Update Java SmartDashboard and LiveWindow to match C++

wpilibj/src/main/java/edu/wpi/first/wpilibj/livewindow/LiveWindow.java

@@ -12,7 +12,6 @@ import edu.wpi.first.networktables.NetworkTableEntry;
 import edu.wpi.first.networktables.NetworkTableInstance;
 import edu.wpi.first.wpilibj.Sendable;
 import edu.wpi.first.wpilibj.command.Scheduler;
-import edu.wpi.first.wpilibj.smartdashboard.SendableBuilderImpl;
 import edu.wpi.first.wpilibj.smartdashboard.SendableRegistry;
 
 
@@ -22,7 +21,6 @@ import edu.wpi.first.wpilibj.smartdashboard.SendableRegistry;
  */
 public class LiveWindow {
   private static class Component {
-    final SendableBuilderImpl m_builder = new SendableBuilderImpl();
     boolean m_firstTime = true;
     boolean m_telemetryEnabled = true;
   }
@@ -73,13 +71,9 @@ public class LiveWindow {
         scheduler.removeAll();
       } else {
         System.out.println("stopping live window mode.");
-        SendableRegistry.foreachLiveWindow(dataHandle,
-            (sendable, name, subsystem, parent, data) -> {
-              if (data != null) {
-                ((Component) data).m_builder.stopLiveWindowMode();
-              }
-              return data;
-          });
+        SendableRegistry.foreachLiveWindow(dataHandle, cbdata -> {
+          cbdata.builder.stopLiveWindowMode();
+        });
         scheduler.enable();
       }
       enabledEntry.setBoolean(enabled);
@@ -111,12 +105,11 @@ public class LiveWindow {
    */
   public static synchronized void disableAllTelemetry() {
     telemetryEnabled = false;
-    SendableRegistry.foreachLiveWindow(dataHandle, (sendable, name, subsystem, parent, data) -> {
-      if (data == null) {
-        data = new Component();
+    SendableRegistry.foreachLiveWindow(dataHandle, cbdata -> {
+      if (cbdata.data == null) {
+        cbdata.data = new Component();
       }
-      ((Component) data).m_telemetryEnabled = false;
-      return data;
+      ((Component) cbdata.data).m_telemetryEnabled = false;
     });
   }
 
@@ -133,19 +126,19 @@ public class LiveWindow {
       return;
     }
 
-    SendableRegistry.foreachLiveWindow(dataHandle, (sendable, name, subsystem, parent, data) -> {
-      if (sendable == null || parent != null) {
-        return data;
+    SendableRegistry.foreachLiveWindow(dataHandle, cbdata -> {
+      if (cbdata.sendable == null || cbdata.parent != null) {
+        return;
       }
 
-      if (data == null) {
-        data = new Component();
+      if (cbdata.data == null) {
+        cbdata.data = new Component();
       }
 
-      Component component = (Component) data;
+      Component component = (Component) cbdata.data;
 
       if (!liveWindowEnabled && !component.m_telemetryEnabled) {
-        return data;
+        return;
       }
 
       if (component.m_firstTime) {
@@ -153,30 +146,29 @@ public class LiveWindow {
         // components to be redefined. This allows default sensor and actuator
         // values to be created that are replaced with the custom names from
         // users calling setName.
-        if (name.isEmpty()) {
-          return data;
+        if (cbdata.name.isEmpty()) {
+          return;
         }
-        NetworkTable ssTable = liveWindowTable.getSubTable(subsystem);
+        NetworkTable ssTable = liveWindowTable.getSubTable(cbdata.subsystem);
         NetworkTable table;
         // Treat name==subsystem as top level of subsystem
-        if (name.equals(subsystem)) {
+        if (cbdata.name.equals(cbdata.subsystem)) {
           table = ssTable;
         } else {
-          table = ssTable.getSubTable(name);
+          table = ssTable.getSubTable(cbdata.name);
         }
-        table.getEntry(".name").setString(name);
-        component.m_builder.setTable(table);
-        sendable.initSendable(component.m_builder);
+        table.getEntry(".name").setString(cbdata.name);
+        cbdata.builder.setTable(table);
+        cbdata.sendable.initSendable(cbdata.builder);
         ssTable.getEntry(".type").setString("LW Subsystem");
 
         component.m_firstTime = false;
       }
 
       if (startLiveWindow) {
-        component.m_builder.startLiveWindowMode();
+        cbdata.builder.startLiveWindowMode();
       }
-      component.m_builder.updateTable();
-      return data;
+      cbdata.builder.updateTable();
     });
 
     startLiveWindow = false;

wpilibj/src/main/java/edu/wpi/first/wpilibj/smartdashboard/SendableBuilderImpl.java

