CanteenPageFragment.kt now displays the count of offers that have been hidden due to allergen and dietary preferences

app/src/main/java/com/denizk0461/weserplaner/adapter/CanteenOfferItemAdapter.kt

@@ -2,6 +2,7 @@ package com.denizk0461.weserplaner.adapter
 
 import android.content.res.ColorStateList
 import android.view.LayoutInflater
+import android.view.View
 import android.view.ViewGroup
 import androidx.appcompat.content.res.AppCompatResources
 import androidx.recyclerview.widget.DiffUtil
@@ -29,8 +30,16 @@ class CanteenOfferItemAdapter(
     private val displayColours: Boolean,
 ) : RecyclerView.Adapter<CanteenOfferItemAdapter.OfferViewHolder>() {
 
+    /**
+     * Offers to display.
+     */
     private val offers: MutableList<CanteenOfferGroup> = mutableListOf()
 
+    /**
+     * Difference between filtered list and the list fetched from the website.
+     */
+    private var difference: Int = 0
+
     /**
      * View holder class for parent class
      *
@@ -43,7 +52,7 @@ class CanteenOfferItemAdapter(
             ItemCanteenBinding.inflate(
                 LayoutInflater.from(parent.context),
                 parent,
-                false
+                false,
             )
         )
     }
@@ -52,9 +61,36 @@ class CanteenOfferItemAdapter(
     override fun getItemCount(): Int = offers.size
 
     override fun onBindViewHolder(holder: OfferViewHolder, position: Int) {
+
         // Retrieve item for current position
         val currentItem = offers[position]
 
+        // Context for easier reference
+        val context = holder.binding.root.context
+
+        holder.binding.canteenCard.visibility = if (currentItem.date == "ALL\$HIDDEN") {
+            View.GONE
+        } else {
+            View.VISIBLE
+        }
+
+        // Display
+        if (position == (offers.size - 1) && difference > 0) {
+            holder.binding.textDifference.apply {
+                visibility = View.VISIBLE
+                text = if (difference == 1) {
+                    context.getString(R.string.canteen_item_difference_text_one)
+                } else {
+                    context.getString(R.string.canteen_item_difference_text_other, difference)
+                }
+            }
+        } else {
+            holder.binding.textDifference.apply {
+                visibility = View.GONE
+                text = ""
+            }
+        }
+
         /*
          * Children of the line container MUST be removed before any are added, as otherwise, during
          * recycling, lines will be duplicated when they are scrolled off the visible screen area
@@ -69,34 +105,36 @@ class CanteenOfferItemAdapter(
 
             // Set the text to "No offers" (localised)
             holder.binding.textCategory.text =
-                holder.binding.root.context.getString(R.string.canteen_no_offer_header)
+                context.getString(R.string.canteen_no_offer_header)
 
             // Inflate a single line without binding it to the line container
             val line = ItemCanteenLineBinding.inflate(
-                LayoutInflater.from(holder.binding.root.context),
+                LayoutInflater.from(context),
             )
 
             // Set content to tell the user that no offers are available (localised)
             line.textContent.text =
-                holder.binding.root.context.getString(R.string.canteen_no_offer_desc)
+                context.getString(R.string.canteen_no_offer_desc)
 
             // Inflate a new icon holder
-            val img = ItemIconBinding.inflate(LayoutInflater.from(holder.binding.root.context))
+            val img = ItemIconBinding.inflate(LayoutInflater.from(context))
 
             // Retrieve data for the dietary preference
-            val (_, drawableId, colourId) = DietaryPreferences.getData(DietaryPreferences.ERROR.ordinal)
+            val (_, drawableId, colourId) = DietaryPreferences.getData(
+                DietaryPreferences.ERROR.ordinal,
+            )
 
             // Set a cross icon
             img.imageView.setImageDrawable(
                 AppCompatResources.getDrawable(
-                    holder.binding.root.context,
+                    context,
                     drawableId,
                 )
             )
 
             // Set tint of the icon; themed to the preference, if the user has the option enabled
             img.imageView.imageTintList = ColorStateList.valueOf(
-                holder.binding.root.context.theme.getThemedColor(
+                context.theme.getThemedColor(
                     if (displayColours) {
                         colourId
                     } else {
@@ -119,7 +157,7 @@ class CanteenOfferItemAdapter(
             currentItem.offers.forEach { offer ->
                 // Inflate the new line without binding it to the line container
                 val line = ItemCanteenLineBinding.inflate(
-                    LayoutInflater.from(holder.binding.root.context),
+                    LayoutInflater.from(context),
                 )
 
