[NavigationRail] Add submenu support

PiperOrigin-RevId: 670703103

Author: imhappi

.github/workflow/STALE_ISSUES_WORKFLOW.yml

@@ -24,7 +24,6 @@
 
 import android.content.Context;
 import android.content.res.Resources;
-import androidx.appcompat.view.menu.MenuBuilder;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
@@ -71,10 +70,9 @@ public BottomNavigationMenuView(@NonNull Context context) {
 
   @Override
   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
-    final MenuBuilder menu = getMenu();
     final int width = MeasureSpec.getSize(widthMeasureSpec);
     // Use visible item count to calculate widths
-    final int visibleCount = menu.getVisibleItems().size();
+    final int visibleCount = getCurrentVisibleContentItemCount();
     // Use total item counts to measure children
     final int totalCount = getChildCount();
     tempChildWidths.clear();

lib/java/com/google/android/material/bottomnavigation/BottomNavigationMenuView.java

@@ -37,5 +37,5 @@
   <dimen name="m3_bottom_nav_item_active_indicator_height">@dimen/m3_comp_navigation_bar_active_indicator_height</dimen>
   <dimen name="m3_bottom_nav_item_active_indicator_margin_horizontal">4dp</dimen>
 
-  <dimen name="m3_expressive_item_expanded_active_indicator_height">40dp</dimen>
+  <dimen name="m3_bottom_nav_item_expanded_active_indicator_height">40dp</dimen>
 </resources>

lib/java/com/google/android/material/bottomnavigation/res/values/dimens.xml

@@ -105,6 +105,6 @@
     <item name="marginHorizontal">@dimen/m3_bottom_nav_item_active_indicator_margin_horizontal</item>
     <item name="shapeAppearance">@style/ShapeAppearance.M3.Comp.NavigationBar.ActiveIndicator.Shape</item>
     <item name="android:color">@macro/m3_comp_navigation_bar_active_indicator_color</item>
-    <item name="expandedHeight">@dimen/m3_expressive_item_expanded_active_indicator_height</item>
+    <item name="expandedHeight">@dimen/m3_bottom_nav_item_expanded_active_indicator_height</item>
   </style>
 </resources>

lib/java/com/google/android/material/bottomnavigation/res/values/styles.xml

@@ -36,7 +36,6 @@
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
 import androidx.appcompat.view.menu.MenuItemImpl;
-import androidx.appcompat.view.menu.MenuView;
 import androidx.appcompat.widget.TooltipCompat;
 import android.text.TextUtils;
 import android.util.Log;
@@ -85,7 +84,8 @@
  * @hide
  */
 @RestrictTo(LIBRARY_GROUP)
-public abstract class NavigationBarItemView extends FrameLayout implements MenuView.ItemView {
+public abstract class NavigationBarItemView extends FrameLayout
+    implements NavigationBarMenuItemView {
   private static final int INVALID_ITEM_POSITION = -1;
   private static final int UNSET_VALUE = -1;
   private static final int[] CHECKED_STATE_SET = {android.R.attr.state_checked};
@@ -156,6 +156,8 @@ public abstract class NavigationBarItemView extends FrameLayout implements MenuV
   @ItemIconGravity private int itemIconGravity;
   private int badgeFixedEdge = BadgeDrawable.BADGE_FIXED_EDGE_START;
   @ItemGravity private int itemGravity = NavigationBarView.ITEM_GRAVITY_TOP_CENTER;
+  private boolean expanded = false;
+  private boolean onlyShowWhenExpanded = false;
 
   public NavigationBarItemView(@NonNull Context context) {
     super(context);
@@ -184,7 +186,7 @@ public NavigationBarItemView(@NonNull Context context) {
     setFocusable(true);
     calculateTextScaleFactors(smallLabel.getTextSize(), largeLabel.getTextSize());
     activeIndicatorExpandedDesiredHeight = getResources().getDimensionPixelSize(
-        R.dimen.m3_expressive_item_expanded_active_indicator_height_default);
+        R.dimen.m3_navigation_item_expanded_active_indicator_height_default);
 
