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- /**
- * @license Copyright (c) 2003-2018, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md.
- */
- /**
- * @module engine/view/position
- */
- import TreeWalker from './treewalker';
- import compareArrays from '@ckeditor/ckeditor5-utils/src/comparearrays';
- import CKEditorError from '@ckeditor/ckeditor5-utils/src/ckeditorerror';
- import EditableElement from './editableelement';
- /**
- * Position in the tree. Position is always located before or after a node.
- */
- export default class Position {
- /**
- * Creates a position.
- *
- * @param {module:engine/view/node~Node|module:engine/view/documentfragment~DocumentFragment} parent Position parent.
- * @param {Number} offset Position offset.
- */
- constructor( parent, offset ) {
- /**
- * Position parent.
- *
- * @readonly
- * @member {module:engine/view/node~Node|module:engine/view/documentfragment~DocumentFragment}
- * module:engine/view/position~Position#parent
- */
- this.parent = parent;
- /**
- * Position offset.
- *
- * @readonly
- * @member {Number} module:engine/view/position~Position#offset
- */
- this.offset = offset;
- }
- /**
- * Node directly after the position. Equals `null` when there is no node after position or position is located
- * inside text node.
- *
- * @readonly
- * @type {module:engine/view/node~Node|null}
- */
- get nodeAfter() {
- if ( this.parent.is( 'text' ) ) {
- return null;
- }
- return this.parent.getChild( this.offset ) || null;
- }
- /**
- * Node directly before the position. Equals `null` when there is no node before position or position is located
- * inside text node.
- *
- * @readonly
- * @type {module:engine/view/node~Node|null}
- */
- get nodeBefore() {
- if ( this.parent.is( 'text' ) ) {
- return null;
- }
- return this.parent.getChild( this.offset - 1 ) || null;
- }
- /**
- * Is `true` if position is at the beginning of its {@link module:engine/view/position~Position#parent parent}, `false` otherwise.
- *
- * @readonly
- * @type {Boolean}
- */
- get isAtStart() {
- return this.offset === 0;
- }
- /**
- * Is `true` if position is at the end of its {@link module:engine/view/position~Position#parent parent}, `false` otherwise.
- *
- * @readonly
- * @type {Boolean}
- */
- get isAtEnd() {
- const endOffset = this.parent.is( 'text' ) ? this.parent.data.length : this.parent.childCount;
- return this.offset === endOffset;
- }
- /**
- * Position's root, that is the root of the position's parent element.
- *
- * @readonly
- * @type {module:engine/view/node~Node|module:engine/view/documentfragment~DocumentFragment}
- */
- get root() {
- return this.parent.root;
- }
- /**
- * {@link module:engine/view/editableelement~EditableElement EditableElement} instance that contains this position, or `null` if
- * position is not inside an editable element.
- *
- * @type {module:engine/view/editableelement~EditableElement|null}
- */
- get editableElement() {
- let editable = this.parent;
- while ( !( editable instanceof EditableElement ) ) {
- if ( editable.parent ) {
- editable = editable.parent;
- } else {
- return null;
- }
- }
- return editable;
- }
- /**
- * Returns a new instance of Position with offset incremented by `shift` value.
- *
- * @param {Number} shift How position offset should get changed. Accepts negative values.
- * @returns {module:engine/view/position~Position} Shifted position.
- */
- getShiftedBy( shift ) {
- const shifted = Position._createAt( this );
- const offset = shifted.offset + shift;
- shifted.offset = offset < 0 ? 0 : offset;
- return shifted;
- }
- /**
- * Gets the farthest position which matches the callback using
- * {@link module:engine/view/treewalker~TreeWalker TreeWalker}.
- *
- * For example:
- *
- * getLastMatchingPosition( value => value.type == 'text' ); // <p>{}foo</p> -> <p>foo[]</p>
- * getLastMatchingPosition( value => value.type == 'text', { direction: 'backward' } ); // <p>foo[]</p> -> <p>{}foo</p>
- * getLastMatchingPosition( value => false ); // Do not move the position.
