taler-android

ProductsFragment.kt (6645B)

---

 /*
  * This file is part of GNU Taler
  * (C) 2020 Taler Systems S.A.
  *
  * GNU Taler is free software; you can redistribute it and/or modify it under the
  * terms of the GNU General Public License as published by the Free Software
  * Foundation; either version 3, or (at your option) any later version.
  *
  * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
 
 package net.taler.merchantpos.order
 
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.View.GONE
 import android.view.View.INVISIBLE
 import android.view.View.VISIBLE
 import android.view.ViewGroup
 import android.widget.ImageView
 import android.widget.TextView
 import com.google.android.material.card.MaterialCardView
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.recyclerview.widget.AsyncListDiffer
 import androidx.recyclerview.widget.DiffUtil.ItemCallback
 import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.RecyclerView.Adapter
 import androidx.recyclerview.widget.RecyclerView.ViewHolder
 import net.taler.lib.android.base64Bitmap
 import net.taler.merchantpos.MainViewModel
 import net.taler.merchantpos.R
 import net.taler.merchantpos.config.ConfigProduct
 import net.taler.merchantpos.databinding.FragmentProductsBinding
 import net.taler.merchantpos.order.ProductAdapter.ProductViewHolder
 
 interface ProductSelectionListener {
     fun onProductSelected(product: ConfigProduct)
 }
 
 class ProductsFragment : Fragment(), ProductSelectionListener {
 
     private val viewModel: MainViewModel by activityViewModels()
     private val orderManager by lazy { viewModel.orderManager }
     private val adapter = ProductAdapter(this)
 
     private lateinit var ui: FragmentProductsBinding
 
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View? {
         ui = FragmentProductsBinding.inflate(inflater, container, false)
         return ui.root
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         ui.productsList.apply {
             adapter = this@ProductsFragment.adapter
             layoutManager = GridLayoutManager(requireContext(), 3)
         }
 
         orderManager.products.observe(viewLifecycleOwner, { products ->
             if (products == null) {
                 adapter.setItems(emptyList())
             } else {
                 adapter.setItems(products)
             }
             ui.progressBar.visibility = INVISIBLE
         })
     }
 
     override fun onProductSelected(product: ConfigProduct) {
         orderManager.addProduct(orderManager.currentOrderId.value!!, product)
         viewModel.configManager.refreshInventory()
     }
 
 }
 
 private class ProductAdapter(
     private val listener: ProductSelectionListener
 ) : Adapter<ProductViewHolder>() {
     init {
         setHasStableIds(true)
     }
 
     private val itemCallback = object : ItemCallback<ConfigProduct>() {
         override fun areItemsTheSame(oldItem: ConfigProduct, newItem: ConfigProduct): Boolean {
             return oldItem.stableKey == newItem.stableKey
         }
 
         override fun areContentsTheSame(oldItem: ConfigProduct, newItem: ConfigProduct): Boolean {
             return oldItem.displayName == newItem.displayName &&
                 oldItem.displayDescription == newItem.displayDescription &&
                 oldItem.displayPrice == newItem.displayPrice &&
                 oldItem.image == newItem.image &&
                 oldItem.availableToSell == newItem.availableToSell &&
                 oldItem.remainingStock == newItem.remainingStock
         }
     }
     private val differ = AsyncListDiffer(this, itemCallback)
 
     override fun getItemCount() = differ.currentList.size
 
     override fun getItemId(position: Int): Long {
         return differ.currentList[position].stableKey.hashCode().toLong()
     }
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ProductViewHolder {
         val view =
             LayoutInflater.from(parent.context).inflate(R.layout.list_item_product, parent, false)
         return ProductViewHolder(view)
     }
 
     override fun onBindViewHolder(holder: ProductViewHolder, position: Int) {
         holder.bind(differ.currentList[position])
     }
 
     fun setItems(items: List<ConfigProduct>) {
         differ.submitList(items.toList())
     }
 
     inner class ProductViewHolder(private val v: View) : ViewHolder(v) {
         private val name: TextView = v.findViewById(R.id.name)
         private val description: TextView = v.findViewById(R.id.description)
         private val price: TextView = v.findViewById(R.id.price)
         private val image: ImageView = v.findViewById(R.id.image)
         private val unavailable: TextView = v.findViewById(R.id.unavailableLabel)
         private val card: MaterialCardView = v as MaterialCardView
 
         fun bind(product: ConfigProduct) {
             name.text = product.displayName
             val productDescription = product.displayDescription
             if (productDescription == null) {
                 description.visibility = GONE
             } else {
                 description.visibility = VISIBLE
                 description.text = productDescription
             }
             price.text = product.displayPrice
 
             // base64 encoded image
             val bitmap = product.image?.base64Bitmap
             if (bitmap == null) {
                 image.visibility = GONE
             } else {
                 image.visibility = VISIBLE
                 image.setImageBitmap(bitmap)
             }
 
             unavailable.visibility = if (product.availableToSell) GONE else VISIBLE
             unavailable.text = when {
                 product.availableToSell -> ""
                 product.remainingStock == 0 -> v.context.getString(R.string.product_out_of_stock)
                 else -> v.context.getString(R.string.product_unavailable)
             }
             card.isEnabled = product.availableToSell
             v.isEnabled = product.availableToSell
             v.alpha = if (product.availableToSell) 1f else 0.5f
             v.setOnClickListener {
                 if (product.availableToSell) listener.onProductSelected(product)
             }
         }
     }
 
 }