openlayers/src/ol/control/Rotate.js

/**
 * @module ol/control/Rotate
 */

import Control from '../control/Control.js';
import {CLASS_CONTROL, CLASS_HIDDEN, CLASS_UNSELECTABLE} from '../css.js';
import {easeOut} from '../easing.js';
import {listen} from '../events.js';
import EventType from '../events/EventType.js';
import {inherits} from '../util.js';


/**
 * @typedef {Object} Options
 * @property {string} [className='ol-rotate'] CSS class name.
 * @property {string|Element} [label='⇧'] Text label to use for the rotate button.
 * Instead of text, also an element (e.g. a `span` element) can be used.
 * @property {string} [tipLabel='Reset rotation'] Text label to use for the rotate tip.
 * @property {number} [duration=250] Animation duration in milliseconds.
 * @property {boolean} [autoHide=true] Hide the control when rotation is 0.
 * @property {function(module:ol/MapEvent)} [render] Function called when the control should
 * be re-rendered. This is called in a `requestAnimationFrame` callback.
 * @property {function()} [resetNorth] Function called when the control is clicked.
 * This will override the default `resetNorth`.
 * @property {Element|string} [target] Specify a target if you want the control to be
 * rendered outside of the map's viewport.
 */


/**
 * @classdesc
 * A button control to reset rotation to 0.
 * To style this control use css selector `.ol-rotate`. A `.ol-hidden` css
 * selector is added to the button when the rotation is 0.
 *
 * @constructor
 * @extends {module:ol/control/Control}
 * @param {module:ol/control/Rotate~Options=} opt_options Rotate options.
 * @api
 */
const Rotate = function(opt_options) {

  const options = opt_options ? opt_options : {};

  const className = options.className !== undefined ? options.className : 'ol-rotate';

  const label = options.label !== undefined ? options.label : '\u21E7';

  /**
   * @type {Element}
   * @private
   */
  this.label_ = null;

  if (typeof label === 'string') {
    this.label_ = document.createElement('span');
    this.label_.className = 'ol-compass';
    this.label_.textContent = label;
  } else {
    this.label_ = label;
    this.label_.classList.add('ol-compass');
  }

  const tipLabel = options.tipLabel ? options.tipLabel : 'Reset rotation';

  const button = document.createElement('button');
  button.className = className + '-reset';
  button.setAttribute('type', 'button');
  button.title = tipLabel;
  button.appendChild(this.label_);

  listen(button, EventType.CLICK,
    Rotate.prototype.handleClick_, this);

  const cssClasses = className + ' ' + CLASS_UNSELECTABLE + ' ' + CLASS_CONTROL;
  const element = document.createElement('div');
  element.className = cssClasses;
  element.appendChild(button);

  this.callResetNorth_ = options.resetNorth ? options.resetNorth : undefined;

  Control.call(this, {
    element: element,
    render: options.render || render,
    target: options.target
  });

  /**
   * @type {number}
   * @private
   */
  this.duration_ = options.duration !== undefined ? options.duration : 250;

  /**
   * @type {boolean}
   * @private
   */
  this.autoHide_ = options.autoHide !== undefined ? options.autoHide : true;

  /**
   * @private
   * @type {number|undefined}
   */
  this.rotation_ = undefined;

  if (this.autoHide_) {
    this.element.classList.add(CLASS_HIDDEN);
  }

};

inherits(Rotate, Control);


/**
 * @param {Event} event The event to handle
 * @private
 */
Rotate.prototype.handleClick_ = function(event) {
  event.preventDefault();
  if (this.callResetNorth_ !== undefined) {
    this.callResetNorth_();
  } else {
    this.resetNorth_();
  }
};


/**
 * @private
 */
Rotate.prototype.resetNorth_ = function() {
  const map = this.getMap();
  const view = map.getView();
  if (!view) {
    // the map does not have a view, so we can't act
    // upon it
    return;
  }
  if (view.getRotation() !== undefined) {
    if (this.duration_ > 0) {
      view.animate({
        rotation: 0,
        duration: this.duration_,
        easing: easeOut
      });
    } else {
      view.setRotation(0);
    }
  }
};


/**
 * Update the rotate control element.
 * @param {module:ol/MapEvent} mapEvent Map event.
 * @this {module:ol/control/Rotate}
 * @api
 */
export function render(mapEvent) {
  const frameState = mapEvent.frameState;
  if (!frameState) {
    return;
  }
  const rotation = frameState.viewState.rotation;
  if (rotation != this.rotation_) {
    const transform = 'rotate(' + rotation + 'rad)';
    if (this.autoHide_) {
      const contains = this.element.classList.contains(CLASS_HIDDEN);
      if (!contains && rotation === 0) {
        this.element.classList.add(CLASS_HIDDEN);
      } else if (contains && rotation !== 0) {
        this.element.classList.remove(CLASS_HIDDEN);
      }
    }
    this.label_.style.msTransform = transform;
    this.label_.style.webkitTransform = transform;
    this.label_.style.transform = transform;
  }
  this.rotation_ = rotation;
}

export default Rotate;