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- /**
- * @license Copyright (c) 2003-2020, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
- /**
- * @module engine/model/position
- */
- import TreeWalker from './treewalker';
- import compareArrays from '@ckeditor/ckeditor5-utils/src/comparearrays';
- import CKEditorError from '@ckeditor/ckeditor5-utils/src/ckeditorerror';
- // To check if component is loaded more than once.
- import '@ckeditor/ckeditor5-utils/src/version';
- /**
- * Represents a position in the model tree.
- *
- * A position is represented by its {@link module:engine/model/position~Position#root} and
- * a {@link module:engine/model/position~Position#path} in that root.
- *
- * You can create position instances via its constructor or the `createPosition*()` factory methods of
- * {@link module:engine/model/model~Model} and {@link module:engine/model/writer~Writer}.
- *
- * **Note:** Position is based on offsets, not indexes. This means that a position between two text nodes
- * `foo` and `bar` has offset `3`, not `1`. See {@link module:engine/model/position~Position#path} for more information.
- *
- * Since a position in the model is represented by a {@link module:engine/model/position~Position#root position root} and
- * {@link module:engine/model/position~Position#path position path} it is possible to create positions placed in non-existing places.
- * This requirement is important for operational transformation algorithms.
- *
- * Also, {@link module:engine/model/operation/operation~Operation operations}
- * kept in the {@link module:engine/model/document~Document#history document history}
- * are storing positions (and ranges) which were correct when those operations were applied, but may not be correct
- * after the document has changed.
- *
- * When changes are applied to the model, it may also happen that {@link module:engine/model/position~Position#parent position parent}
- * will change even if position path has not changed. Keep in mind, that if a position leads to non-existing element,
- * {@link module:engine/model/position~Position#parent} and some other properties and methods will throw errors.
- *
- * In most cases, position with wrong path is caused by an error in code, but it is sometimes needed, as described above.
- */
- export default class Position {
- /**
- * Creates a position.
- *
- * @param {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment} root Root of the position.
- * @param {Array.<Number>} path Position path. See {@link module:engine/model/position~Position#path}.
- * @param {module:engine/model/position~PositionStickiness} [stickiness='toNone'] Position stickiness.
- * See {@link module:engine/model/position~PositionStickiness}.
- */
- constructor( root, path, stickiness = 'toNone' ) {
- if ( !root.is( 'element' ) && !root.is( 'documentFragment' ) ) {
- /**
- * Position root is invalid.
- *
- * Positions can only be anchored in elements or document fragments.
- *
- * @error model-position-root-invalid
- */
- throw new CKEditorError(
- 'model-position-root-invalid: Position root invalid.',
- root
- );
- }
- if ( !( path instanceof Array ) || path.length === 0 ) {
- /**
- * Position path must be an array with at least one item.
- *
- * @error model-position-path-incorrect-format
- * @param path
- */
- throw new CKEditorError(
- 'model-position-path-incorrect-format: Position path must be an array with at least one item.',
- root,
- { path }
- );
- }
- // Normalize the root and path when element (not root) is passed.
- if ( root.is( 'rootElement' ) ) {
- path = path.slice();
- } else {
- path = [ ...root.getPath(), ...path ];
- root = root.root;
- }
- /**
- * Root of the position path.
- *
- * @readonly
- * @member {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment}
- * module:engine/model/position~Position#root
- */
- this.root = root;
- /**
- * Position of the node in the tree. **Path contains offsets, not indexes.**
- *
- * Position can be placed before, after or in a {@link module:engine/model/node~Node node} if that node has
- * {@link module:engine/model/node~Node#offsetSize} greater than `1`. Items in position path are
- * {@link module:engine/model/node~Node#startOffset starting offsets} of position ancestors, starting from direct root children,
- * down to the position offset in it's parent.
