Refactored preference functions so that view models cannot access preferences directly, instead having to use get/set methods, which also solves a potential bug source of defining different default values for certain properties in different view models

app/src/main/java/com/denizk0461/weserplaner/data/StwParser.kt

@@ -198,7 +198,7 @@ class StwParser(application: Application) {
                              *
                              * Hence, getIntPreference() + 2
                              */
-                            repo.getIntPreference(SettingsPreferences.PRICING) + 2
+                            repo.getPreferencePricing() + 2
                         ),
                         dietaryPreferences = prefs.deconstruct(),
                         allergens = filteredText.second,

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

@@ -46,8 +46,10 @@ class AppRepository(app: Application) {
          */
         fun getRepositoryInstance(app: Application): AppRepository {
             if (!::repo.isInitialized) {
+                synchronized(Object::class.java) {
                     repo = AppRepository(app)
                 }
+            }
             return repo
         }
     }
@@ -251,7 +253,144 @@ class AppRepository(app: Application) {
      */
     fun insertItems(items: List<OfferItem>) { dao.insertItems(items) }
 
-    // --- settings preferences --- //
+    // --- user-set preferences --- //
+
+    /**
+     * This value determines which allergens the user wants to have displayed or hidden.
+     */
+    fun getPreferenceAllergenConfig(): String = getStringPreference(
+        SettingsPreferences.ALLERGEN_CONFIG,
+        defaultValue = AllergenPreferences.TEMPLATE,
+    )
+    /**
+     * This value determines how many allergens the user wants to have displayed or hidden.
+     */
+    fun getPreferenceAllergenConfigCount(): Int = getPreferenceAllergenConfig().run {
+        if (isBlank()) 0 else split(",").count()
+    }
+    fun setPreferenceAllergenConfig(newValue: String) {
+        setPreference(SettingsPreferences.ALLERGEN_CONFIG, newValue)
+    }
+
+    /**
+     * This value determines whether the user wants to have allergens marked.
+     */
+    fun getPreferenceAllergen(): Boolean = getBooleanPreference(
+        SettingsPreferences.ALLERGEN,
+        defaultValue = true,
+    )
+    fun setPreferenceAllergen(newValue: Boolean) {
+        setPreference(SettingsPreferences.ALLERGEN, newValue)
+    }
+
+    /**
+     * This value determines which canteen the user has selected.
+     */
+    fun getPreferenceColour(): Boolean = getBooleanPreference(
+        SettingsPreferences.COLOUR_PREFS,
+        defaultValue = true,
+    )
+    fun setPreferenceColour(newValue: Boolean) {
+        setPreference(SettingsPreferences.COLOUR_PREFS, newValue)
+    }
+
+    /**
+     * This value determines which canteen the user has selected.
+     */
+    fun getPreferenceCanteen(): Int = getIntPreference(
+        SettingsPreferences.CANTEEN,
+    )
+    fun setPreferenceCanteen(newValue: Int) {
+        setPreference(SettingsPreferences.CANTEEN, newValue)
+    }
+
+    /**
+     * This value determines whether the user has opened the canteen fragment before.
+     */
+    fun getPreferenceHasOpenedCanteen(): Boolean = getBooleanPreference(
+        SettingsPreferences.HAS_OPENED_CANTEEN,
+    )
+    fun setPreferenceHasOpenedCanteen(newValue: Boolean) {
+        setPreference(SettingsPreferences.HAS_OPENED_CANTEEN, newValue)
+    }
+
+    /**
+     * This value determines whether the user wants to have the next course in their schedule
+     * highlighted.
+     */
+    fun getPreferenceCourseHighlighting(): Boolean = getBooleanPreference(
+            SettingsPreferences.COURSE_HIGHLIGHTING,
+            defaultValue = true,
+        )
+    fun setPreferenceCourseHighlighting(newValue: Boolean) {
+        setPreference(SettingsPreferences.COURSE_HIGHLIGHTING, newValue)
+    }
+
+    /**
+     * This value determines whether the user wants their timetable to launch with the current day.
+     */
+    fun getPreferenceCurrentDay(): Boolean = getBooleanPreference(
+            SettingsPreferences.CURRENT_DAY,
+            defaultValue = true,
+        )
+    fun setPreferenceCurrentDay(newValue: Boolean) {
+        setPreference(SettingsPreferences.CURRENT_DAY, newValue)
+    }
+
+    /**
+     * Determines whether the user is launching the app for the first time.
+     */
+    fun getPreferenceFirstLaunch(): Boolean = getBooleanPreference(
+            SettingsPreferences.FIRST_LAUNCH,
+            defaultValue = true,
+        )
+    fun setPreferenceFirstLaunch(newValue: Boolean) {
+        setPreference(SettingsPreferences.FIRST_LAUNCH, newValue)
+    }
+
+    /**
+     * This value determines which fragment the user wants the app to start with. Order is equal to
+     * the order that the items are arranged in in the bottom nav bar.
+     */
+    fun getPreferenceLaunchFragment(): Int = getIntPreference(
+            SettingsPreferences.LAUNCH_FRAGMENT_ON_START,
+        )
+    fun setPreferenceLaunchFragment(newValue: Int) {
+        setPreference(SettingsPreferences.LAUNCH_FRAGMENT_ON_START, newValue)
+    }
+
+    /**
+     * This value determines which fragment the user wants the app to start with. Order is equal to
+     * the order that the items are arranged in in the bottom nav bar.
+     */
+    fun getPreferencePricing(): Int = getIntPreference(
+        SettingsPreferences.PRICING,
+    )
+    fun setPreferencePricing(newValue: Int) {
+        setPreference(SettingsPreferences.PRICING, newValue)
+    }
+
+    /**
+     * This value determines whether the user opts into submitting crash reports.
+     */
+    fun getPreferenceDataHandling(): Boolean = getBooleanPreference(
+        SettingsPreferences.DATA_HANDLING,
+    )
+    fun setPreferenceDataHandling(newValue: Boolean) {
+        setPreference(SettingsPreferences.DATA_HANDLING, newValue)
+    }
+
+    /**
+     * This value determines whether the user has enabled experimental settings.
+     */
+    fun getPreferenceExperimentalSettingsEnabled(): Boolean = getBooleanPreference(
+        SettingsPreferences.EXPERIMENTAL_ENABLED,
+    )
+    fun setPreferenceExperimentalSettingsEnabled(newValue: Boolean) {
+        setPreference(SettingsPreferences.EXPERIMENTAL_ENABLED, newValue)
+    }
+
+    // --- private preference handlers preferences --- //
 
