Fixed a bug that would cause the tab for a day without canteen offers to not be shown, causing the offers for the next days to be shifted over, thus not showing the offers for the last day that's available online. I know I didn't explain that very well, but it's fixed now anyway, soo (: also made some minor visual adjustments to margins and colours

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

@@ -10,10 +10,7 @@ import androidx.fragment.app.viewModels
 import androidx.lifecycle.LiveData
 import com.denizk0461.studip.adapter.CanteenOfferPageAdapter
 import com.denizk0461.studip.databinding.FragmentCanteenBinding
-import com.denizk0461.studip.model.CanteenOffer
-import com.denizk0461.studip.model.CanteenOfferGroup
-import com.denizk0461.studip.model.CanteenOfferGroupElement
-import com.denizk0461.studip.model.DietaryPreferences
+import com.denizk0461.studip.model.*
 import com.denizk0461.studip.viewmodel.CanteenViewModel
 import com.google.android.material.tabs.TabLayoutMediator
 
@@ -25,8 +22,6 @@ class CanteenFragment : Fragment() {
     // onDestroyView.
     private val binding get() = _binding!!
 
-    private var dates = listOf<String>()
-
     private lateinit var liveData: LiveData<List<CanteenOffer>>
 
     private lateinit var viewPagerAdapter: CanteenOfferPageAdapter
@@ -77,7 +72,7 @@ class CanteenFragment : Fragment() {
         viewPagerAdapter = CanteenOfferPageAdapter(listOf(), 0, getPrefRegex())
         binding.viewPager.adapter = viewPagerAdapter
 
-        createTabLayoutMediator()
+        createTabLayoutMediator(listOf())
 
         liveData = viewModel.allOffers
         liveData.observe(viewLifecycleOwner) { offers ->
@@ -85,12 +80,13 @@ class CanteenFragment : Fragment() {
 
             val groupedElements = offers.groupElements().distinct()
 
-            dates = groupedElements.map { it.date }.distinct()
-            createTabLayoutMediator()
+//            dates = groupedElements.map { it.date }.distinct()
+            val newDates = viewModel.getDates()
+            createTabLayoutMediator(newDates)
 
-            this.dateSize = dates.size
+            dateSize = newDates.size
 
-            viewPagerAdapter.setNewItems(groupedElements, dates.size)
+            viewPagerAdapter.setNewItems(groupedElements, dateSize)
 
             // TODO this must be changed. if an exception is raised, then this will not fire
             binding.swipeRefreshLayout.isRefreshing = false
@@ -105,10 +101,10 @@ class CanteenFragment : Fragment() {
         }
     }
 
-    private fun createTabLayoutMediator() {
+    private fun createTabLayoutMediator(dates: List<OfferDate>) {
         if (dates.isNotEmpty()) {
             TabLayoutMediator(binding.dayTabLayout, binding.viewPager) { tab, position ->
-                tab.text = dates[position]
+                tab.text = dates[position].date
             }.attach()
         }
     }
@@ -127,7 +123,7 @@ class CanteenFragment : Fragment() {
         viewModel.getPreference(pref)
 
     private fun getPrefRegex(): Regex {
-        val prefs = viewModel.getDietaryPrefs().deconstruct().replace('f', '.')
+        val prefs = viewModel.getDietaryPrefs().deconstruct()//.replace('f', '.')
 
         val template = ".........."