Implement HSV/HSL color decoding and use Colormath lib for hex decoding

iamgio · Sep 18, 2024 · 19e4977 · 19e4977
1 parent af5b3b5
commit 19e4977
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Showing 9 changed files with 128 additions and 33 deletions.
diff --git a/core/build.gradle.kts b/core/build.gradle.kts
@@ -7,4 +7,5 @@ dependencies {
     testImplementation(kotlin("test"))
     implementation("org.apache.logging.log4j:log4j-core:2.23.1")
     implementation("org.apache.commons:commons-text:1.11.0")
+    implementation("com.github.ajalt.colormath:colormath:3.6.0")
 }
diff --git a/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/Color.kt b/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/Color.kt
@@ -14,15 +14,22 @@ data class Color(
     val red: Int,
     val green: Int,
     val blue: Int,
-    val alpha: Double = 1.0,
+    val alpha: Double = MAX_ALPHA,
 ) : RenderRepresentable {
     override fun <T> accept(visitor: RenderRepresentableVisitor<T>) = visitor.visit(this)
 
     /**
      * @see eu.iamgio.quarkdown.misc.color.decoder.decode
      */
     companion object {
+        /**
+         * Maximum value for RGB components.
+         */
         const val MAX_RGB = 255
+
+        /**
+         * Maximum value for alpha component.
+         */
         const val MAX_ALPHA = 1.0
     }
 }
diff --git a/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/ColorDecoder.kt b/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/ColorDecoder.kt
@@ -5,7 +5,7 @@ import eu.iamgio.quarkdown.misc.color.Color
 /**
  * A strategy to decode a [Color] from a raw string.
  */
-sealed interface ColorDecoder {
+interface ColorDecoder {
     /**
      * Decodes a [Color] from a raw string.
      * @param raw raw string
@@ -22,5 +22,12 @@ sealed interface ColorDecoder {
  */
 fun Color.Companion.decode(
     raw: String,
-    vararg decoders: ColorDecoder = arrayOf(HexColorDecoder, RgbColorDecoder, RgbaColorDecoder, ColorNameDecoder),
+    vararg decoders: ColorDecoder =
+        arrayOf(
+            HexColorDecoder,
+            RgbColorDecoder,
+            RgbaColorDecoder,
+            HsvHslColorDecoder,
+            NamedColorDecoder,
+        ),
 ): Color? = decoders.firstNotNullOfOrNull { it.decode(raw) }
diff --git a/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/ColorDecoderUtils.kt b/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/ColorDecoderUtils.kt
@@ -0,0 +1,28 @@
+package eu.iamgio.quarkdown.misc.color.decoder
+
+import eu.iamgio.quarkdown.misc.color.Color
+
+/**
+ * @param awtColor Java AWT color
+ * @return a [Color] from a Java AWT color
+ */
+fun Color.Companion.from(awtColor: java.awt.Color): Color =
+    Color(
+        red = awtColor.red,
+        green = awtColor.green,
+        blue = awtColor.blue,
+        alpha = awtColor.alpha.toDouble() / 255,
+    )
+
+/**
+ * @param colormathColor Colormath color
+ * @return a [Color] from a Colormath color
+ */
+fun Color.Companion.from(colormathColor: com.github.ajalt.colormath.Color): Color =
+    with(colormathColor.toSRGB()) {
+        Color(
+            red = (r * MAX_RGB).toInt(),
+            green = (g * MAX_RGB).toInt(),
+            blue = (b * MAX_RGB).toInt(),
+        )
+    }
diff --git a/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/HexColorDecoder.kt b/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/HexColorDecoder.kt
@@ -1,5 +1,6 @@
 package eu.iamgio.quarkdown.misc.color.decoder
 
+import com.github.ajalt.colormath.model.RGB
 import eu.iamgio.quarkdown.misc.color.Color
 