     /**
      * Retrieves a user-set boolean preference.
@@ -259,53 +398,53 @@ class AppRepository(app: Application) {
      * @param pref  preference to retrieve
      * @return      whether the user set this preference
      */
-    fun getBooleanPreference(pref: SettingsPreferences, defaultValue: Boolean = false): Boolean =
+    private fun getBooleanPreference(pref: SettingsPreferences, defaultValue: Boolean = false): Boolean =
         prefs.getBoolean(pref.key, defaultValue)
 
-    /**
-     * Retrieves a user-set string preference.
-     *
-     * @param pref  preference to retrieve
-     * @return      string that was set
-     */
-    fun getStringPreference(pref: SettingsPreferences, defaultValue: String = ""): String =
-        prefs.getString(pref.key, defaultValue) ?: ""
-
-    /**
-     * Retrieves a user-set integer preference.
-     *
-     * @param pref  preference to retrieve
-     * @return      whether the user set this preference
-     */
-    fun getIntPreference(pref: SettingsPreferences): Int = prefs.getInt(pref.key, 0)
-
     /**
      * Updates a user-set boolean preference.
      *
      * @param pref      preference to set
      * @param newValue  new value to set the preference to
      */
-    fun setPreference(pref: SettingsPreferences, newValue: Boolean) {
+    private fun setPreference(pref: SettingsPreferences, newValue: Boolean) {
         prefs.edit().putBoolean(pref.key, newValue).apply()
     }
 
