[Catalog][Predictive Back][Bottom Sheet] Update bottom sheet state handling to be more accurate in demos

Fixes inaccurate state label text and back callback enabled flag after rotation

Resolves #3573
Resolves #3575
Resolves #3577

Resolves #3574
Resolves #3576
Resolves #3578

PiperOrigin-RevId: 566286622

Author: dsn5ft

catalog/java/io/material/catalog/bottomappbar/BottomAppBarMainDemoFragment.java

@@ -208,25 +208,12 @@ protected void setUpBottomDrawer(View view) {
     bottomDrawerBehavior = BottomSheetBehavior.from(bottomDrawer);
     bottomDrawerBehavior.setUpdateImportantForAccessibilityOnSiblings(true);
     bottomDrawerBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
+    bottomDrawer.post(() -> updateBackHandlingEnabled(bottomDrawerBehavior.getState()));
     bottomDrawerBehavior.addBottomSheetCallback(
         new BottomSheetCallback() {
           @Override
           public void onStateChanged(@NonNull View bottomSheet, int newState) {
-            switch (newState) {
-              case BottomSheetBehavior.STATE_EXPANDED:
-              case BottomSheetBehavior.STATE_HALF_EXPANDED:
-                bottomDrawerOnBackPressedCallback.setEnabled(true);
-                break;
-              case BottomSheetBehavior.STATE_COLLAPSED:
-              case BottomSheetBehavior.STATE_HIDDEN:
-                bottomDrawerOnBackPressedCallback.setEnabled(false);
-                break;
-              case BottomSheetBehavior.STATE_DRAGGING:
-              case BottomSheetBehavior.STATE_SETTLING:
-              default:
-                // Do nothing, only change callback enabled for "stable" states.
-                break;
-            }
+            updateBackHandlingEnabled(newState);
 
             if (newState == BottomSheetBehavior.STATE_HIDDEN) {
               barNavView.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
@@ -245,6 +232,24 @@ public void onSlide(@NonNull View bottomSheet, float slideOffset) {}
         v -> bottomDrawerBehavior.setState(BottomSheetBehavior.STATE_HALF_EXPANDED));
   }
 
+  private void updateBackHandlingEnabled(int state) {
+    switch (state) {
+      case BottomSheetBehavior.STATE_EXPANDED:
+      case BottomSheetBehavior.STATE_HALF_EXPANDED:
+        bottomDrawerOnBackPressedCallback.setEnabled(true);
+        break;
+      case BottomSheetBehavior.STATE_COLLAPSED:
+      case BottomSheetBehavior.STATE_HIDDEN:
+        bottomDrawerOnBackPressedCallback.setEnabled(false);
+        break;
+      case BottomSheetBehavior.STATE_DRAGGING:
+      case BottomSheetBehavior.STATE_SETTLING:
+      default:
+        // Do nothing, only change callback enabled for "stable" states.
+        break;
+    }
+  }
+
   private void showSnackbar(CharSequence text) {
     Snackbar.make(coordinatorLayout, text, Snackbar.LENGTH_SHORT)
         .setAnchorView(fab.getVisibility() == View.VISIBLE ? fab : bar)

catalog/java/io/material/catalog/bottomsheet/BottomSheetMainDemoFragment.java

@@ -153,6 +153,12 @@ public View onCreateDemoView(
     persistentBottomSheetBehavior = BottomSheetBehavior.from(bottomSheetPersistent);
     persistentBottomSheetBehavior.addBottomSheetCallback(
         createBottomSheetCallback(bottomSheetText));
+    bottomSheetPersistent.post(
+        () -> {
+          int state = persistentBottomSheetBehavior.getState();
+          updateStateTextView(bottomSheetPersistent, bottomSheetText, state);
+          updateBackHandlingEnabled(state);
+        });
     setupBackHandling(persistentBottomSheetBehavior);
 
     Button button1 = view.findViewById(R.id.cat_bottomsheet_button);
@@ -251,39 +257,39 @@ protected int getStandardBottomSheetLayout() {
   }
 
   private BottomSheetCallback createBottomSheetCallback(@NonNull TextView text) {
-    // Set up BottomSheetCallback
-    BottomSheetCallback bottomSheetCallback =
-        new BottomSheetCallback() {
-          @Override
-          public void onStateChanged(@NonNull View bottomSheet, int newState) {
+    return new BottomSheetCallback() {
+      @Override
+      public void onStateChanged(@NonNull View bottomSheet, int newState) {
+        updateStateTextView(bottomSheet, text, newState);
+      }
 
