navigation/navigation-ui/src/main/java/androidx/navigation/ui/ActionBarOnDestinationChangedListener.kt

/*
 * Copyright 2018 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 androidx.navigation.ui

import android.graphics.drawable.Drawable
import androidx.annotation.StringRes
import androidx.appcompat.app.AppCompatActivity

/**
 * The OnDestinationChangedListener specifically for keeping the ActionBar updated. This handles
 * both updating the title and updating the Up Indicator, transitioning between the drawer icon and
 * up arrow as needed.
 */
internal class ActionBarOnDestinationChangedListener(
    private val activity: AppCompatActivity,
    configuration: AppBarConfiguration
) :
    AbstractAppBarOnDestinationChangedListener(
        checkNotNull(activity.drawerToggleDelegate) {
                "Activity $activity does not have a DrawerToggleDelegate set"
            }
            .actionBarThemedContext,
        configuration
    ) {
    override fun setTitle(title: CharSequence?) {
        val actionBar =
            checkNotNull(activity.supportActionBar) {
                "Activity $activity does not have an ActionBar set via setSupportActionBar()"
            }
        actionBar.title = title
    }

    override fun setNavigationIcon(icon: Drawable?, @StringRes contentDescription: Int) {
        val actionBar =
            checkNotNull(activity.supportActionBar) {
                "Activity $activity does not have an ActionBar set via setSupportActionBar()"
            }
        actionBar.setDisplayHomeAsUpEnabled(icon != null)
        val delegate =
            checkNotNull(activity.drawerToggleDelegate) {
                "Activity $activity does not have a DrawerToggleDelegate set"
            }
        delegate.setActionBarUpIndicator(icon, contentDescription)
    }
}