Added a block for Python's None (#208)

* Replaced blockly's logic_null block with a custom blocks for Python's None.

Sorted imports and customBlocks in setup_custom_blocks.ts.

* Create a shadow block for None if an argument of a python function has a default value of None.

* Addressed review comments.

Author: lizlooney

src/blocks/mrc_none.ts

@@ -0,0 +1,55 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview Block for Python's None keyword.
+ * @author [email protected] (Liz Looney)
+ */
+
+
+import * as Blockly from 'blockly';
+import { MRC_STYLE_NONE } from '../themes/styles'
+import { Order, PythonGenerator } from 'blockly/python';
+
+export const BLOCK_NAME = 'mrc_none';
+
+export function setup() {
+  Blockly.Blocks[BLOCK_NAME] = {
+    init: function() {
+      this.setOutput(true); // no type for None
+      this.appendDummyInput()
+          .appendField(Blockly.Msg.NONE);
+      this.setStyle(MRC_STYLE_NONE);
+      this.setTooltip(Blockly.Msg.NONE_TOOLTIP);
+    },
+  };
+}
+
+export function pythonFromBlock(
+    _block: Blockly.Block,
+    _generator: PythonGenerator,
+): [string, Order] {
+  return ['None', Order.ATOMIC];
+}
+
+export function createNoneShadowValue(): any {
+  return {
+    'shadow': {
+      'type': 'mrc_none',
+    },
+  }
+}

src/blocks/setup_custom_blocks.ts

@@ -1,42 +1,44 @@
 
 import * as CallPythonFunction from './mrc_call_python_function';
+import * as ClassMethodDef from './mrc_class_method_def';
+import * as Component from './mrc_component';
+import * as Event from './mrc_event';
+import * as EventHandler from './mrc_event_handler';
+import * as GetParameter from './mrc_get_parameter';
 import * as GetPythonEnumValue from './mrc_get_python_enum_value';
 import * as GetPythonVariable from './mrc_get_python_variable';
 import * as ListAddItem from './mrc_list_add_item';
 import * as MathMinMax from './mrc_math_min_max';
+import * as Mechanism from './mrc_mechanism';
+import * as MechanismComponentHolder from './mrc_mechanism_component_holder';
 import * as MiscComment from './mrc_misc_comment';
 import * as MiscEvaluateButIgnoreResult from './mrc_misc_evaluate_but_ignore_result';
-import * as SetPythonVariable from './mrc_set_python_variable';
-import * as ClassMethodDef from './mrc_class_method_def';
-import * as Mechanism from './mrc_mechanism';
-import * as Component from './mrc_component';
-import * as MechanismContainerHolder from './mrc_mechanism_component_holder';
-import * as Port from './mrc_port';
+import * as None from './mrc_none';
 import * as OpModeDetails from './mrc_opmode_details';
-import * as Event from './mrc_event';
-import * as GetParameter from './mrc_get_parameter';
 import * as ParameterMutator from './mrc_param_container'
-import * as EventHandler from './mrc_event_handler';
+import * as Port from './mrc_port';
+import * as SetPythonVariable from './mrc_set_python_variable';
 
 const customBlocks = [
   CallPythonFunction,
   ClassMethodDef,
+  Component,
+  Event,
+  EventHandler,
+  GetParameter,
   GetPythonEnumValue,
   GetPythonVariable,
   ListAddItem,
   MathMinMax,
+  Mechanism,
+  MechanismComponentHolder,
   MiscComment,
   MiscEvaluateButIgnoreResult,
-  SetPythonVariable,
-  Mechanism,
-  Component,
-  MechanismContainerHolder,
-  Port,
+  None,
   OpModeDetails,
-  Event,
-  GetParameter,
   ParameterMutator,
-  EventHandler,
+  Port,
+  SetPythonVariable,
 ];
 
 export const setup = function(forBlock: any) {

src/blocks/tokens.ts

@@ -42,6 +42,8 @@ export function customTokens(t: (key: string) => string): typeof Blockly.Msg {
     EVALUATE_BUT_IGNORE_RESULT: t('BLOCKLY.EVALUATE_BUT_IGNORE_RESULT'),
     EVALUATE_BUT_IGNORE_RESULT_TOOLTIP:
       t('BLOCKLY.TOOLTIP.EVALUATE_BUT_IGNORE_RESULT'),
+    NONE: t('BLOCKLY.NONE'),
+    NONE_TOOLTIP: t('BLOCKLY.TOOLTIP.NONE'),
     AUTO: t('BLOCKLY.AUTO'),
     TELEOP: t('BLOCKLY.TELEOP'),
     TEST: t('BLOCKLY.TEST'),

src/blocks/utils/value.ts

@@ -21,6 +21,7 @@
 
 import { getAlias } from './python';
 import * as variable from './variable';
+import { createNoneShadowValue } from '../mrc_none';
 
 
 export function valueForFunctionArgInput(argType: string, argDefaultValue: string): any {
@@ -50,9 +51,7 @@ export function valueForFunctionArgInput(argType: string, argDefaultValue: strin
       break;
     case 'str':
       if (argDefaultValue === 'None') {
-        // TODO(lizlooney): Make a block for python None
-        // In RobotPy function hal.report(), the arg named feature has a default value of None.
-        return null;
+        return createNoneShadowValue()
       }
       // If argDefaultValue is surrounded by single or double quotes, it's a literal string.
       if (argDefaultValue.startsWith("'") && argDefaultValue.endsWith("'") ||

