[wpilib] Allow SendableCameraWrappers to take arbitrary URLs (#3850)

Useful for adding cameras that are streamed from a coprocessor

Co-authored-by: Peter Johnson <johnson.peter@gmail.com>
Co-authored-by: Sam Carlberg <sam.carlberg@gmail.com>

wpilibc/src/main/native/include/frc/shuffleboard/SendableCameraWrapper.h

@@ -7,9 +7,13 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #ifndef DYNAMIC_CAMERA_SERVER
 #include <cscore_oo.h>
+#include <fmt/format.h>
+#include <networktables/NetworkTable.h>
+#include <networktables/NetworkTableInstance.h>
 #else
 namespace cs {
 class VideoSource;
@@ -20,6 +24,7 @@ using CS_Source = CS_Handle;  // NOLINT
 
 #include <wpi/sendable/Sendable.h>
 #include <wpi/sendable/SendableHelper.h>
+#include <wpi/span.h>
 
 namespace frc {
 
@@ -28,8 +33,8 @@ class SendableCameraWrapper;
 namespace detail {
 constexpr const char* kProtocol = "camera_server://";
 std::shared_ptr<SendableCameraWrapper>& GetSendableCameraWrapper(
-    CS_Source source);
-void AddToSendableRegistry(wpi::Sendable* sendable, std::string name);
+    std::string_view cameraName);
+void AddToSendableRegistry(wpi::Sendable* sendable, std::string_view name);
 }  // namespace detail
 
 /**
@@ -46,9 +51,9 @@ class SendableCameraWrapper
    * Creates a new sendable wrapper. Private constructor to avoid direct
    * instantiation with multiple wrappers floating around for the same camera.
    *
-   * @param source the source to wrap
+   * @param cameraName the name of the camera to wrap
    */
-  SendableCameraWrapper(CS_Source source, const private_init&);
+  SendableCameraWrapper(std::string_view cameraName, const private_init&);
 
   /**
    * Gets a sendable wrapper object for the given video source, creating the
@@ -61,6 +66,9 @@ class SendableCameraWrapper
   static SendableCameraWrapper& Wrap(const cs::VideoSource& source);
   static SendableCameraWrapper& Wrap(CS_Source source);
 
+  static SendableCameraWrapper& Wrap(std::string_view cameraName,
+                                     wpi::span<const std::string> cameraUrls);
+
   void InitSendable(wpi::SendableBuilder& builder) override;
 
  private:
@@ -68,11 +76,9 @@ class SendableCameraWrapper
 };
 
 #ifndef DYNAMIC_CAMERA_SERVER
-inline SendableCameraWrapper::SendableCameraWrapper(CS_Source source,
+inline SendableCameraWrapper::SendableCameraWrapper(std::string_view name,
                                                     const private_init&)
     : m_uri(detail::kProtocol) {
-  CS_Status status = 0;
-  auto name = cs::GetSourceName(source, &status);
   detail::AddToSendableRegistry(this, name);
   m_uri += name;
 }
@@ -83,12 +89,27 @@ inline SendableCameraWrapper& SendableCameraWrapper::Wrap(
 }
 
 inline SendableCameraWrapper& SendableCameraWrapper::Wrap(CS_Source source) {
-  auto& wrapper = detail::GetSendableCameraWrapper(source);
+  CS_Status status = 0;
+  auto name = cs::GetSourceName(source, &status);
+  auto& wrapper = detail::GetSendableCameraWrapper(name);
   if (!wrapper) {
-    wrapper = std::make_shared<SendableCameraWrapper>(source, private_init{});
+    wrapper = std::make_shared<SendableCameraWrapper>(name, private_init{});
   }
   return *wrapper;
 }
+
+inline SendableCameraWrapper& SendableCameraWrapper::Wrap(
+    std::string_view cameraName, wpi::span<const std::string> cameraUrls) {
+  auto& wrapper = detail::GetSendableCameraWrapper(cameraName);
+  if (!wrapper) {
+    wrapper =
+        std::make_shared<SendableCameraWrapper>(cameraName, private_init{});
+  }
+  auto streams = fmt::format("/CameraPublisher/{}/streams", cameraName);
+  nt::NetworkTableInstance::GetDefault().GetEntry(streams).SetStringArray(
+      cameraUrls);
+  return *wrapper;
+}
 #endif
 
 }  // namespace frc

wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardContainer.h

@@ -127,6 +127,18 @@ class ShuffleboardContainer : public virtual ShuffleboardValue {
    */
   ComplexWidget& Add(std::string_view title, const cs::VideoSource& video);
 
+  /**
+   * Adds a widget to this container to display a video stream.
+   *
+   * @param title      the title of the widget
+   * @param cameraName the name of the streamed camera
+   * @param cameraUrls the URLs with which the dashboard can access the camera
+   * stream
+   * @return a widget to display the camera stream
+   */
+  ComplexWidget& AddCamera(std::string_view title, std::string_view cameraName,
+                           wpi::span<const std::string> cameraUrls);
+
   /**
    * Adds a widget to this container to display the given sendable.
    *
@@ -526,4 +538,10 @@ inline frc::ComplexWidget& frc::ShuffleboardContainer::Add(
     std::string_view title, const cs::VideoSource& video) {
   return Add(title, frc::SendableCameraWrapper::Wrap(video));
 }
+
+inline frc::ComplexWidget& frc::ShuffleboardContainer::AddCamera(
+    std::string_view title, std::string_view cameraName,
+    wpi::span<const std::string> cameraUrls) {
+  return Add(title, frc::SendableCameraWrapper::Wrap(cameraName, cameraUrls));
+}
 #endif