 /**
@@ -8,15 +9,10 @@ import eu.iamgio.quarkdown.misc.color.Color
 object HexColorDecoder : ColorDecoder {
     override fun decode(raw: String): Color? {
         if (raw.firstOrNull() != '#') return null
-        val hex = raw.drop(1) // The '#' character is skipped.
-
+        // Converted by Colormath.
         return try {
-            Color(
-                red = hex.substring(0, 2).toInt(16),
-                green = hex.substring(2, 4).toInt(16),
-                blue = hex.substring(4, 6).toInt(16),
-            )
-        } catch (e: NumberFormatException) {
+            Color.from(RGB(raw))
+        } catch (e: IllegalArgumentException) {
             null
         }
     }

diff --git a/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/HsvHslColorDecoder.kt b/core/src/main/kotlin/eu/iamgio/quarkdown/misc/color/decoder/HsvHslColorDecoder.kt
@@ -0,0 +1,59 @@
+package eu.iamgio.quarkdown.misc.color.decoder
+
+import com.github.ajalt.colormath.model.HSL
+import com.github.ajalt.colormath.model.HSV
+import eu.iamgio.quarkdown.misc.color.Color
+
+/**
+ * Maximum value for the hue component.
+ */
+private const val MAX_HUE = 360
+
+/**
+ * Maximum value for saturation and lightness/value components.
+ */
+private const val MAX_SVL = 100
+
+/**
+ * Decodes a [Color] from an HSV or HSL string (e.g. `hsv(208, 70, 66)` or `hsl(208, 54, 43)`).
+ */
+object HsvHslColorDecoder : ColorDecoder {
+    override fun decode(raw: String): Color? {
+        if (!raw.startsWith("hsl(") && !raw.startsWith("hsv(")) return null
+
+        // HSL and HSV have the same structure (a degree (0-360) and two percentages (0-100)).
+        for (method in arrayOf('l', 'v')) {
+            val match = Regex("hs$method\\((\\d{1,3}), ?(\\d{1,3}), ?(\\d{1,3})\\)").find(raw) ?: continue
+            val (h, s, lv) =
+                match.destructured.let { (h, s, lv) ->
+                    Triple(
+                        // Hue (0-360).
+                        h.toFloatOrNull()
+                            ?.rem(MAX_HUE), // e.g. 520 % 360 = 160
+                        // Normalized saturation (0-1).
+                        s.toFloatOrNull()
+                            ?.takeIf { it <= MAX_SVL }
+                            ?.div(MAX_SVL), // [0, 100] -> [0, 1]
+                        // Normalized lightness/value (0-1).
+                        lv.toFloatOrNull()
+                            ?.takeIf { it <= MAX_SVL }
+                            ?.div(MAX_SVL), // [0, 100] -> [0, 1]
+                    )
+                }
+
+            if (h == null || s == null || lv == null) continue
+
+            // Colormath color to be converted.
+            val color =
+                when (method) {
+                    'l' -> HSL(h, s, lv)
+                    'v' -> HSV(h, s, lv)
+                    else -> return null // Impossible
+                }
+
+            return Color.from(color)
+        }
+
+        return null
+    }
+}
diff --git a/...wn/misc/color/decoder/ColorNameDecoder.kt → ...n/misc/color/decoder/NamedColorDecoder.kt b/...wn/misc/color/decoder/ColorNameDecoder.kt → ...n/misc/color/decoder/NamedColorDecoder.kt
@@ -7,22 +7,10 @@ import eu.iamgio.quarkdown.misc.color.Color
  * Decodes a [Color] from the name (case-insensitive) of a native [java.awt.Color] color (e.g. `red`)
  * @see java.awt.Color
  */
-object ColorNameDecoder : ColorDecoder {
-    /**
-     * @param awtColor Java AWT color
-     * @return a [Color] from a Java AWT color
-     */
-    private fun fromAWT(awtColor: java.awt.Color): Color =
-        Color(
-            red = awtColor.red,
-            green = awtColor.green,
-            blue = awtColor.blue,
-            alpha = awtColor.alpha.toDouble() / 255,
-        )
-
+object NamedColorDecoder : ColorDecoder {
     override fun decode(raw: String): Color? {
         // Name representation (e.g. red, GREEN, bLuE).
         val awtColor = ReflectionUtils.getConstantByName<java.awt.Color>(raw)
-        return awtColor?.let(::fromAWT)
+        return awtColor?.let { Color.from(it) }
     }
 }
diff --git a/core/src/main/kotlin/eu/iamgio/quarkdown/parser/InlineTokenParser.kt b/core/src/main/kotlin/eu/iamgio/quarkdown/parser/InlineTokenParser.kt
@@ -42,6 +42,7 @@ import eu.iamgio.quarkdown.lexer.tokens.TextSymbolToken
 import eu.iamgio.quarkdown.lexer.tokens.UrlAutolinkToken
 import eu.iamgio.quarkdown.misc.color.Color
 import eu.iamgio.quarkdown.misc.color.decoder.HexColorDecoder
+import eu.iamgio.quarkdown.misc.color.decoder.HsvHslColorDecoder
 import eu.iamgio.quarkdown.misc.color.decoder.RgbColorDecoder
 import eu.iamgio.quarkdown.misc.color.decoder.RgbaColorDecoder
 import eu.iamgio.quarkdown.misc.color.decoder.decode
@@ -228,7 +229,8 @@ class InlineTokenParser(private val context: MutableContext) : InlineTokenVisito
         // If null, no additional content is present.
         val content: CodeSpan.ContentInfo? =
             // Color decoding. Named colors are disabled due to performance reasons.
-            Color.decode(text, HexColorDecoder, RgbColorDecoder, RgbaColorDecoder)?.let(CodeSpan::ColorContent)
+            Color.decode(text, HexColorDecoder, RgbColorDecoder, RgbaColorDecoder, HsvHslColorDecoder)
+                ?.let(CodeSpan::ColorContent)
 