- *
- * ROOT
- * |- P before: [ 0 ] after: [ 1 ]
- * |- UL before: [ 1 ] after: [ 2 ]
- * |- LI before: [ 1, 0 ] after: [ 1, 1 ]
- * | |- foo before: [ 1, 0, 0 ] after: [ 1, 0, 3 ]
- * |- LI before: [ 1, 1 ] after: [ 1, 2 ]
- * |- bar before: [ 1, 1, 0 ] after: [ 1, 1, 3 ]
- *
- * `foo` and `bar` are representing {@link module:engine/model/text~Text text nodes}. Since text nodes has offset size
- * greater than `1` you can place position offset between their start and end:
- *
- * ROOT
- * |- P
- * |- UL
- * |- LI
- * | |- f^o|o ^ has path: [ 1, 0, 1 ] | has path: [ 1, 0, 2 ]
- * |- LI
- * |- b^a|r ^ has path: [ 1, 1, 1 ] | has path: [ 1, 1, 2 ]
- *
- * @readonly
- * @member {Array.<Number>} module:engine/model/position~Position#path
- */
- this.path = path;
- /**
- * Position stickiness. See {@link module:engine/model/position~PositionStickiness}.
- *
- * @member {module:engine/model/position~PositionStickiness} module:engine/model/position~Position#stickiness
- */
- this.stickiness = stickiness;
- }
- /**
- * Offset at which this position is located in its {@link module:engine/model/position~Position#parent parent}. It is equal
- * to the last item in position {@link module:engine/model/position~Position#path path}.
- *
- * @type {Number}
- */
- get offset() {
- return this.path[ this.path.length - 1 ];
- }
- set offset( newOffset ) {
- this.path[ this.path.length - 1 ] = newOffset;
- }
- /**
- * Parent element of this position.
- *
- * Keep in mind that `parent` value is calculated when the property is accessed.
- * If {@link module:engine/model/position~Position#path position path}
- * leads to a non-existing element, `parent` property will throw error.
- *
- * Also it is a good idea to cache `parent` property if it is used frequently in an algorithm (i.e. in a long loop).
- *
- * @readonly
- * @type {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment}
- */
- get parent() {
- let parent = this.root;
- for ( let i = 0; i < this.path.length - 1; i++ ) {
- parent = parent.getChild( parent.offsetToIndex( this.path[ i ] ) );
- if ( !parent ) {
- throw new CKEditorError( 'model-position-path-incorrect: The position\'s path is incorrect.', this, { position: this } );
- }
- }
- if ( parent.is( '$text' ) ) {
- /**
- * The position's path is incorrect. This means that a position does not point to
- * a correct place in the tree and hence, some of its methods and getters cannot work correctly.
- *
- * **Note**: Unlike DOM and view positions, in the model, the
- * {@link module:engine/model/position~Position#parent position's parent} is always an element or a document fragment.
- * The last offset in the {@link module:engine/model/position~Position#path position's path} is the point in this element where
- * this position points.
- *
- * Read more about model positions and offsets in
- * the {@glink framework/guides/architecture/editing-engine#indexes-and-offsets Editing engine architecture guide}.
- *
- * @error position-incorrect-path
- * @param {module:engine/model/position~Position} position The incorrect position.
- */
- throw new CKEditorError( 'model-position-path-incorrect: The position\'s path is incorrect.', this, { position: this } );
- }
- return parent;
- }
- /**
- * Position {@link module:engine/model/position~Position#offset offset} converted to an index in position's parent node. It is
- * equal to the {@link module:engine/model/node~Node#index index} of a node after this position. If position is placed
- * in text node, position index is equal to the index of that text node.
- *
- * @readonly
- * @type {Number}
- */
- get index() {
- return this.parent.offsetToIndex( this.offset );
- }
- /**
- * Returns {@link module:engine/model/text~Text text node} instance in which this position is placed or `null` if this
- * position is not in a text node.
- *
- * @readonly
- * @type {module:engine/model/text~Text|null}
- */
- get textNode() {
- return getTextNodeAtPosition( this, this.parent );
- }
- /**
- * Node directly after this position or `null` if this position is in text node.
- *
- * @readonly
- * @type {module:engine/model/node~Node|null}
- */
- get nodeAfter() {
- // Cache the parent and reuse for performance reasons. See #6579 and #6582.
- const parent = this.parent;
- return getNodeAfterPosition( this, parent, getTextNodeAtPosition( this, parent ) );
- }
- /**
- * Node directly before this position or `null` if this position is in text node.
- *
- * @readonly
- * @type {module:engine/model/node~Node|null}
- */
- get nodeBefore() {
- // Cache the parent and reuse for performance reasons. See #6579 and #6582.
