Sketch Image Loader

Translations: 简体中文

Sketch is an image loading library specially designed for Compose Multiplatform and Android View. It has the following features:

• Multiple sources: Supports loading images from multiple sources such as http, file, compose.resource, android asset/content/resource, etc.
• Powerful functions: Supports three-level caching, automatically cancels requests, automatically adjusts image size, automatically rotates images according to Exif Orientation, etc.
• Rich functions: Supports Animated image, SVG images, Base64 images, and video frames
• Easy to expand: Supports expansion of various aspects such as caching, decoding, transformation, transition, placeholder, etc.
• Special functions: Practical extensions such as pausing downloads when cellular data is provided, pausing loading during list scrolling, image type badges, download progress indicators, etc.
• Modern: Completely based on Kotlin and Kotlin coroutine design

Download

Published to mavenCentral

${LAST_VERSION}: (Not included 'v')

Compose Multiplatform:

// Provides the core functions of Sketch as well as singletons and extension 
// functions that rely on singleton implementations
implementation("io.github.panpf.sketch4:sketch-compose:${LAST_VERSION}")

Important

To improve the performance of compose, please copy compose_compiler_config.conf under the sketch-core module file to your project and configure it according to the Compose Stability Configuration documentation

Android View:

// Provides the core functions of Sketch as well as singletons and extension 
// functions that rely on singleton implementations
implementation("io.github.panpf.sketch4:sketch-view:${LAST_VERSION}")

There are also some optional modules:

// Use Android or Skia's built-in decoder to decode gif, webp, heif and other animated images and play them
implementation("io.github.panpf.sketch4:sketch-animated:${LAST_VERSION}")

// [Android only] Use GifDrawable of the android-gif-drawable library to decode gif and play it
implementation("io.github.panpf.sketch4:sketch-animated-koralgif:${LAST_VERSION}")

// Support accessing compose resources through uri or placeholder, fallback, error, etc.
implementation("io.github.panpf.sketch4:sketch-compose-resources:${LAST_VERSION}")
implementation("io.github.panpf.sketch4:sketch-extensions-compose-resources:${LAST_VERSION}")

// Provides practical functions such as download progress, pausing loading during list scrolling, 
// saving cellular data, image type badge, loading apk icons and installed app icons, etc.
implementation("io.github.panpf.sketch4:sketch-extensions-compose:${LAST_VERSION}")
implementation("io.github.panpf.sketch4:sketch-extensions-view:${LAST_VERSION}")

// [JVM only] Supports using OkHttp to download images
implementation("io.github.panpf.sketch4:sketch-http-okhttp:${LAST_VERSION}")

// [JVM only] Supports using ktor to download images
implementation("io.github.panpf.sketch4:sketch-http-ktor:${LAST_VERSION}")

// Support SVG images
implementation("io.github.panpf.sketch4:sketch-svg:${LAST_VERSION}")

// [Android only] Use Android's built-in MediaMetadataRetriever class to decode video frames
implementation("io.github.panpf.sketch4:sketch-video:${LAST_VERSION}")

// [Android only] Decoding video frames using wseemann's FFmpegMediaMetadataRetriever library
implementation("io.github.panpf.sketch4:sketch-video-ffmpeg:${LAST_VERSION}")

Tip

• sketch-compose, sketch-view Modules all depend on the singleton provided by the sketch-singleton module. If you don’t need the singleton, you can directly rely on their *-core version.
• On Android sketch-compose and sketch-view can be used together

R8 / Proguard

Sketch itself does not need to configure any obfuscation rules, but you may need to configure it for the indirectly dependent Kotlin Coroutines, OkHttp, Okio Add obfuscation configuration

Quickly Started

Compose Multiplatform:

// val imageUri = "/Users/my/Downloads/image.jpg"
// val imageUri = "compose.resource://files/sample.png"
val imageUri = "https://www.sample.com/image.jpg"

AsyncImage(
    uri = imageUri,
    contentDescription = "photo"
)

AsyncImage(
    uri = imageUri,
    state = rememberAsyncImageState(ComposableImageOptions {
        placeholder(Res.drawable.placeholder)
        error(Res.drawable.error)
        crossfade()
        // There is a lot more...
    }),
    contentDescription = "photo"
)

AsyncImage(
    rqeuest = ComposableImageRequest(imageUri) {
        placeholder(Res.drawable.placeholder)
        error(Res.drawable.error)
        crossfade()
        // There is a lot more...
    },
    contentDescription = "photo"
)