     // TODO(b/138148581): Support displaying a badge on label-only bottom navigation views.
     innerContentContainer.addOnLayoutChangeListener(
@@ -258,10 +260,17 @@ public void initialize(@NonNull MenuItemImpl itemData, int menuType) {
     if (VERSION.SDK_INT > VERSION_CODES.M) {
       TooltipCompat.setTooltipText(this, tooltipText);
     }
-    setVisibility(itemData.isVisible() ? View.VISIBLE : View.GONE);
+    updateVisibility();
     this.initialized = true;
   }
 
+  private void updateVisibility() {
+    if (itemData != null) {
+      setVisibility(
+          itemData.isVisible() && (expanded || !onlyShowWhenExpanded) ? View.VISIBLE : View.GONE);
+    }
+  }
+
   /**
    * Remove state so this View can be reused.
    *
@@ -310,7 +319,7 @@ private void updateItemIconGravity() {
     if (itemIconGravity == ITEM_ICON_GRAVITY_START) {
       sideMargin =
           getResources()
-              .getDimensionPixelSize(R.dimen.m3_expressive_navigation_item_leading_trailing_space);
+              .getDimensionPixelSize(R.dimen.m3_navigation_item_leading_trailing_space);
       labelGroupTopMargin = 0;
       labelGroupSideMargin = activeIndicatorLabelPadding;
       badgeFixedEdge = BadgeDrawable.BADGE_FIXED_EDGE_END;
@@ -350,6 +359,28 @@ public void setItemIconGravity(@ItemIconGravity int iconGravity) {
     }
   }
 
+  @Override
+  public void setExpanded(boolean expanded) {
+    this.expanded = expanded;
+    updateVisibility();
+  }
+
+  @Override
+  public boolean isExpanded() {
+    return this.expanded;
+  }
+
+  @Override
+  public void setOnlyShowWhenExpanded(boolean onlyShowWhenExpanded) {
+    this.onlyShowWhenExpanded = onlyShowWhenExpanded;
+    updateVisibility();
+  }
+
+  @Override
+  public boolean isOnlyVisibleWhenExpanded() {
+    return this.onlyShowWhenExpanded;
+  }
+
   @Override
   @Nullable
   public MenuItemImpl getItemData() {

lib/java/com/google/android/material/navigation/NavigationBarItemView.java

@@ -20,6 +20,8 @@
 
 import android.content.Context;
 import androidx.appcompat.view.menu.MenuBuilder;
+import androidx.appcompat.view.menu.MenuItemImpl;
+import androidx.appcompat.view.menu.SubMenuBuilder;
 import android.view.MenuItem;
 import android.view.SubMenu;
 import androidx.annotation.NonNull;
@@ -37,12 +39,17 @@ public final class NavigationBarMenu extends MenuBuilder {
 
   @NonNull private final Class<?> viewClass;
   private final int maxItemCount;
+  private final boolean subMenuSupported;
 
   public NavigationBarMenu(
-      @NonNull Context context, @NonNull Class<?> viewClass, int maxItemCount) {
+      @NonNull Context context,
+      @NonNull Class<?> viewClass,
+      int maxItemCount,
+      boolean subMenuSupported) {
     super(context);
     this.viewClass = viewClass;
     this.maxItemCount = maxItemCount;
+    this.subMenuSupported = subMenuSupported;
   }
 
   /** Returns the maximum number of items that can be shown in NavigationBarMenu. */
@@ -53,8 +60,14 @@ public int getMaxItemCount() {
   @NonNull
   @Override
   public SubMenu addSubMenu(int group, int id, int categoryOrder, @NonNull CharSequence title) {
-    throw new UnsupportedOperationException(
-        viewClass.getSimpleName() + " does not support submenus");
+    if (!subMenuSupported) {
+      throw new UnsupportedOperationException(
+          viewClass.getSimpleName() + " does not support submenus");
+    }
+    final MenuItemImpl item = (MenuItemImpl) addInternal(group, id, categoryOrder, title);
+    final SubMenuBuilder subMenu = new NavigationBarSubMenu(getContext(), this, item);
+    item.setSubMenu(subMenu);
+    return subMenu;
   }
 
