src/cobalt/debug/remote/devtools/front_end/terminal/xterm.js/addons/fit/fit.js

/**
 * Fit terminal columns and rows to the dimensions of its DOM element.
 *
 * ## Approach
 * - Rows: Truncate the division of the terminal parent element height by the terminal row height.
 *
 * - Columns: Truncate the division of the terminal parent element width by the terminal character
 * width (apply display: inline at the terminal row and truncate its width with the current
 * number of columns).
 * @module xterm/addons/fit/fit
 * @license MIT
 */

(function (fit) {
  if (typeof exports === 'object' && typeof module === 'object') {
    /*
     * CommonJS environment
     */
    module.exports = fit(require('../../xterm'));
  } else if (typeof define == 'function') {
    /*
     * Require.js is available
     */
    define(['../../xterm'], fit);
  } else {
    /*
     * Plain browser environment
     */
    fit(window.Terminal);
  }
})(function (Xterm) {
  var exports = {};

  exports.proposeGeometry = function (term) {
    if (!term.element.parentElement) {
      return null;
    }
    var parentElementStyle = window.getComputedStyle(term.element.parentElement),
        parentElementHeight = parseInt(parentElementStyle.getPropertyValue('height')),
        parentElementWidth = Math.max(0, parseInt(parentElementStyle.getPropertyValue('width')) - 17),
        elementStyle = window.getComputedStyle(term.element),
        elementPaddingVer = parseInt(elementStyle.getPropertyValue('padding-top')) + parseInt(elementStyle.getPropertyValue('padding-bottom')),
        elementPaddingHor = parseInt(elementStyle.getPropertyValue('padding-right')) + parseInt(elementStyle.getPropertyValue('padding-left')),
        availableHeight = parentElementHeight - elementPaddingVer,
        availableWidth = parentElementWidth - elementPaddingHor,
        container = term.rowContainer,
        subjectRow = term.rowContainer.firstElementChild,
        contentBuffer = subjectRow.innerHTML,
        characterHeight,
        rows,
        characterWidth,
        cols,
        geometry;

    subjectRow.style.display = 'inline';
    subjectRow.innerHTML = 'W'; // Common character for measuring width, although on monospace
    characterWidth = subjectRow.getBoundingClientRect().width;
    subjectRow.style.display = ''; // Revert style before calculating height, since they differ.
    characterHeight = subjectRow.getBoundingClientRect().height;
    subjectRow.innerHTML = contentBuffer;

    rows = parseInt(availableHeight / characterHeight);
    cols = parseInt(availableWidth / characterWidth);

    geometry = {cols: cols, rows: rows};
    return geometry;
  };

  exports.fit = function (term) {
    var geometry = exports.proposeGeometry(term);

    if (geometry) {
      term.resize(geometry.cols, geometry.rows);
    }
  };

  Xterm.prototype.proposeGeometry = function () {
    return exports.proposeGeometry(this);
  };

  Xterm.prototype.fit = function () {
    return exports.fit(this);
  };

  return exports;
});