documentfragment.js 4.7 KB

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  1. /**
  2. * @license Copyright (c) 2003-2016, CKSource - Frederico Knabben. All rights reserved.
  3. * For licensing, see LICENSE.md.
  4. */
  5. import Text from './text.js';
  6. import mix from '../../utils/mix.js';
  7. import isIterable from '../../utils/isiterable.js';
  8. import EmitterMixin from '../../utils/emittermixin.js';
  9. /**
  10. * DocumentFragment class.
  11. *
  12. * @memberOf engine.view
  13. */
  14. export default class DocumentFragment {
  15. /**
  16. * Creates new DocumentFragment instance.
  17. *
  18. * @param {engine.view.Node|Iterable.<engine.view.Node>} [children] List of nodes to be inserted into
  19. * created document fragment.
  20. */
  21. constructor( children ) {
  22. /**
  23. * Array of child nodes.
  24. *
  25. * @protected
  26. * @member {Array.<engine.view.Element>} engine.view.DocumentFragment#_children
  27. */
  28. this._children = [];
  29. if ( children ) {
  30. this.insertChildren( 0, children );
  31. }
  32. }
  33. /**
  34. * Iterates over nodes added to this DocumentFragment.
  35. */
  36. [ Symbol.iterator ]() {
  37. return this._children[ Symbol.iterator ]();
  38. }
  39. /**
  40. * Artificial root of `DocumentFragment`. Returns itself. Added for compatibility reasons.
  41. *
  42. * @readonly
  43. * @type {engine.model.DocumentFragment}
  44. */
  45. get root() {
  46. return this;
  47. }
  48. /**
  49. * Returns ancestor elements of `DocumentFragment`, which is an empty array. Added for compatibility reasons.
  50. *
  51. * @returns {Array}
  52. */
  53. getAncestors() {
  54. return [];
  55. }
  56. /**
  57. * {@link engine.view.DocumentFragment#insertChildren Insert} a child node or a list of child nodes at the end
  58. * and sets the parent of these nodes to this fragment.
  59. *
  60. * @param {engine.view.Node|Iterable.<engine.view.Node>} nodes Node or the list of nodes to be inserted.
  61. * @returns {Number} Number of appended nodes.
  62. */
  63. appendChildren( nodes ) {
  64. return this.insertChildren( this.getChildCount(), nodes );
  65. }
  66. /**
  67. * Gets child at the given index.
  68. *
  69. * @param {Number} index Index of child.
  70. * @returns {engine.view.Node} Child node.
  71. */
  72. getChild( index ) {
  73. return this._children[ index ];
  74. }
  75. /**
  76. * Gets the number of elements in fragment.
  77. *
  78. * @returns {Number} The number of elements.
  79. */
  80. getChildCount() {
  81. return this._children.length;
  82. }
  83. /**
  84. * Gets index of the given child node. Returns `-1` if child node is not found.
  85. *
  86. * @param {engine.view.Node} node Child node.
  87. * @returns {Number} Index of the child node.
  88. */
  89. getChildIndex( node ) {
  90. return this._children.indexOf( node );
  91. }
  92. /**
  93. * Gets child nodes iterator.
  94. *
  95. * @returns {Iterable.<engine.view.Node>} Child nodes iterator.
  96. */
  97. getChildren() {
  98. return this._children[ Symbol.iterator ]();
  99. }
  100. /**
  101. * Inserts a child node or a list of child nodes on the given index and sets the parent of these nodes to
  102. * this fragment.
  103. *
  104. * @param {Number} index Position where nodes should be inserted.
  105. * @param {engine.view.Node|Iterable.<engine.view.Node>} nodes Node or list of nodes to be inserted.
  106. * @returns {Number} Number of inserted nodes.
  107. */
  108. insertChildren( index, nodes ) {
  109. this._fireChange( 'children', this );
  110. let count = 0;
  111. nodes = normalize( nodes );
  112. for ( let node of nodes ) {
  113. node.parent = this;
  114. this._children.splice( index, 0, node );
  115. index++;
  116. count++;
  117. }
  118. return count;
  119. }
  120. /**
  121. * Returns `true` if there are no nodes inside this document fragment, `false` otherwise.
  122. *
  123. * @returns {Boolean}
  124. */
  125. isEmpty() {
  126. return this.getChildCount() === 0;
  127. }
  128. /**
  129. * Removes number of child nodes starting at the given index and set the parent of these nodes to `null`.
  130. *
  131. * @param {Number} index Number of the first node to remove.
  132. * @param {Number} [howMany=1] Number of nodes to remove.
  133. * @returns {Array.<engine.view.Node>} The array of removed nodes.
  134. */
  135. removeChildren( index, howMany = 1 ) {
  136. this._fireChange( 'children', this );
  137. for ( let i = index; i < index + howMany; i++ ) {
  138. this._children[ i ].parent = null;
  139. }
  140. return this._children.splice( index, howMany );
  141. }
  142. /**
  143. * Fires `change` event with given type of the change.
  144. *
  145. * @private
  146. * @param {engine.view.ChangeType} type Type of the change.
  147. * @param {engine.view.Node} node Changed node.
  148. * @fires engine.view.Node#change
  149. */
  150. _fireChange( type, node ) {
  151. this.fire( 'change:' + type, node );
  152. }
  153. }
  154. mix( DocumentFragment, EmitterMixin );
  155. // Converts strings to Text and non-iterables to arrays.
  156. //
  157. // @param {String|engine.view.Node|Iterable.<String|engine.view.Node>}
  158. // @return {Iterable.<engine.view.Node>}
  159. function normalize( nodes ) {
  160. // Separate condition because string is iterable.
  161. if ( typeof nodes == 'string' ) {
  162. return [ new Text( nodes ) ];
  163. }
  164. if ( !isIterable( nodes ) ) {
  165. nodes = [ nodes ];
  166. }
  167. // Array.from to enable .map() on non-arrays.
  168. return Array.from( nodes ).map( ( node ) => typeof node == 'string' ? new Text( node ) : node );
  169. }