[glass] Add more widgets (#2947)

This adds the following widgets:
- Speed Controller
- Gyroscope
- Command
- Subsystem
- PIDController
- Scheduler

glass/src/libnt/native/cpp/NTCommandScheduler.cpp

@@ -0,0 +1,55 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "glass/networktables/NTCommandScheduler.h"
+
+#include <iostream>
+
+using namespace glass;
+
+NTCommandSchedulerModel::NTCommandSchedulerModel(wpi::StringRef path)
+    : NTCommandSchedulerModel(nt::GetDefaultInstance(), path) {}
+
+NTCommandSchedulerModel::NTCommandSchedulerModel(NT_Inst instance,
+                                                 wpi::StringRef path)
+    : m_nt(instance),
+      m_name(m_nt.GetEntry(path + "/.name")),
+      m_commands(m_nt.GetEntry(path + "/Names")),
+      m_ids(m_nt.GetEntry(path + "/Ids")),
+      m_cancel(m_nt.GetEntry(path + "/Cancel")),
+      m_nameValue(path.rsplit('/').second) {
+  m_nt.AddListener(m_name);
+  m_nt.AddListener(m_commands);
+  m_nt.AddListener(m_ids);
+  m_nt.AddListener(m_cancel);
+  Update();
+}
+
+void NTCommandSchedulerModel::CancelCommand(size_t index) {
+  if (index < m_idsValue.size())
+    nt::SetEntryValue(
+        m_cancel, nt::NetworkTableValue::MakeDoubleArray({m_idsValue[index]}));
+}
+
+void NTCommandSchedulerModel::Update() {
+  for (auto&& event : m_nt.PollListener()) {
+    if (event.entry == m_name) {
+      if (event.value && event.value->IsString())
+        m_nameValue = event.value->GetString();
+    } else if (event.entry == m_commands) {
+      if (event.value && event.value->IsStringArray())
+        m_commandsValue = event.value->GetStringArray();
+    } else if (event.entry == m_ids) {
+      if (event.value && event.value->IsDoubleArray())
+        m_idsValue = event.value->GetDoubleArray();
+    }
+  }
+}
+
+bool NTCommandSchedulerModel::Exists() {
+  return m_nt.IsConnected() && nt::GetEntryType(m_commands) != NT_UNASSIGNED;
+}