Add a unique colors list to the palettes for use by heatmaps.

atlas-chart/src/main/scala/com/netflix/atlas/chart/model/Palette.scala

@@ -18,43 +18,39 @@ package com.netflix.atlas.chart.model
 import java.awt.Color
 import java.io.FileNotFoundException
 import java.util.concurrent.ConcurrentHashMap
-
 import com.netflix.atlas.chart.Colors
 import com.netflix.atlas.core.util.Strings
 
-case class Palette(name: String, colors: Int => Color) {
+import scala.collection.immutable.ArraySeq
 
-  def withAlpha(alpha: Int): Palette = {
+case class Palette(name: String, colorArray: ArraySeq[Color]) {
 
-    def f(i: Int): Color = {
-      val c = colors(i)
-      new Color(c.getRed, c.getGreen, c.getBlue, alpha)
-    }
-    Palette(name, f)
+  override def equals(obj: Any): Boolean = {
+    if (obj == null) return false
+    if (!obj.isInstanceOf[Palette]) return false
+    val other = obj.asInstanceOf[Palette]
+    if (!name.equals(other.name)) return false
+    colorArray.equals(other.colorArray)
   }
 
-  def withVisionType(vision: VisionType): Palette = {
+  def withAlpha(alpha: Int): Palette =
+    Palette(name, colorArray.map(c => new Color(c.getRed, c.getGreen, c.getBlue, alpha)))
 
-    def f(i: Int): Color = {
-      val c = colors(i)
-      vision.convert(c)
-    }
-    Palette(s"${vision.name}_$name", f)
-  }
+  def withVisionType(vision: VisionType): Palette =
+    Palette(s"${vision.name}_$name", colorArray.map(vision.convert(_)))
 
   /**
     * Convert colors from another palette into grayscale. For information about the conversion
     * see: http://www.johndcook.com/blog/2009/08/24/algorithms-convert-color-grayscale/.
     */
-  def asGrayscale: Palette = {
-
-    def f(i: Int): Color = {
-      val c = colors(i)
-      val v = (0.21 * c.getRed + 0.72 * c.getGreen + 0.07 * c.getBlue).toInt
-      new Color(v, v, v, c.getAlpha)
-    }
-    Palette(s"grayscale_$name", f)
-  }
+  def asGrayscale: Palette =
+    Palette(
+      s"grayscale_$name",
+      colorArray.map { c =>
+        val v = (0.21 * c.getRed + 0.72 * c.getGreen + 0.07 * c.getBlue).toInt
+        new Color(v, v, v, c.getAlpha)
+      }
+    )
 
   def iterator: Iterator[Color] = new Iterator[Color] {
 
@@ -64,9 +60,24 @@ case class Palette(name: String, colors: Int => Color) {
 
     override def next(): Color = {
       pos += 1
-      colors(pos)
+      if (pos >= colorArray.length) pos = 0
+      colorArray(pos)
     }
   }
+
+  /**
+    * Rotates through the colors in the palette based on the index, returning a
+    * deterministic color.
+    *
+    * @param i
+    *   A positive integer value.
+    * @return
+    *   A deterministic color in the palette.
+    */
+  def colors(i: Int): Color = {
+    val index = math.abs(i) % colorArray.length
+    colorArray(index)
+  }
 }
 
 object Palette {
@@ -121,7 +132,7 @@ object Palette {
 
   def fromArray(name: String, colors: Array[Color]): Palette = {
     require(colors.nonEmpty, "palette must contain at least one color")
-    Palette(name, i => colors(math.abs(i) % colors.length))
+    Palette(name, ArraySeq.from(colors))
   }
 
   /**
@@ -143,7 +154,7 @@ object Palette {
   }
 
   def singleColor(c: Color): Palette = {
-    Palette("%08X".format(c.getRGB), _ => c)
+    Palette("%08X".format(c.getRGB), ArraySeq(c))
   }
 
   def brighter(c: Color, n: Int): Palette = {

atlas-chart/src/test/scala/com/netflix/atlas/chart/model/PaletteSuite.scala

@@ -36,19 +36,22 @@ class PaletteSuite extends FunSuite {
   test("colors:f00") {
     val p = Palette.create("colors:f00")
     assertEquals(p.colors(0), Color.RED)
+    assertEquals(1, p.colorArray.size)
   }
 
   test("colors:f00,00ff00") {
     val p = Palette.create("colors:f00,00ff00")
     assertEquals(p.colors(0), Color.RED)
     assertEquals(p.colors(1), Color.GREEN)
+    assertEquals(2, p.colorArray.size)
   }
 
   test("colors:f00,00ff00,ff0000ff") {
     val p = Palette.create("colors:f00,00ff00,ff0000ff")
     assertEquals(p.colors(0), Color.RED)
     assertEquals(p.colors(1), Color.GREEN)
     assertEquals(p.colors(2), Color.BLUE)
+    assertEquals(3, p.colorArray.size)
   }
 
   test("(,)") {
@@ -66,24 +69,28 @@ class PaletteSuite extends FunSuite {
   test("(,f00,)") {
     val p = Palette.create("(,f00,)")
     assertEquals(p.colors(0), Color.RED)
+    assertEquals(1, p.colorArray.size)
   }
 
   test("(,f00,00ff00,)") {
     val p = Palette.create("(,f00,00ff00,)")
     assertEquals(p.colors(0), Color.RED)
     assertEquals(p.colors(1), Color.GREEN)
+    assertEquals(2, p.colorArray.size)
   }
 
   test("(,f00,00ff00,ff0000ff,)") {
     val p = Palette.create("(,f00,00ff00,ff0000ff,)")
     assertEquals(p.colors(0), Color.RED)
     assertEquals(p.colors(1), Color.GREEN)
     assertEquals(p.colors(2), Color.BLUE)
+    assertEquals(3, p.colorArray.size)
   }
 
   test("armytage") {
     val p = Palette.create("armytage")
     assertEquals(p.colors(0), new Color(0, 117, 220))
+    assertEquals(24, p.colorArray.size)
   }
 
   test("foo") {