src/i18n/locales/en/translation.json

@@ -49,6 +49,7 @@
         "COMPONENTS": "Components",
         "EVENTS": "Events",
         "EVALUATE_BUT_IGNORE_RESULT": "evaluate but ignore result",
+        "NONE": "None",
         "TYPE": "Type",
         "ENABLED": "Enabled",
         "DISPLAY_NAME": "Display Name",
@@ -57,6 +58,7 @@
         "NO_MECHANISM_CONTENTS": "No Mechanism Contents",
         "TOOLTIP":{
             "EVALUATE_BUT_IGNORE_RESULT": "Executes the connected block and ignores the result.  Allows you to call a function and ignore the return value.",
+            "NONE": "Returns None.",
             "OPMODE_TYPE": "What sort of OpMode this is",
             "OPMODE_ENABLED": "Whether the OpMode is shown on Driver Station",
             "OPMODE_NAME": "The name shown on the Driver Station.  If blank will use the class name.",

src/i18n/locales/es/translation.json

@@ -50,6 +50,7 @@
         "COMPONENTS": "Componentes",
         "EVENTS": "Eventos",
         "EVALUATE_BUT_IGNORE_RESULT": "evaluar pero ignorar resultado",
+        "NONE": "None",
         "TYPE": "Tipo",
         "ENABLED": "Habilitado",
         "DISPLAY_NAME": "Nombre a Mostrar",
@@ -58,6 +59,7 @@
         "NO_MECHANISM_CONTENTS": "Sin Contenido de Mecanismo",
         "TOOLTIP": {
             "EVALUATE_BUT_IGNORE_RESULT": "Ejecuta el bloque conectado e ignora el resultado. Te permite llamar una función e ignorar el valor de retorno.",
+            "NONE": "No devuelve ninguno.",
             "OPMODE_TYPE": "Qué tipo de OpMode es este",
             "OPMODE_ENABLED": "Si el OpMode se muestra en la Estación del Conductor",
             "OPMODE_NAME": "El nombre mostrado en la Estación del Conductor. Si está en blanco usará el nombre de la clase.",
@@ -82,4 +84,4 @@
             "TEST": "Prueba"
         }
     }
-}
+}

src/i18n/locales/he/translation.json

@@ -49,6 +49,7 @@
         "COMPONENTS": "רכיבים",
         "EVENTS": "אירועים",
         "EVALUATE_BUT_IGNORE_RESULT": "הערך אך התעלם מהתוצאה",
+        "NONE": "אַף לֹא אֶחָד",
         "TYPE": "סוג",
         "ENABLED": "מופעל",
         "DISPLAY_NAME": "שם תצוגה",
@@ -57,6 +58,7 @@
         "NO_MECHANISM_CONTENTS": "אין תוכן מנגנון",
         "TOOLTIP":{
             "EVALUATE_BUT_IGNORE_RESULT": "מריץ את הבלוק המחובר ומתעלם מהתוצאה. מאפשר לך לקרוא לפונקציה ולהתעלם מערך ההחזרה.",
+            "NONE": "החזרות אין.",
             "OPMODE_TYPE": "איזה סוג של מצב פעולה זה",
             "OPMODE_ENABLED": "האם מצב הפעולה מוצג בתחנת הנהג",
             "OPMODE_NAME": "השם המוצג בתחנת הנהג. אם ריק ישתמש בשם הכיתה.",

src/themes/styles.ts

@@ -26,6 +26,7 @@ export const MRC_STYLE_ENUM = 'mrc_style_enum';
 export const MRC_STYLE_VARIABLES = 'mrc_style_variables';
 export const MRC_STYLE_COMMENTS = 'mrc_style_comments';
 export const MRC_STYLE_MISC = 'mrc_style_misc';
+export const MRC_STYLE_NONE = 'mrc_style_none';
 export const MRC_STYLE_CLASS_BLOCKS = 'mrc_style_class_blocks';
 export const MRC_CATEGORY_STYLE_METHODS = 'mrc_category_style_methods';
 export const MRC_STYLE_MECHANISMS = 'mrc_style_mechanisms';
@@ -38,6 +39,7 @@ export const MRC_CATEGORY_STYLE_COMPONENTS = 'mrc_category_style_components';
 export const add_mrc_styles = function (theme: Blockly.Theme): Blockly.Theme {
     const procedureStyle = theme.blockStyles['procedure_blocks'];
     const variableStyle = theme.blockStyles['variable_blocks'];
+    const logicStyle = theme.blockStyles['logic_blocks'];
 
     theme.setBlockStyle(MRC_STYLE_FUNCTIONS, {
         ...procedureStyle
@@ -74,12 +76,14 @@ export const add_mrc_styles = function (theme: Blockly.Theme): Blockly.Theme {
         colourTertiary: "#494984",
         hat: ""
     });
+    theme.setBlockStyle(MRC_STYLE_NONE, {
+        ...logicStyle
+    });
     theme.setBlockStyle(MRC_STYLE_MECHANISMS, {
         colourPrimary: "#5b61a5",
         colourSecondary: "#dedfed",
         colourTertiary: "#494e84",
         hat: ""
-
     });
     theme.setBlockStyle(MRC_STYLE_COMPONENTS, {
         colourPrimary: "#5b80a5",

src/toolbox/logic_category.ts

@@ -43,7 +43,7 @@ export const getCategory = () => (
         },
         {
             kind: 'block',
-            type: 'logic_null',
+            type: 'mrc_none',
         },
         {
             kind: 'block',