Tweak NavigationUI to disable multiple backstack and use custom anim

app/src/main/java/androidx/navigation/ui/NavigationUI.kt

@@ -0,0 +1,48 @@
+package androidx.navigation.ui
+
+import android.view.Menu
+import android.view.MenuItem
+import androidx.annotation.IdRes
+import androidx.navigation.ActivityNavigator
+import androidx.navigation.NavController
+import androidx.navigation.NavDestination
+import androidx.navigation.NavDestination.Companion.hierarchy
+import androidx.navigation.NavGraph.Companion.findStartDestination
+import androidx.navigation.NavOptions
+
+fun onNavDestinationSelected2(item: MenuItem, navController: NavController): Boolean {
+    val builder = NavOptions.Builder().setLaunchSingleTop(true)
+    if (
+        navController.currentDestination!!.parent!!.findNode(item.itemId)
+                is ActivityNavigator.Destination
+    ) {
+        builder.setEnterAnim(R.anim.nav_default_enter_anim)
+            .setExitAnim(R.anim.nav_default_exit_anim)
+            .setPopEnterAnim(R.anim.nav_default_pop_enter_anim)
+            .setPopExitAnim(R.anim.nav_default_pop_exit_anim)
+    } else {
+        builder.setEnterAnim(com.hippo.ehviewer.R.anim.scene_open_enter)
+            .setExitAnim(com.hippo.ehviewer.R.anim.scene_open_exit)
+            .setPopEnterAnim(com.hippo.ehviewer.R.anim.scene_close_enter)
+            .setPopExitAnim(com.hippo.ehviewer.R.anim.scene_close_exit)
+    }
+    if (item.order and Menu.CATEGORY_SECONDARY == 0) {
+        builder.setPopUpTo(
+            navController.graph.findStartDestination().id,
+            inclusive = false,
+            saveState = false
+        )
+    }
+    val options = builder.build()
+    return try {
+        // TODO provide proper API instead of using Exceptions as Control-Flow.
+        navController.navigate(item.itemId, null, options)
+        // Return true only if the destination we've navigated to matches the MenuItem
+        navController.currentDestination?.matchDestination(item.itemId) == true
+    } catch (e: IllegalArgumentException) {
+        false
+    }
+}
+
+fun NavDestination.matchDestination(@IdRes destId: Int): Boolean =
+    hierarchy.any { it.id == destId }

app/src/main/java/com/hippo/ehviewer/ui/MainActivity.kt

@@ -34,13 +34,17 @@ import androidx.activity.OnBackPressedCallback
 import androidx.annotation.RequiresApi
 import androidx.annotation.StringRes
 import androidx.core.view.GravityCompat
+import androidx.customview.widget.Openable
 import androidx.drawerlayout.widget.DrawerLayout
 import androidx.drawerlayout.widget.DrawerLayout.DrawerListener
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.lifecycleScope
 import androidx.navigation.NavController
 import androidx.navigation.fragment.NavHostFragment
+import androidx.navigation.ui.NavigationUI
+import androidx.navigation.ui.onNavDestinationSelected2
 import androidx.navigation.ui.setupWithNavController
+import com.google.android.material.bottomsheet.BottomSheetBehavior
 import com.google.android.material.snackbar.Snackbar
 import com.hippo.app.BaseDialogBuilder
 import com.hippo.app.EditTextDialogBuilder
@@ -231,6 +235,26 @@ class MainActivity : EhActivity() {
         }
         binding.drawView.addDrawerListener(mDrawerOnBackPressedCallback)
         binding.navView.setupWithNavController(navController)
+
+        // Trick: Tweak NavigationUI to disable multiple backstack
+        binding.navView.setNavigationItemSelectedListener {
+            val navigationView = binding.navView
+            val handled = onNavDestinationSelected2(it, navController)
+            if (handled) {
+                val parent = navigationView.parent
+                if (parent is Openable) {
+                    parent.close()
+                } else {
+                    val bottomSheetBehavior = NavigationUI.findBottomSheetBehavior(navigationView)
+                    if (bottomSheetBehavior != null) {
+                        bottomSheetBehavior.state = BottomSheetBehavior.STATE_HIDDEN
+                    }
+                }
+            }
+            handled
+        }
+        // Trick End
+
         if (savedInstanceState == null) {
             if (intent.action != Intent.ACTION_MAIN) {
                 onNewIntent(intent)