feature(api): Speedup *Color#asHexString

api/src/main/java/net/kyori/adventure/text/format/ShadowColor.java

@@ -182,12 +182,7 @@ static ShadowColor shadowColor(final ARGBLike argb) {
    * @since 4.18.0
    */
   default String asHexString() {
-    final int argb = this.value();
-    final int a = (argb >> 24) & 0xFF;
-    final int r = (argb >> 16) & 0xFF;
-    final int g = (argb >> 8) & 0xFF;
-    final int b = argb & 0xFF;
-    return String.format("#%02X%02X%02X%02X", r, g, b, a);
+    return ShadowColorImpl.asHexString(this.value());
   }
 
   /**

api/src/main/java/net/kyori/adventure/text/format/ShadowColorImpl.java

@@ -23,8 +23,22 @@
  */
 package net.kyori.adventure.text.format;
 
+import java.util.HexFormat;
+
 // value is argb
 record ShadowColorImpl(int value) implements ShadowColor {
   static final int NONE_VALUE = 0;
   static final ShadowColorImpl NONE = new ShadowColorImpl(NONE_VALUE);
+  static final HexFormat HEX_FORMATTER = HexFormat.of().withUpperCase();
+
+  /**
+   * Convert an ARGB value to a hex string in the format of #RRGGBBAA.
+   *
+   * @param argb the ARGB value
+   * @return the uppercase hex string
+   */
+  static String asHexString(final int argb) {
+    final int rgba = Integer.rotateLeft(argb, Byte.SIZE);
+    return '#' + HEX_FORMATTER.toHexDigits(rgba, 8);
+  }
 }

api/src/main/java/net/kyori/adventure/text/format/TextColor.java

@@ -24,7 +24,6 @@
 package net.kyori.adventure.text.format;
 
 import java.util.List;
-import java.util.Locale;
 import net.kyori.adventure.util.HSVLike;
 import net.kyori.adventure.util.RGBLike;
 import org.jetbrains.annotations.Range;
@@ -212,14 +211,7 @@ static TextColor color(final float r, final float g, final float b) {
    * @since 4.0.0
    */
   default String asHexString() {
-    final StringBuilder result = new StringBuilder();
-    result.append(HEX_PREFIX);
-    final String hex = Integer.toHexString(this.value());
-    for (int i = 0; i < 6 - hex.length(); i++) {
-      result.append('0');
-    }
-    result.append(hex);
-    return result.toString().toUpperCase(Locale.ROOT);
+    return TextColorImpl.hexString(this.value());
   }
 
   /**

api/src/main/java/net/kyori/adventure/text/format/TextColorImpl.java

@@ -23,11 +23,13 @@
  */
 package net.kyori.adventure.text.format;
 
+import java.util.HexFormat;
 import net.kyori.adventure.util.HSVLike;
 import org.jetbrains.annotations.Debug;
 
 @Debug.Renderer(text = "asHexString()")
 record TextColorImpl(int value) implements TextColor {
+  private static final HexFormat HEX_FORMATTER = HexFormat.of().withUpperCase();
 
   @Override
   public String toString() {
@@ -50,4 +52,14 @@ static float distance(final HSVLike self, final HSVLike other) {
     final float valueDiff = self.v() - other.v();
     return hueDistance * hueDistance + saturationDiff * saturationDiff + valueDiff * valueDiff;
   }
+
+  /**
+   * Parses a value into an RGB hex string using the format #RRGGBB.
+   *
+   * @param value the value in RRGGBB in the range of 0x0 to 0xffffff
+   * @return an uppercase hex string
+   */
+  public static String hexString(final int value) {
+    return HEX_CHARACTER + HEX_FORMATTER.toHexDigits(value, 6);
+  }
 }

api/src/test/java/net/kyori/adventure/text/format/NamedTextColorTest.java

@@ -55,6 +55,11 @@ void testSimple() {
     assertNearest(NamedTextColor.DARK_GRAY, 0x4c4c4c);
   }
 
+  @Test
+  void testAsHexString() {
+    assertEquals("#FF5555", NamedTextColor.RED.asHexString());
+  }
+
   private static void assertNearest(final NamedTextColor expected, final int value) {
     final NamedTextColor nearest = NamedTextColor.nearestTo(TextColor.color(value));
     assertEquals(expected, nearest);

api/src/test/java/net/kyori/adventure/text/format/ShadowColorTest.java

@@ -87,4 +87,10 @@ void testEquality() {
       )
       .testEquals();
   }
+
+  @Test
+  void testAsHexString() {
+    assertEquals("#AABBCCDD", ShadowColor.shadowColor(0xDDAABBCC).asHexString());
+    assertEquals("#FFFFFFFF", ShadowColor.shadowColor(0xFFFFFFFF).asHexString());
+  }
 }

api/src/test/java/net/kyori/adventure/text/format/TextColorTest.java

@@ -133,4 +133,9 @@ void testCSSHexStringThreeDigit() {
     final TextColor original = TextColor.color(0x77ff11);
     assertEquals(original, TextColor.fromCSSHexString("#7f1"));
   }
+
+  @Test
+  void testAsHexString() {
+    assertEquals("#7F1E2D", TextColor.color(0x7f1e2d).asHexString());
+  }
 }