BAEL-2760

core-kotlin-2/src/main/kotlin/com/baeldung/range/CustomColor.kt

@@ -0,0 +1,56 @@
+package com.baeldung.range
+
+import java.lang.IllegalStateException
+
+class CustomColor(val rgb: Int): Comparable<CustomColor> {
+
+    override fun compareTo(other: CustomColor): Int {
+        return this.rgb.compareTo(other.rgb)
+    }
+
+    operator fun rangeTo(that: CustomColor) = ColorRange(this,that)
+
+    operator fun inc(): CustomColor {
+        return CustomColor(rgb + 1)
+    }
+
+    init {
+        if(rgb < 0x000000 || rgb > 0xFFFFFF){
+            throw IllegalStateException("RGB must be between 0 and 16777215")
+        }
+    }
+
+    override fun toString(): String {
+        return "CustomColor(rgb=$rgb)"
+    }
+}
+class ColorRange(override val start: CustomColor,
+                override val endInclusive: CustomColor) : ClosedRange<CustomColor>, Iterable<CustomColor>{
+
+    override fun iterator(): Iterator<CustomColor> {
+        return ColorIterator(start, endInclusive)
+    }
+}
+
+class ColorIterator(val start: CustomColor, val endInclusive: CustomColor) : Iterator<CustomColor> {
+
+    var initValue = start
+
+    override fun hasNext(): Boolean {
+        return initValue <= endInclusive
+    }
+
+    override fun next(): CustomColor {
+        return initValue++
+    }
+}
+
+fun main(args: Array<String>) {
+    val a = CustomColor(0xABCDEF)
+    val b = CustomColor(-1)
+    val c = CustomColor(0xABCDFF)
+
+    for(color in a..c){
+        println(color)
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/CustomColorTest.kt

@@ -0,0 +1,41 @@
+package com.baeldung.range
+
+import org.junit.Test
+import java.lang.IllegalStateException
+import kotlin.test.assertFailsWith
+import kotlin.test.assertTrue
+
+class CustomColorTest {
+
+    @Test
+    fun testInvalidConstructor(){
+        assertFailsWith(IllegalStateException::class){
+            CustomColor(-1)
+        }
+    }
+
+    @Test
+    fun assertHas10Colors(){
+        assertTrue {
+            val a = CustomColor(1)
+            val b = CustomColor(10)
+            val range = a..b
+            for(cc in range){
+                println(cc)
+            }
+            range.toList().size == 10
+        }
+    }
+
+    @Test
+    fun assertContains0xCCCCCC(){
+        assertTrue {
+            val a = CustomColor(0xBBBBBB)
+            val b = CustomColor(0xDDDDDD)
+            val range = a..b
+            range.contains(CustomColor(0xCCCCCC))
+        }
+    }
+
+}
+