Fix bookmark action in reader

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/ReaderActivity.kt

@@ -212,6 +212,7 @@ class ReaderActivity :
 			viewBinding.toastView.hide()
 		}
 		viewBinding.toolbarBottom.invalidateMenu()
+		invalidateOptionsMenu()
 	}
 
 	override fun onGridTouch(area: TapGridArea): Boolean {

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/ReaderTopMenuProvider.kt

@@ -19,7 +19,7 @@ class ReaderTopMenuProvider(
 	override fun onPrepareMenu(menu: Menu) {
 		menu.findItem(R.id.action_bookmark)?.let { bookmarkItem ->
 			val hasPages = viewModel.content.value.pages.isNotEmpty()
-			bookmarkItem.isVisible = hasPages
+			bookmarkItem.isEnabled = hasPages
 			if (hasPages) {
 				val hasBookmark = viewModel.isBookmarkAdded.value
 				bookmarkItem.setTitle(if (hasBookmark) R.string.bookmark_remove else R.string.bookmark_add)

app/src/main/res/menu/opt_reader_top.xml

@@ -7,10 +7,9 @@
 
 	<item
 		android:id="@+id/action_bookmark"
+		android:enabled="false"
 		android:icon="@drawable/ic_bookmark"
 		android:title="@string/bookmark_add"
-		android:visible="false"
+		app:showAsAction="always" />
-		app:showAsAction="always"
-		tools:visible="true" />
 
 </menu>