@blockly/field-colour/src/blocks/colourRandom.ts

A Blockly colour field.

/**
 * @license
 * Copyright 2024 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import {Block, common as BlocklyCommon} from 'blockly/core';
import {
  JavascriptGenerator,
  Order as JavascriptOrder,
} from 'blockly/javascript';
import {DartGenerator, Order as DartOrder} from 'blockly/dart';
import {LuaGenerator, Order as LuaOrder} from 'blockly/lua';
import {PhpGenerator, Order as PhpOrder} from 'blockly/php';
import {PythonGenerator, Order as PythonOrder} from 'blockly/python';
import {registerFieldColour} from '../field_colour';
import {Generators} from './generatorsType';

/** The name this block is registered under. */
export const BLOCK_NAME = 'colour_random';

// Block for random colour.
const jsonDefinition = {
  type: BLOCK_NAME,
  message0: '%{BKY_COLOUR_RANDOM_TITLE}',
  output: 'Colour',
  helpUrl: '%{BKY_COLOUR_RANDOM_HELPURL}',
  style: 'colour_blocks',
  tooltip: '%{BKY_COLOUR_RANDOM_TOOLTIP}',
};

/**
 * Javascript block generator function.
 *
 * @param block The Block instance to generate code for.
 * @param generator The JavascriptGenerator calling the function.
 * @returns A tuple containing the code string and precedence.
 */
export function toJavascript(
  block: Block,
  generator: JavascriptGenerator,
): [string, JavascriptOrder] {
  // Generate a random colour.
  const functionName = generator.provideFunction_(
    'colourRandom',
    `
function ${generator.FUNCTION_NAME_PLACEHOLDER_}() {
  var num = Math.floor(Math.random() * 0x1000000);
  return '#' + ('00000' + num.toString(16)).substr(-6);
}
`,
  );
  const code = functionName + '()';
  return [code, JavascriptOrder.FUNCTION_CALL];
}

/**
 * Dart block generator function.
 *
 * @param block The Block instance to generate code for.
 * @param generator The DartGenerator calling the function.
 * @returns A tuple containing the code string and precedence.
 */
export function toDart(
  block: Block,
  generator: DartGenerator,
): [string, DartOrder] {
  // Generate a random colour.
  // TODO(#7600): find better approach than casting to any to override
  // CodeGenerator declaring .definitions protected.
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  (generator as any).definitions_['import_dart_math'] =
    "import 'dart:math' as Math;";
  const functionName = generator.provideFunction_(
    'colour_random',
    `
String ${generator.FUNCTION_NAME_PLACEHOLDER_}() {
  String hex = '0123456789abcdef';
  var rnd = new Math.Random();
  return '#\${hex[rnd.nextInt(16)]}\${hex[rnd.nextInt(16)]}'
      '\${hex[rnd.nextInt(16)]}\${hex[rnd.nextInt(16)]}'
      '\${hex[rnd.nextInt(16)]}\${hex[rnd.nextInt(16)]}';
}
`,
  );
  const code = functionName + '()';
  return [code, DartOrder.UNARY_POSTFIX];
}

/**
 * Lua block generator function.
 *
 * @param block The Block instance to generate code for.
 * @param generator The LuaGenerator calling the function.
 * @returns A tuple containing the code string and precedence.
 */
export function toLua(
  block: Block,
  generator: LuaGenerator,
): [string, LuaOrder] {
  // Generate a random colour.
  const code = 'string.format("#%06x", math.random(0, 2^24 - 1))';
  return [code, LuaOrder.HIGH];
}

/**
 * PHP block generator function.
 *
 * @param block The Block instance to generate code for.
 * @param generator The PhpGenerator calling the function.
 * @returns A tuple containing the code string and precedence.
 */
export function toPhp(
  block: Block,
  generator: PhpGenerator,
): [string, PhpOrder] {
  // Generate a random colour.
  const functionName = generator.provideFunction_(
    'colour_random',
    `
function ${generator.FUNCTION_NAME_PLACEHOLDER_}() {
  return '#' . str_pad(dechex(mt_rand(0, 0xFFFFFF)), 6, '0', STR_PAD_LEFT);
}
`,
  );
  const code = functionName + '()';
  return [code, PhpOrder.FUNCTION_CALL];
}

/**
 * Python block generator function.
 *
 * @param block The Block instance to generate code for.
 * @param generator The PythonGenerator calling the function.
 * @returns A tuple containing the code string and precedence.
 */
export function toPython(
  block: Block,
  generator: PythonGenerator,
): [string, PythonOrder] {
  // Generate a random colour.
  // TODO(#7600): find better approach than casting to any to override
  // CodeGenerator declaring .definitions protected.
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  (generator as any).definitions_['import_random'] = 'import random';
  const code = "'#%06x' % random.randint(0, 2**24 - 1)";
  return [code, PythonOrder.FUNCTION_CALL];
}

const definitionsDict = BlocklyCommon.createBlockDefinitionsFromJsonArray([
  jsonDefinition,
]);

/** The colour_random BlockDefinition. */
export const blockDefinition = definitionsDict[BLOCK_NAME];

/**
 * Install the `colour_picker` block and all of its dependencies.
 *
 * @param gens The CodeGenerators to install per-block
 *     generators on.
 */
export function installBlock(gens: Generators = {}) {
  registerFieldColour();
  BlocklyCommon.defineBlocks(definitionsDict);
  if (gens.javascript) gens.javascript.forBlock[BLOCK_NAME] = toJavascript;
  if (gens.dart) gens.dart.forBlock[BLOCK_NAME] = toDart;
  if (gens.lua) gens.lua.forBlock[BLOCK_NAME] = toLua;
  if (gens.php) gens.php.forBlock[BLOCK_NAME] = toPhp;
  if (gens.python) gens.python.forBlock[BLOCK_NAME] = toPython;
}