   @Override

lib/java/com/google/android/material/navigation/NavigationBarMenu.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.material.navigation;
+
+import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
+
+import androidx.appcompat.view.menu.MenuBuilder;
+import androidx.appcompat.view.menu.MenuPresenter;
+import android.view.MenuItem;
+import android.view.SubMenu;
+import androidx.annotation.NonNull;
+import androidx.annotation.RestrictTo;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Wrapper class for {@link MenuBuilder} that adds methods to support submenus as a part of the
+ * menu.
+ *
+ * @hide
+ */
+@RestrictTo(LIBRARY_GROUP)
+public class NavigationBarMenuBuilder {
+
+  private final MenuBuilder menuBuilder;
+  private final List<MenuItem> items;
+  private int contentItemCount = 0;
+  private int visibleContentItemCount = 0;
+  private int visibleMainItemCount = 0;
+
+  NavigationBarMenuBuilder(MenuBuilder menuBuilder) {
+    this.menuBuilder = menuBuilder;
+    items = new ArrayList<>();
+    refreshItems();
+  }
+
+  /**
+   * Returns total number of items in the menu, including submenus and submenu items. For example,
+   * a Menu with items {Item, SubMenu, SubMenuItem} would have a size of 3.
+   */
+  public int size() {
+    return items.size();
+  }
+
+  /**
+   * Returns number of content (non-subheader) items in the menu.
+   */
+  public int getContentItemCount() {
+    return contentItemCount;
+  }
+
+  /**
+   * Returns number of visible content (non-subheader) items in the menu.
+   */
+  public int getVisibleContentItemCount() {
+    return visibleContentItemCount;
+  }
+
+  /**
+   * Returns number of visible main items in the menu, which correspond to any content items that
+   * are not under a subheader.
+   */
+  public int getVisibleMainContentItemCount() {
+    return visibleMainItemCount;
+  }
+
+  /**
+   * Returns the item at the position i.
+   */
+  @NonNull
+  public MenuItem getItemAt(int i) {
+    return items.get(i);
+  }
+
+  /**
+   * Calls the underlying {@link MenuBuilder#performItemAction(MenuItem, MenuPresenter, int)}
+   */
+  public boolean performItemAction(
+      @NonNull MenuItem item, @NonNull MenuPresenter presenter, int flags) {
+    return menuBuilder.performItemAction(item, presenter, flags);
+  }
+
+  /**
+   * Refresh the items to match the current state of the underlying {@link MenuBuilder}.
+   */
+  public void refreshItems() {
+    items.clear();
+    contentItemCount = 0;
+    visibleContentItemCount = 0;
+    visibleMainItemCount = 0;
+    for (int i = 0; i < menuBuilder.size(); i++) {
+      MenuItem item = menuBuilder.getItem(i);
+      items.add(item);
+      if (item.hasSubMenu()) {
+        SubMenu subMenu = item.getSubMenu();
+        for (int j = 0; j < subMenu.size(); j++) {
+          MenuItem submenuItem = subMenu.getItem(j);
+          if (!item.isVisible()) {
+            submenuItem.setVisible(false);
+          }
+          items.add(submenuItem);
+          contentItemCount++;
+          if (submenuItem.isVisible()) {
+            visibleContentItemCount++;
+          }
+        }
+      } else {
+        contentItemCount++;
+        if (item.isVisible()) {
+          visibleContentItemCount++;
+          visibleMainItemCount++;
+        }
+      }
+    }
+  }
+}

lib/java/com/google/android/material/navigation/NavigationBarMenuBuilder.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.material.navigation;
+
+import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
+
+import androidx.appcompat.view.menu.MenuView;
+import androidx.annotation.RestrictTo;
+
+/**
+ * Interface for views that represent the Navigation Bar menu items.
+ *
+ * @hide
+ */
+@RestrictTo(LIBRARY_GROUP)
+public interface NavigationBarMenuItemView extends MenuView.ItemView {
+  /** Update the bar expanded state in item. */
+  void setExpanded(boolean expanded);
+
+  /** Whether or not the item's bar expanded state is expanded. */
+  boolean isExpanded();
+
+  /** Set whether or not to only show the item when expanded. */
+  void setOnlyShowWhenExpanded(boolean onlyShowWhenExpanded);
+
+  /** Whether or not to only show the item when expanded. */
+  boolean isOnlyVisibleWhenExpanded();
+}