gecko-dev/toolkit/content/widgets/checkbox.js

/* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

// This is loaded into all XUL windows. Wrap in a block to prevent
// leaking to window scope.
{
class MozCheckbox extends MozElements.BaseText {
  constructor() {
    super();

    // While it would seem we could do this by handling oncommand, we need can't
    // because any external oncommand handlers might get called before ours, and
    // then they would see the incorrect value of checked.
    this.addEventListener("click", (event) => {
      if (event.button === 0 && !this.disabled) {
        this.checked = !this.checked;
      }
    });
    this.addEventListener("keypress", (event) => {
      if (event.key == " ") {
        this.checked = !this.checked;
        // Prevent page from scrolling on the space key.
        event.preventDefault();
      }
    });
  }

  static get inheritedAttributes() {
    return {
      ".checkbox-check": "disabled,checked",
      ".checkbox-label": "text=label,accesskey",
      ".checkbox-icon": "src",
    };
  }

  connectedCallback() {
    if (this.delayConnectedCallback()) {
      return;
    }

    if (!MozCheckbox.contentFragment) {
      let content = `
        <image class="checkbox-check"/>
        <hbox class="checkbox-label-box" flex="1">
          <image class="checkbox-icon"/>
          <label class="checkbox-label" flex="1"/>
        </hbox>
      `;
      MozCheckbox.contentFragment = MozXULElement.parseXULToFragment(content);
    }

    this.textContent = "";
    let fragment =
      this.ownerDocument.importNode(MozCheckbox.contentFragment, true);
    this.appendChild(fragment);

    this.initializeAttributeInheritance();
  }

  set checked(val) {
    let change = (val != (this.getAttribute("checked") == "true"));
    if (val) {
      this.setAttribute("checked", "true");
    } else {
      this.removeAttribute("checked");
    }

    if (change) {
      let event = document.createEvent("Events");
      event.initEvent("CheckboxStateChange", true, true);
      this.dispatchEvent(event);
    }
    return val;
  }

  get checked() {
    return this.getAttribute("checked") == "true";
  }
}

MozCheckbox.contentFragment = null;

customElements.define("checkbox", MozCheckbox);
}