- const parent = this.parent;
- return getNodeBeforePosition( this, parent, getTextNodeAtPosition( this, parent ) );
- }
- /**
- * Is `true` if position is at the beginning of its {@link module:engine/model/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/model/position~Position#parent parent}, `false` otherwise.
- *
- * @readonly
- * @type {Boolean}
- */
- get isAtEnd() {
- return this.offset == this.parent.maxOffset;
- }
- /**
- * Checks whether this position is before or after given position.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {module:engine/model/position~Position} otherPosition Position to compare with.
- * @returns {module:engine/model/position~PositionRelation}
- */
- compareWith( otherPosition ) {
- if ( this.root != otherPosition.root ) {
- return 'different';
- }
- const result = compareArrays( this.path, otherPosition.path );
- switch ( result ) {
- case 'same':
- return 'same';
- case 'prefix':
- return 'before';
- case 'extension':
- return 'after';
- default:
- return this.path[ result ] < otherPosition.path[ result ] ? 'before' : 'after';
- }
- }
- /**
- * Gets the farthest position which matches the callback using
- * {@link module:engine/model/treewalker~TreeWalker TreeWalker}.
- *
- * For example:
- *
- * getLastMatchingPosition( value => value.type == 'text' );
- * // <paragraph>[]foo</paragraph> -> <paragraph>foo[]</paragraph>
- *
- * getLastMatchingPosition( value => value.type == 'text', { direction: 'backward' } );
- * // <paragraph>foo[]</paragraph> -> <paragraph>[]foo</paragraph>
- *
- * getLastMatchingPosition( value => false );
- * // Do not move the position.
- *
- * @param {Function} skip Callback function. Gets {@link module:engine/model/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/model/treewalker~TreeWalker}.
- *
- * @returns {module:engine/model/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 a path to this position's parent. Parent path is equal to position {@link module:engine/model/position~Position#path path}
- * but without the last item.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @returns {Array.<Number>} Path to the parent.
- */
- getParentPath() {
- return this.path.slice( 0, -1 );
- }
- /**
- * Returns ancestors array of this position, that is this position's parent and its ancestors.
- *
- * @returns {Array.<module:engine/model/item~Item>} Array with ancestors.
- */
- getAncestors() {
- const parent = this.parent;
- if ( parent.is( 'documentFragment' ) ) {
- return [ parent ];
- } else {
- return parent.getAncestors( { includeSelf: true } );
- }
- }
- /**
- * Returns the parent element of the given name. Returns null if the position is not inside the desired parent.
- *
- * @param {String} parentName The name of the parent element to find.
- * @returns {module:engine/model/element~Element|null}
- */
- findAncestor( parentName ) {
- const parent = this.parent;
- if ( parent.is( 'element' ) ) {
- return parent.findAncestor( parentName, { includeSelf: true } );
- }
- return null;
- }
- /**
- * Returns the slice of two position {@link #path paths} which is identical. The {@link #root roots}
- * of these two paths must be identical.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {module:engine/model/position~Position} position The second position.
- * @returns {Array.<Number>} The common path.
- */
- getCommonPath( position ) {
- if ( this.root != position.root ) {
- return [];
- }
- // We find on which tree-level start and end have the lowest common ancestor
- const cmp = compareArrays( this.path, position.path );
- // If comparison returned string it means that arrays are same.
- const diffAt = ( typeof cmp == 'string' ) ? Math.min( this.path.length, position.path.length ) : cmp;
- return this.path.slice( 0, diffAt );
- }
- /**
- * Returns an {@link module:engine/model/element~Element} or {@link module:engine/model/documentfragment~DocumentFragment}
- * which is a common ancestor of both positions. The {@link #root roots} of these two positions must be identical.
- *
- * @param {module:engine/model/position~Position} position The second position.
- * @returns {module:engine/model/element~Element|module:engine/model/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 ];
- }
- /**
- * Returns a new instance of `Position`, that has same {@link #parent parent} but it's offset
- * is shifted by `shift` value (can be a negative value).
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {Number} shift Offset shift. Can be a negative value.
- * @returns {module:engine/model/position~Position} Shifted position.