@@ -79,6 +79,14 @@ public class SendableBuilderImpl implements SendableBuilder {
     return m_table;
   }
 
+  /**
+   * Return whether this sendable has an associated table.
+   * @return True if it has a table, false if not.
+   */
+  public boolean hasTable() {
+    return m_table != null;
+  }
+
   /**
    * Return whether this sendable should be treated as an actuator.
    *
@@ -148,6 +156,14 @@ public class SendableBuilderImpl implements SendableBuilder {
     }
   }
 
+  /**
+   * Clear properties.
+   */
+  public void clearProperties() {
+    stopListeners();
+    m_properties.clear();
+  }
+
   /**
    * Set the string representation of the named data type that will be used by the smart dashboard
    * for this sendable.

wpilibj/src/main/java/edu/wpi/first/wpilibj/smartdashboard/SendableRegistry.java

@@ -11,7 +11,9 @@ import java.lang.ref.WeakReference;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.WeakHashMap;
+import java.util.function.Consumer;
 
+import edu.wpi.first.networktables.NetworkTable;
 import edu.wpi.first.wpilibj.DriverStation;
 import edu.wpi.first.wpilibj.Sendable;
 
@@ -30,6 +32,7 @@ public class SendableRegistry {
     }
 
     WeakReference<Sendable> m_sendable;
+    SendableBuilderImpl m_builder = new SendableBuilderImpl();
     String m_name;
     String m_subsystem = "Ungrouped";
     WeakReference<Sendable> m_parent;
@@ -384,21 +387,71 @@ public class SendableRegistry {
   }
 
   /**
-   * Functional interface for foreachLiveWindow().
+   * Publishes an object in the registry to a network table.
+   *
+   * @param sendable object
+   * @param table network table
    */
-  @FunctionalInterface
-  public interface LiveWindowForeachCallback {
+  public static synchronized void publish(Sendable sendable, NetworkTable table) {
+    Component comp = getOrAdd(sendable);
+    comp.m_builder.clearProperties();
+    comp.m_builder.setTable(table);
+    sendable.initSendable(comp.m_builder);
+    comp.m_builder.updateTable();
+    comp.m_builder.startListeners();
+  }
+
+  /**
+   * Updates network table information from an object.
+   *
+   * @param sendable object
+   */
+  public static synchronized void update(Sendable sendable) {
+    Component comp = components.get(sendable);
+    if (comp != null) {
+      comp.m_builder.updateTable();
+    }
+  }
+
+  /**
+   * Data passed to foreachLiveWindow() callback function.
+   */
+  public static class CallbackData {
     /**
-     * Callback.
-     *
-     * @param sendable sendable object
-     * @param name name
-     * @param subsystem subsystem
-     * @param parent parent sendable object
-     * @param data data stored in object with setData()
-     * @return data to be stored back into object, or null if none/don't modify
+     * Sendable object.
      */
-    Object call(Sendable sendable, String name, String subsystem, Sendable parent, Object data);
+    @SuppressWarnings("MemberName")
+    public Sendable sendable;
+
+    /**
+     * Name.
+     */
+    @SuppressWarnings("MemberName")
+    public String name;
+
+    /**
+     * Subsystem.
+     */
+    @SuppressWarnings("MemberName")
+    public String subsystem;
+
+    /**
+     * Parent sendable object.
+     */
+    @SuppressWarnings("MemberName")
+    public Sendable parent;
+
+    /**
+     * Data stored in object with setData().  Update this to change the data.
+     */
+    @SuppressWarnings("MemberName")
+    public Object data;
+
+    /**
+     * Sendable builder for the sendable.
+     */
+    @SuppressWarnings("MemberName")
+    public SendableBuilderImpl builder;
   }
 