- *
- * @param {Function} skip Callback function. Gets {@link module:engine/view/treewalker~TreeWalkerValue} and should
- * return `true` if the value should be skipped or `false` if not.
- * @param {Object} options Object with configuration options. See {@link module:engine/view/treewalker~TreeWalker}.
- *
- * @returns {module:engine/view/position~Position} The position after the last item which matches the `skip` callback test.
- */
- getLastMatchingPosition( skip, options = {} ) {
- options.startPosition = this;
- const treeWalker = new TreeWalker( options );
- treeWalker.skip( skip );
- return treeWalker.position;
- }
- /**
- * Returns ancestors array of this position, that is this position's parent and it's ancestors.
- *
- * @returns {Array} Array with ancestors.
- */
- getAncestors() {
- if ( this.parent.is( 'documentFragment' ) ) {
- return [ this.parent ];
- } else {
- return this.parent.getAncestors( { includeSelf: true } );
- }
- }
- /**
- * Returns a {@link module:engine/view/node~Node} or {@link module:engine/view/documentfragment~DocumentFragment}
- * which is a common ancestor of both positions.
- *
- * @param {module:engine/view/position~Position} position
- * @returns {module:engine/view/node~Node|module:engine/view/documentfragment~DocumentFragment|null}
- */
- getCommonAncestor( position ) {
- const ancestorsA = this.getAncestors();
- const ancestorsB = position.getAncestors();
- let i = 0;
- while ( ancestorsA[ i ] == ancestorsB[ i ] && ancestorsA[ i ] ) {
- i++;
- }
- return i === 0 ? null : ancestorsA[ i - 1 ];
- }
- /**
- * Checks whether this position equals given position.
- *
- * @param {module:engine/view/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} True if positions are same.
- */
- isEqual( otherPosition ) {
- return ( this.parent == otherPosition.parent && this.offset == otherPosition.offset );
- }
- /**
- * Checks whether this position is located before given position. When method returns `false` it does not mean that
- * this position is after give one. Two positions may be located inside separate roots and in that situation this
- * method will still return `false`.
- *
- * @see module:engine/view/position~Position#isAfter
- * @see module:engine/view/position~Position#compareWith
- * @param {module:engine/view/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} Returns `true` if this position is before given position.
- */
- isBefore( otherPosition ) {
- return this.compareWith( otherPosition ) == 'before';
- }
- /**
- * Checks whether this position is located after given position. When method returns `false` it does not mean that
- * this position is before give one. Two positions may be located inside separate roots and in that situation this
- * method will still return `false`.
- *
- * @see module:engine/view/position~Position#isBefore
- * @see module:engine/view/position~Position#compareWith
- * @param {module:engine/view/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} Returns `true` if this position is after given position.
- */
- isAfter( otherPosition ) {
- return this.compareWith( otherPosition ) == 'after';
- }
- /**
- * Checks whether this position is before, after or in same position that other position. Two positions may be also
- * different when they are located in separate roots.
- *
- * @param {module:engine/view/position~Position} otherPosition Position to compare with.
- * @returns {module:engine/view/position~PositionRelation}
- */
- compareWith( otherPosition ) {
- if ( this.root !== otherPosition.root ) {
- return 'different';
- }
- if ( this.isEqual( otherPosition ) ) {
- return 'same';
- }
- // Get path from root to position's parent element.
- const thisPath = this.parent.is( 'node' ) ? this.parent.getPath() : [];
- const otherPath = otherPosition.parent.is( 'node' ) ? otherPosition.parent.getPath() : [];
- // Add the positions' offsets to the parents offsets.
- thisPath.push( this.offset );
- otherPath.push( otherPosition.offset );
- // Compare both path arrays to find common ancestor.
- const result = compareArrays( thisPath, otherPath );
- switch ( result ) {
- case 'prefix':
- return 'before';
- case 'extension':
- return 'after';
- default:
- return thisPath[ result ] < otherPath[ result ] ? 'before' : 'after';
- }
- }
- /**
- * Creates a {@link module:engine/view/treewalker~TreeWalker TreeWalker} instance with this positions as a start position.