- */
- getShiftedBy( shift ) {
- const shifted = this.clone();
- const offset = shifted.offset + shift;
- shifted.offset = offset < 0 ? 0 : offset;
- return shifted;
- }
- /**
- * Checks whether this position is after given position.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @see module:engine/model/position~Position#isBefore
- * @param {module:engine/model/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} True if this position is after given position.
- */
- isAfter( otherPosition ) {
- return this.compareWith( otherPosition ) == 'after';
- }
- /**
- * Checks whether this position is before given position.
- *
- * **Note:** watch out when using negation of the value returned by this method, because the negation will also
- * be `true` if positions are in different roots and you might not expect this. You should probably use
- * `a.isAfter( b ) || a.isEqual( b )` or `!a.isBefore( p ) && a.root == b.root` in most scenarios. If your
- * condition uses multiple `isAfter` and `isBefore` checks, build them so they do not use negated values, i.e.:
- *
- * if ( a.isBefore( b ) && c.isAfter( d ) ) {
- * // do A.
- * } else {
- * // do B.
- * }
- *
- * or, if you have only one if-branch:
- *
- * if ( !( a.isBefore( b ) && c.isAfter( d ) ) {
- * // do B.
- * }
- *
- * rather than:
- *
- * if ( !a.isBefore( b ) || && !c.isAfter( d ) ) {
- * // do B.
- * } else {
- * // do A.
- * }
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {module:engine/model/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} True if this position is before given position.
- */
- isBefore( otherPosition ) {
- return this.compareWith( otherPosition ) == 'before';
- }
- /**
- * Checks whether this position is equal to given position.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {module:engine/model/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} True if positions are same.
- */
- isEqual( otherPosition ) {
- return this.compareWith( otherPosition ) == 'same';
- }
- /**
- * Checks whether this position is touching given position. Positions touch when there are no text nodes
- * or empty nodes in a range between them. Technically, those positions are not equal but in many cases
- * they are very similar or even indistinguishable.
- *
- * @param {module:engine/model/position~Position} otherPosition Position to compare with.
- * @returns {Boolean} True if positions touch.
- */
- isTouching( otherPosition ) {
- let left = null;
- let right = null;
- const compare = this.compareWith( otherPosition );
- switch ( compare ) {
- case 'same':
- return true;
- case 'before':
- left = Position._createAt( this );
- right = Position._createAt( otherPosition );
- break;
- case 'after':
- left = Position._createAt( otherPosition );
- right = Position._createAt( this );
- break;
- default:
- return false;
- }
- // Cached for optimization purposes.
- let leftParent = left.parent;
- while ( left.path.length + right.path.length ) {
- if ( left.isEqual( right ) ) {
- return true;
- }
- if ( left.path.length > right.path.length ) {
- if ( left.offset !== leftParent.maxOffset ) {
- return false;
- }
- left.path = left.path.slice( 0, -1 );
- leftParent = leftParent.parent;
- left.offset++;
- } else {
- if ( right.offset !== 0 ) {
- return false;
- }
- right.path = right.path.slice( 0, -1 );
- }
- }
- }
- /**
- * Checks whether this object is of the given.
- *
- * position.is( 'position' ); // -> true
- * position.is( 'model:position' ); // -> true
- *
- * position.is( 'view:position' ); // -> false
- * position.is( 'documentSelection' ); // -> false
- *
- * {@link module:engine/model/node~Node#is Check the entire list of model objects} which implement the `is()` method.
- *
- * @param {String} type
- * @returns {Boolean}
- */
- is( type ) {
- return type === 'position' || type === 'model:position';
- }
- /**
- * Checks if two positions are in the same parent.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {module:engine/model/position~Position} position Position to compare with.
- * @returns {Boolean} `true` if positions have the same parent, `false` otherwise.
- */
- hasSameParentAs( position ) {
- if ( this.root !== position.root ) {
- return false;
- }
- const thisParentPath = this.getParentPath();
- const posParentPath = position.getParentPath();
- return compareArrays( thisParentPath, posParentPath ) == 'same';
- }
- /**
- * Returns a copy of this position that is transformed by given `operation`.
- *
- * The new position's parameters are updated accordingly to the effect of the `operation`.