         return CodeSpan(text, content)
     }

diff --git a/core/src/test/kotlin/eu/iamgio/quarkdown/ValueFactoryTest.kt b/core/src/test/kotlin/eu/iamgio/quarkdown/ValueFactoryTest.kt
@@ -13,6 +13,7 @@ import eu.iamgio.quarkdown.function.value.LambdaValue
 import eu.iamgio.quarkdown.function.value.NumberValue
 import eu.iamgio.quarkdown.function.value.StringValue
 import eu.iamgio.quarkdown.function.value.data.Range
+import eu.iamgio.quarkdown.function.value.factory.IllegalRawValueException
 import eu.iamgio.quarkdown.function.value.factory.ValueFactory
 import eu.iamgio.quarkdown.misc.color.Color
 import kotlin.test.Test
@@ -34,7 +35,7 @@ class ValueFactoryTest {
     @Test
     fun number() {
         assertEquals(NumberValue(42), ValueFactory.number("42"))
-        assertEquals(16.3F, ValueFactory.number("16.3")?.unwrappedValue)
+        assertEquals(16.3F, ValueFactory.number("16.3").unwrappedValue)
         assertFails { ValueFactory.number("num") }
         assertFails { ValueFactory.number("16.3.2") }
     }
@@ -120,17 +121,23 @@ class ValueFactoryTest {
         assertEquals(Color(145, 168, 50), ValueFactory.color("rgb(145, 168, 50)").unwrappedValue)
         assertEquals(Color(120, 111, 93), ValueFactory.color("rgb(120,111,93)").unwrappedValue)
         assertEquals(Color(120, 111, 93, 0.5), ValueFactory.color("rgba(120, 111, 93, 0.5)").unwrappedValue)
-        assertFails { ValueFactory.color("abc") }
-        assertFails { ValueFactory.color("#hello") }
-        assertFails { ValueFactory.color("rgb(300, 200, 200)") }
-        assertFails { ValueFactory.color("rgb(300, 200, 200, 0.8)") }
-        assertFails { ValueFactory.color("rgba(100, 200, 200, 1.5)") }
+        assertEquals(Color(50, 113, 168), ValueFactory.color("hsv(208, 70, 66)").unwrappedValue)
+        assertEquals(Color(50, 113, 168), ValueFactory.color("hsv(568, 70, 66)").unwrappedValue)
+        assertEquals(Color(50, 113, 168), ValueFactory.color("hsl(208, 54, 43)").unwrappedValue)
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("abc") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("#hello") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("rgb(300, 200, 200)") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("rgb(300, 200, 200, 0.8)") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("rgba(100, 200, 200, 1.5)") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("hsl(120, 105, 20)") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("hsv(120, 10,200)") }
+        assertFailsWith<IllegalRawValueException> { ValueFactory.color("hsv(20, 10, 50, 10)") }
     }
 
     @Test
     fun enum() {
         @Suppress("UNCHECKED_CAST")
-        val values = Size.Unit.values() as Array<Enum<*>>
+        val values = Size.Unit.entries.toTypedArray() as Array<Enum<*>>
 
         assertEquals(Size.Unit.PX, ValueFactory.enum("px", values)!!.unwrappedValue)
         assertEquals(Size.Unit.CM, ValueFactory.enum("CM", values)!!.unwrappedValue)