Add resource cache

core/src/main/java/com/kylecorry/andromeda/core/system/ResourceCache.kt

@@ -0,0 +1,43 @@
+package com.kylecorry.andromeda.core.system
+
+import android.content.res.Resources
+import android.os.Build
+import java.util.*
+
+class ResourceCache(private val resources: Resources) {
+
+    private var lastLocale = getLocale()
+    private val cache = mutableMapOf<Int, String>()
+    private val lock = Any()
+
+    fun getString(id: Int): String {
+        synchronized(lock) {
+            val currentLocale = getLocale()
+            if (lastLocale != currentLocale) {
+                cache.clear()
+                lastLocale = currentLocale
+            }
+
+            if (cache.containsKey(id)) {
+                return cache[id]!!
+            }
+            val string = resources.getString(id)
+            cache[id] = string
+            return string
+        }
+    }
+
+    fun getString(id: Int, vararg formatArgs: Any): String {
+        val raw = getString(id)
+        return String.format(lastLocale, raw, *formatArgs)
+    }
+
+    private fun getLocale(): Locale {
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            resources.configuration.locales[0]
+        } else {
+            @Suppress("DEPRECATION")
+            resources.configuration.locale
+        }
+    }
+}