android/support/design/internal/BottomNavigationMenu.java

/*
 * Copyright (C) 2016 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 android.support.design.internal;

import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;

import android.content.Context;
import android.support.annotation.RestrictTo;
import android.support.v7.view.menu.MenuBuilder;
import android.support.v7.view.menu.MenuItemImpl;
import android.view.MenuItem;
import android.view.SubMenu;

/**
 * @hide
 */
@RestrictTo(LIBRARY_GROUP)
public final class BottomNavigationMenu extends MenuBuilder {
    public static final int MAX_ITEM_COUNT = 5;

    public BottomNavigationMenu(Context context) {
        super(context);
    }

    @Override
    public SubMenu addSubMenu(int group, int id, int categoryOrder, CharSequence title) {
        throw new UnsupportedOperationException("BottomNavigationView does not support submenus");
    }

    @Override
    protected MenuItem addInternal(int group, int id, int categoryOrder, CharSequence title) {
        if (size() + 1 > MAX_ITEM_COUNT) {
            throw new IllegalArgumentException(
                    "Maximum number of items supported by BottomNavigationView is " + MAX_ITEM_COUNT
                            + ". Limit can be checked with BottomNavigationView#getMaxItemCount()");
        }
        stopDispatchingItemsChanged();
        final MenuItem item = super.addInternal(group, id, categoryOrder, title);
        if (item instanceof MenuItemImpl) {
            ((MenuItemImpl) item).setExclusiveCheckable(true);
        }
        startDispatchingItemsChanged();
        return item;
    }
}