UI Paging for Chirps History Pre-Consensus Protocol Integration

fe2-android/app/src/main/java/com/github/dedis/popstellar/repository/SocialMediaRepository.kt

@@ -21,6 +21,7 @@ import io.reactivex.subjects.BehaviorSubject
 import io.reactivex.subjects.Subject
 import java.util.EnumMap
 import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.atomic.AtomicInteger
 import java.util.function.Consumer
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -102,6 +103,14 @@ constructor(appDatabase: AppDatabase, application: Application) {
     return getLaoChirps(laoId).reactionByChirpId[chirpId] ?: emptySet()
   }
 
+  fun queryMoreChirps(laoId: String) {
+    getLaoChirps(laoId).queryMoreChirps()
+  }
+
+  fun canQueryMoreChirps(laoId: String): Boolean {
+    return !getLaoChirps(laoId).isEndOfChirps()
+  }
+
   /**
    * @param laoId of the lao we want to observe the chirp list
    * @return an observable set of message ids whose correspond to the set of chirp published on the
@@ -132,7 +141,6 @@ constructor(appDatabase: AppDatabase, application: Application) {
                 { err: Throwable ->
                   Timber.tag(TAG).e(err, "Error in persisting reaction %s", reaction.id)
                 }))
-
     // Retrieve Lao data and add the reaction to it
     return getLaoChirps(laoId).addReaction(reaction)
   }
@@ -171,6 +179,11 @@ constructor(appDatabase: AppDatabase, application: Application) {
     private val chirps = ConcurrentHashMap<MessageID, Chirp>()
     private val chirpSubjects = ConcurrentHashMap<MessageID, Subject<Chirp>>()
     private val chirpsSubject: Subject<Set<MessageID>> = BehaviorSubject.createDefault(emptySet())
+    // TODO : used to fake page loading, to be removed when we will be able to request only wanted
+    // chirps. Maxime Teuber @Kaz-ookid - April 2024
+    private var chirpsLoaded: AtomicInteger = AtomicInteger(0)
+    private var storageIsLoaded: Boolean = false
+    private var reachedEndOfChirps: Boolean = false
 
     // Reactions
     val reactionByChirpId = ConcurrentHashMap<MessageID, MutableSet<Reaction>>()
@@ -179,6 +192,7 @@ constructor(appDatabase: AppDatabase, application: Application) {
 
     init {
       loadStorage()
+      chirpsLoaded.set(CHIRPS_PAGE_SIZE)
     }
 
     fun add(chirp: Chirp) {
@@ -188,6 +202,11 @@ constructor(appDatabase: AppDatabase, application: Application) {
         Timber.tag(TAG).w("A chirp with id %s already exist : %s", id, old)
         return
       }
+      if (storageIsLoaded) {
+        // TODO : used to fake page loading, to be removed when we will be able to request only
+        // wanted chirps. Maxime Teuber @Kaz-ookid - April 2024
+        chirpsLoaded.incrementAndGet()
+      }
 
       // Update repository data
       chirps[id] = chirp
@@ -199,6 +218,23 @@ constructor(appDatabase: AppDatabase, application: Application) {
       chirpsSubject.toSerialized().onNext(HashSet(chirps.keys))
     }
 
+    // TODO : used to fake page loading, to be removed when we will be able to request only wanted
+    // chirps. Maxime Teuber @Kaz-ookid - April 2024
+    // Either here or directly in DB, we should query to servers the CHIRPS_PAGE_SIZE next chirps,
+    // and not all of them.
+    fun queryMoreChirps() {
+      val previousSize = getChirpsSubject().blockingFirst().size
+      chirpsLoaded.addAndGet(CHIRPS_PAGE_SIZE)
+      chirpsSubject.onNext(
+          chirps.keys.sortedByDescending { chirps[it]?.timestamp }.take(chirpsLoaded.get()).toSet())
+      val newSize = getChirpsSubject().blockingFirst().size
+      // if did not load CHIRPS_PAGE_SIZE chirps, then we reached the end of the chirps.
+      if (newSize - previousSize != CHIRPS_PAGE_SIZE) {
+        chirpsLoaded.set(newSize)
+        reachedEndOfChirps = true
+      }
+    }
+
     fun addReaction(reaction: Reaction): Boolean {
       // Check if the associated chirp is present
       val chirp = chirps[reaction.chirpId] ?: return false
@@ -279,7 +315,17 @@ constructor(appDatabase: AppDatabase, application: Application) {
     }
 
     fun getChirpsSubject(): Observable<Set<MessageID>> {
-      return chirpsSubject
+      // TODO : used to fake page loading, to be removed when we will be able to request only wanted
+      // chirps. Maxime Teuber @Kaz-ookid - April 2024
+      // would normally return chirpsSubject directly
+      return chirpsSubject.map {
+        chirps.keys.sortedByDescending { chirps[it]?.timestamp }.take(chirpsLoaded.get()).toSet()
+      }
+    }
+
+    /** Check if the end of the chirps history has been reached */
+    fun isEndOfChirps(): Boolean {
+      return reachedEndOfChirps
     }
 
