Initial commit

src/main/kotlin/nya/kitsunyan/foxydroid/utility/extension/Text.kt

@@ -0,0 +1,59 @@
+@file:Suppress("PackageDirectoryMismatch")
+package nya.kitsunyan.foxydroid.utility.extension.text
+
+import android.util.Log
+import java.util.Locale
+
+fun <T: CharSequence> T.nullIfEmpty(): T? {
+  return if (isNullOrEmpty()) null else this
+}
+
+private val sizeFormats = listOf("%.0f B", "%.0f kB", "%.1f MB", "%.2f GB")
+
+fun Long.formatSize(): String {
+  val (size, index) = generateSequence(Pair(this.toFloat(), 0)) { (size, index) -> if (size >= 1000f)
+    Pair(size / 1000f, index + 1) else null }.take(sizeFormats.size).last()
+  return sizeFormats[index].format(Locale.US, size)
+}
+
+fun Char.halfByte(): Int {
+  return when (this) {
+    in '0' .. '9' -> this - '0'
+    in 'a' .. 'f' -> this - 'a' + 10
+    in 'A' .. 'F' -> this - 'A' + 10
+    else -> -1
+  }
+}
+
+fun CharSequence.unhex(): ByteArray? {
+  return if (length % 2 == 0) {
+    val ints = windowed(2, 2, false).map {
+      val high = it[0].halfByte()
+      val low = it[1].halfByte()
+      if (high >= 0 && low >= 0) {
+        (high shl 4) or low
+      } else {
+        -1
+      }
+    }
+    if (ints.any { it < 0 }) null else ints.map { it.toByte() }.toByteArray()
+  } else {
+    null
+  }
+}
+
+fun ByteArray.hex(): String {
+  val builder = StringBuilder()
+  for (byte in this) {
+    builder.append("%02x".format(Locale.US, byte.toInt() and 0xff))
+  }
+  return builder.toString()
+}
+
+fun Any.debug(message: String) {
+  val tag = this::class.java.name.let {
+    val index = it.lastIndexOf('.')
+    if (index >= 0) it.substring(index + 1) else it
+  }.replace('$', '.')
+  Log.d(tag, message)
+}