PDF rendering the easy way

pdf_page_item.xml

<?xml version="1.0" encoding="utf-8"?>
<ImageView
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/imageView"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:layout_marginVertical="8dp"
  android:importantForAccessibility="no"
  android:scaleType="fitCenter"
  />

PdfAdapter.kt

class PdfAdapter(
  // this would come from the ViewModel so we don't need to recreate it on config change 
  // and the VM can close it within onCleared()
  private val renderer: PdfRenderer,
  // this would come from the Activity/Fragment based on the display metrics
  private val pageWidth: Int
) : RecyclerView.Adapter<PdfAdapter.ViewHolder>() {

  class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {

    fun bind(bitmap: Bitmap) = (itemView as ImageView).setImageBitmap(bitmap)
  }

  override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
    ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.pdf_page_item, parent, false))

  override fun getItemCount() = renderer.pageCount

  override fun onBindViewHolder(holder: ViewHolder, position: Int) = 
    holder.bind(renderer.openPage(position).renderAndClose(pageWidth))
}

PdfHelper.kt

suspend fun renderSinglePage(filePath: String, width: Int) = withContext(Dispatchers.IO) {
  PdfRenderer(ParcelFileDescriptor.open(File(filePath), ParcelFileDescriptor.MODE_READ_ONLY)).use { renderer ->
    renderer.openPage(0).renderAndClose(width)
  }
}

PdfRendererExtensions.kt

fun PdfRenderer.Page.renderAndClose(width: Int) = use {
  val bitmap = createBitmap(width)
  render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY)
  bitmap
}

private fun PdfRenderer.Page.createBitmap(bitmapWidth: Int): Bitmap {
  val bitmap = Bitmap.createBitmap(
    bitmapWidth, (bitmapWidth.toFloat() / width * height).toInt(), Bitmap.Config.ARGB_8888
  )

  val canvas = Canvas(bitmap)
  canvas.drawColor(Color.WHITE)
  canvas.drawBitmap(bitmap, 0f, 0f, null)

  return bitmap
}

Thank you for this code, really help me a lot.

Can we add annotations using PdfRenderer

Where this renderSinglePage method is used?

How to render pdf with clickable links？