-            switch (newState) {
-              case BottomSheetBehavior.STATE_DRAGGING:
-                text.setText(R.string.cat_bottomsheet_state_dragging);
-                break;
-              case BottomSheetBehavior.STATE_EXPANDED:
-                text.setText(R.string.cat_bottomsheet_state_expanded);
-                break;
-              case BottomSheetBehavior.STATE_COLLAPSED:
-                text.setText(R.string.cat_bottomsheet_state_collapsed);
-                break;
-              case BottomSheetBehavior.STATE_HALF_EXPANDED:
-                BottomSheetBehavior<View> bottomSheetBehavior =
-                    BottomSheetBehavior.from(bottomSheet);
-                text.setText(
-                    getString(
-                        R.string.cat_bottomsheet_state_half_expanded,
-                        bottomSheetBehavior.getHalfExpandedRatio()));
-                break;
-              default:
-                break;
-            }
-          }
+      @Override
+      public void onSlide(@NonNull View bottomSheet, float slideOffset) {}
+    };
+  }
 
-          @Override
-          public void onSlide(@NonNull View bottomSheet, float slideOffset) {}
-        };
-    return bottomSheetCallback;
+  private void updateStateTextView(@NonNull View bottomSheet, @NonNull TextView text, int state) {
+    switch (state) {
+      case BottomSheetBehavior.STATE_DRAGGING:
+        text.setText(R.string.cat_bottomsheet_state_dragging);
+        break;
+      case BottomSheetBehavior.STATE_EXPANDED:
+        text.setText(R.string.cat_bottomsheet_state_expanded);
+        break;
+      case BottomSheetBehavior.STATE_COLLAPSED:
+        text.setText(R.string.cat_bottomsheet_state_collapsed);
+        break;
+      case BottomSheetBehavior.STATE_HALF_EXPANDED:
+        BottomSheetBehavior<View> bottomSheetBehavior =
+            BottomSheetBehavior.from(bottomSheet);
+        text.setText(
+            getString(
+                R.string.cat_bottomsheet_state_half_expanded,
+                bottomSheetBehavior.getHalfExpandedRatio()));
+        break;
+      default:
+        break;
+    }
   }
 
   private void setupBackHandling(BottomSheetBehavior<View> behavior) {
@@ -294,25 +300,29 @@ private void setupBackHandling(BottomSheetBehavior<View> behavior) {
         new BottomSheetCallback() {
           @Override
           public void onStateChanged(@NonNull View bottomSheet, int newState) {
-            switch (newState) {
-              case BottomSheetBehavior.STATE_EXPANDED:
-              case BottomSheetBehavior.STATE_HALF_EXPANDED:
-                persistentBottomSheetBackCallback.setEnabled(true);
-                break;
-              case BottomSheetBehavior.STATE_COLLAPSED:
-              case BottomSheetBehavior.STATE_HIDDEN:
-                persistentBottomSheetBackCallback.setEnabled(false);
-                break;
-              case BottomSheetBehavior.STATE_DRAGGING:
-              case BottomSheetBehavior.STATE_SETTLING:
-              default:
-                // Do nothing, only change callback enabled for "stable" states.
-                break;
-            }
+            updateBackHandlingEnabled(newState);
           }
 
           @Override
           public void onSlide(@NonNull View bottomSheet, float slideOffset) {}
         });
   }
+
+  private void updateBackHandlingEnabled(int state) {
+    switch (state) {
+      case BottomSheetBehavior.STATE_EXPANDED:
+      case BottomSheetBehavior.STATE_HALF_EXPANDED:
+        persistentBottomSheetBackCallback.setEnabled(true);
+        break;
+      case BottomSheetBehavior.STATE_COLLAPSED:
+      case BottomSheetBehavior.STATE_HIDDEN:
+        persistentBottomSheetBackCallback.setEnabled(false);
+        break;
+      case BottomSheetBehavior.STATE_DRAGGING:
+      case BottomSheetBehavior.STATE_SETTLING:
+      default:
+        // Do nothing, only change callback enabled for "stable" states.
+        break;
+    }
+  }
 }