[Predictive Back][Bottom Sheet] Fix bug where standard hideable botto…

…m sheets don't stay hidden after predictive back It wasn't an issue for modal bottom sheets because they dismiss the whole window when the bottom sheet behavior is hidden Also updated Bottom App Bar demo drawer to opt into predictive back, which is a standard hideable bottom sheet PiperOrigin-RevId: 520312905
material-components · Mar 29, 2023 · 2c23d2a · 2c23d2a
1 parent 1159923
commit 2c23d2a
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Showing 2 changed files with 41 additions and 4 deletions.
diff --git a/catalog/java/io/material/catalog/bottomappbar/BottomAppBarMainDemoFragment.java b/catalog/java/io/material/catalog/bottomappbar/BottomAppBarMainDemoFragment.java
@@ -18,6 +18,7 @@
 
 import io.material.catalog.R;
 
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
@@ -28,10 +29,12 @@
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.accessibility.AccessibilityEvent;
+import android.window.BackEvent;
 import androidx.activity.OnBackPressedCallback;
 import androidx.annotation.LayoutRes;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
 import androidx.coordinatorlayout.widget.CoordinatorLayout;
 import com.google.android.material.bottomappbar.BottomAppBar;
 import com.google.android.material.bottomappbar.BottomAppBarTopEdgeTreatment;
@@ -56,9 +59,27 @@ public class BottomAppBarMainDemoFragment extends DemoFragment {
 
   private final OnBackPressedCallback bottomDrawerOnBackPressedCallback =
       new OnBackPressedCallback(/* enabled= */ false) {
+        @RequiresApi(VERSION_CODES.UPSIDE_DOWN_CAKE)
+        @Override
+        public void handleOnBackStarted(@NonNull BackEvent backEvent) {
+          bottomDrawerBehavior.startBackProgress(backEvent);
+        }
+
+        @RequiresApi(VERSION_CODES.UPSIDE_DOWN_CAKE)
+        @Override
+        public void handleOnBackProgressed(@NonNull BackEvent backEvent) {
+          bottomDrawerBehavior.updateBackProgress(backEvent);
+        }
+
         @Override
         public void handleOnBackPressed() {
-          bottomDrawerBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
+          bottomDrawerBehavior.handleBackInvoked();
+        }
+
+        @RequiresApi(VERSION_CODES.UPSIDE_DOWN_CAKE)
+        @Override
+        public void handleOnBackCancelled() {
+          bottomDrawerBehavior.cancelBackProgress();
         }
       };
 
@@ -196,9 +217,22 @@ protected void setUpBottomDrawer(View view) {
         new BottomSheetCallback() {
           @Override
           public void onStateChanged(@NonNull View bottomSheet, int newState) {
-            bottomDrawerOnBackPressedCallback.setEnabled(
-                newState == BottomSheetBehavior.STATE_EXPANDED
-                    || newState == BottomSheetBehavior.STATE_HALF_EXPANDED);
+            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;
+            }
+
             if (newState == BottomSheetBehavior.STATE_HIDDEN) {
               barNavView.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
             }

diff --git a/lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java b/lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java
@@ -1597,6 +1597,9 @@ public void handleBackInvoked() {
             public void onAnimationEnd(Animator animation) {
               // Hide immediately following the built-in predictive back slide down animation.
               setStateInternal(STATE_HIDDEN);
+              if (viewRef != null && viewRef.get() != null) {
+                viewRef.get().requestLayout();
+              }
             }
           });
     } else {