chrome/browser/resources/pdf/elements/viewer-download-controls.ts

// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'chrome://resources/cr_elements/cr_action_menu/cr_action_menu.js';
import 'chrome://resources/cr_elements/cr_icon_button/cr_icon_button.js';
import 'chrome://resources/cr_elements/icons.m.js';
import './icons.html.js';
import './pdf-shared.css.js';

import {AnchorAlignment, CrActionMenuElement} from 'chrome://resources/cr_elements/cr_action_menu/cr_action_menu.js';
import {CrIconButtonElement} from 'chrome://resources/cr_elements/cr_icon_button/cr_icon_button.js';
import {PromiseResolver} from 'chrome://resources/js/promise_resolver.m.js';
import {PolymerElement} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';

import {SaveRequestType} from '../constants.js';

import {getTemplate} from './viewer-download-controls.html.js';

export interface ViewerDownloadControlsElement {
  $: {
    download: CrIconButtonElement,
    menu: CrActionMenuElement,
  };
}

export class ViewerDownloadControlsElement extends PolymerElement {
  static get is() {
    return 'viewer-download-controls';
  }

  static get template() {
    return getTemplate();
  }

  static get properties() {
    return {
      hasEdits: Boolean,

      hasEnteredAnnotationMode: Boolean,

      isFormFieldFocused: {
        type: Boolean,
        observer: 'onFormFieldFocusedChanged_',
      },

      downloadHasPopup_: {
        type: String,
        computed: 'computeDownloadHasPopup_(hasEdits,' +
            'hasEnteredAnnotationMode)',
      },

      menuOpen_: {
        type: Boolean,
        reflectToAttribute: true,
        value: false,
      },
    };
  }

  hasEdits: boolean;
  hasEnteredAnnotationMode: boolean;
  isFormFieldFocused: boolean;
  private downloadHasPopup_: string;
  private menuOpen_: boolean;
  private waitForFormFocusChange_: PromiseResolver<boolean>|null = null;

  isMenuOpen(): boolean {
    return this.menuOpen_;
  }

  closeMenu() {
    this.$.menu.close();
  }

  private onOpenChanged_(e: CustomEvent<{value: boolean}>) {
    this.menuOpen_ = e.detail.value;
  }

  private hasEditsToSave_(): boolean {
    return this.hasEnteredAnnotationMode || this.hasEdits;
  }

  /**
   * @return The value for the aria-haspopup attribute for the download button.
   */
  private computeDownloadHasPopup_(): string {
    return this.hasEditsToSave_() ? 'menu' : 'false';
  }

  private showDownloadMenu_() {
    this.$.menu.showAt(this.$.download, {
      anchorAlignmentX: AnchorAlignment.CENTER,
    });
    // For tests
    this.dispatchEvent(new CustomEvent(
        'download-menu-shown-for-testing', {bubbles: true, composed: true}));
  }

  private onDownloadClick_() {
    this.waitForEdits_().then(hasEdits => {
      if (hasEdits) {
        this.showDownloadMenu_();
      } else {
        this.dispatchSaveEvent_(SaveRequestType.ORIGINAL);
      }
    });
  }

  /**
   * @return Promise that resolves with true if the PDF has edits and/or
   *     annotations, and false otherwise.
   */
  private waitForEdits_(): Promise<boolean> {
    if (this.hasEditsToSave_()) {
      return Promise.resolve(true);
    }
    if (!this.isFormFieldFocused) {
      return Promise.resolve(false);
    }
    this.waitForFormFocusChange_ = new PromiseResolver();
    return this.waitForFormFocusChange_.promise;
  }

  private onFormFieldFocusedChanged_() {
    if (!this.waitForFormFocusChange_) {
      return;
    }

    this.waitForFormFocusChange_.resolve(this.hasEdits);
    this.waitForFormFocusChange_ = null;
  }

  private dispatchSaveEvent_(type: SaveRequestType) {
    this.dispatchEvent(
        new CustomEvent('save', {detail: type, bubbles: true, composed: true}));
  }

  private onDownloadOriginalClick_() {
    this.dispatchSaveEvent_(SaveRequestType.ORIGINAL);
    this.$.menu.close();
  }

  private onDownloadEditedClick_() {
    this.dispatchSaveEvent_(
        this.hasEnteredAnnotationMode ? SaveRequestType.ANNOTATION :
                                        SaveRequestType.EDITED);
    this.$.menu.close();
  }
}

declare global {
  interface HTMLElementTagNameMap {
    'viewer-download-controls': ViewerDownloadControlsElement;
  }
}

customElements.define(
    ViewerDownloadControlsElement.is, ViewerDownloadControlsElement);