Implemented chips for selecting dietary preferences

app/src/main/java/com/denizk0461/studip/fragment/CanteenFragment.kt

@@ -4,11 +4,14 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.core.view.children
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
 import com.denizk0461.studip.adapter.CanteenOfferPageAdapter
 import com.denizk0461.studip.databinding.FragmentCanteenBinding
+import com.denizk0461.studip.model.DietaryPreferences
 import com.denizk0461.studip.viewmodel.CanteenViewModel
+import com.google.android.material.chip.Chip
 import com.google.android.material.tabs.TabLayoutMediator
 
 class CanteenFragment : Fragment() {
@@ -32,6 +35,45 @@ class CanteenFragment : Fragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
+        /* Since this removes the view before immediately adding it back, this method causes a
+         * flicker. Note for the future: implement a more efficient / better-looking method.
+         *
+         * TODO order the chips alphabetically
+         */
+        for (chip in binding.chipsPreference.children) {
+            val nChip = chip as Chip
+            nChip.setOnCheckedChangeListener { buttonView, _ ->
+                val index = binding.chipsPreference.indexOfChild(buttonView)
+                binding.chipsPreference.removeView(buttonView)
+                binding.chipsPreference.addView(buttonView, index)
+            }
+        }
+
+        val chipMap = mapOf<Chip, DietaryPreferences>(
+            binding.chipPrefFair to DietaryPreferences.FAIR,
+            binding.chipPrefFish to DietaryPreferences.FISH,
+            binding.chipPrefPoultry to DietaryPreferences.POULTRY,
+            binding.chipPrefLamb to DietaryPreferences.LAMB,
+            binding.chipPrefVital to DietaryPreferences.VITAL,
+            binding.chipPrefBeef to DietaryPreferences.BEEF,
+            binding.chipPrefPork to DietaryPreferences.PORK,
+            binding.chipPrefVegetarian to DietaryPreferences.VEGETARIAN,
+            binding.chipPrefVegan to DietaryPreferences.VEGAN,
+            binding.chipPrefGame to DietaryPreferences.GAME,
+        )
+
+        chipMap.forEach { chip, pref ->
+            chip.isChecked = getPreference(pref)
+            chip.setOnCheckedChangeListener { _, newValue ->
+                setPreference(pref, newValue)
+            }
+        }
+
+        binding.chipPrefFair
+        binding.chipPrefFair.setOnCheckedChangeListener { _, newValue ->
+            setPreference(DietaryPreferences.FAIR, newValue)
+        }
+
         viewPagerAdapter = CanteenOfferPageAdapter(listOf(), 0)
         binding.viewPager.adapter = viewPagerAdapter
 
@@ -49,9 +91,11 @@ class CanteenFragment : Fragment() {
         }
 
         binding.swipeRefreshLayout.setOnRefreshListener {
-            viewModel.fetchOffers {
+            viewModel.fetchOffers(onRefreshUpdate = { status ->
+
+            }, onFinish = {
 //                binding.swipeRefreshLayout.isRefreshing = false
-            }
+            })
         }
     }
 
@@ -67,4 +111,12 @@ class CanteenFragment : Fragment() {
         super.onDestroyView()
         _binding = null
     }
+
+    private fun setPreference(pref: DietaryPreferences, newValue: Boolean) {
+        viewModel.setPreference(pref, newValue)
+        // notifyDataSetChanged?
+    }
+
+    private fun getPreference(pref: DietaryPreferences): Boolean =
+        viewModel.getPreference(pref)
 }