[fieldImages] Add utilities to simplify loading of fields (#4456)

fieldImages/CMakeLists.txt

@@ -7,6 +7,9 @@ if (WITH_JAVA)
     find_package(Java REQUIRED)
     include(UseJava)
 
+    file(GLOB JACKSON_JARS "${WPILIB_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar")
+    set(CMAKE_JAVA_INCLUDE_PATH fieldImages.jar ${JACKSON_JARS})
+
     file(GLOB_RECURSE JAVA_SOURCES src/main/java/*.java)
     file(GLOB_RECURSE JAVA_RESOURCES src/main/native/resources/*.json src/main/native/resources/*.png src/main/native/resources/*.jpg)
     add_jar(field_images_jar SOURCES ${JAVA_SOURCES} RESOURCES NAMESPACE "edu/wpi/first/fields" ${JAVA_RESOURCES} OUTPUT_NAME fieldImages)

fieldImages/build.gradle

@@ -13,6 +13,12 @@ if (!project.hasProperty('onlylinuxathena') && !project.hasProperty('onlylinuxar
         apply plugin: 'windows-resources'
     }
 
+    dependencies {
+        implementation "com.fasterxml.jackson.core:jackson-annotations:2.12.4"
+        implementation "com.fasterxml.jackson.core:jackson-core:2.12.4"
+        implementation "com.fasterxml.jackson.core:jackson-databind:2.12.4"
+    }
+
     ext {
         nativeName = 'fieldImages'
         baseId = nativeName

fieldImages/src/main/java/edu/wpi/fields/FieldConfig.java

@@ -0,0 +1,90 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.fields;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class FieldConfig {
+  public static class Corners {
+    @JsonProperty("top-left")
+    public double[] m_topLeft;
+
+    @JsonProperty("bottom-right")
+    public double[] m_bottomRight;
+  }
+
+  @JsonProperty("game")
+  public String m_game;
+
+  @JsonProperty("field-image")
+  public String m_fieldImage;
+
+  @JsonProperty("field-corners")
+  public Corners m_fieldCorners;
+
+  @JsonProperty("field-size")
+  public double[] m_fieldSize;
+
+  @JsonProperty("field-unit")
+  public String m_fieldUnit;
+
+  public FieldConfig() {}
+
+  @SuppressWarnings("deprecation")
+  public URL getImageUrl() {
+    return getClass().getResource(Fields.kBaseResourceDir + m_fieldImage);
+  }
+
+  @SuppressWarnings("deprecation")
+  public InputStream getImageAsStream() {
+    return getClass().getResourceAsStream(Fields.kBaseResourceDir + m_fieldImage);
+  }
+
+  /**
+   * Loads a predefined field configuration from a resource file.
+   *
+   * @param field The predefined field
+   * @return The field configuration
+   * @throws IOException Throws if the file could not be loaded
+   */
+  public static FieldConfig loadField(Fields field) throws IOException {
+    return loadFromResource(field.m_resourceFile);
+  }
+
+  /**
+   * Loads a field configuration from a file on disk.
+   *
+   * @param file The json file to load
+   * @return The field configuration
+   * @throws IOException Throws if the file could not be loaded
+   */
+  public static FieldConfig loadFromFile(Path file) throws IOException {
+    try (BufferedReader reader = Files.newBufferedReader(file)) {
+      return new ObjectMapper().readerFor(FieldConfig.class).readValue(reader);
+    }
+  }
+
+  /**
+   * Loads a field configuration from a resource file located inside the programs jar file.
+   *
+   * @param resourcePath The path to the resource file
+   * @return The field configuration
+   * @throws IOException Throws if the resoure could not be loaded
+   */
+  public static FieldConfig loadFromResource(String resourcePath) throws IOException {
+    try (InputStream stream = FieldConfig.class.getResourceAsStream(resourcePath);
+        InputStreamReader reader = new InputStreamReader(stream)) {
+      return new ObjectMapper().readerFor(FieldConfig.class).readValue(reader);
+    }
+  }
+}

fieldImages/src/main/java/edu/wpi/fields/FieldImages.java

@@ -1,25 +0,0 @@
-// Copyright (c) FIRST and other WPILib contributors.
-// Open Source Software; you can modify and/or share it under the terms of
-// the WPILib BSD license file in the root directory of this project.
-
-package edu.wpi.fields;
-
-public class FieldImages {
-  public static final String k2018PowerUpFieldConfig = "/edu/wpi/first/fields/2018-powerup.json";
-  public static final String k2019DeepSpaceFieldConfig =
-      "/edu/wpi/first/fields/2019-deepspace.json";
-  public static final String k2020InfiniteRechargeFieldConfig =
-      "/edu/wpi/first/fields/2020-infiniterecharge.json";
-  public static final String k2021InfiniteRechargeFieldConfig =
-      "/edu/wpi/first/fields/2021-infiniterecharge.json";
-  public static final String k2021BarrelFieldConfig =
-      "/edu/wpi/first/fields/2021-barrelracingpath.json";
-  public static final String k2021BounceFieldConfig = "/edu/wpi/first/fields/2021-bouncepath.json";
-  public static final String k2021GalacticSearchAFieldConfig =
-      "/edu/wpi/first/fields/2021-galacticsearcha.json";
-  public static final String k2021GalacticSearchBFieldConfig =
-      "/edu/wpi/first/fields/2021-galacticsearchb.json";
-  public static final String k2021SlalomFieldConfig = "/edu/wpi/first/fields/2021-slalompath.json";
-  public static final String k2022RapidReactFieldConfig =
-      "/edu/wpi/first/fields/2022-rapidreact.json";
-}

fieldImages/src/main/java/edu/wpi/fields/Fields.java

@@ -0,0 +1,29 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.fields;
+
+public enum Fields {
+  k2018PowerUp("2018-powerup.json"),
+  k2019DeepSpace("2019-deepspace.json"),
+  k2020InfiniteRecharge("2020-infiniterecharge.json"),
+  k2021InfiniteRecharge("2021-infiniterecharge.json"),
+  k2021Barrel("2021-barrelracingpath.json"),
+  k2021Bounce("2021-bouncepath.json"),
+  k2021GalacticSearchA("2021-galacticsearcha.json"),
+  k2021GalacticSearchB("2021-galacticsearchb.json"),
+  k2021Slalom("2021-slalompath.json"),
+  k2022RapidReact("2022-rapidreact.json");
+
+  public static final String kBaseResourceDir = "/edu/wpi/first/fields/";
+
+  /** Alias to the current game. */
+  public static final Fields kDefaultField = k2022RapidReact;
+
+  public final String m_resourceFile;
+
+  Fields(String resourceFile) {
+    m_resourceFile = kBaseResourceDir + resourceFile;
+  }
+}

fieldImages/src/test/java/edu/wpi/fields/LoadConfigTest.java

@@ -0,0 +1,19 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.fields;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+
+class LoadConfigTest {
+  @ParameterizedTest
+  @EnumSource(Fields.class)
+  void testLoad(Fields field) {
+    FieldConfig config = Assertions.assertDoesNotThrow(() -> FieldConfig.loadField(field));
+
+    Assertions.assertNotNull(config.getImageUrl());
+  }
+}