[wpilib] MechanismLigament2d: Add getters for color and line weight (#3947)

Also add missing locking in C++.

wpilibc/src/main/native/cpp/smartdashboard/MechanismLigament2d.cpp

@@ -49,7 +49,20 @@ void MechanismLigament2d::SetLineWeight(double lineWidth) {
   Flush();
 }
 
+Color8Bit MechanismLigament2d::GetColor() {
+  std::scoped_lock lock(m_mutex);
+  if (m_colorEntry) {
+    auto color = m_colorEntry.GetString("");
+    std::strncpy(m_color, color.c_str(), sizeof(m_color));
+    m_color[sizeof(m_color) - 1] = '\0';
+  }
+  unsigned int r = 0, g = 0, b = 0;
+  std::sscanf(m_color, "#%02X%02X%02X", &r, &g, &b);
+  return {static_cast<int>(r), static_cast<int>(g), static_cast<int>(b)};
+}
+
 double MechanismLigament2d::GetAngle() {
+  std::scoped_lock lock(m_mutex);
   if (m_angleEntry) {
     m_angle = m_angleEntry.GetDouble(0.0);
   }
@@ -57,12 +70,21 @@ double MechanismLigament2d::GetAngle() {
 }
 
 double MechanismLigament2d::GetLength() {
+  std::scoped_lock lock(m_mutex);
   if (m_lengthEntry) {
     m_length = m_lengthEntry.GetDouble(0.0);
   }
   return m_length;
 }
 
+double MechanismLigament2d::GetLineWeight() {
+  std::scoped_lock lock(m_mutex);
+  if (m_weightEntry) {
+    m_weight = m_weightEntry.GetDouble(0.0);
+  }
+  return m_weight;
+}
+
 void MechanismLigament2d::SetLength(double length) {
   std::scoped_lock lock(m_mutex);
   m_length = length;

wpilibc/src/main/native/include/frc/smartdashboard/MechanismLigament2d.h

@@ -34,7 +34,14 @@ class MechanismLigament2d : public MechanismObject2d {
    *
    * @param color the color of the line
    */
-  void SetColor(const frc::Color8Bit& color);
+  void SetColor(const Color8Bit& color);
+
+  /**
+   * Get the ligament color.
+   *
+   * @return the color of the line
+   */
+  Color8Bit GetColor();
 
   /**
    * Set the ligament's length.
@@ -71,6 +78,13 @@ class MechanismLigament2d : public MechanismObject2d {
    */
   void SetLineWeight(double lineWidth);
 
+  /**
+   * Get the line thickness.
+   *
+   * @return the line thickness
+   */
+  double GetLineWeight();
+
  protected:
   void UpdateEntries(std::shared_ptr<nt::NetworkTable> table) override;