     @Throws(UnknownChirpException::class)
@@ -342,6 +388,7 @@ constructor(appDatabase: AppDatabase, application: Application) {
                                                 chirp.id)
                                       }))
                         })
+                    storageIsLoaded = true
                   },
                   { err: Throwable ->
                     Timber.tag(TAG).e(err, "No chirp found in the storage for lao %s", laoId)
@@ -350,6 +397,7 @@ constructor(appDatabase: AppDatabase, application: Application) {
   }
 
   companion object {
+    private const val CHIRPS_PAGE_SIZE: Int = 10
     private val TAG = SocialMediaRepository::class.java.simpleName
   }
 }

fe2-android/app/src/main/java/com/github/dedis/popstellar/ui/lao/socialmedia/ChirpListFragment.kt

@@ -4,6 +4,8 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.Button
+import androidx.core.content.ContextCompat
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentManager
 import com.github.dedis.popstellar.R
@@ -39,6 +41,7 @@ class ChirpListFragment : Fragment() {
     super.onViewCreated(view, savedInstanceState)
     setupSendButton()
     setupListViewAdapter()
+    addLoadMoreButtonToListView()
   }
 
   override fun onResume() {
@@ -62,6 +65,31 @@ class ChirpListFragment : Fragment() {
     listView.adapter = mChirpListAdapter
   }
 
+  private fun addLoadMoreButtonToListView() {
+    val footerView =
+        layoutInflater.inflate(R.layout.chirp_load_more_button, binding.chirpsList, false)
+    val buttonLoadMoreChirps = footerView.findViewById<Button>(R.id.button_load_more_chirps)
+    buttonLoadMoreChirps.setOnClickListener {
+      socialMediaViewModel.loadMoreChirps()
+      if (!socialMediaViewModel.canLoadMoreChirps) {
+        disableLoadMoreButton()
+      }
+    }
+    binding.chirpsList.addFooterView(footerView, null, false)
+    if (!socialMediaViewModel.canLoadMoreChirps) {
+      disableLoadMoreButton()
+    }
+  }
+
+  private fun disableLoadMoreButton() {
+    val loadMoreButton = view?.findViewById<Button>(R.id.button_load_more_chirps)
+    loadMoreButton?.let { button ->
+      button.text = getString(R.string.load_more_chirps_disabled)
+      button.setBackgroundColor(ContextCompat.getColor(requireContext(), R.color.gray))
+      button.isEnabled = false
+    }
+  }
+
   companion object {
     val TAG: String = SocialMediaSendFragment::class.java.simpleName
 

fe2-android/app/src/main/java/com/github/dedis/popstellar/ui/lao/socialmedia/SocialMediaViewModel.kt

@@ -60,6 +60,9 @@ constructor(
   private val mNumberCharsLeft = MutableLiveData<Int>()
   val bottomNavigationTab = MutableLiveData(SocialMediaTab.HOME)
 
+  val canLoadMoreChirps: Boolean
+    get() = socialMediaRepository.canQueryMoreChirps(laoId)
+
   private val disposables: CompositeDisposable = CompositeDisposable()
 
   override fun onCleared() {
@@ -250,6 +253,10 @@ constructor(
             // the view are done on the thread. Otherwise, the app might crash
             .observeOn(schedulerProvider.mainThread())
 
+  fun loadMoreChirps() {
+    socialMediaRepository.queryMoreChirps(laoId)
+  }
+
   @Throws(UnknownChirpException::class)
   fun getReactions(chirpId: MessageID): Observable<Set<Reaction>> {
     return socialMediaRepository

fe2-android/app/src/main/res/layout/chirp_list_fragment.xml

@@ -15,8 +15,8 @@
 
       <ListView
         android:id="@+id/chirps_list"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
+          android:layout_width="match_parent"
+          android:layout_height="match_parent"
         android:divider="@color/categoryTab"
         android:dividerHeight="@dimen/social_media_divider_height"
         tools:listitem="@layout/chirp_card" />

fe2-android/app/src/main/res/layout/chirp_load_more_button.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <Button
+        android:id="@+id/button_load_more_chirps"
+        android:layout_width="@dimen/large_button_width"
+        android:layout_height="@dimen/small_button_height"
+        android:text="@string/load_more_chirps"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintBottom_toBottomOf="parent"
+        tools:ignore="MissingConstraints,SpUsage" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>

fe2-android/app/src/main/res/values/dimens.xml

@@ -40,6 +40,7 @@
   <dimen name="standard_button_height">55dp</dimen>
   <dimen name="standard_button_width">105dp</dimen>
   <dimen name="small_button_width">95dp</dimen>
+    <dimen name="small_button_height">45dp</dimen>
   <dimen name="large_button_width">125dp</dimen>
   <dimen name="standard_button_text_size">16dp</dimen>
   <dimen name="big_button_text_size">22sp</dimen>

fe2-android/app/src/main/res/values/strings.xml

@@ -281,6 +281,8 @@
   <string name="love_button">love button</string>
   <string name="deleted_chirp">Deleted chirp!</string>
   <string name="deleted_chirp_2">Chirp is deleted.</string>
+  <string name="load_more_chirps">Load more</string>
+  <string name="load_more_chirps_disabled">No more</string>
 
   <!-- PoPCHA -->
   <string name="popcha">PoPCHA</string>