                 // Set text values
@@ -144,7 +182,7 @@ class CanteenOfferItemAdapter(
                 // Iterate through all icons that need to be displayed
                 indices.forEach { index ->
                     // Inflate a new icon holder
-                    val img = ItemIconBinding.inflate(LayoutInflater.from(holder.binding.root.context))
+                    val img = ItemIconBinding.inflate(LayoutInflater.from(context))
 
                     // Retrieve data for the dietary preference
                     val (_, drawableId, colourId) = DietaryPreferences.getData(index)
@@ -152,14 +190,14 @@ class CanteenOfferItemAdapter(
                     // Set the appropriate icon
                     img.imageView.setImageDrawable(
                         AppCompatResources.getDrawable(
-                            holder.binding.root.context,
+                            context,
                             drawableId,
                         )
                     )
 
                     // Set tint of the icon
                     img.imageView.imageTintList = ColorStateList.valueOf(
-                        holder.binding.root.context.theme.getThemedColor(
+                        context.theme.getThemedColor(
                             if (displayColours) {
                                 colourId
                             } else {
@@ -193,7 +231,9 @@ class CanteenOfferItemAdapter(
      *
      * @param newData   new dataset to be displayed
      */
-    fun setNewData(newData: List<CanteenOfferGroup>) {
+    fun setNewData(newData: List<CanteenOfferGroup>, difference: Int) {
+        this.difference = difference
+
         // Calculate the difference between the old list and the new list
         val diffResult = DiffUtil.calculateDiff(AppDiffUtilCallback(offers, newData))
 
@@ -205,6 +245,9 @@ class CanteenOfferItemAdapter(
 
         // Tell the DiffUtil which items have changed between the two lists
         diffResult.dispatchUpdatesTo(this)
+
+        // Force an update on the last item to display how many items have been hidden
+        notifyItemChanged(offers.size - 1)
     }
 
     /**

app/src/main/java/com/denizk0461/weserplaner/db/AppRepository.kt

@@ -263,7 +263,7 @@ class AppRepository(app: Application) {
         defaultValue = AllergenPreferences.TEMPLATE,
     )
     /**
-     * This value determines how many allergens the user wants to have displayed or hidden.
+     * This value determines how many allergens the user wants to have hidden.
      */
     fun getPreferenceAllergenConfigCount(): Int = getPreferenceAllergenConfig().run {
         if (isBlank()) 0 else split(",").count()

app/src/main/java/com/denizk0461/weserplaner/fragment/CanteenPageFragment.kt

@@ -84,36 +84,75 @@ class CanteenPageFragment : AppFragment(), CanteenOfferItemAdapter.OnClickListen
 
             // Observe offers and re-set them if they change
             viewModel.getOffersByDay(currentDay).observe(viewLifecycleOwner) { offers ->
+                // Refresh temporarily stored offer list
                 offerList.clear()
                 offerList.addAll(offers)
-                recyclerViewAdapter.setNewData(offers.filterElements().groupElements().distinct())
+
+                // Set new data
+                recyclerViewAdapter.setData(offers)
             }
         }
 
-        // Retrieve parent fragment to access its functions
+        // Set up FAB behaviour for parent fragment's FAB if activity is not null
-        val navHostFragment = activity?.supportFragmentManager?.fragments?.get(0) as? NavHostFragment
+        activity?.let { activity ->
-        val parent = navHostFragment?.childFragmentManager?.primaryNavigationFragment as? CanteenFragment
+            // Retrieve parent fragment to access its functions
+            val navHostFragment = activity
+                .supportFragmentManager
+                .fragments[0] as NavHostFragment
+            val parentFragment = navHostFragment
+                .childFragmentManager
+                .primaryNavigationFragment as CanteenFragment
 
