up

app/src/main/java/io/legado/app/ui/changesource/ChangeSourceDialog.kt

@@ -26,12 +26,12 @@ class ChangeSourceDialog : DialogFragment(),
         const val tag = "changeSourceDialog"
 
         fun newInstance(name: String, author: String): ChangeSourceDialog {
-            val changeSourceDialog = ChangeSourceDialog()
+            return ChangeSourceDialog().apply {
                 val bundle = Bundle()
                 bundle.putString("name", name)
                 bundle.putString("author", author)
-            changeSourceDialog.arguments = bundle
+                arguments = bundle
-            return changeSourceDialog
+            }
         }
     }
 

app/src/main/java/io/legado/app/ui/main/bookshelf/BooksFragment.kt

@@ -25,6 +25,17 @@ import org.jetbrains.anko.startActivity
 
 class BooksFragment : VMBaseFragment<BooksViewModel>(R.layout.fragment_books),
     BooksAdapter.CallBack {
+
+    companion object {
+        fun newInstance(position: Int): BooksFragment {
+            return BooksFragment().apply {
+                val bundle = Bundle()
+                bundle.putInt("position", position)
+                arguments = bundle
+            }
+        }
+    }
+
     override val viewModel: BooksViewModel
         get() = getViewModel(BooksViewModel::class.java)
 

app/src/main/java/io/legado/app/ui/main/bookshelf/BookshelfAdapter.kt

@@ -11,7 +11,7 @@ class BookshelfAdapter(fragment: Fragment) : FragmentStateAdapter(fragment) {
     }
 
     override fun createFragment(position: Int): Fragment {
-        return BooksFragment()
+        return BooksFragment.newInstance(position)
     }
 
 }

app/src/main/java/io/legado/app/ui/main/bookshelf/BookshelfFragment.kt

@@ -12,6 +12,7 @@ import androidx.lifecycle.Observer
 import androidx.paging.LivePagedListBuilder
 import androidx.paging.PagedList
 import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.viewpager2.widget.ViewPager2
 import io.legado.app.App
 import io.legado.app.R
 import io.legado.app.base.VMBaseFragment
@@ -36,6 +37,7 @@ class BookshelfFragment : VMBaseFragment<BookshelfViewModel>(R.layout.fragment_b
     private lateinit var booksAdapter: BooksAdapter
     private lateinit var bookGroupAdapter: BookGroupAdapter
     private var bookGroupLiveData: LiveData<PagedList<BookGroup>>? = null
+    private var position = -1
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         setSupportToolbar(toolbar)
@@ -63,6 +65,13 @@ class BookshelfFragment : VMBaseFragment<BookshelfViewModel>(R.layout.fragment_b
         rv_book_group.adapter = bookGroupAdapter
         bookGroupAdapter.callBack = this
         view_pager_bookshelf.adapter = BookshelfAdapter(this)
+        view_pager_bookshelf.registerOnPageChangeCallback(object :
+            ViewPager2.OnPageChangeCallback() {
+            override fun onPageSelected(position: Int) {
+                super.onPageSelected(position)
+                this@BookshelfFragment.position = position
+            }
+        })
         observeEvent<String>(Bus.UP_BOOK) { booksAdapter.notification(it) }
     }