Transitioned from a fairly custom solution to using a colour palette generated by the Material Theme Builder to simplify colour management. Also began work on a bottom sheet for displaying allergens and additives in canteen offers.

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

@@ -8,16 +8,37 @@ import com.denizk0461.studip.databinding.ItemCanteenBinding
 import com.denizk0461.studip.databinding.ItemCanteenLineBinding
 import com.denizk0461.studip.databinding.ItemIconBinding
 import com.denizk0461.studip.model.CanteenOfferGroup
+import com.denizk0461.studip.model.CanteenOfferGroupElement
 
 /**
  * Custom RecyclerView adapter that lays out the offers of a given canteen on a given day.
  *
  * @param offers            list of all offers filtered by canteen and day, grouped by category
+ * @param onClickListener   used for listening to clicks and long presses
  */
 class CanteenOfferItemAdapter(
-    private val offers: List<CanteenOfferGroup>
+    private val offers: List<CanteenOfferGroup>,
+    private val onClickListener: OnClickListener
 ) : RecyclerView.Adapter<CanteenOfferItemAdapter.OfferViewHolder>() {
 
+    /**
+     * Provides a converting function between the index of a dietary preference and its according
+     * icon.
+     */
+    private val indexToDrawable: Map<Int, Int> = mapOf(
+        0 to R.drawable.handshake,
+        1 to R.drawable.fish,
+        2 to R.drawable.chicken,
+        3 to R.drawable.sheep,
+        4 to R.drawable.yoga,
+        5 to R.drawable.cow,
+        6 to R.drawable.pig,
+        7 to R.drawable.leaf,
+        8 to R.drawable.carrot,
+        9 to R.drawable.deer,
+        10 to R.drawable.circle,
+    )
+
     /**
      * View holder class for parent class
      *
@@ -86,26 +107,39 @@ class CanteenOfferItemAdapter(
                 line.imageViewContainer.addView(img.root)
             }
 
+            // Set up single click listener
+            line.root.setOnClickListener {
+                onClickListener.onClick(offer)
+            }
+
+            // Set up long press listener
+            line.root.setOnLongClickListener {
+                onClickListener.onLongClick(offer)
+            }
             // Bind the new line to the line container
             holder.binding.lineContainer.addView(line.root)
         }
     }
 
     /**
-     * Provides a converting function between the index of a dietary preference and its according
-     * icon.
+     * Interface used to evaluate clicks and long presses on a given item.
      */
-    private val indexToDrawable: Map<Int, Int> = mapOf(
-        0 to R.drawable.handshake,
-        1 to R.drawable.fish,
-        2 to R.drawable.chicken,
-        3 to R.drawable.sheep,
-        4 to R.drawable.yoga,
-        5 to R.drawable.cow,
-        6 to R.drawable.pig,
-        7 to R.drawable.leaf,
-        8 to R.drawable.carrot,
-        9 to R.drawable.deer,
-        10 to R.drawable.circle,
-    )
+    interface OnClickListener {
+
+        /**
+         * Executed when an item has been clicked.
+         *
+         * @param offer item that has been clicked
+         */
+        fun onClick(offer: CanteenOfferGroupElement)
+
+
+        /**
+         * Executed when an item has been long-pressed.
+         *
+         * @param offer item that has been long-pressed
+         * @return      whether the long press was successful
+         */
+        fun onLongClick(offer: CanteenOfferGroupElement): Boolean
+    }
 }

app/src/main/java/com/denizk0461/studip/adapter/CanteenOfferPageAdapter.kt

@@ -16,10 +16,12 @@ import com.denizk0461.studip.model.CanteenOfferGroup
  * @param daysCovered   tells for how many days offers are available for.
  *                      Example: if the next two weeks are available, Monday through Friday and
  *                      excluding weekends, this value should be 10.
+ * @param onClickListener   for managing click and long press events
  */
 class CanteenOfferPageAdapter(
     private var offers: List<CanteenOfferGroup>,
     private var daysCovered: Int,
+    private val onClickListener: CanteenOfferItemAdapter.OnClickListener,
 ) : RecyclerView.Adapter<CanteenOfferPageAdapter.CanteenOfferPageViewHolder>() {
 
     /**
@@ -50,8 +52,12 @@ class CanteenOfferPageAdapter(
             /*
              * Create new adapter for every page. Attribute position denotes day that will be set up
              * by the newly created adapter (0 = Monday, 4 = Friday)
+             * TODO check if the filtered list is empty, and tell the user if it is
              */
-            adapter = CanteenOfferItemAdapter(offers.filter { it.dateId == position }) // TODO check if empty
+            adapter = CanteenOfferItemAdapter(
+                offers.filter { it.dateId == position },
+                onClickListener
+            )
 
