Changed TextSheet to use a ViewModel for showing content that is fetched from the database. Uses TextSheetContentId to determine which LiveData to observe.

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

@@ -14,6 +14,7 @@ import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
 import com.denizk0461.weserplaner.R
 import com.denizk0461.weserplaner.exception.AcademicQuarterNotApplicableException
 import com.denizk0461.weserplaner.exception.ParcelNotFoundException
+import com.denizk0461.weserplaner.model.TextSheetContentId
 import com.denizk0461.weserplaner.sheet.TextSheet
 import com.google.android.material.snackbar.Snackbar
 import kotlin.jvm.Throws
@@ -72,10 +73,15 @@ fun Resources.Theme.showErrorSnackBar(view: CoordinatorLayout, text: String, anc
  * @param content   text content of the sheet
  * @return          sheet with text added
  */
-fun getTextSheet(header: String, content: String): TextSheet = TextSheet().also { sheet ->
+fun getTextSheet(
+    header: String,
+    content: String = "",
+    contentId: Int = TextSheetContentId.PASS_RAW_STRING
+): TextSheet = TextSheet().also { sheet ->
     val bundle = Bundle()
     bundle.putString("header", header)
     bundle.putString("content", content)
+    bundle.putInt("contentId", contentId)
     bundle.putBoolean("isCancellable", true)
     sheet.arguments = bundle
 }

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

@@ -194,4 +194,20 @@ interface AppDAO {
      */
     @Query("SELECT openingHours, news FROM offer_canteen LIMIT 1")
     fun getCanteenInfo(): CanteenOfferTuple
+
+    /**
+     * Retrieve opening hours for the fetched canteen.
+     *
+     * @return opening hours for the canteen
+     */
+    @Query("SELECT openingHours FROM offer_canteen LIMIT 1")
+    fun getCanteenOpeningHours(): LiveData<String>
+
+    /**
+     * Retrieve news for the fetched canteen.
+     *
+     * @return news for the canteen
+     */
+    @Query("SELECT news FROM offer_canteen LIMIT 1")
+    fun getCanteenNews(): LiveData<String>
 }

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

@@ -78,6 +78,20 @@ class AppRepository(app: Application) {
      */
     fun getCanteenInfo(): CanteenOfferTuple = dao.getCanteenInfo()
 
+    /**
+     * Retrieve opening hours for the fetched canteen.
+     *
+     * @return opening hours for the canteen
+     */
+    fun getCanteenOpeningHours(): LiveData<String> = dao.getCanteenOpeningHours()
+
+    /**
+     * Retrieve news for the fetched canteen.
+     *
+     * @return news for the canteen
+     */
+    fun getCanteenNews(): LiveData<String> = dao.getCanteenNews()
+
     /**
      * Retrieves all canteen offers that match given day.
      *

app/src/main/java/com/denizk0461/weserplaner/exception/InvalidContentIdException.kt

@@ -0,0 +1,6 @@
+package com.denizk0461.weserplaner.exception
+
+import java.io.IOException
+
+class InvalidContentIdException : IOException() {
+}

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

@@ -41,13 +41,13 @@ class CanteenFragment : AppFragment() {
      * Locally saved opening hours to quickly access them without querying the database on every
      * opening of the bottom sheet.
      */
-    private var openingHours: String = ""
+//    private var openingHours: String = ""
 
     /**
      * Locally saved news to quickly access them without querying the database on every opening of
      * the corresponding bottom sheet.
      */
-    private var news: String = ""
+//    private var news: String = ""
 
     /**
      * Locally stored dates to populate the TabLayout with.
@@ -76,7 +76,7 @@ class CanteenFragment : AppFragment() {
         binding.buttonNotifications.setOnClickListener {
             openBottomSheet(getTextSheet(
                 getString(R.string.canteen_news_sheet_title),
-                news,
+                contentId = TextSheetContentId.NEWS,
             ))
         }
 
@@ -114,7 +114,7 @@ class CanteenFragment : AppFragment() {
                         R.string.canteen_opening_hours,
                         getCurrentlySelectedCanteenName()
                     ),
-                    openingHours
+                    contentId = TextSheetContentId.OPENING_HOURS,
                 )
             )
         }
@@ -181,10 +181,11 @@ class CanteenFragment : AppFragment() {
 
             // Retrieve further information about this canteen from the database
             viewModel.getCanteenInfo().also { info ->
-                openingHours = info.openingHours
+                /*
-                news = info.news
+                 * Set visibility of the notifications icon depending on whether news are available.
-
+                 * TODO change this to a BadgeDrawable later
-                binding.buttonNotifications.visibility = if (news.isBlank()) {
+                 */
+                binding.buttonNotifications.visibility = if (info.news.isBlank()) {
                     View.GONE
                 } else {
                     View.VISIBLE

app/src/main/java/com/denizk0461/weserplaner/model/TextSheetContentId.kt

@@ -0,0 +1,8 @@
+package com.denizk0461.weserplaner.model
+
+object TextSheetContentId {
+
+    const val PASS_RAW_STRING = -1
+    const val OPENING_HOURS = 0
+    const val NEWS = 1
+}

app/src/main/java/com/denizk0461/weserplaner/sheet/TextSheet.kt

@@ -2,9 +2,13 @@ package com.denizk0461.weserplaner.sheet
 
 import android.os.Bundle
 import android.view.View
+import androidx.fragment.app.viewModels
 import com.denizk0461.weserplaner.R
 import com.denizk0461.weserplaner.data.viewBinding
 import com.denizk0461.weserplaner.databinding.SheetTextBinding
+import com.denizk0461.weserplaner.exception.InvalidContentIdException
+import com.denizk0461.weserplaner.model.TextSheetContentId
+import com.denizk0461.weserplaner.viewmodel.TextSheetViewModel
 
