[wpilib] Add hex string constructor to Color and Color8Bit

wpilibc/src/main/native/include/frc/util/Color.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <algorithm>
+#include <stdexcept>
 #include <string>
 
 namespace frc {
@@ -811,6 +812,23 @@ class Color {
     }
   }
 
+  /**
+   * Create a Color from a hex string. Throws an exception if the Hex String is
+   * invalid.
+   *
+   * @param hexString a string of the format <code>#RRGGBB</code>
+   * @return Color object from hex string.
+   */
+  static constexpr Color FromHexString(std::string hexString) {
+    if (hexString.length() != 7 || !hexString.starts_with("#")) {
+      throw std::invalid_argument("Invalid Hex String for Color");
+    }
+
+    int r, g, b;
+    std::sscanf(hexString.c_str(), "#%02x%02x%02x", &r, &g, &b);
+    return Color(r / 255, g / 255, b / 255);
+  }
+
   /**
    * Return this color represented as a hex string.
    *

wpilibc/src/main/native/include/frc/util/Color8Bit.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <algorithm>
+#include <stdexcept>
 #include <string>
 
 #include "Color.h"
@@ -44,6 +45,23 @@ class Color8Bit {
     return Color(red / 255.0, green / 255.0, blue / 255.0);
   }
 
+  /**
+   * Create a Color8Bit from a hex string. Throws an exception if the Hex String
+   * is invalid.
+   *
+   * @param hexString a string of the format <code>#RRGGBB</code>
+   * @return Color8Bit object from hex string.
+   */
+  static constexpr Color8Bit FromHexString(std::string hexString) {
+    if (hexString.length() != 7 || !hexString.starts_with("#")) {
+      throw std::invalid_argument("Invalid Hex String for Color");
+    }
+
+    int r, g, b;
+    std::sscanf(hexString.c_str(), "#%02x%02x%02x", &r, &g, &b);
+    return Color8Bit(r, g, b);
+  }
+
   constexpr bool operator==(const Color8Bit&) const = default;
 
   /**

wpilibj/src/main/java/edu/wpi/first/wpilibj/util/Color.java

@@ -115,6 +115,22 @@ public static Color fromHSV(int h, int s, int v) {
     }
   }
 
+  /**
+   * Create a Color from a hex string. Throws an exception if the Hex String is invalid.
+   *
+   * @param hexString a string of the format <code>#RRGGBB</code>
+   * @return Color object from hex string.
+   */
+  public static Color fromHexString(String hexString) {
+    if (hexString.length() != 7 || !hexString.startsWith("#"))
+      throw new IllegalArgumentException("Invalid Hex String");
+
+    return new Color(
+        Integer.valueOf(hexString.substring(1, 3), 16) / 255.0,
+        Integer.valueOf(hexString.substring(3, 5), 16) / 255.0,
+        Integer.valueOf(hexString.substring(5, 7), 16) / 255.0);
+  }
+
   @Override
   public boolean equals(Object other) {
     if (this == other) {

wpilibj/src/main/java/edu/wpi/first/wpilibj/util/Color8Bit.java

@@ -36,6 +36,22 @@ public Color8Bit(Color color) {
     this((int) (color.red * 255), (int) (color.green * 255), (int) (color.blue * 255));
   }
 
+  /**
+   * Create a Color8Bit from a hex string. Throws an exception if the Hex String is invalid.
+   *
+   * @param hexString a string of the format <code>#RRGGBB</code>
+   * @return Color8Bit object from hex string.
+   */
+  public static Color8Bit fromHexString(String hexString) {
+    if (hexString.length() != 7 || !hexString.startsWith("#"))
+      throw new IllegalArgumentException("Invalid Hex String");
+
+    return new Color8Bit(
+        Integer.valueOf(hexString.substring(1, 3), 16),
+        Integer.valueOf(hexString.substring(3, 5), 16),
+        Integer.valueOf(hexString.substring(5, 7), 16));
+  }
+
   @Override
   public boolean equals(Object other) {
     if (this == other) {