blockly/core/workspace_comment.ts

/**
 * @license
 * Copyright 2017 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * Object representing a code comment on the workspace.
 *
 * @class
 */
import * as goog from '../closure/goog/goog.js';
goog.declareModuleId('Blockly.WorkspaceComment');

import type {CommentMove} from './events/events_comment_move.js';
import * as eventUtils from './events/utils.js';
import {Coordinate} from './utils/coordinate.js';
import * as idGenerator from './utils/idgenerator.js';
import * as xml from './utils/xml.js';
import type {Workspace} from './workspace.js';


/**
 * Class for a workspace comment.
 *
 * @alias Blockly.WorkspaceComment
 */
export class WorkspaceComment {
  id: string;
  protected xy_: Coordinate;
  protected height_: number;
  protected width_: number;
  protected RTL: boolean;

  private deletable_ = true;

  private movable_ = true;

  private editable_ = true;
  protected content_: string;

  /** Whether this comment has been disposed. */
  protected disposed_ = false;
  /** @internal */
  isComment = true;

  /**
   * @param workspace The block's workspace.
   * @param content The content of this workspace comment.
   * @param height Height of the comment.
   * @param width Width of the comment.
   * @param opt_id Optional ID.  Use this ID if provided, otherwise create a new
   *     ID.
   */
  constructor(
      public workspace: Workspace, content: string, height: number,
      width: number, opt_id?: string) {
    this.id = opt_id && !workspace.getCommentById(opt_id) ?
        opt_id :
        idGenerator.genUid();

    workspace.addTopComment(this);

    /**
     * The comment's position in workspace units.  (0, 0) is at the workspace's
     * origin; scale does not change this value.
     */
    this.xy_ = new Coordinate(0, 0);

    /**
     * The comment's height in workspace units.  Scale does not change this
     * value.
     */
    this.height_ = height;

    /**
     * The comment's width in workspace units.  Scale does not change this
     * value.
     */
    this.width_ = width;

    this.RTL = workspace.RTL;

    this.content_ = content;

    WorkspaceComment.fireCreateEvent(this);
  }

  /**
   * Dispose of this comment.
   *
   * @internal
   */
  dispose() {
    if (this.disposed_) {
      return;
    }

    if (eventUtils.isEnabled()) {
      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_DELETE))(this));
    }
    // Remove from the list of top comments and the comment database.
    this.workspace.removeTopComment(this);
    this.disposed_ = true;
  }

  // Height, width, x, and y are all stored on even non-rendered comments, to
  // preserve state if you pass the contents through a headless workspace.

  /**
   * Get comment height.
   *
   * @returns Comment height.
   * @internal
   */
  getHeight(): number {
    return this.height_;
  }

  /**
   * Set comment height.
   *
   * @param height Comment height.
   * @internal
   */
  setHeight(height: number) {
    this.height_ = height;
  }

  /**
   * Get comment width.
   *
   * @returns Comment width.
   * @internal
   */
  getWidth(): number {
    return this.width_;
  }

  /**
   * Set comment width.
   *
   * @param width comment width.
   * @internal
   */
  setWidth(width: number) {
    this.width_ = width;
  }

  /**
   * Get stored location.
   *
   * @returns The comment's stored location.
   *   This is not valid if the comment is currently being dragged.
   * @internal
   */
  getXY(): Coordinate {
    return new Coordinate(this.xy_.x, this.xy_.y);
  }

  /**
   * Move a comment by a relative offset.
   *
   * @param dx Horizontal offset, in workspace units.
   * @param dy Vertical offset, in workspace units.
   * @internal
   */
  moveBy(dx: number, dy: number) {
    const event =
        new (eventUtils.get(eventUtils.COMMENT_MOVE))(this) as CommentMove;
    this.xy_.translate(dx, dy);
    event.recordNew();
    eventUtils.fire(event);
  }

  /**
   * Get whether this comment is deletable or not.
   *
   * @returns True if deletable.
   * @internal
   */
  isDeletable(): boolean {
    return this.deletable_ &&
        !(this.workspace && this.workspace.options.readOnly);
  }

  /**
   * Set whether this comment is deletable or not.
   *
   * @param deletable True if deletable.
   * @internal
   */
  setDeletable(deletable: boolean) {
    this.deletable_ = deletable;
  }

  /**
   * Get whether this comment is movable or not.
   *
   * @returns True if movable.
   * @internal
   */
  isMovable(): boolean {
    return this.movable_ &&
        !(this.workspace && this.workspace.options.readOnly);
  }

  /**
   * Set whether this comment is movable or not.
   *
   * @param movable True if movable.
   * @internal
   */
  setMovable(movable: boolean) {
    this.movable_ = movable;
  }