- *
- * For example, if `n` nodes are inserted before the position, the returned position {@link ~Position#offset} will be
- * increased by `n`. If the position was in a merged element, it will be accordingly moved to the new element, etc.
- *
- * This method is safe to use it on non-existing positions (for example during operational transformation).
- *
- * @param {module:engine/model/operation/operation~Operation} operation Operation to transform by.
- * @returns {module:engine/model/position~Position} Transformed position.
- */
- getTransformedByOperation( operation ) {
- let result;
- switch ( operation.type ) {
- case 'insert':
- result = this._getTransformedByInsertOperation( operation );
- break;
- case 'move':
- case 'remove':
- case 'reinsert':
- result = this._getTransformedByMoveOperation( operation );
- break;
- case 'split':
- result = this._getTransformedBySplitOperation( operation );
- break;
- case 'merge':
- result = this._getTransformedByMergeOperation( operation );
- break;
- default:
- result = Position._createAt( this );
- break;
- }
- return result;
- }
- /**
- * Returns a copy of this position transformed by an insert operation.
- *
- * @protected
- * @param {module:engine/model/operation/insertoperation~InsertOperation} operation
- * @returns {module:engine/model/position~Position}
- */
- _getTransformedByInsertOperation( operation ) {
- return this._getTransformedByInsertion( operation.position, operation.howMany );
- }
- /**
- * Returns a copy of this position transformed by a move operation.
- *
- * @protected
- * @param {module:engine/model/operation/moveoperation~MoveOperation} operation
- * @returns {module:engine/model/position~Position}
- */
- _getTransformedByMoveOperation( operation ) {
- return this._getTransformedByMove( operation.sourcePosition, operation.targetPosition, operation.howMany );
- }
- /**
- * Returns a copy of this position transformed by a split operation.
- *
- * @protected
- * @param {module:engine/model/operation/splitoperation~SplitOperation} operation
- * @returns {module:engine/model/position~Position}
- */
- _getTransformedBySplitOperation( operation ) {
- const movedRange = operation.movedRange;
- const isContained = movedRange.containsPosition( this ) ||
- ( movedRange.start.isEqual( this ) && this.stickiness == 'toNext' );
- if ( isContained ) {
- return this._getCombined( operation.splitPosition, operation.moveTargetPosition );
- } else {
- if ( operation.graveyardPosition ) {
- return this._getTransformedByMove( operation.graveyardPosition, operation.insertionPosition, 1 );
- } else {
- return this._getTransformedByInsertion( operation.insertionPosition, 1 );
- }
- }
- }
- /**
- * Returns a copy of this position transformed by merge operation.
- *
- * @protected
- * @param {module:engine/model/operation/mergeoperation~MergeOperation} operation
- * @returns {module:engine/model/position~Position}
- */
- _getTransformedByMergeOperation( operation ) {
- const movedRange = operation.movedRange;
- const isContained = movedRange.containsPosition( this ) || movedRange.start.isEqual( this );
- let pos;
- if ( isContained ) {
- pos = this._getCombined( operation.sourcePosition, operation.targetPosition );
- if ( operation.sourcePosition.isBefore( operation.targetPosition ) ) {
- // Above happens during OT when the merged element is moved before the merged-to element.
- pos = pos._getTransformedByDeletion( operation.deletionPosition, 1 );
- }
- } else if ( this.isEqual( operation.deletionPosition ) ) {
- pos = Position._createAt( operation.deletionPosition );
- } else {
- pos = this._getTransformedByMove( operation.deletionPosition, operation.graveyardPosition, 1 );
- }
- return pos;
- }
- /**
- * Returns a copy of this position that is updated by removing `howMany` nodes starting from `deletePosition`.
- * It may happen that this position is in a removed node. If that is the case, `null` is returned instead.
- *
- * @protected
- * @param {module:engine/model/position~Position} deletePosition Position before the first removed node.
- * @param {Number} howMany How many nodes are removed.
- * @returns {module:engine/model/position~Position|null} Transformed position or `null`.
- */
- _getTransformedByDeletion( deletePosition, howMany ) {
- const transformed = Position._createAt( this );
- // This position can't be affected if deletion was in a different root.
