KotlinPinBoard

An async remote resource downloading library with sample pin board application using Android Jetpack written in Kotlin. ** Read the Wiki to know more about the project.**

Technologies

• Android
• Kotlin
• Jetpack
• MVVM
• Repository Pattern
• LiveData
• Coroutine
• Retrofit
• Navigation Component
• Paging Library
• Android Data Binding
• Androidx Testing
• Mockito

Modules:

1. lib_pin_downloader (Async Downloader library)

Features:

• Download Bitmap
• Download Json and serialize to kotlin data object
• Abstraction for supporting future data types
• Cache Data in LruCache
• If data is present in the cache then return from cache otherwise fetch from remote service and add to cache
• Uses 1/8 of the total allocated memory for caching and evicts less frequent item when cache reaches its limit
• Local Unit Test with 100% test coverage

Usage:

The root build.gradle should look like

allprojects {
    repositories {
        google()
        jcenter()
        maven { url "https://jitpack.io" }
    }
}

and in the app module build.gradle add following

dependencies {
    implementation 'com.github.Roaim:KotlinPinBoard:v2.5'
}

To download bitmap image :

fun downloadAndDisplayBitmap(lifecycleOwner: LifecycleOwner, imageView: ImageView?, url : String) {
        val bitmapPinDownloader = BitmapPinDownloader()
        bitmapPinDownloader.download(url).observe(lifecycleOwner, Observer {
            imageView?.setImageBitmap(it)
        })
}

To download json :

fun downloadJson(lifecycleOwner: LifecycleOwner, url: String) {
        JsonPinDownloader().download(url)
            .observe(lifecycleOwner, Observer { jsonElement ->
                // process jsonElement
                    ...
                // or convert it to pojo
                val poJo = jsonElement?.toPoJo<Unit>(PojoModel::class.java)
                    ...
         })
}

2. sample_pinboard_app (Sample Gallery App)

Features:

• Uses PinDownloader library module to load json and bitmap files
• Display images in Gallery by RecyclerView and PagedListAdapter
• Load more data when scrolling to the end of the list
• Upon clicking on an item navigate to full image screen with the help of Navigation Component

Preview:

Yet to come

• Efficiently decoding Bitmap by following Official documentation
• Make PinDownloader<T> return a sealed class object Pin<T> containing Loading, Success, Failure data classes instead of returning just T
• Publish the library to Jitpack.io/Bintray
• LocalUnitTests, IntegrationTests and UITests