lib/web/overlay_manager.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2020 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @licend The above is the entire license notice for the
 * Javascript code in this page
 */
"use strict";

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

class OverlayManager {
  constructor() {
    this._overlays = {};
    this._active = null;
    this._keyDownBound = this._keyDown.bind(this);
  }

  get active() {
    return this._active;
  }

  async register(name, element, callerCloseMethod = null, canForceClose = false) {
    let container;

    if (!name || !element || !(container = element.parentNode)) {
      throw new Error("Not enough parameters.");
    } else if (this._overlays[name]) {
      throw new Error("The overlay is already registered.");
    }

    this._overlays[name] = {
      element,
      container,
      callerCloseMethod,
      canForceClose
    };
  }

  async unregister(name) {
    if (!this._overlays[name]) {
      throw new Error("The overlay does not exist.");
    } else if (this._active === name) {
      throw new Error("The overlay cannot be removed while it is active.");
    }

    delete this._overlays[name];
  }

  async open(name) {
    if (!this._overlays[name]) {
      throw new Error("The overlay does not exist.");
    } else if (this._active) {
      if (this._overlays[name].canForceClose) {
        this._closeThroughCaller();
      } else if (this._active === name) {
        throw new Error("The overlay is already active.");
      } else {
        throw new Error("Another overlay is currently active.");
      }
    }

    this._active = name;

    this._overlays[this._active].element.classList.remove("hidden");

    this._overlays[this._active].container.classList.remove("hidden");

    window.addEventListener("keydown", this._keyDownBound);
  }

  async close(name) {
    if (!this._overlays[name]) {
      throw new Error("The overlay does not exist.");
    } else if (!this._active) {
      throw new Error("The overlay is currently not active.");
    } else if (this._active !== name) {
      throw new Error("Another overlay is currently active.");
    }

    this._overlays[this._active].container.classList.add("hidden");

    this._overlays[this._active].element.classList.add("hidden");

    this._active = null;
    window.removeEventListener("keydown", this._keyDownBound);
  }

  _keyDown(evt) {
    if (this._active && evt.keyCode === 27) {
      this._closeThroughCaller();

      evt.preventDefault();
    }
  }

  _closeThroughCaller() {
    if (this._overlays[this._active].callerCloseMethod) {
      this._overlays[this._active].callerCloseMethod();
    }

    if (this._active) {
      this.close(this._active);
    }
  }

}

exports.OverlayManager = OverlayManager;