-        // Set up scroll change listener to shrink and extend FAB accordingly
+            // Set up scroll change listener to shrink and extend FAB accordingly
-        binding.recyclerView.setOnScrollChangeListener { _, _, scrollY, _, oldScrollY ->
+            binding.recyclerView.setOnScrollChangeListener { _, _, scrollY, _, oldScrollY ->
-            // Calculate the vertical scroll difference
+                // Calculate the vertical scroll difference
-            val dy = scrollY - oldScrollY
+                val dy = scrollY - oldScrollY
-            if (dy > 0) {
+                if (dy > 0) {
-                // If scrolling down, shrink the FAB
+                    // If scrolling down, shrink the FAB
-                parent?.shrinkFab()
+                    parentFragment.shrinkFab()
-            } else if (dy < 0) {
+                } else if (dy < 0) {
-                // If scrolling up, extend the FAB
+                    // If scrolling up, extend the FAB
-                parent?.extendFab()
+                    parentFragment.extendFab()
+                }
             }
         }
 
-        // Observe dietary preference updates and re-set the items if a change is detected
+        /*
+         * Observe dietary preference updates and re-set the items if a change is detected to force
+         * an update.
+         */
         viewModel.dietaryPreferencesUpdate.observe(viewLifecycleOwner) {
-            // Re-set the list of items to the recycler view, forcing an update
+            // Re-set data
-            recyclerViewAdapter.setNewData(offerList.filterElements().groupElements().distinct())
+            recyclerViewAdapter.setData(offerList)
         }
     }
 
+    private fun CanteenOfferItemAdapter.setData(offers: List<CanteenOffer>) {
+        /*
+         * Filter items that contain user-selected allergens or user-excluded dietary
+         * preferences.
+         */
+        val filteredOffers = offers.filterElements()
+
+        // Put elements into groups
+        val groupedOffers = filteredOffers.groupElements().distinct()
+
+        val difference = offers.size - filteredOffers.size
+
+        val newOffers = if (groupedOffers.isEmpty() && difference > 0) {
+            listOf(CanteenOfferGroup(
+                "ALL\$HIDDEN", 0, "", "", listOf(),
+            ))
+        } else groupedOffers
+
+        // Set new items into the adapter
+        setNewData(
+            newOffers,
+            // Difference is calculated from the unfiltered and filtered data sets
+            difference,
+        )
+    }
+
     /**
      * Groups [CanteenOffer] elements by their categories into [CanteenOfferGroup] elements and
      * filters for the user's dietary preferences.
@@ -130,7 +169,7 @@ class CanteenPageFragment : AppFragment(), CanteenOfferItemAdapter.OnClickListen
                 category,
                 canteen,
                 filter {
-                    it.category == category && it.date == date && it.canteen == canteen
+                    it.category == category && it.canteen == canteen
                 }.map {
                     // Map the individual items to their respective groups
                     CanteenOfferGroupElement(

app/src/main/res/layout/item_canteen.xml

@@ -4,9 +4,11 @@
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:paddingHorizontal="8dp"
-    android:paddingVertical="4dp">
+    android:paddingVertical="4dp"
+    android:orientation="vertical">
 
     <com.google.android.material.card.MaterialCardView
+        android:id="@+id/canteen_card"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         style="@style/Widget.Material3.CardView.Outlined">
@@ -45,4 +47,10 @@
 
     </com.google.android.material.card.MaterialCardView>
 
+    <TextView
+        android:id="@+id/text_difference"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_horizontal"/>
+
 </androidx.appcompat.widget.LinearLayoutCompat>

app/src/main/res/values-de/strings.xml

@@ -24,6 +24,9 @@
     <string name="fetch_error_webpage_snack">Du musst deinen Stundenplan öffnen!</string>
     <string name="canteen_fetch_error">Mensaplan konnte nicht heruntergeladen werden!</string>
 
+    <string name="canteen_item_difference_text_one">Ein Angebot aufgrund deiner Präferenzen versteckt.</string>
+    <string name="canteen_item_difference_text_other">%d Angebote aufgrund deiner Präferenzen versteckt.</string>
+
     <string name="event_empty_fetch_button">Lade deinen Stundenplan von Stud.IP herunter</string>
 
     <!-- plurals string resource cannot be used here because Android doesn't treat 0 differently from 2 -->

app/src/main/res/values/strings.xml

@@ -25,6 +25,9 @@
     <string name="fetch_error_webpage_snack">You must navigate to your schedule!</string>
     <string name="canteen_fetch_error">Couldn\'t retrieve the canteen plan!</string>
 
+    <string name="canteen_item_difference_text_one">One offer hidden due to your preferences.</string>
+    <string name="canteen_item_difference_text_other">%d offers hidden due to your preferences.</string>
+
     <string name="event_empty_fetch_button">Download your schedule from Stud.IP</string>
 
     <!-- plurals resource cannot be used here; view German translation for details -->