- if ( this.root != deletePosition.root ) {
- return transformed;
- }
- if ( compareArrays( deletePosition.getParentPath(), this.getParentPath() ) == 'same' ) {
- // If nodes are removed from the node that is pointed by this position...
- if ( deletePosition.offset < this.offset ) {
- // And are removed from before an offset of that position...
- if ( deletePosition.offset + howMany > this.offset ) {
- // Position is in removed range, it's no longer in the tree.
- return null;
- } else {
- // Decrement the offset accordingly.
- transformed.offset -= howMany;
- }
- }
- } else if ( compareArrays( deletePosition.getParentPath(), this.getParentPath() ) == 'prefix' ) {
- // If nodes are removed from a node that is on a path to this position...
- const i = deletePosition.path.length - 1;
- if ( deletePosition.offset <= this.path[ i ] ) {
- // And are removed from before next node of that path...
- if ( deletePosition.offset + howMany > this.path[ i ] ) {
- // If the next node of that path is removed return null
- // because the node containing this position got removed.
- return null;
- } else {
- // Otherwise, decrement index on that path.
- transformed.path[ i ] -= howMany;
- }
- }
- }
- return transformed;
- }
- /**
- * Returns a copy of this position that is updated by inserting `howMany` nodes at `insertPosition`.
- *
- * @protected
- * @param {module:engine/model/position~Position} insertPosition Position where nodes are inserted.
- * @param {Number} howMany How many nodes are inserted.
- * @returns {module:engine/model/position~Position} Transformed position.
- */
- _getTransformedByInsertion( insertPosition, howMany ) {
- const transformed = Position._createAt( this );
- // This position can't be affected if insertion was in a different root.
- if ( this.root != insertPosition.root ) {
- return transformed;
- }
- if ( compareArrays( insertPosition.getParentPath(), this.getParentPath() ) == 'same' ) {
- // If nodes are inserted in the node that is pointed by this position...
- if ( insertPosition.offset < this.offset || ( insertPosition.offset == this.offset && this.stickiness != 'toPrevious' ) ) {
- // And are inserted before an offset of that position...
- // "Push" this positions offset.
- transformed.offset += howMany;
- }
- } else if ( compareArrays( insertPosition.getParentPath(), this.getParentPath() ) == 'prefix' ) {
- // If nodes are inserted in a node that is on a path to this position...
- const i = insertPosition.path.length - 1;
- if ( insertPosition.offset <= this.path[ i ] ) {
- // And are inserted before next node of that path...
- // "Push" the index on that path.
- transformed.path[ i ] += howMany;
- }
- }
- return transformed;
- }
- /**
- * Returns a copy of this position that is updated by moving `howMany` nodes from `sourcePosition` to `targetPosition`.
- *
- * @protected
- * @param {module:engine/model/position~Position} sourcePosition Position before the first element to move.
- * @param {module:engine/model/position~Position} targetPosition Position where moved elements will be inserted.
- * @param {Number} howMany How many consecutive nodes to move, starting from `sourcePosition`.
- * @returns {module:engine/model/position~Position} Transformed position.
- */
- _getTransformedByMove( sourcePosition, targetPosition, howMany ) {
- // Update target position, as it could be affected by nodes removal.
- targetPosition = targetPosition._getTransformedByDeletion( sourcePosition, howMany );
- if ( sourcePosition.isEqual( targetPosition ) ) {
- // If `targetPosition` is equal to `sourcePosition` this isn't really any move. Just return position as it is.
- return Position._createAt( this );
- }
- // Moving a range removes nodes from their original position. We acknowledge this by proper transformation.
- const transformed = this._getTransformedByDeletion( sourcePosition, howMany );
- const isMoved = transformed === null ||
- ( sourcePosition.isEqual( this ) && this.stickiness == 'toNext' ) ||
- ( sourcePosition.getShiftedBy( howMany ).isEqual( this ) && this.stickiness == 'toPrevious' );
- if ( isMoved ) {
- // This position is inside moved range (or sticks to it).
- // In this case, we calculate a combination of this position, move source position and target position.
- return this._getCombined( sourcePosition, targetPosition );
- } else {
- // This position is not inside a removed range.
- //
- // In next step, we simply reflect inserting `howMany` nodes, which might further affect the position.
