ink/build/experimental/output.js

React for CLI

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _stringLength = _interopRequireDefault(require("string-length"));

var _sliceAnsi = _interopRequireDefault(require("slice-ansi"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * "Virtual" output class
 *
 * Handles the positioning and saving of the output of each node in the tree.
 * Also responsible for applying transformations to each character of the output.
 *
 * Used to generate the final output of all nodes before writing it to actual output stream (e.g. stdout)
 */
class Output {
  constructor({
    width,
    height
  }) {
    this.width = width;
    this.height = height;
    this.writes = []; // Initialize output array with a specific set of rows, so that margin/padding at the bottom is preserved
  }

  write(x, y, text, {
    transformers
  }) {
    if (!text) {
      return;
    }

    this.writes.push({
      x,
      y,
      text,
      transformers
    });
  }

  get() {
    const output = [];

    for (let y = 0; y < this.height; y++) {
      output.push(' '.repeat(this.width));
    }

    for (const write of this.writes) {
      const {
        x,
        y,
        text,
        transformers
      } = write;
      const lines = text.split('\n');
      let offsetY = 0;

      for (let line of lines) {
        const currentLine = output[y + offsetY]; // Line can be missing if `text` is taller than height of pre-initialized `this.output`

        if (!currentLine) {
          continue;
        }

        const length = (0, _stringLength.default)(line);

        for (const transformer of transformers) {
          line = transformer(line);
        }

        output[y + offsetY] = (0, _sliceAnsi.default)(currentLine, 0, x) + line + (0, _sliceAnsi.default)(currentLine, x + length);
        offsetY++;
      }
    }

    const generatedOutput = output.map(line => line.trimRight()).join('\n');
    return {
      output: generatedOutput,
      height: output.length
    };
  }

}

exports.default = Output;