- *
- * @param {Object} options Object with configuration options. See {@link module:engine/view/treewalker~TreeWalker}
- * @param {module:engine/view/range~Range} [options.boundaries=null] Range to define boundaries of the iterator.
- * @param {Boolean} [options.singleCharacters=false]
- * @param {Boolean} [options.shallow=false]
- * @param {Boolean} [options.ignoreElementEnd=false]
- */
- getWalker( options = {} ) {
- options.startPosition = this;
- return new TreeWalker( options );
- }
- clone() {
- return new Position( this.parent, this.offset );
- }
- /**
- * Creates position at the given location. The location can be specified as:
- *
- * * a {@link module:engine/view/position~Position position},
- * * parent element and offset (offset defaults to `0`),
- * * parent element and `'end'` (sets position at the end of that element),
- * * {@link module:engine/view/item~Item view item} and `'before'` or `'after'` (sets position before or after given view item).
- *
- * This method is a shortcut to other constructors such as:
- *
- * * {@link module:engine/view/position~Position._createBefore},
- * * {@link module:engine/view/position~Position._createAfter}.
- *
- * @protected
- * @param {module:engine/view/item~Item|module:engine/view/position~Position} itemOrPosition
- * @param {Number|'end'|'before'|'after'} [offset] Offset or one of the flags. Used only when
- * first parameter is a {@link module:engine/view/item~Item view item}.
- */
- static _createAt( itemOrPosition, offset ) {
- if ( itemOrPosition instanceof Position ) {
- return new this( itemOrPosition.parent, itemOrPosition.offset );
- } else {
- const node = itemOrPosition;
- if ( offset == 'end' ) {
- offset = node.is( 'text' ) ? node.data.length : node.childCount;
- } else if ( offset == 'before' ) {
- return this._createBefore( node );
- } else if ( offset == 'after' ) {
- return this._createAfter( node );
- } else if ( offset !== 0 && !offset ) {
- /**
- * {@link module:engine/view/view~View#createPositionAt `View#createPositionAt()`}
- * requires the offset to be specified when the first parameter is a view item.
- *
- * @error view-createPositionAt-offset-required
- */
- throw new CKEditorError(
- 'view-createPositionAt-offset-required: ' +
- 'View#createPositionAt() requires the offset when the first parameter is a view item.' );
- }
- return new Position( node, offset );
- }
- }
- /**
- * Creates a new position after given view item.
- *
- * @protected
- * @param {module:engine/view/item~Item} item View item after which the position should be located.
- * @returns {module:engine/view/position~Position}
- */
- static _createAfter( item ) {
- // TextProxy is not a instance of Node so we need do handle it in specific way.
- if ( item.is( 'textProxy' ) ) {
- return new Position( item.textNode, item.offsetInText + item.data.length );
- }
- if ( !item.parent ) {
- /**
- * You can not make a position after a root.
- *
- * @error view-position-after-root
- * @param {module:engine/view/node~Node} root
- */
- throw new CKEditorError( 'view-position-after-root: You can not make position after root.', { root: item } );
- }
- return new Position( item.parent, item.index + 1 );
- }
- /**
- * Creates a new position before given view item.
- *
- * @protected
- * @param {module:engine/view/item~Item} item View item before which the position should be located.
- * @returns {module:engine/view/position~Position}
- */
- static _createBefore( item ) {
- // TextProxy is not a instance of Node so we need do handle it in specific way.
- if ( item.is( 'textProxy' ) ) {
- return new Position( item.textNode, item.offsetInText );
- }
- if ( !item.parent ) {
- /**
- * You cannot make a position before a root.
- *
- * @error view-position-before-root
- * @param {module:engine/view/node~Node} root
- */
- throw new CKEditorError( 'view-position-before-root: You can not make position before root.', { root: item } );
- }
- return new Position( item.parent, item.index );
- }
- }
- /**
- * A flag indicating whether this position is `'before'` or `'after'` or `'same'` as given position.
- * If positions are in different roots `'different'` flag is returned.
- *
- * @typedef {String} module:engine/view/position~PositionRelation
- */
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