Add animations to recyclerview

app/src/main/java/net/underdesk/circolapp/adapters/CircularLetterAdapter.kt

@@ -39,6 +39,7 @@ import net.underdesk.circolapp.data.Circular
 class CircularLetterAdapter(private val circulars: List<Circular>) :
     RecyclerView.Adapter<CircularLetterAdapter.CircularLetterViewHolder>() {
     private lateinit var context: Context
+    private var collapsedItems = -1
 
     inner class CircularLetterViewHolder(view: View) : RecyclerView.ViewHolder(view) {
         var title: TextView = view.circular_title_textview
@@ -69,6 +70,33 @@ class CircularLetterAdapter(private val circulars: List<Circular>) :
         holder.title.text = circulars[position].name
         holder.date.text = circulars[position].date
 
+        if (collapsedItems != position) {
+            holder.collapseButton.setImageDrawable(context.getDrawable(R.drawable.baseline_expand_more_24))
+
+            holder.viewButton.visibility = View.GONE
+            holder.downloadButton.visibility = View.GONE
+            holder.favouriteButton.visibility = View.GONE
+            holder.reminderButton.visibility = View.GONE
+
+            holder.attachmentsList.visibility = View.GONE
+            holder.attachmentsList.adapter = null
+        } else {
+            holder.collapseButton.setImageDrawable(context.getDrawable(R.drawable.baseline_expand_less_24))
+
+            holder.viewButton.visibility = View.VISIBLE
+            holder.downloadButton.visibility = View.VISIBLE
+            holder.favouriteButton.visibility = View.VISIBLE
+            holder.reminderButton.visibility = View.VISIBLE
+
+            if (circulars[position].attachmentsNames.isNotEmpty()) {
+                holder.attachmentsList.visibility = View.VISIBLE
+                holder.attachmentsList.adapter = AttachmentAdapter(
+                    circulars[position].attachmentsNames,
+                    circulars[position].attachmentsUrls
+                )
+            }
+        }
+
         holder.viewButton.setOnClickListener {
             val viewIntent = Intent(Intent.ACTION_VIEW)
             viewIntent.setDataAndType(Uri.parse(circulars[position].url), "application/pdf")
@@ -96,28 +124,14 @@ class CircularLetterAdapter(private val circulars: List<Circular>) :
         }
 
         holder.collapseButton.setOnClickListener {
-            if (holder.viewButton.visibility == View.VISIBLE) {
+            collapsedItems = if (collapsedItems == position) {
-                holder.viewButton.visibility = View.GONE
+                -1
-                holder.downloadButton.visibility = View.GONE
-                holder.favouriteButton.visibility = View.GONE
-                holder.reminderButton.visibility = View.GONE
-
-                holder.attachmentsList.visibility = View.GONE
-                holder.attachmentsList.adapter = null
             } else {
-                holder.viewButton.visibility = View.VISIBLE
+                if (collapsedItems > -1) notifyItemChanged(collapsedItems)
-                holder.downloadButton.visibility = View.VISIBLE
+                position
-                holder.favouriteButton.visibility = View.VISIBLE
+            }
-                holder.reminderButton.visibility = View.VISIBLE
 
-                if (circulars[position].attachmentsNames.isNotEmpty()) {
+            notifyItemChanged(position)
-                    holder.attachmentsList.visibility = View.VISIBLE
-                    holder.attachmentsList.adapter = AttachmentAdapter(
-                        circulars[position].attachmentsNames,
-                        circulars[position].attachmentsUrls
-                    )
-                }
-            }
         }
     }
 

app/src/main/res/drawable/baseline_expand_less_24.xml

@@ -6,5 +6,5 @@
         android:tint="?attr/colorControlNormal">
     <path
         android:fillColor="@android:color/white"
-        android:pathData="M7.41,8.59L12,13.17l4.59,-4.58L18,10l-6,6 -6,-6 1.41,-1.41z"/>
+        android:pathData="M12,8l-6,6 1.41,1.41L12,10.83l4.59,4.58L18,14z"/>
 </vector>

app/src/main/res/drawable/baseline_expand_more_24.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0"
+        android:tint="?attr/colorControlNormal">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M16.59,8.59L12,13.17 7.41,8.59 6,10l6,6 6,-6z"/>
+</vector>

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

@@ -1,13 +1,10 @@
 <?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"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/circulars_list"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="match_parent" />
-        tools:layout_editor_absoluteX="168dp"
-        tools:layout_editor_absoluteY="235dp" />
 </androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -51,7 +51,7 @@
             android:layout_height="wrap_content"
             android:layout_marginEnd="8dp"
             android:adjustViewBounds="true"
-            android:src="@drawable/baseline_keyboard_arrow_down_24"
+            android:src="@drawable/baseline_expand_more_24"
             app:layout_constraintBottom_toTopOf="@+id/circular_reminder_button"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintTop_toTopOf="parent" />