android utils

bitmapUtils.md

URL

fun URL.toBitmap(): Bitmap? {
    return try {
        BitmapFactory.decodeStream(openStream())
    } catch (e: IOException) {
        null
    }
}

fun Bitmap.saveToInternalStorage(context: Context): Uri? {
    val wrapper = ContextWrapper(context)
    var file = wrapper.getDir("images", Context.MODE_PRIVATE)
    file = File(file, "${UUID.randomUUID()}.jpg")
    return try {
        FileOutputStream(file).use { stream ->
            compress(Bitmap.CompressFormat.JPEG, 100, stream)
            stream.flush()
        }
        Uri.parse(file.absolutePath)
    } catch (e: IOException) {
        e.printStackTrace()
        null
    }
}

NavBackStackEntryExt.kt

/**
 * If the lifecycle is not resumed it means this NavBackStackEntry already processed a nav event.
 *
 * This is used to de-duplicate navigation events.
 */
private fun NavBackStackEntry.lifecycleIsResumed() =
    this.lifecycle.currentState == Lifecycle.State.RESUMED

NetworkStatusChecker.kt

/**
 * Checks the Internet connection and performs an action if it's active.
 */
class NetworkStatusChecker(private val connectivityManager: ConnectivityManager?) {

    inline fun performIfConnectedToInternet(action: () -> Unit) {
        if (hasInternetConnection()) {
            action()
        }
    }

    fun hasInternetConnection(): Boolean {
        val network = connectivityManager?.activeNetwork ?: return false
        val capabilities = connectivityManager.getNetworkCapabilities(network) ?: return false

        return capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) ||
            capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) ||
            capabilities.hasTransport(NetworkCapabilities.TRANSPORT_VPN)
    }
}

// check this out instead https://stackoverflow.com/questions/53532406/activenetworkinfo-type-is-deprecated-in-api-level-28

PrivateKeyPemUtils.kt

import okio.ByteString.Companion.decodeBase64
import org.spongycastle.util.encoders.Base64
import java.security.KeyFactory
import java.security.PrivateKey
import java.security.spec.PKCS8EncodedKeySpec

private const val prefix = "-----BEGIN PRIVATE KEY-----\n"
private const val postfix = "\n-----END PRIVATE KEY-----"

fun PrivateKey.toPkcs8Pem(): String {
    val privateKeyBase64 = String(Base64.encode(this.encoded))
    return privateKeyBase64.chunked(64).joinToString(
        separator = "\n",
        prefix = prefix,
        postfix = postfix
    )
}

fun String.toPrivateKey(): PrivateKey {
    return this
        .replace(prefix, "")
        .replace(postfix, "")
        .decodeBase64()?.let { byteString ->
            KeyFactory.getInstance("RSA").generatePrivate(
                PKCS8EncodedKeySpec(byteString.toByteArray())
            )
        } ?: throw IllegalStateException("Failed to parse PrivateKey")
}

uri.md

Uri

encode

Uri.encode(someText)

{SomeClass}Ext.kt
remember{Some}State()