             // Animate creation of new page
             scheduleLayoutAnimation()

app/src/main/java/com/denizk0461/studip/adapter/StudIPEventItemAdapter.kt

@@ -1,11 +1,8 @@
 package com.denizk0461.studip.adapter
 
-import android.content.res.ColorStateList
-import android.util.TypedValue
 import android.view.LayoutInflater
 import android.view.ViewGroup
 import androidx.recyclerview.widget.RecyclerView
-import com.denizk0461.studip.R
 import com.denizk0461.studip.model.StudIPEvent
 import com.denizk0461.studip.databinding.ItemEventBinding
 import java.util.*
@@ -72,42 +69,43 @@ class StudIPEventItemAdapter(
         // Use parsed timeslot string as defined in StudIPEvent#timeslot()
         holder.binding.textTimeslot.text = currentItem.timeslot()
 
+        // TODO highlighting functionality is currently not supported!
         // Set up colours used for highlighting and un-highlighting an item.
-        val colorPrimaryTranslucent = TypedValue()
-        val colorCardBackground = TypedValue()
-        val colorTextHintLighter = TypedValue()
+//        val colorPrimaryTranslucent = TypedValue()
+//        val colorCardBackground = TypedValue()
+//        val colorTextHintLighter = TypedValue()
 
         // Resolve themed attributes to get the right values for day and night modes
-            holder.binding.root.context.theme.apply {
-            resolveAttribute(R.attr.colorPrimaryTranslucent, colorPrimaryTranslucent, true)
-            resolveAttribute(R.attr.colorCardBackground, colorCardBackground, true)
-            resolveAttribute(R.attr.colorTextHintLighter, colorTextHintLighter, true)
-        }
+//        holder.binding.root.context.theme.apply {
+//            resolveAttribute(com.google.android.material.R.attr.colorSecondaryContainer, colorPrimaryTranslucent, true)
+//            resolveAttribute(R.attr.colorCardBackground, colorCardBackground, true)
+//            resolveAttribute(R.attr.colorTextHintLighter, colorTextHintLighter, true)
+//        }
 
         /* Highlight the next upcoming course of the day if the day of the adapter matches the
          * current day, and if no other course has been highlighted, to avoid double highlighting.
          */
-        if (!isAnyCourseHighlighted && currentItem.isCurrentCourse(currentCalendar)) {
-            // Ensure that no other course will be highlighted
-            isAnyCourseHighlighted = true
-
-            holder.binding.cardBackground.apply {
-                // Set the card's background colour to a desaturated shade of the primary colour
-                backgroundTintList = ColorStateList.valueOf(colorPrimaryTranslucent.data)
-
-                // Hide card stroke
-                strokeColor = context.getColor(android.R.color.transparent)
-            }
-        // Otherwise, apply colours to ensure that the item will not be highlighted
-        } else {
-            holder.binding.cardBackground.apply {
-                // Set the card's background colour to its default value
-                backgroundTintList = ColorStateList.valueOf(colorCardBackground.data)
-
-                // Set the card's stroke to its default colour
-                strokeColor = colorTextHintLighter.data
-            }
-        }
+//        if (!isAnyCourseHighlighted && currentItem.isCurrentCourse(currentCalendar)) {
+//            // Ensure that no other course will be highlighted
+//            isAnyCourseHighlighted = true
+//
+//            holder.binding.cardBackground.apply {
+//                // Set the card's background colour to a desaturated shade of the primary colour
+//                backgroundTintList = ColorStateList.valueOf(colorPrimaryTranslucent.data)
+//
+//                // Hide card stroke
+//                strokeColor = context.getColor(android.R.color.transparent)
+//            }
+//        // Otherwise, apply colours to ensure that the item will not be highlighted
+//        } else {
+//            holder.binding.cardBackground.apply {
+//                // Set the card's background colour to its default value
+//                backgroundTintList = ColorStateList.valueOf(colorCardBackground.data)
+//
+//                // Set the card's stroke to its default colour
+//                strokeColor = colorTextHintLighter.data
+//            }
+//        }
 
         // Set up single click listener
         holder.binding.cardBackground.setOnClickListener {

app/src/main/java/com/denizk0461/studip/adapter/StudIPEventPageAdapter.kt

@@ -16,7 +16,7 @@ import com.denizk0461.studip.databinding.ItemScrollablePageBinding
  */
 class StudIPEventPageAdapter(
     private var events: List<StudIPEvent>,
-    private val onClickListener: StudIPEventItemAdapter.OnClickListener
+    private val onClickListener: StudIPEventItemAdapter.OnClickListener,
 ) : RecyclerView.Adapter<StudIPEventPageAdapter.EventPageViewHolder>() {
 
     /**