Adds TriState JNI entry point (#938)

Also adds missing sim TriState DIO HAL call, and a ToDo for later

hal/src/main/native/sim/DIO.cpp

@@ -198,6 +198,23 @@ void HAL_SetDIO(HAL_DigitalHandle dioPortHandle, HAL_Bool value,
   SimDIOData[port->channel].SetValue(value);
 }
 
+/**
+ * Set direction of a DIO channel.
+ *
+ * @param channel The Digital I/O channel
+ * @param input true to set input, false for output
+ */
+void HAL_SetDIODirection(HAL_DigitalHandle dioPortHandle, HAL_Bool input,
+                         int32_t* status) {
+  auto port = digitalChannelHandles->Get(dioPortHandle, HAL_HandleEnum::DIO);
+  if (port == nullptr) {
+    *status = HAL_HANDLE_ERROR;
+    return;
+  }
+
+  SimDIOData[port->channel].SetIsInput(input);
+}
+
 /**
  * Read a digital I/O bit from the FPGA.
  * Get a single value from a digital I/O channel.

wpilibj/src/main/java/edu/wpi/first/wpilibj/hal/DIOJNI.java

@@ -15,8 +15,11 @@ public class DIOJNI extends JNIWrapper {
 
   public static native void freeDIOPort(int dioPortHandle);
 
+  // TODO(Thad): Switch this to use boolean
   public static native void setDIO(int dioPortHandle, short value);
 
+  public static native void setDIODirection(int dioPortHandle, boolean input);
+
   public static native boolean getDIO(int dioPortHandle);
 
   public static native boolean getDIODirection(int dioPortHandle);

wpilibj/src/main/native/cpp/DIOJNI.cpp

@@ -90,6 +90,22 @@ JNIEXPORT void JNICALL Java_edu_wpi_first_wpilibj_hal_DIOJNI_setDIO(
   CheckStatus(env, status);
 }
 
+/*
+ * Class:     edu_wpi_first_wpilibj_hal_DIOJNI
+ * Method:    setDIODirection
+ * Signature: (IZ)V
+ */
+JNIEXPORT void JNICALL Java_edu_wpi_first_wpilibj_hal_DIOJNI_setDIODirection(
+  JNIEnv *env, jclass, jint id, jboolean input) {
+  // DIOJNI_LOG(logDEBUG) << "Calling DIOJNI setDIO";
+  // DIOJNI_LOG(logDEBUG) << "Port Handle = " << (HAL_DigitalHandle)id;
+  // DIOJNI_LOG(logDEBUG) << "IsInput = " << input;
+  int32_t status = 0;
+  HAL_SetDIODirection((HAL_DigitalHandle)id, input, &status);
+  // DIOJNI_LOG(logDEBUG) << "Status = " << status;
+  CheckStatus(env, status);
+}
+
 /*
  * Class:     edu_wpi_first_wpilibj_hal_DIOJNI
  * Method:    getDIO