- return transformed._getTransformedByInsertion( targetPosition, howMany );
- }
- }
- /**
- * Returns a new position that is a combination of this position and given positions.
- *
- * The combined position is a copy of this position transformed by moving a range starting at `source` position
- * to the `target` position. It is expected that this position is inside the moved range.
- *
- * Example:
- *
- * let original = model.createPositionFromPath( root, [ 2, 3, 1 ] );
- * let source = model.createPositionFromPath( root, [ 2, 2 ] );
- * let target = model.createPositionFromPath( otherRoot, [ 1, 1, 3 ] );
- * original._getCombined( source, target ); // path is [ 1, 1, 4, 1 ], root is `otherRoot`
- *
- * Explanation:
- *
- * We have a position `[ 2, 3, 1 ]` and move some nodes from `[ 2, 2 ]` to `[ 1, 1, 3 ]`. The original position
- * was inside moved nodes and now should point to the new place. The moved nodes will be after
- * positions `[ 1, 1, 3 ]`, `[ 1, 1, 4 ]`, `[ 1, 1, 5 ]`. Since our position was in the second moved node,
- * the transformed position will be in a sub-tree of a node at `[ 1, 1, 4 ]`. Looking at original path, we
- * took care of `[ 2, 3 ]` part of it. Now we have to add the rest of the original path to the transformed path.
- * Finally, the transformed position will point to `[ 1, 1, 4, 1 ]`.
- *
- * @protected
- * @param {module:engine/model/position~Position} source Beginning of the moved range.
- * @param {module:engine/model/position~Position} target Position where the range is moved.
- * @returns {module:engine/model/position~Position} Combined position.
- */
- _getCombined( source, target ) {
- const i = source.path.length - 1;
- // The first part of a path to combined position is a path to the place where nodes were moved.
- const combined = Position._createAt( target );
- combined.stickiness = this.stickiness;
- // Then we have to update the rest of the path.
- // Fix the offset because this position might be after `from` position and we have to reflect that.
- combined.offset = combined.offset + this.path[ i ] - source.offset;
- // Then, add the rest of the path.
- // If this position is at the same level as `from` position nothing will get added.
- combined.path = [ ...combined.path, ...this.path.slice( i + 1 ) ];
- return combined;
- }
- /**
- * @inheritDoc
- */
- toJSON() {
- return {
- root: this.root.toJSON(),
- path: Array.from( this.path ),
- stickiness: this.stickiness
- };
- }
- /**
- * Returns a new position that is equal to current position.
- *
- * @returns {module:engine/model/position~Position}
- */
- clone() {
- return new this.constructor( this.root, this.path, this.stickiness );
- }
- /**
- * Creates position at the given location. The location can be specified as:
- *
- * * a {@link module:engine/model/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/model/item~Item model item} and `'before'` or `'after'` (sets position before or after given model item).
- *
- * This method is a shortcut to other factory methods such as:
- *
- * * {@link module:engine/model/position~Position._createBefore},
- * * {@link module:engine/model/position~Position._createAfter}.
- *
- * @param {module:engine/model/item~Item|module:engine/model/position~Position} itemOrPosition
- * @param {Number|'end'|'before'|'after'} [offset] Offset or one of the flags. Used only when the
- * first parameter is a {@link module:engine/model/item~Item model item}.
- * @param {module:engine/model/position~PositionStickiness} [stickiness='toNone'] Position stickiness. Used only when the
- * first parameter is a {@link module:engine/model/item~Item model item}.
- * @protected
- */
- static _createAt( itemOrPosition, offset, stickiness = 'toNone' ) {
- if ( itemOrPosition instanceof Position ) {
- return new Position( itemOrPosition.root, itemOrPosition.path, itemOrPosition.stickiness );
- } else {
- const node = itemOrPosition;
- if ( offset == 'end' ) {
- offset = node.maxOffset;
- } else if ( offset == 'before' ) {
- return this._createBefore( node, stickiness );
- } else if ( offset == 'after' ) {
- return this._createAfter( node, stickiness );
- } else if ( offset !== 0 && !offset ) {
- /**
- * {@link module:engine/model/model~Model#createPositionAt `Model#createPositionAt()`}
- * requires the offset to be specified when the first parameter is a model item.