  /**
   * Get whether this comment is editable or not.
   *
   * @returns True if editable.
   */
  isEditable(): boolean {
    return this.editable_ &&
        !(this.workspace && this.workspace.options.readOnly);
  }

  /**
   * Set whether this comment is editable or not.
   *
   * @param editable True if editable.
   */
  setEditable(editable: boolean) {
    this.editable_ = editable;
  }

  /**
   * Returns this comment's text.
   *
   * @returns Comment text.
   * @internal
   */
  getContent(): string {
    return this.content_;
  }

  /**
   * Set this comment's content.
   *
   * @param content Comment content.
   * @internal
   */
  setContent(content: string) {
    if (this.content_ !== content) {
      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_CHANGE))(
          this, this.content_, content));
      this.content_ = content;
    }
  }

  /**
   * Encode a comment subtree as XML with XY coordinates.
   *
   * @param opt_noId True if the encoder should skip the comment ID.
   * @returns Tree of XML elements.
   * @internal
   */
  toXmlWithXY(opt_noId?: boolean): Element {
    const element = this.toXml(opt_noId);
    element.setAttribute('x', `${Math.round(this.xy_.x)}`);
    element.setAttribute('y', `${Math.round(this.xy_.y)}`);
    element.setAttribute('h', `${this.height_}`);
    element.setAttribute('w', `${this.width_}`);
    return element;
  }

  /**
   * Encode a comment subtree as XML, but don't serialize the XY coordinates.
   * This method avoids some expensive metrics-related calls that are made in
   * toXmlWithXY().
   *
   * @param opt_noId True if the encoder should skip the comment ID.
   * @returns Tree of XML elements.
   * @internal
   */
  toXml(opt_noId?: boolean): Element {
    const commentElement = xml.createElement('comment');
    if (!opt_noId) {
      commentElement.id = this.id;
    }
    commentElement.textContent = this.getContent();
    return commentElement;
  }

  /**
   * Fire a create event for the given workspace comment, if comments are
   * enabled.
   *
   * @param comment The comment that was just created.
   * @internal
   */
  static fireCreateEvent(comment: WorkspaceComment) {
    if (eventUtils.isEnabled()) {
      const existingGroup = eventUtils.getGroup();
      if (!existingGroup) {
        eventUtils.setGroup(true);
      }
      try {
        eventUtils.fire(
            new (eventUtils.get(eventUtils.COMMENT_CREATE))(comment));
      } finally {
        if (!existingGroup) {
          eventUtils.setGroup(false);
        }
      }
    }
  }

  /**
   * Decode an XML comment tag and create a comment on the workspace.
   *
   * @param xmlComment XML comment element.
   * @param workspace The workspace.
   * @returns The created workspace comment.
   * @internal
   */
  static fromXml(xmlComment: Element, workspace: Workspace): WorkspaceComment {
    const info = WorkspaceComment.parseAttributes(xmlComment);

    const comment =
        new WorkspaceComment(workspace, info.content, info.h, info.w, info.id);

    const xmlX = xmlComment.getAttribute('x');
    const xmlY = xmlComment.getAttribute('y');
    const commentX = xmlX ? parseInt(xmlX, 10) : NaN;
    const commentY = xmlY ? parseInt(xmlY, 10) : NaN;
    if (!isNaN(commentX) && !isNaN(commentY)) {
      comment.moveBy(commentX, commentY);
    }

    WorkspaceComment.fireCreateEvent(comment);
    return comment;
  }

  /**
   * Decode an XML comment tag and return the results in an object.
   *
   * @param xml XML comment element.
   * @returns An object containing the id, size, position, and comment string.
   * @internal
   */
  static parseAttributes(xml: Element): {
    id: string,
    w: number,
    h: number,
    x: number,
    y: number,
    content: string
  } {
    const xmlH = xml.getAttribute('h');
    const xmlW = xml.getAttribute('w');
    const xmlX = xml.getAttribute('x');
    const xmlY = xml.getAttribute('y');
    const xmlId = xml.getAttribute('id');

    if (!xmlId) {
      throw new Error('No ID present in XML comment definition.');
    }

    return {
      id: xmlId,
      // The height of the comment in workspace units, or 100 if not specified.
      h: xmlH ? parseInt(xmlH) : 100,
      // The width of the comment in workspace units, or 100 if not specified.
      w: xmlW ? parseInt(xmlW) : 100,
      // The x position of the comment in workspace coordinates, or NaN if not
      // specified in the XML.
      x: xmlX ? parseInt(xmlX) : NaN,
      // The y position of the comment in workspace coordinates, or NaN if not
      // specified in the XML.
      y: xmlY ? parseInt(xmlY) : NaN,
      content: xml.textContent ?? '',
    };
  }
}