Using compound drawables for centered toolbar

and making the library text centered even with the dropdown arrow showing

app/src/main/java/eu/kanade/tachiyomi/ui/base/CenteredToolbar.kt

@@ -4,7 +4,7 @@ import android.content.Context
 import android.util.AttributeSet
 import androidx.appcompat.graphics.drawable.DrawerArrowDrawable
 import com.google.android.material.appbar.MaterialToolbar
-import eu.kanade.tachiyomi.util.view.gone
+import eu.kanade.tachiyomi.R
 import kotlinx.android.synthetic.main.main_activity.view.*
 
 class CenteredToolbar@JvmOverloads constructor(context: Context, attrs: AttributeSet? = null) :
@@ -14,7 +14,7 @@ class CenteredToolbar@JvmOverloads constructor(context: Context, attrs: Attribut
         if (navigationIcon is DrawerArrowDrawable) {
             super.setTitle(resId)
             toolbar_title.text = null
-            dropdown?.gone()
+            hideDropdown()
         } else {
             toolbar_title.text = context.getString(resId)
             super.setTitle(null)
@@ -25,10 +25,23 @@ class CenteredToolbar@JvmOverloads constructor(context: Context, attrs: Attribut
         if (navigationIcon is DrawerArrowDrawable) {
             super.setTitle(title)
             toolbar_title.text = ""
-            dropdown?.gone()
+            hideDropdown()
         } else {
             toolbar_title.text = title
             super.setTitle(null)
         }
     }
+
+    fun showDropdown(down: Boolean = true) {
+        toolbar_title.setCompoundDrawablesRelativeWithIntrinsicBounds(R.drawable.ic_blank_24dp, 0,
+        if (down) {
+            R.drawable.ic_arrow_drop_down_24dp
+        } else {
+            R.drawable.ic_arrow_drop_up_24dp
+        }, 0)
+    }
+
+    fun hideDropdown() {
+        toolbar_title.setCompoundDrawablesWithIntrinsicBounds(0, 0, 0, 0)
+    }
 }

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryController.kt

@@ -621,19 +621,17 @@ class LibraryController(
             LibraryUpdateService.setListener(this)
             recycler_cover.isClickable = false
             recycler_cover.isFocusable = false
-            if (onRoot) {
-                activity?.dropdown?.visibleIf(!singleCategory)
-            }
+            showDropdown()
         } else {
             closeTip()
-            activity?.dropdown?.gone()
+            activity?.toolbar?.hideDropdown()
         }
     }
 
     override fun onChangeEnded(handler: ControllerChangeHandler, type: ControllerChangeType) {
         super.onChangeEnded(handler, type)
         if (!type.isEnter) {
-            activity?.dropdown?.gone()
+            activity?.toolbar?.hideDropdown()
         }
     }
 
@@ -681,9 +679,7 @@ class LibraryController(
             recycler.itemAnimator = DefaultItemAnimator()
         }
         singleCategory = presenter.categories.size <= 1
-        if (onRoot) {
-            activity?.dropdown?.visibleIf(!singleCategory)
-        }
+        showDropdown()
         progress.gone()
         if (!freshStart) {
             justStarted = false
@@ -712,6 +708,15 @@ class LibraryController(
             }
             if (!hasMovedHopper && isAnimatingHopper == null) {
                 showSlideAnimation()
+        }
+    }
+
+    private fun showDropdown() {
+        if (onRoot) {
+            if (!singleCategory) {
+                activity?.toolbar?.showDropdown()
+            } else {
+                activity?.toolbar?.hideDropdown()
             }
         }
     }

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

@@ -49,22 +49,15 @@
                     style="@style/TextAppearance.AppCompat.Widget.ActionBar.Title"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
+                    android:drawableTint="?actionBarTintColor"
                     android:ellipsize="end"
                     android:gravity="start"
                     android:maxLines="1"
                     android:textColor="?actionBarTintColor"
                     android:textSize="20sp"
+                    tools:drawableEnd="@drawable/ic_arrow_drop_down_24dp"
+                    tools:drawableStart="@drawable/ic_blank_24dp"
                     tools:text="Title Text" />
-
-                <ImageView
-                    android:id="@+id/dropdown"
-                    android:visibility="gone"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:layout_gravity="center"
-                    android:layout_marginStart="4dp"
-                    android:src="@drawable/ic_arrow_drop_down_24dp"
-                    android:tint="?actionBarTintColor" />
             </LinearLayout>
         </eu.kanade.tachiyomi.ui.base.CenteredToolbar>
     </com.google.android.material.appbar.AppBarLayout>