 /**
  * Bottom sheet used for displaying any sort of text to the user.
@@ -14,22 +18,49 @@ class TextSheet : AppSheet(R.layout.sheet_text) {
     // View binding
     private val binding: SheetTextBinding by viewBinding(SheetTextBinding::bind)
 
+    // View model; used to retrieve certain texts as LiveData rather than receiving the raw string
+    private val viewModel: TextSheetViewModel by viewModels()
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
         // Retrieve headline for the window
         val header = arguments?.getString("header") ?: ""
 
-        // Retrieve content for the window
+        /*
-        val content = arguments?.getString("content") ?: ""
+         * Retrieve certain ID to denote which text content LiveData should be observed; if this is
+         * -1, assume that a raw string has been passed instead
+         */
+        val contentId = arguments?.getInt("contentId") ?: TextSheetContentId.PASS_RAW_STRING
+
+        // Check whether an ID has passed to use LiveData
+        val content = if (contentId == TextSheetContentId.PASS_RAW_STRING) {
+            // Retrieve content for the window as raw string if this has been picked
+            arguments?.getString("content") ?: ""
+        } else "" // This empty string will be unused
 
         // Set whether the sheet should be cancellable by actions such as swiping
         val isSheetCancellable = arguments?.getBoolean("isCancellable") == true
 
-        // Set text values
+        /*
-        binding.apply {
+         * Set text header.
-            textHeader.text = header
+         * TODO update this when contentId is set and canteen could change while the sheet is open!
-            textContent.text = content
+         */
+        binding.textHeader.text = header
+
+        // Set content to raw string passed if ID says so
+        if (contentId == -1) {
+            binding.textContent.text = content
+        } else (when (contentId) {
+            // Observe LiveData if corresponding ID has been passed
+            TextSheetContentId.OPENING_HOURS -> viewModel.getCanteenOpeningHours()
+            TextSheetContentId.NEWS -> viewModel.getCanteenNews()
+            else -> throw InvalidContentIdException()
+        }).observe(viewLifecycleOwner) { observedContent ->
+            // Show the content
+            binding.textContent.text = (observedContent ?: "")
+                // If the content is empty, tell the user
+                .ifBlank { emptyContentStringFor(contentId) }
         }
 
         // Set up an appropriate close button depending on whether the sheet is cancellable
@@ -45,4 +76,16 @@ class TextSheet : AppSheet(R.layout.sheet_text) {
             binding.buttonCancel.visibility = View.GONE
         }
     }
+
+    /**
+     * Retrieves a string to show to the user if the content is empty.
+     *
+     * @param contentId used to determine which string res should be used
+     * @return          localised string to show the user
+     */
+    private fun emptyContentStringFor(contentId: Int) = getString(when (contentId) {
+        TextSheetContentId.OPENING_HOURS -> R.string.text_sheet_empty_opening_hours
+        TextSheetContentId.NEWS -> R.string.text_sheet_empty_news
+        else -> R.string.error_generic
+    })
 }

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

@@ -0,0 +1,23 @@
+package com.denizk0461.weserplaner.viewmodel
+
+import android.app.Application
+import androidx.lifecycle.LiveData
+
+class TextSheetViewModel(application: Application) : AppViewModel(application) {
+
+    /**
+     * Retrieve opening hours for the fetched canteen.
+     * Used when contentId = [com.denizk0461.weserplaner.model.TextSheetContentId.OPENING_HOURS]
+     *
+     * @return opening hours for the canteen
+     */
+    fun getCanteenOpeningHours(): LiveData<String> = repo.getCanteenOpeningHours()
+
+    /**
+     * Retrieve news for the fetched canteen.
+     * Used when contentId = [com.denizk0461.weserplaner.model.TextSheetContentId.NEWS]
+     *
+     * @return news for the canteen
+     */
+    fun getCanteenNews(): LiveData<String> = repo.getCanteenNews()
+}

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

@@ -31,7 +31,7 @@
                     android:layout_height="wrap_content"
                     android:text="@string/title_food"
                     android:textSize="28sp"
-                    android:fontFamily="@font/lato_bolditalic"
+                    android:fontFamily="@font/lato_blackitalic"
                     android:singleLine="true"
                     android:ellipsize="marquee"
                     android:marqueeRepeatLimit="marquee_forever"

