Fix badge alignment on details screen

app/src/main/java/org/koitharu/kotatsu/utils/ViewBadge.kt

@@ -0,0 +1,62 @@
+package org.koitharu.kotatsu.utils
+
+import android.view.View
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.LifecycleOwner
+import com.google.android.material.badge.BadgeDrawable
+import com.google.android.material.badge.BadgeUtils
+
+class ViewBadge(
+	private val anchor: View,
+	lifecycleOwner: LifecycleOwner,
+) : View.OnLayoutChangeListener, DefaultLifecycleObserver {
+
+	private var badgeDrawable: BadgeDrawable? = null
+
+	var counter: Int
+		get() = badgeDrawable?.number ?: 0
+		set(value) {
+			val badge = badgeDrawable ?: initBadge()
+			badge.number = value
+			badge.isVisible = value > 0
+		}
+
+	init {
+		lifecycleOwner.lifecycle.addObserver(this)
+	}
+
+	override fun onLayoutChange(
+		v: View?,
+		left: Int,
+		top: Int,
+		right: Int,
+		bottom: Int,
+		oldLeft: Int,
+		oldTop: Int,
+		oldRight: Int,
+		oldBottom: Int,
+	) {
+		val badge = badgeDrawable ?: return
+		BadgeUtils.setBadgeDrawableBounds(badge, anchor, null)
+	}
+
+	override fun onDestroy(owner: LifecycleOwner) {
+		super.onDestroy(owner)
+		clearBadge()
+	}
+
+	private fun initBadge(): BadgeDrawable {
+		val badge = BadgeDrawable.create(anchor.context)
+		anchor.addOnLayoutChangeListener(this)
+		BadgeUtils.attachBadgeDrawable(badge, anchor)
+		badgeDrawable = badge
+		return badge
+	}
+
+	private fun clearBadge() {
+		val badge = badgeDrawable ?: return
+		anchor.removeOnLayoutChangeListener(this)
+		BadgeUtils.detachBadgeDrawable(badge, anchor)
+		badgeDrawable = null
+	}
+}