feat: 双击书架图标返回顶部

app/src/main/java/io/legado/app/ui/main/MainActivity.kt

@@ -30,10 +30,12 @@ import org.jetbrains.anko.toast
 
 class MainActivity : VMBaseActivity<MainViewModel>(R.layout.activity_main),
     BottomNavigationView.OnNavigationItemSelectedListener,
+    BottomNavigationView.OnNavigationItemReselectedListener,
     ViewPager.OnPageChangeListener by ViewPager.SimpleOnPageChangeListener() {
     override val viewModel: MainViewModel
         get() = getViewModel(MainViewModel::class.java)
     private var exitTime: Long = 0
+    private var bookshelfReselected: Long = 0
     private var pagePosition = 0
     private val fragmentId = arrayOf(0, 1, 2, 3)
     private val fragmentMap = mapOf<Int, Fragment>(
@@ -50,6 +52,7 @@ class MainActivity : VMBaseActivity<MainViewModel>(R.layout.activity_main),
         view_pager_main.adapter = TabFragmentPageAdapter(supportFragmentManager)
         view_pager_main.addOnPageChangeListener(this)
         bottom_navigation_view.setOnNavigationItemSelectedListener(this)
+        bottom_navigation_view.setOnNavigationItemReselectedListener(this)
         bottom_navigation_view.menu.findItem(R.id.menu_rss).isVisible = AppConfig.isShowRSS
     }
 
@@ -74,6 +77,18 @@ class MainActivity : VMBaseActivity<MainViewModel>(R.layout.activity_main),
         return false
     }
 
+    override fun onNavigationItemReselected(item: MenuItem) {
+        when (item.itemId) {
+            R.id.menu_bookshelf -> {
+                if (System.currentTimeMillis() - bookshelfReselected > 300) {
+                    bookshelfReselected = System.currentTimeMillis()
+                } else {
+                    (fragmentMap[0] as? BookshelfFragment)?.gotoTop()
+                }
+            }
+        }
+    }
+
     private fun upVersion() {
         if (getPrefInt(PreferKey.versionCode) != App.INSTANCE.versionCode) {
             putPrefInt(PreferKey.versionCode, App.INSTANCE.versionCode)

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

@@ -266,6 +266,10 @@ class BookshelfFragment : VMBaseFragment<BookshelfViewModel>(R.layout.fragment_b
         }
     }
 
+    fun gotoTop() {
+        fragmentMap[selectedGroup.groupId]?.gotoTop()
+    }
+
     private inner class TabFragmentPageAdapter internal constructor(fm: FragmentManager) :
         FragmentStatePagerAdapter(fm, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
 

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

@@ -16,6 +16,7 @@ import io.legado.app.constant.BookType
 import io.legado.app.constant.EventBus
 import io.legado.app.constant.PreferKey
 import io.legado.app.data.entities.Book
+import io.legado.app.help.AppConfig
 import io.legado.app.help.IntentDataHelp
 import io.legado.app.lib.theme.ATH
 import io.legado.app.lib.theme.accentColor
@@ -122,6 +123,14 @@ class BooksFragment : BaseFragment(R.layout.fragment_books),
         return booksAdapter.getItems()
     }
 
+    fun gotoTop() {
+        if (AppConfig.isEInkMode) {
+            rv_bookshelf.scrollToPosition(0)
+        } else {
+            rv_bookshelf.smoothScrollToPosition(0)
+        }
+    }
+
     override fun open(book: Book) {
         when (book.type) {
             BookType.audio ->