+    /**
+     * Retrieves a user-set string preference.
+     *
+     * @param pref  preference to retrieve
+     * @return      string that was set
+     */
+    private fun getStringPreference(pref: SettingsPreferences, defaultValue: String = ""): String =
+        prefs.getString(pref.key, defaultValue) ?: ""
+
     /**
      * Updates a user-set string preference.
      *
      * @param pref      preference to set
      * @param newValue  new value to set the preference to
      */
-    fun setPreference(pref: SettingsPreferences, newValue: String) {
+    private fun setPreference(pref: SettingsPreferences, newValue: String) {
         prefs.edit().putString(pref.key, newValue).apply()
     }
 
+    /**
+     * Retrieves a user-set integer preference.
+     *
+     * @param pref  preference to retrieve
+     * @return      whether the user set this preference
+     */
+    private fun getIntPreference(pref: SettingsPreferences): Int = prefs.getInt(pref.key, 0)
+
     /**
      * Updates a user-set integer preference.
      *
      * @param pref      preference to set
      * @param newValue  new value to set the preference to
      */
-    fun setPreference(pref: SettingsPreferences, newValue: Int) {
+    private fun setPreference(pref: SettingsPreferences, newValue: Int) {
         prefs.edit().putInt(pref.key, newValue).apply()
     }
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/AllergenConfigViewModel.kt

@@ -1,8 +1,6 @@
 package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
-import com.denizk0461.weserplaner.model.AllergenPreferences
-import com.denizk0461.weserplaner.model.SettingsPreferences
 
 class AllergenConfigViewModel(application: Application) : AppViewModel(application) {
 
@@ -10,8 +8,6 @@ class AllergenConfigViewModel(application: Application) : AppViewModel(applicati
      * This value determines which allergens the user wants to have displayed or hidden.
      */
     var preferenceAllergenConfig: String
-        get() = repo.getStringPreference(
+        get() = repo.getPreferenceAllergenConfig()
-            SettingsPreferences.ALLERGEN_CONFIG, defaultValue = AllergenPreferences.TEMPLATE
+        set(value) { repo.setPreferenceAllergenConfig(value) }
-        )
-        set(newValue) { repo.setPreference(SettingsPreferences.ALLERGEN_CONFIG, newValue) }
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/CanteenPageViewModel.kt

@@ -2,10 +2,8 @@ package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
 import androidx.lifecycle.LiveData
-import com.denizk0461.weserplaner.model.AllergenPreferences
 import com.denizk0461.weserplaner.model.CanteenOffer
 import com.denizk0461.weserplaner.model.DietaryPreferences
-import com.denizk0461.weserplaner.model.SettingsPreferences
 
 class CanteenPageViewModel(app: Application) : AppViewModel(app) {
 
@@ -33,19 +31,17 @@ class CanteenPageViewModel(app: Application) : AppViewModel(app) {
      * This value determines which allergens the user wants to have displayed or hidden.
      */
     val preferenceAllergenConfig: String
-        get() = repo.getStringPreference(
+        get() = repo.getPreferenceAllergenConfig()
-            SettingsPreferences.ALLERGEN_CONFIG, defaultValue = AllergenPreferences.TEMPLATE
-        )
 
     /**
      * This value determines whether the user wants to have allergens marked.
      */
     val preferenceAllergen: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.ALLERGEN, defaultValue = true)
+        get() = repo.getPreferenceAllergen()
 
     /**
      * This value determines which canteen the user has selected.
      */
     val preferenceColour: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.COLOUR_PREFS, defaultValue = true)
+        get() = repo.getPreferenceColour()
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/CanteenViewModel.kt

@@ -78,13 +78,13 @@ class CanteenViewModel(app: Application) : AppViewModel(app) {
      * This value determines which canteen the user has selected.
      */
     var preferenceCanteen: Int
-        get() = repo.getIntPreference(SettingsPreferences.CANTEEN)
+        get() = repo.getPreferenceCanteen()
-        set(newValue) { repo.setPreference(SettingsPreferences.CANTEEN, newValue) }
+        set(newValue) { repo.setPreferenceCanteen(newValue) }
 
