flipper/docs/setup/images-plugin.md

id, title, sidebar_label

id	title	sidebar_label
images-plugin	Images Setup	Images

Currently, the images plugin only supports Fresco for Android as backend, but just like the network plugin, support for other image loading libraries could easily be added. Send us a PR!

Fresco and Android

The Fresco images plugin is shipped as a separate Maven artifact:

dependencies {
  debugImplementation 'com.facebook.flipper:flipper-images-plugin:0.25.0'
}

After including the plugin in your dependencies, you can add it to the client:

import com.facebook.flipper.plugins.fresco.FrescoFlipperPlugin;

client.addPlugin(new FrescoFlipperPlugin());

The FrescoFlipperPlugin constructor offers a whole lot of configuration options which can be useful if you have an advanced setup of Fresco in your application:

FrescoFlipperPlugin(
      DebugImageTracker imageTracker,
      PlatformBitmapFactory bitmapFactory,
      @Nullable FlipperObjectHelper flipperObjectHelper,
      DebugMemoryManager memoryManager,
      FlipperPerfLogger perfLogger,
      @Nullable FrescoFlipperDebugPrefHelper debugPrefHelper,
      @Nullable CloseableReferenceLeakTracker closeableReferenceLeakTracker) { ... }

Leak Tracking

The Flipper plugin can help you track down CloseableReferences who have not had close() called on them. This can have a negative impact on the performance of your application.

To enable this functionality, you need to create a CloseableReferenceLeakTracker and set it in both your ImagePipelineConfig for Fresco and the FrescoPluginPlugin on creation.

import com.facebook.imagepipeline.debug.FlipperCloseableReferenceLeakTracker;

// ...

FlipperCloseableReferenceLeakTracker leakTracker = new FlipperCloseableReferenceLeakTracker();

new ImagePipelineConfig.Builder()
    // ...
    .setCloseableReferenceLeakTracker(leakTracker)
    .build();


client.addPlugin(new FrescoFlipperPlugin(
    new FlipperImageTracker(),
    Fresco.getImagePipelineFactory().getPlatformBitmapFactory(),
    null,
    new NoOpDebugMemoryManager(),
    new NoOpFlipperPerfLogger(),
    null,
    leakTracker));

Attribution

In order to annotate images with the context they are used in, you have to set a caller context when loading the image. This can be any object, so for the simplest case, a String will suffice.

String callerContext = "my_feature";

// For DraweeViews:
draweeView.setImageURI(uri, callerContext);

// For prefetching:
ImagePipeline imagePipeline = Fresco.getImagePipeline();
imagePipeline.prefetchToDiskCache(imageRequest, callerContext);

// For manually fetching an image:
DataSource<CloseableReference<CloseableImage>>
    dataSource = imagePipeline.fetchDecodedImage(imageRequest, callerContext);

If a caller context is supplied, the image will be properly attributed in the Flipper image plugin.