Android-Glide-分析01-Glide的初始化以及RequestManager對象的創建過程

Glide的初始化

public static RequestManager with(@NonNull View view)
public static RequestManager with(@NonNull Activity activity)
public static RequestManager with(@NonNull FragmentActivity activity)
public static RequestManager with(@NonNull Fragment fragment)
public static RequestManager with(@NonNull FragmentActivity activity)

以上一系列方法內部都是都會執行
   public static RequestManager with(xxx) {
    return getRetriever(xxx).get(xxx);
  }
  private static RequestManagerRetriever getRetriever(@Nullable Context context) {
    //...略
    //Glide對象的創建由GlideBulder完成
    return Glide.get(context).getRequestManagerRetriever();
  }
  private static RequestManagerRetriever getRetriever(@Nullable Context context)    {
   //...略
    return Glide.get(context).getRequestManagerRetriever();
  }
  public RequestManagerRetriever getRequestManagerRetriever() {
    return requestManagerRetriever;
  }
  
	//單例創建Glide對象
  public static Glide get(@NonNull Context context) {
    if (glide == null) {
      synchronized (Glide.class) {
        if (glide == null) {
          checkAndInitializeGlide(context);
        }
      }
    }

    return glide;
  }
   private static void checkAndInitializeGlide(@NonNull Context context) {
    //略...
    isInitializing = true;
    initializeGlide(context);
    isInitializing = false;
  }
  private static void initializeGlide(@NonNull Context context) {
    initializeGlide(context, new GlideBuilder());
  }
  //創建靜態Glide對象，並初始化成員變量
  private static void initializeGlide(@NonNull Context context, @NonNull GlideBuilder builder) {
  	//...略
  //生成的com.bumptech.glide.GeneratedAppGlideModuleImpl 對象的java類，是由com.github.bumptech.glide:compiler:4.9.0， 利用com.squareup:javapoet開源項目動態生成出來的。
  //GeneratedAppGlideModuleImpl生成器，可以參考，https://github.com/bumptech/glide/tree/master/annotation/compiler/src/main/java/com/bumptech/glide/annotation/compiler
  //JavaPoet開源項目的簡單使用，可以參考:https://blog.csdn.net/With__Sunshine/article/details/106010852
  GeneratedAppGlideModule annotationGeneratedModule = getAnnotationGeneratedGlideModules();
    //...略
    Glide glide = builder.build(applicationContext);
    //...略
    Glide.glide = glide;
  }

GlideBuilder,Glide成員變量的構建者

public final class GlideBuilder {
  private final Map<Class<?>, TransitionOptions<?, ?>> defaultTransitionOptions = new ArrayMap<>();
  private Engine engine;
  private BitmapPool bitmapPool;
  private ArrayPool arrayPool;
  private MemoryCache memoryCache;
  private GlideExecutor sourceExecutor;
  private GlideExecutor diskCacheExecutor;
  private DiskCache.Factory diskCacheFactory;
  private MemorySizeCalculator memorySizeCalculator;
  private ConnectivityMonitorFactory connectivityMonitorFactory;
  private int logLevel = Log.INFO;
  private RequestOptions defaultRequestOptions = new RequestOptions();
  @Nullable
  private RequestManagerFactory requestManagerFactory;
  private GlideExecutor animationExecutor;
  private boolean isActiveResourceRetentionAllowed;
  @Nullable
  private List<RequestListener<Object>> defaultRequestListeners;
  private boolean isLoggingRequestOriginsEnabled;

  Glide build(@NonNull Context context) {
    if (sourceExecutor == null) {
      sourceExecutor = GlideExecutor.newSourceExecutor();
    }

    if (diskCacheExecutor == null) {
      diskCacheExecutor = GlideExecutor.newDiskCacheExecutor();
    }

    if (animationExecutor == null) {
      animationExecutor = GlideExecutor.newAnimationExecutor();
    }

    if (memorySizeCalculator == null) {
      memorySizeCalculator = new MemorySizeCalculator.Builder(context).build();
    }

    if (connectivityMonitorFactory == null) {
      connectivityMonitorFactory = new DefaultConnectivityMonitorFactory();
    }

    if (bitmapPool == null) {
      int size = memorySizeCalculator.getBitmapPoolSize();
      if (size > 0) {
        bitmapPool = new LruBitmapPool(size);
      } else {
        bitmapPool = new BitmapPoolAdapter();
      }
    }

    if (arrayPool == null) {
      arrayPool = new LruArrayPool(memorySizeCalculator.getArrayPoolSizeInBytes());
    }

    if (memoryCache == null) {
      memoryCache = new LruResourceCache(memorySizeCalculator.getMemoryCacheSize());
    }

    if (diskCacheFactory == null) {
      diskCacheFactory = new InternalCacheDiskCacheFactory(context);
    }

    if (engine == null) {
      engine =
          new Engine(
              memoryCache,
              diskCacheFactory,
              diskCacheExecutor,
              sourceExecutor,
              GlideExecutor.newUnlimitedSourceExecutor(),
              GlideExecutor.newAnimationExecutor(),
              isActiveResourceRetentionAllowed);
    }

    if (defaultRequestListeners == null) {
      defaultRequestListeners = Collections.emptyList();
    } else {
      defaultRequestListeners = Collections.unmodifiableList(defaultRequestListeners);
    }

    RequestManagerRetriever requestManagerRetriever =
        new RequestManagerRetriever(requestManagerFactory);

    return new Glide(
        context,
        engine,
        memoryCache,
        bitmapPool,
        arrayPool,
        requestManagerRetriever,
        connectivityMonitorFactory,
        logLevel,
        defaultRequestOptions.lock(),
        defaultTransitionOptions,
        defaultRequestListeners,
        isLoggingRequestOriginsEnabled);
  }
 }