Adding Animation when expanding/collapsing sections in source filter sheet

app/src/main/java/eu/kanade/tachiyomi/ui/source/filter/GroupItem.kt

@@ -11,7 +11,7 @@ import eu.davidea.flexibleadapter.items.ISectionable
 import eu.davidea.viewholders.ExpandableViewHolder
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.source.model.Filter
-import eu.kanade.tachiyomi.util.view.setVectorCompat
+import eu.kanade.tachiyomi.util.view.setAnimVectorCompat
 
 class GroupItem(val filter: Filter.Group<*>) : AbstractExpandableHeaderItem<GroupItem.Holder, ISectionable<*, *>>() {
 
@@ -34,11 +34,11 @@ class GroupItem(val filter: Filter.Group<*>) : AbstractExpandableHeaderItem<Grou
     override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<RecyclerView.ViewHolder>>, holder: Holder, position: Int, payloads: MutableList<Any?>?) {
         holder.title.text = filter.name
 
-        holder.icon.setVectorCompat(
+        holder.icon.setAnimVectorCompat(
             if (isExpanded) {
-                R.drawable.ic_expand_less_24dp
+                R.drawable.expand_more_to_less
             } else {
-                R.drawable.ic_expand_more_24dp
+                R.drawable.expand_less_to_more
             }
         )
 

app/src/main/java/eu/kanade/tachiyomi/ui/source/filter/SortGroup.kt

@@ -8,7 +8,7 @@ import eu.davidea.flexibleadapter.items.IFlexible
 import eu.davidea.flexibleadapter.items.ISectionable
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.source.model.Filter
-import eu.kanade.tachiyomi.util.view.setVectorCompat
+import eu.kanade.tachiyomi.util.view.setAnimVectorCompat
 
 class SortGroup(val filter: Filter.Sort) : AbstractExpandableHeaderItem<SortGroup.Holder, ISectionable<*, *>>() {
 
@@ -31,11 +31,11 @@ class SortGroup(val filter: Filter.Sort) : AbstractExpandableHeaderItem<SortGrou
     override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<RecyclerView.ViewHolder>>, holder: Holder, position: Int, payloads: MutableList<Any?>?) {
         holder.title.text = filter.name
 
-        holder.icon.setVectorCompat(
+        holder.icon.setAnimVectorCompat(
             if (isExpanded) {
-                R.drawable.ic_expand_less_24dp
+                R.drawable.expand_more_to_less
             } else {
-                R.drawable.ic_expand_more_24dp
+                R.drawable.expand_less_to_more
             }
         )
 

app/src/main/java/eu/kanade/tachiyomi/util/view/ImageViewExtensions.kt

@@ -2,6 +2,7 @@ package eu.kanade.tachiyomi.util.view
 
 import android.widget.ImageView
 import androidx.annotation.DrawableRes
+import androidx.vectordrawable.graphics.drawable.AnimatedVectorDrawableCompat
 import androidx.vectordrawable.graphics.drawable.VectorDrawableCompat
 
 /**
@@ -17,3 +18,13 @@ fun ImageView.setVectorCompat(@DrawableRes drawable: Int, tint: Int? = null) {
     }
     setImageDrawable(vector)
 }
+
+fun ImageView.setAnimVectorCompat(@DrawableRes drawable: Int, tint: Int? = null) {
+    val vector = AnimatedVectorDrawableCompat.create(context, drawable)
+    if (tint != null) {
+        vector?.mutate()
+        vector?.setTint(tint)
+    }
+    setImageDrawable(vector)
+    vector?.start()
+}

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

@@ -0,0 +1,28 @@
+<animated-vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt">
+    <aapt:attr name="android:drawable">
+        <vector
+            android:name="vector"
+            android:width="24dp"
+            android:height="24dp"
+            android:viewportWidth="24"
+            android:viewportHeight="24">
+            <path
+                android:name="path"
+                android:pathData="M 18 14 L 12 8 L 6 14 L 7.41 15.41 L 12 10.83 L 16.59 15.41 L 18 14"
+                android:fillColor="#000000"/>
+        </vector>
+    </aapt:attr>
+    <target android:name="path">
+        <aapt:attr name="android:animation">
+            <objectAnimator
+                android:propertyName="pathData"
+                android:duration="250"
+                android:valueFrom="M 18 14 L 12 8 L 6 14 L 7.41 15.41 L 12 10.83 L 16.59 15.41 L 18 14"
+                android:valueTo="M 16.59 8.59 L 12 13.17 L 7.41 8.59 L 6 10 L 12 16 L 18 10 L 16.59 8.59"
+                android:valueType="pathType"
+                android:interpolator="@android:interpolator/fast_out_slow_in"/>
+        </aapt:attr>
+    </target>
+</animated-vector>

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

@@ -0,0 +1,28 @@
+<animated-vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt">
+    <aapt:attr name="android:drawable">
+        <vector
+            android:name="vector"
+            android:width="24dp"
+            android:height="24dp"
+            android:viewportWidth="24"
+            android:viewportHeight="24">
+            <path
+                android:name="path"
+                android:pathData="M 16.59 8.59 L 12 13.17 L 7.41 8.59 L 6 10 L 12 16 L 18 10 L 16.59 8.59"
+                android:fillColor="#000000"/>
+        </vector>
+    </aapt:attr>
+    <target android:name="path">
+        <aapt:attr name="android:animation">
+            <objectAnimator
+                android:propertyName="pathData"
+                android:duration="250"
+                android:valueFrom="M 16.59 8.59 L 12 13.17 L 7.41 8.59 L 6 10 L 12 16 L 18 10 L 16.59 8.59"
+                android:valueTo="M 18 14 L 12 8 L 6 14 L 7.41 15.41 L 12 10.83 L 16.59 15.41 L 18 14"
+                android:valueType="pathType"
+                android:interpolator="@android:interpolator/fast_out_slow_in"/>
+        </aapt:attr>
+    </target>
+</animated-vector>

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

@@ -5,7 +5,7 @@
     android:layout_width="match_parent"
     android:layout_height="?attr/listPreferredItemHeightSmall"
     android:gravity="center_vertical"
-    android:background="?android:attr/colorBackground"
+    android:background="@drawable/rect_ripple"
     android:orientation="horizontal"
     android:paddingStart="?attr/listPreferredItemPaddingStart"
     android:paddingEnd="?attr/listPreferredItemPaddingEnd">

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

@@ -10,7 +10,7 @@
 
     <eu.kanade.tachiyomi.widget.MaterialSpinnerView
         android:id="@+id/nav_view_item"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="6dp"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         tools:entries="@array/viewers_selector"