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Android Kotlin section recycler adapter
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| /* | |
| * ------------------------------------------------------------ | |
| * "THE BEERWARE LICENSE" (Revision 42): | |
| * github.com/xtenduke wrote this code. As long as you retain this | |
| * notice, you can do whatever you want with this stuff. If we | |
| * meet someday, and you think this stuff is worth it, you can | |
| * buy me a beer in return. | |
| * ------------------------------------------------------------ | |
| * | |
| * This class is designed implement a 'similar' structure to TableView sections from iOS UIKit | |
| */ | |
| abstract class SectionAdapter<VH : RecyclerView.ViewHolder> : RecyclerView.Adapter<VH>() { | |
| /** | |
| * Override getItemCount to instead call getItemCount(section: Int) | |
| */ | |
| override fun getItemCount(): Int { | |
| val sectionCount = getSectionCount() | |
| var count = 0 | |
| for(i in 0 until sectionCount) { | |
| count += getItemCount(i) | |
| } | |
| return count | |
| } | |
| /** | |
| * Get the item count per section | |
| */ | |
| abstract fun getItemCount(section: Int): Int | |
| /** | |
| * Get the section count | |
| */ | |
| abstract fun getSectionCount(): Int | |
| /** | |
| * Overridden to change the second parameter name from viewType to section | |
| */ | |
| abstract override fun onCreateViewHolder(parent: ViewGroup, section: Int): VH | |
| /** | |
| * Abstract method for onBindViewHolder with section | |
| */ | |
| abstract fun onBindViewHolder(holder: VH, position: Int, section: Int) | |
| /** | |
| * We need to turn our adapter position into a relative position based on the number | |
| * of items in each section | |
| */ | |
| override fun onBindViewHolder(holder: VH, position: Int) { | |
| //derive section and position from position | |
| //loop over all sections | |
| var itemCount = 0 | |
| var innerPosition = position | |
| for(i in 0..getSectionCount()) { | |
| itemCount += getItemCount(i) | |
| if(position < itemCount) { | |
| onBindViewHolder(holder, innerPosition, i) | |
| return | |
| } else { | |
| innerPosition -= getItemCount(i) | |
| } | |
| } | |
| } | |
| /** | |
| * Lookup Section based off adapter position | |
| */ | |
| override fun getItemViewType(position: Int): Int { | |
| var itemCount = 0 | |
| for(i in 0..getSectionCount()) { | |
| itemCount += getItemCount(i) | |
| if (position < itemCount) { | |
| return i | |
| } | |
| } | |
| return super.getItemViewType(position) | |
| } | |
| } |
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