() returns the ViewHolder

private fun getViewHolderForItem(i: Int): EditViewHolder? {
        var obj: Any? = null
        if (getViewForPage(i) == null) {
            return null
        }
        val viewForPage = getViewForPage(i)
        if (viewForPage != null) {
            obj = viewForPage.tag
        }
        return obj as EditViewHolder?
    }

This function below which is getViewForItem returns the particular view


private fun getViewForPage(i: Int): View? {
        if (binding.editViewPager.size >= i) {

            val childAt: View = binding.editViewPager.getChildAt(0)
            
            val viewGroup: ViewGroup = childAt as ViewGroup
            val childCount: Int = viewGroup.childCount

            for (i2 in 0 until childCount) {
                val childAt2: View? = viewGroup.getChildAt(i2)
                if (childAt2 != null) {
                    val tag = childAt2.tag

                    if ((tag as EditViewHolder).getPageNum() == i) {

                        return childAt2
                    }
                }
            }
        }
        return null
    }

And then you can make use of this in the following manner for getting the current bitmap of the ViewPager

val viewHolder = getViewHolderForPage(binding.editViewPager.currentItem)
                    val bitmap = viewHolder?.getImageView()?.drawable?.toBitmap()

And for setting the bitmap back to the ViewPager

     viewHolder.getImageView().setImageBitmap(bitmap)
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