     /**
      * This value determines whether the user has opened the canteen fragment before.
      */
     var preferenceHasOpenedCanteen: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.HAS_OPENED_CANTEEN)
+        get() = repo.getPreferenceHasOpenedCanteen()
-        set(newValue) { repo.setPreference(SettingsPreferences.HAS_OPENED_CANTEEN, newValue) }
+        set(newValue) { repo.setPreferenceHasOpenedCanteen(newValue) }
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/EventPageViewModel.kt

@@ -2,7 +2,6 @@ package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
 import androidx.lifecycle.LiveData
-import com.denizk0461.weserplaner.model.SettingsPreferences
 import com.denizk0461.weserplaner.model.StudIPEvent
 
 /**
@@ -24,8 +23,5 @@ class EventPageViewModel(app: Application) : AppViewModel(app) {
      * highlighted.
      */
     val preferenceCourseHighlighting: Boolean
-        get() = repo.getBooleanPreference(
+        get() = repo.getPreferenceCourseHighlighting()
-            SettingsPreferences.COURSE_HIGHLIGHTING,
-            defaultValue = true
-        )
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/EventViewModel.kt

@@ -2,7 +2,6 @@ package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
 import androidx.lifecycle.LiveData
-import com.denizk0461.weserplaner.model.SettingsPreferences
 
 /**
  * View model for [com.denizk0461.weserplaner.fragment.EventFragment]
@@ -22,18 +21,12 @@ class EventViewModel(app: Application) : AppViewModel(app) {
      * This value determines whether the user wants their timetable to launch with the current day.
      */
     val preferenceCurrentDay: Boolean
-        get() = repo.getBooleanPreference(
+        get() = repo.getPreferenceCurrentDay()
-            SettingsPreferences.CURRENT_DAY,
-            defaultValue = true,
-        )
 
     /**
      * Determines whether the user is launching the app for the first time.
      */
     var preferenceFirstLaunch: Boolean
-        get() = repo.getBooleanPreference(
+        get() = repo.getPreferenceFirstLaunch()
-            SettingsPreferences.FIRST_LAUNCH,
+        set(value) { repo.setPreferenceFirstLaunch(value) }
-            defaultValue = true,
-        )
-        set(value) { repo.setPreference(SettingsPreferences.FIRST_LAUNCH, value) }
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/MainViewModel.kt

@@ -1,7 +1,6 @@
 package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
-import com.denizk0461.weserplaner.model.SettingsPreferences
 
 /**
  * View model for [com.denizk0461.weserplaner.activity.MainActivity]
@@ -15,5 +14,5 @@ class MainViewModel(application: Application) : AppViewModel(application) {
      * the order that the items are arranged in in the bottom nav bar.
      */
     val preferenceLaunchFragment: Int
-        get() = repo.getIntPreference(SettingsPreferences.LAUNCH_FRAGMENT_ON_START)
+        get() = repo.getPreferenceLaunchFragment()
 }

app/src/main/java/com/denizk0461/weserplaner/viewmodel/SettingsViewModel.kt

@@ -1,8 +1,6 @@
 package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
-import com.denizk0461.weserplaner.model.AllergenPreferences
-import com.denizk0461.weserplaner.model.SettingsPreferences
 
 /**
  * View model for [com.denizk0461.weserplaner.fragment.SettingsFragment]
@@ -15,76 +13,66 @@ class SettingsViewModel(app: Application) : AppViewModel(app) {
      * This value determines whether the user wants their timetable to launch with the current day.
      */
     var preferenceCurrentDay: Boolean
-        get() = repo.getBooleanPreference(
+        get() = repo.getPreferenceCurrentDay()
-            SettingsPreferences.CURRENT_DAY,
+        set(newValue) { repo.setPreferenceCurrentDay(newValue) }
-            defaultValue = true,
-        )
-        set(newValue) { repo.setPreference(SettingsPreferences.CURRENT_DAY, newValue) }
 