   /**
@@ -406,26 +459,32 @@ public class SendableRegistry {
    * It is *not* safe to call other SendableRegistry functions from the
    * callback.
    *
-   * @param dataHandle data handle to get data pointer passed to callback
+   * @param dataHandle data handle to get data object passed to callback
    * @param callback function to call for each object
    */
   @SuppressWarnings({"PMD.CyclomaticComplexity", "PMD.AvoidInstantiatingObjectsInLoops",
                      "PMD.AvoidCatchingThrowable"})
   public static synchronized void foreachLiveWindow(int dataHandle,
-      LiveWindowForeachCallback callback) {
+      Consumer<CallbackData> callback) {
+    CallbackData cbdata = new CallbackData();
     for (Component comp : components.values()) {
-      Sendable sendable = comp.m_sendable.get();
-      if (sendable != null && comp.m_liveWindow) {
-        Sendable parent = null;
+      cbdata.sendable = comp.m_sendable.get();
+      if (cbdata.sendable != null && comp.m_liveWindow) {
+        cbdata.name = comp.m_name;
+        cbdata.subsystem = comp.m_subsystem;
         if (comp.m_parent != null) {
-          parent = comp.m_parent.get();
+          cbdata.parent = comp.m_parent.get();
+        } else {
+          cbdata.parent = null;
         }
-        Object data = null;
         if (comp.m_data != null && dataHandle < comp.m_data.length) {
-          data = comp.m_data[dataHandle];
+          cbdata.data = comp.m_data[dataHandle];
+        } else {
+          cbdata.data = null;
         }
+        cbdata.builder = comp.m_builder;
         try {
-          data = callback.call(sendable, comp.m_name, comp.m_subsystem, parent, data);
+          callback.accept(cbdata);
         } catch (Throwable throwable) {
           Throwable cause = throwable.getCause();
           if (cause != null) {
@@ -436,13 +495,13 @@ public class SendableRegistry {
                   + throwable.toString(), false);
           comp.m_liveWindow = false;
         }
-        if (data != null) {
+        if (cbdata.data != null) {
           if (comp.m_data == null) {
             comp.m_data = new Object[dataHandle + 1];
           } else if (dataHandle >= comp.m_data.length) {
             comp.m_data = Arrays.copyOf(comp.m_data, dataHandle + 1);
           }
-          comp.m_data[dataHandle] = data;
+          comp.m_data[dataHandle] = cbdata.data;
         }
       }
     }

wpilibj/src/main/java/edu/wpi/first/wpilibj/smartdashboard/SmartDashboard.java

@@ -27,28 +27,19 @@ import edu.wpi.first.wpilibj.Sendable;
  * laptop. Users can put values into and get values from the SmartDashboard.
  */
 @SuppressWarnings({"PMD.GodClass", "PMD.TooManyMethods"})
-public class SmartDashboard {
+public final class SmartDashboard {
   /**
    * The {@link NetworkTable} used by {@link SmartDashboard}.
    */
   private static final NetworkTable table =
       NetworkTableInstance.getDefault().getTable("SmartDashboard");
 
-  private static class Data {
-    Data(Sendable sendable) {
-      m_sendable = sendable;
-    }
-
-    final Sendable m_sendable;
-    final SendableBuilderImpl m_builder = new SendableBuilderImpl();
-  }
-
   /**
    * A table linking tables in the SmartDashboard to the {@link Sendable} objects they
    * came from.
    */
   @SuppressWarnings("PMD.UseConcurrentHashMap")
-  private static final Map<String, Data> tablesToData = new HashMap<>();
+  private static final Map<String, Sendable> tablesToData = new HashMap<>();
 
   /**
    * The executor for listener tasks; calls listener tasks synchronously from main thread.
@@ -71,19 +62,13 @@ public class SmartDashboard {
    * @param data the value
    * @throws IllegalArgumentException If key is null
    */
+  @SuppressWarnings("PMD.CompareObjectsWithEquals")
   public static synchronized void putData(String key, Sendable data) {
-    Data sddata = tablesToData.get(key);
-    if (sddata == null || sddata.m_sendable != data) {
-      if (sddata != null) {
-        sddata.m_builder.stopListeners();
-      }
-      sddata = new Data(data);
-      tablesToData.put(key, sddata);
+    Sendable sddata = tablesToData.get(key);
+    if (sddata == null || sddata != data) {
+      tablesToData.put(key, data);
       NetworkTable dataTable = table.getSubTable(key);
-      sddata.m_builder.setTable(dataTable);
-      data.initSendable(sddata.m_builder);
-      sddata.m_builder.updateTable();
-      sddata.m_builder.startListeners();
+      SendableRegistry.publish(data, dataTable);
       dataTable.getEntry(".name").setString(key);
     }
   }
@@ -111,11 +96,11 @@ public class SmartDashboard {
    * @throws IllegalArgumentException  if the key is null
    */
   public static synchronized Sendable getData(String key) {
-    Data data = tablesToData.get(key);
+    Sendable data = tablesToData.get(key);
     if (data == null) {
       throw new IllegalArgumentException("SmartDashboard data does not exist: " + key);
     } else {
-      return data.m_sendable;
+      return data;
     }
   }
 
@@ -543,8 +528,8 @@ public class SmartDashboard {
    * Puts all sendable data to the dashboard.
    */
   public static synchronized void updateValues() {
-    for (Data data : tablesToData.values()) {
-      data.m_builder.updateTable();
+    for (Sendable data : tablesToData.values()) {
+      SendableRegistry.update(data);
     }
     // Execute posted listener tasks
     listenerExecutor.runListenerTasks();