src/com/android/launcher3/LauncherApplication.java

/*
 * Copyright (C) 2023 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.android.launcher3;

import android.app.Application;

import com.android.launcher3.dagger.DaggerLauncherAppComponent;
import com.android.launcher3.dagger.LauncherAppComponent;
import com.android.launcher3.dagger.LauncherBaseAppComponent;

/**
 * Main application class for Launcher
 */
public class LauncherApplication extends Application {

    private volatile LauncherBaseAppComponent mAppComponent;
    @Override
    public void onCreate() {
        super.onCreate();
        MainProcessInitializer.initialize(this);
    }

    public LauncherAppComponent getAppComponent() {
        if (mAppComponent == null) {
            synchronized (this) {
                // Check for null again, as it may have been assigned on a different thread. This
                // avoids holding synchronization locks everytime.
                if (mAppComponent == null) {
                    // Initialize the dagger component on demand as content providers can get
                    // accessed before the Launcher application (b/36917845#comment4)
                    initDaggerComponent(DaggerLauncherAppComponent.builder());
                }
            }
        }
        // Since supertype setters will return a supertype.builder and @Component.Builder types
        // must not have any generic types.
        // We need to cast mAppComponent to {@link LauncherAppComponent} since appContext()
        // method is defined in the super class LauncherBaseComponent#Builder.
        return (LauncherAppComponent) mAppComponent;
    }

    /**
     * Init with the desired dagger component.
     */
    public void initDaggerComponent(LauncherAppComponent.Builder componentBuilder) {
        mAppComponent = componentBuilder.appContext(this).build();
    }
}