From 1252d4f2639b2c98136b3de5a1e16a0facc56a78 Mon Sep 17 00:00:00 2001
From: manabu-nakamura <ma.nakamura@gmail.com>
Date: Thu, 28 Sep 2023 14:48:40 +0000
Subject: [PATCH] [Catalog][Predictive Back][Navigation Drawer] Update
 navigation drawer state handling to be more accurate in custom drawer demo

Partially addresses https://github.com/material-components/material-components-android/issues/3593
Resolves https://github.com/material-components/material-components-android/pull/3596

GIT_ORIGIN_REV_ID=9ca19b41473caa9bb303c7ac1ed2c5191cb4b081
PiperOrigin-RevId: 569180296
---
 .../CustomNavigationDrawerDemoActivity.java   | 74 +++++++++++--------
 1 file changed, 44 insertions(+), 30 deletions(-)

diff --git a/catalog/java/io/material/catalog/navigationdrawer/CustomNavigationDrawerDemoActivity.java b/catalog/java/io/material/catalog/navigationdrawer/CustomNavigationDrawerDemoActivity.java
index 19bbd0bfa0f..5f3726d0015 100644
--- a/catalog/java/io/material/catalog/navigationdrawer/CustomNavigationDrawerDemoActivity.java
+++ b/catalog/java/io/material/catalog/navigationdrawer/CustomNavigationDrawerDemoActivity.java
@@ -86,40 +86,12 @@ public View onCreateDemoView(
         new SimpleDrawerListener() {
           @Override
           public void onDrawerOpened(@NonNull View drawerView) {
-            currentDrawerView = drawerView;
-            sideContainerBackHelper = new MaterialSideContainerBackHelper(drawerView);
-
-            if (VERSION.SDK_INT >= VERSION_CODES.UPSIDE_DOWN_CAKE) {
-              if (drawerOnBackAnimationCallback == null) {
-                drawerOnBackAnimationCallback = createOnBackAnimationCallback();
-              }
-              drawerLayout.post(
-                  () ->
-                      getOnBackInvokedDispatcher()
-                          .registerOnBackInvokedCallback(
-                              OnBackInvokedDispatcher.PRIORITY_OVERLAY,
-                              drawerOnBackAnimationCallback));
-            } else {
-              getOnBackPressedDispatcher()
-                  .addCallback(
-                      CustomNavigationDrawerDemoActivity.this, drawerOnBackPressedCallback);
-            }
+            registerBackCallback(drawerView);
           }
 
           @Override
           public void onDrawerClosed(@NonNull View drawerView) {
-            currentDrawerView = null;
-            sideContainerBackHelper = null;
-
-            if (VERSION.SDK_INT >= VERSION_CODES.UPSIDE_DOWN_CAKE) {
-              if (drawerOnBackAnimationCallback != null) {
-                getOnBackInvokedDispatcher()
-                    .unregisterOnBackInvokedCallback(drawerOnBackAnimationCallback);
-                drawerOnBackAnimationCallback = null;
-              }
-            } else {
-              drawerOnBackPressedCallback.remove();
-            }
+            unregisterBackCallback();
           }
         });
 
@@ -127,9 +99,51 @@ public void onDrawerClosed(@NonNull View drawerView) {
     view.findViewById(R.id.show_end_drawer_gravity)
         .setOnClickListener(v -> drawerLayout.openDrawer(endDrawer));
 
+    drawerLayout.post(
+        () -> {
+          View startDrawer = view.findViewById(R.id.custom_drawer_start);
+          if (drawerLayout.isDrawerOpen(startDrawer)) {
+            registerBackCallback(startDrawer);
+          } else if (drawerLayout.isDrawerOpen(endDrawer)) {
+            registerBackCallback(endDrawer);
+          }
+        });
+
     return view;
   }
 
+  private void registerBackCallback(@NonNull View drawerView) {
+    currentDrawerView = drawerView;
+    sideContainerBackHelper = new MaterialSideContainerBackHelper(drawerView);
+
+    if (VERSION.SDK_INT >= VERSION_CODES.UPSIDE_DOWN_CAKE) {
+      if (drawerOnBackAnimationCallback == null) {
+        drawerOnBackAnimationCallback = createOnBackAnimationCallback();
+      }
+      drawerLayout.post(
+          () ->
+              getOnBackInvokedDispatcher()
+                  .registerOnBackInvokedCallback(
+                      OnBackInvokedDispatcher.PRIORITY_OVERLAY, drawerOnBackAnimationCallback));
+    } else {
+      getOnBackPressedDispatcher().addCallback(this, drawerOnBackPressedCallback);
+    }
+  }
+
+  private void unregisterBackCallback() {
+    currentDrawerView = null;
+    sideContainerBackHelper = null;
+
+    if (VERSION.SDK_INT >= VERSION_CODES.UPSIDE_DOWN_CAKE) {
+      if (drawerOnBackAnimationCallback != null) {
+        getOnBackInvokedDispatcher().unregisterOnBackInvokedCallback(drawerOnBackAnimationCallback);
+        drawerOnBackAnimationCallback = null;
+      }
+    } else {
+      drawerOnBackPressedCallback.remove();
+    }
+  }
+
   @Override
   protected boolean shouldShowDefaultDemoActionBar() {
     return false;