     /**
      * This value determines whether the user wants to have the next course in their schedule
      * highlighted.
      */
     var preferenceCourseHighlighting: Boolean
-        get() = repo.getBooleanPreference(
+        get() = repo.getPreferenceCourseHighlighting()
-            SettingsPreferences.COURSE_HIGHLIGHTING,
+        set(newValue) { repo.setPreferenceCourseHighlighting(newValue) }
-            defaultValue = true
-        )
-        set(newValue) { repo.setPreference(SettingsPreferences.COURSE_HIGHLIGHTING, newValue) }
 
     /**
      * This value determines whether the user wants to have allergens marked.
      */
     var preferenceAllergen: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.ALLERGEN, defaultValue = true)
+        get() = repo.getPreferenceAllergen()
-        set(newValue) { repo.setPreference(SettingsPreferences.ALLERGEN, newValue) }
+        set(newValue) { repo.setPreferenceAllergen(newValue) }
 
     /**
      * This value determines how many allergens the user wants to have displayed or hidden.
      */
     val preferenceAllergenConfigCount: Int
-        get() = repo.getStringPreference(
+        get() = repo.getPreferenceAllergenConfigCount()
-            SettingsPreferences.ALLERGEN_CONFIG, defaultValue = AllergenPreferences.TEMPLATE
-        ).run {
-            if (isBlank()) 0 else split(",").count()
-        }
 
     /**
      * This value determines which fragment the user wants the app to start with. Order is equal to
      * the order that the items are arranged in in the bottom nav bar.
      */
     var preferencePricing: Int
-        get() = repo.getIntPreference(SettingsPreferences.PRICING)
+        get() = repo.getPreferencePricing()
-        set(newValue) { repo.setPreference(SettingsPreferences.PRICING, newValue) }
+        set(newValue) { repo.setPreferencePricing(newValue) }
 
     /**
      * This value determines which fragment the user wants the app to start with. Order is equal to
      * the order that the items are arranged in in the bottom nav bar.
      */
     var preferenceLaunchFragment: Int
-        get() = repo.getIntPreference(SettingsPreferences.LAUNCH_FRAGMENT_ON_START)
+        get() = repo.getPreferenceLaunchFragment()
-        set(newValue) { repo.setPreference(SettingsPreferences.LAUNCH_FRAGMENT_ON_START, newValue) }
+        set(newValue) { repo.setPreferenceLaunchFragment(newValue) }
 
     /**
      * This value determines which canteen the user has selected.
      */
     var preferenceColour: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.COLOUR_PREFS, defaultValue = true)
+        get() = repo.getPreferenceColour()
-        set(newValue) { repo.setPreference(SettingsPreferences.COLOUR_PREFS, newValue) }
+        set(newValue) { repo.setPreferenceColour(newValue) }
 
     /**
      * This value determines whether the user opts into submitting crash reports.
      */
     var preferenceDataHandling: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.DATA_HANDLING)
+        get() = repo.getPreferenceDataHandling()
-        set(newValue) { repo.setPreference(SettingsPreferences.DATA_HANDLING, newValue) }
+        set(newValue) { repo.setPreferenceDataHandling(newValue) }
 
     /**
      * This value determines whether the user has enabled experimental settings.
      */
     var preferenceExperimentalSettingsEnabled: Boolean
-        get() = repo.getBooleanPreference(SettingsPreferences.EXPERIMENTAL_ENABLED)
+        get() = repo.getPreferenceExperimentalSettingsEnabled()
-        set(newValue) { repo.setPreference(SettingsPreferences.EXPERIMENTAL_ENABLED, newValue) }
+        set(newValue) { repo.setPreferenceExperimentalSettingsEnabled(newValue) }
 
     // --- functions for dev codes --- //
 

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

@@ -20,7 +20,8 @@
             <androidx.constraintlayout.widget.ConstraintLayout
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:layout_marginHorizontal="16dp">
+                android:layout_marginStart="16dp"
+                android:layout_marginEnd="8dp">
 
                 <TextView
                     android:id="@+id/app_title_bar"
@@ -30,6 +31,7 @@
                     android:textSize="28sp"
                     android:layout_marginTop="16dp"
                     android:layout_marginBottom="8dp"
+                    android:layout_marginEnd="4dp"
                     android:fontFamily="@font/lato_blackitalic"
                     android:singleLine="true"
                     android:ellipsize="marquee"