@blockly/field-colour

A Blockly field and blocks for choosing and combining colours.

yarn add @blockly/field-colour

npm install @blockly/field-colour --save

If you want to use this field in a block definition, you must install it by calling registerFieldColour before instantiating your blocks. If another field is registered under the same name (field_colour), this field will overwrite it.

If you install the blocks in this package, the field will automatically be installed.

The colour field stores a string as its value, and a string as its text. Its value is a string with the format #rrggbb, while its text may be a string with the format #rgb if possible.

import * as Blockly from 'blockly';
import {registerFieldColour} from '@blockly/field-colour';

registerFieldColour();
Blockly.Blocks['test_field_colour'] = {
  init: function () {
    this.appendDummyInput()
      .appendField('colour: ')
      .appendField(
        new FieldColour('#ff4040', null, {
          colourOptions: [
            '#ff4040',
            '#ff8080',
            '#ffc0c0',
            '#4040ff',
            '#8080ff',
            '#c0c0ff',
          ],
          colourTitles: [
            'dark pink',
            'pink',
            'light pink',
            'dark blue',
            'blue',
            'light blue',
          ],
          columns: 3,
        }),
        'FIELDNAME',
      );
  },
};

import * as Blockly from 'blockly';
import {registerFieldColour} from '@blockly/field-colour';

registerFieldColour();
Blockly.defineBlocksWithJsonArray([
  {
    type: 'test_field_colour',
    message0: 'colour: %1',
    args0: [
      {
        type: 'field_colour',
        name: 'FIELDNAME',
        colour: '#ff4040',
        colourOptions: [
          '#ff4040',
          '#ff8080',
          '#ffc0c0',
          '#4040ff',
          '#8080ff',
          '#c0c0ff',
        ],
        colourTitles: [
          'dark pink',
          'pink',
          'light pink',
          'dark blue',
          'blue',
          'light blue',
        ],
        columns: 3,
      },
    ],
  },
]);

The colour constructor takes in the following:

• an optional value
• an optional validator
• an optional map of options, including:
  • colourOptions
  • colourTitles
  • columns

The value should be a string in the format #rrggbb. If no value is given or the given value is invalid, the first entry in the default colours array will be used.

The following options can also be set in JSON:

• colourOptions
• colourTitles
• columns

Or they can be set using JavaScript hooks.

The setColours function can be used to set the colour options of a colour field. It takes in an array of colour strings, which must be defined in #rrggbb format, and an optional array of tooltips. If the tooltip array is not provided, the default tooltip array will be used.

Tooltips and colours are matched based on array index, not based on value. If the colours array is longer than the tooltip array, the tooltips for the extra colours will be their #rrggbb value.

The setColumns function sets the number of columns in the colour picker.

{
  "type": "example_colour",
  "message0": "colour: %1",
  "args0": [
    {
      "type": "field_colour",
      "name": "COLOUR",
      "colour": "#ff4040"
    }
  ],
  "extensions": ["set_colours_extension"]
}

Blockly.Extensions.register('set_colours_extension', function () {
  var field = this.getField('COLOUR');
  field.setColours(
    ['#ff4040', '#ff8080', '#ffc0c0', '#4040ff', '#8080ff', '#c0c0ff'],
    ['dark pink', 'pink', 'light pink', 'dark blue', 'blue', 'light blue'],
  );
  field.setColumns(3);
});

This is done using a JSON extension.

Blockly.Blocks['example_colour'] = {
  init: function () {
    var field = new Blockly.FieldColour('#ff4040');
    field.setColours(
      ['#ff4040', '#ff8080', '#ffc0c0', '#4040ff', '#8080ff', '#c0c0ff'],
      ['dark pink', 'pink', 'light pink', 'dark blue', 'blue', 'light blue'],
    );
    field.setColumns(3);
    this.appendDummyInput().appendField('colour:').appendField(field, 'COLOUR');
  },
};

Note: For information on validators in general see Validators.

A colour field's value is a #rrggbb format string, so any validators must accept a #rrggbb format string, and return a #rrggbb format string, null, or undefined.

Here is an example of a validator that changes the colour of the block to match the colour of the field.

function(newValue) {
  this.getSourceBlock().setColour(newValue);
  return newValue;
}

This package also provides four blocks related to the colour field. Each block has generators in JavaScript, Python, PHP, Lua, and Dart.

• "colour_blend" takes in two colours and a ratio and outputs a single colour.
• "colour_picker" is a simple block with just the colour field and an output.
• "colour_random" generates a random colour.
• "colour_rgb" generates a colour based on red, green, and blue values.

You can install all four blocks by calling installAllBlocks. This will install the blocks and all of their dependencies, including the colour field. When calling installAllBlocks—or any of the individual installSomeBlock functions—you can supply one or more CodeGenerator instances (e.g. javascriptGenerator), and the install function will also install the correct generator function for each block for the corresponding language(s).

import {javascriptGenerator} from 'blockly/javascript';
import {dartGenerator} from 'blockly/dart';
import {phpGenerator} from 'blockly/php';
import {pythonGenerator} from 'blockly/python';
import {luaGenerator} from 'blockly/lua';
import {installAllBlocks as installColourBlocks} from '@blockly/field-colour';

// Installs all four blocks, the colour field, and all language generators.
installColourBlocks({
  javascript: javascriptGenerator,
  dart: dartGenerator,
  lua: luaGenerator,
  python: pythonGenerator,
  php: phpGenerator,
});

If you only want to install a single block, you can call that block's installBlock function. The generators parameter is the same.

import {javascriptGenerator} from 'blockly/javascript';
import {colourBlend} from '@blockly/field-colour';

// Installs the colour_blend block, the colour field,
// and the generator for colour_blend in JavaScript.
colourBlend.installBlock({
  javascript: javascriptGenerator,
});

The blocks in this package contain text that can be localized into multiple languages. As of August 2024, the relevant messages are included in the core Blockly language files.

If your blocks show %{BKY_COLOUR_BLEND_TITLE} or similar text instead of the expected text, make sure that you either:

• Import the default Blockly modules, which includes the English langfiles, or
• Explicitly import a language and call setLocale before using these blocks.

For more information on Blockly's approach to localization, see the Localize Blocks developer guide.

• setColours: Sets the colour options, and optionally the titles for the options. The colours should be an array of #rrggbb strings.
• setColumns: Sets the number of columns the dropdown should have.

Apache 2.0