Image(
    painter = rememberAsyncImagePainter(
        request = ComposableImageRequest(imageUri) {
            placeholder(Res.drawable.placeholder)
            error(Res.drawable.error)
            crossfade()
            // There is a lot more...
        }
    ),
    contentDescription = "photo"
)

Tip

placeholder(Res.drawable.placeholder) needs to import the sketch-compose-resources module

Android View:

// val imageUri = "/sdcard/download/image.jpg"
// val imageUri = "asset://image.jpg"
// val imageUri = "content://media/external/images/media/88484"
val imageUri = "https://www.sample.com/image.jpg"

imageView.loadImage(imageUri)

imageView.loadImage(imageUri) {
    placeholder(R.drawable.placeholder)
    error(R.drawable.error)
    crossfade()
    // There is a lot more...
}

val request = ImageRequest(context, imageUri) {
    placeholder(R.drawable.placeholder)
    error(R.drawable.error)
    crossfade()
    target(imageView)
    // There is a lot more...
}
context.sketch.enqueue(request)

For more information about Uri, image types, platform differences, Sketch customization, ImageRequest, etc., please view the 《Getting Started》 document

Documents

Basic functions:

• Get Started
• Compose
• AnimatedImage: GIF、WEBP、HEIF
• Resize: Modify the image size
• Transformation: Transformation image
• Transition: Display images in cool transitions
• StateImage: Placeholder and error images
• Listener: Listen for request status and download progress
• DownloadCache: Understand download caching to avoid repeated downloads
• ResultCache: Understand result caching to avoid duplicate conversions
• MemoryCache: Understand memory caching to avoid repeated loading
• Fetcher: Learn about Fetcher and extend new URI types
• Decode: Understand the decoding process of Sketch
• Target: Apply the load results to the target
• HttpStack: Learn about the HTTP section and using okhttp
• SVG: Decode SVG still images
• VideoFrames: Decode video frames
• ExifOrientation: Correct the image orientation
• ImageOptions: Manage image configurations in a unified manner
• RequestInterceptor: Intercept ImageRequest
• Preload images into memory
• Download images
• Lifecycle
• Log

Featured functions:

• SketchImageView: Configure the request through XML attributes
• Improve the clarity of long images in grid lists
• Displays the download progress
• Displays the image type corner
• Pause image downloads on cellular data to save data
• The list slides to pause the loading of images
• Displays an icon for an apk file or installed app

Change log

Please review the CHANGELOG.md file

About version 4.0

• The maven groupId is upgraded to io.github.panpf.sketch4, so versions 2.* and 3.* will not prompt for upgrade
• Version 4.0 is specially built for Compose Multiplatform, so there are many breaking changes in the API, please upgrade with caution
• Version 4.0 has made a lot of simplifications and is much simpler than version 3.0, please check the update log for details
• Android minimum API raised to API 21
• Kotlin version upgraded to 2.0.0

Special thanks

• coil-kt/coil: Sketch uses some code from Coil, including framework, compose and sketch-animated movie part
• koral--/android-gif-drawable: animated-koralgif
• wseemann/FFmpegMediaMetadataRetriever: video-ffmpeg
• BigBadaboom/androidsvg: svg

Run source code

Prepare the environment:

1. Android Studio: Koala+ (2024.1.1+)
2. JDK: 17+
3. Use kdoctor to check the running environment and follow the prompts to install the required software
4. Android Studio installs the Kotlin Multiplatform and Compose Multiplatform IDE Supportplugins

Run the sample app:

1. Clone the project and open it using Android Studio
2. The running configurations of each platform have been added to the .run directory. After synchronization is completed, directly select the running configuration of the corresponding platform in the running configuration drop-down box at the top of Android Studio and click Run.
3. The running configuration of the ios platform requires you to manually create it according to the template, as follows:
   1. Copy the .run/iosSample.run.template.xml file and remove the .template suffix. The .ignore file has been configured to ignore iosSample.run.xml
   2. Click Edit Configurations in the run configuration drop-down box at the top, select iosSample and then configure Execute target

My Projects

The following are my other open source projects. If you are interested, you can learn about them:

• zoomimage: Library for zoom images, supported Android View, Compose and Compose Multiplatform; supported double-click zoom, One or two fingers gesture zoom, single-finger drag, inertial sliding, positioning, rotation, super-large image subsampling and other functions.
• assembly-adapter: A library on Android that provides multi-type Item implementations for various adapters. Incidentally, it also provides the most powerful divider for RecyclerView.
• sticky-item-decoration: RecyclerView sticky item implementation

License

Apache 2.0. See the LICENSE file for details.