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

@@ -18,7 +18,7 @@
             android:layout_height="wrap_content"
             android:text="@string/title_schedule"
             android:textSize="28sp"
-            android:fontFamily="@font/lato_bolditalic"
+            android:fontFamily="@font/lato_blackitalic"
             android:layout_marginHorizontal="16dp"
             android:layout_marginTop="16dp"
             android:layout_marginBottom="8dp"

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

@@ -20,7 +20,7 @@
             android:layout_marginHorizontal="16dp"
             android:layout_marginTop="16dp"
             android:layout_marginBottom="8dp"
-            android:fontFamily="@font/lato_bolditalic"
+            android:fontFamily="@font/lato_blackitalic"
             android:text="@string/title_settings"
             app:layout_scrollFlags="scroll|exitUntilCollapsed"
             android:textSize="28sp"/>

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

@@ -1,7 +1,8 @@
-<resources>
+<resources xmlns:tools="http://schemas.android.com/tools">
 <!--    <string name="app_name">sixminutes</string>-->
 
     <string name="toast_first_launch">Hey, danke, dass Du meine App ausprobierst! ~Deniz</string>
+    <string name="error_generic">Ein Fehler ist aufgetreten.</string>
 
     <string name="monday">Montag</string>
     <string name="tuesday">Dienstag</string>
@@ -68,6 +69,10 @@
     <string name="canteen_fab_switch_canteen_content_desc">Wechsle Mensa</string>
     <string name="canteen_fab_refresh_content_desc">Aktualisiere Angebote</string>
 
+    <!-- TODO replace 'this canteen' with %s -->
+    <string name="text_sheet_empty_opening_hours">The Öffnungszeiten für diese Mensa können nicht angezeigt werden.</string>
+    <string name="text_sheet_empty_news">Es sind keine Neuigkeiten verfügbar.</string>
+
     <string name="sheet_licences_header">Lizenzen</string>
 
     <string name="title_schedule">Dein Stundenplan</string>
@@ -79,7 +84,7 @@
 
     <string name="mensa_uni">Uni-Mensa</string>
     <string name="cafe_central">Café Central</string>
-    <string name="mensa_nw1">Mensa NW1</string>
+    <string name="mensa_nw1" tools:ignore="Typos">Mensa NW1</string>
     <string name="cafeteria_gw2">Cafeteria GW2</string>
     <string name="mensa_neustadt">Mensa Neustadtswall</string>
     <string name="mensa_werder">Mensa Werderstraße</string>

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

@@ -1,7 +1,8 @@
-<resources>
+<resources xmlns:tools="http://schemas.android.com/tools">
     <string name="app_name" translatable="false">WeserPlaner</string>
 
     <string name="toast_first_launch">Hey, thank you for trying out my app! ~Deniz</string>
+    <string name="error_generic">An error occurred.</string>
 
     <string name="monday">Monday</string>
     <string name="tuesday">Tuesday</string>
@@ -69,6 +70,10 @@
     <string name="canteen_fab_switch_canteen_content_desc">Switch canteen</string>
     <string name="canteen_fab_refresh_content_desc">Refresh offers</string>
 
+    <!-- TODO replace 'this canteen' with %s -->
+    <string name="text_sheet_empty_opening_hours">The opening hours for this canteen could not be downloaded.</string>
+    <string name="text_sheet_empty_news">No news are available.</string>
+
     <string name="sheet_licences_header">Licences</string>
     <string name="sheet_licences_content" translatable="false">Android developer resources by Google.\nhttps://developer.android.com/\nandroidx.appcompat:appcompat:1.6.1\nandroidx.constraintlayout:constraintlayout:2.1.4\nandroidx.core:core-ktx:1.10.0\nandroidx.fragment:fragment-ktx:1.6.0-beta01\nandroidx.navigation:navigation-fragment-ktx:2.5.3\nandroidx.navigation:navigation-ui-ktx:2.5.3\nandroidx.preference:preference-ktx:1.2.0\nandroidx.room:room-runtime:2.5.1\nandroidx.room:room-compiler:2.5.1\nandroidx.swiperefreshlayout:swiperefreshlayout:1.2.0-alpha01\n\nDesign guidelines, icons, and colour palette by Google.\nhttps://m3.material.io/\ncom.google.android.material:material:1.9.0\n\nAdditional icons by Flaticon.\nhttps://www.flaticon.com/\n\nWeb scraping functionality by Jonathan Hedley.\nhttps://jhy.io/\nhttps://jsoup.org/\norg.jsoup:jsoup:1.15.4\n\nApp developed by Deniz Düzgören.\ndenizk0461@gmail.com\ndeniz7@uni-bremen.de</string>
 
@@ -81,7 +86,7 @@
 
     <string name="mensa_uni">Uni-Mensa</string>
     <string name="cafe_central">Café Central</string>
-    <string name="mensa_nw1">Mensa NW1</string>
+    <string name="mensa_nw1" tools:ignore="Typos">Mensa NW1</string>
     <string name="cafeteria_gw2">Cafeteria GW2</string>
     <string name="mensa_neustadt">Mensa Neustadtswall</string>
     <string name="mensa_werder">Mensa Werderstraße</string>