- *
- * @error model-createPositionAt-offset-required
- */
- throw new CKEditorError(
- 'model-createPositionAt-offset-required: ' +
- 'Model#createPositionAt() requires the offset when the first parameter is a model item.',
- [ this, itemOrPosition ]
- );
- }
- if ( !node.is( 'element' ) && !node.is( 'documentFragment' ) ) {
- /**
- * Position parent have to be a model element or model document fragment.
- *
- * @error model-position-parent-incorrect
- */
- throw new CKEditorError(
- 'model-position-parent-incorrect: Position parent have to be a element or document fragment.',
- [ this, itemOrPosition ]
- );
- }
- const path = node.getPath();
- path.push( offset );
- return new this( node.root, path, stickiness );
- }
- }
- /**
- * Creates a new position, after given {@link module:engine/model/item~Item model item}.
- *
- * @param {module:engine/model/item~Item} item Item after which the position should be placed.
- * @param {module:engine/model/position~PositionStickiness} [stickiness='toNone'] Position stickiness.
- * @returns {module:engine/model/position~Position}
- * @protected
- */
- static _createAfter( item, stickiness ) {
- if ( !item.parent ) {
- /**
- * You can not make a position after a root element.
- *
- * @error model-position-after-root
- * @param {module:engine/model/item~Item} root
- */
- throw new CKEditorError(
- 'model-position-after-root: You cannot make a position after root.',
- [ this, item ],
- { root: item }
- );
- }
- return this._createAt( item.parent, item.endOffset, stickiness );
- }
- /**
- * Creates a new position, before the given {@link module:engine/model/item~Item model item}.
- *
- * @param {module:engine/model/item~Item} item Item before which the position should be placed.
- * @param {module:engine/model/position~PositionStickiness} [stickiness='toNone'] Position stickiness.
- * @returns {module:engine/model/position~Position}
- * @protected
- */
- static _createBefore( item, stickiness ) {
- if ( !item.parent ) {
- /**
- * You can not make a position before a root element.
- *
- * @error model-position-before-root
- * @param {module:engine/model/item~Item} root
- */
- throw new CKEditorError(
- 'model-position-before-root: You cannot make a position before root.',
- item,
- { root: item }
- );
- }
- return this._createAt( item.parent, item.startOffset, stickiness );
- }
- /**
- * Creates a `Position` instance from given plain object (i.e. parsed JSON string).
- *
- * @param {Object} json Plain object to be converted to `Position`.
- * @param {module:engine/model/document~Document} doc Document object that will be position owner.
- * @returns {module:engine/model/position~Position} `Position` instance created using given plain object.
- */
- static fromJSON( json, doc ) {
- if ( json.root === '$graveyard' ) {
- const pos = new Position( doc.graveyard, json.path );
- pos.stickiness = json.stickiness;
- return pos;
- }
- if ( !doc.getRoot( json.root ) ) {
- /**
- * Cannot create position for document. Root with specified name does not exist.
- *
- * @error model-position-fromjson-no-root
- * @param {String} rootName
- */
- throw new CKEditorError(
- 'model-position-fromjson-no-root: Cannot create position for document. Root with specified name does not exist.',
- doc,
- { rootName: json.root }
- );
- }
- return new Position( doc.getRoot( json.root ), json.path, json.stickiness );
- }
- // @if CK_DEBUG_ENGINE // toString() {
- // @if CK_DEBUG_ENGINE // return `${ this.root } [ ${ this.path.join( ', ' ) } ]`;
- // @if CK_DEBUG_ENGINE // }
- // @if CK_DEBUG_ENGINE // log() {
- // @if CK_DEBUG_ENGINE // console.log( 'ModelPosition: ' + this );
- // @if CK_DEBUG_ENGINE // }
- }
- /**
- * 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/model/position~PositionRelation
- */
- /**
- * Represents how position is "sticking" with neighbour nodes. Used to define how position should be transformed (moved)
- * in edge cases. Possible values: `'toNone'`, `'toNext'`, `'toPrevious'`.
- *
- * Examples:
- *
- * Insert. Position is at | and nodes are inserted at the same position, marked as ^:
- *
- * - sticks to none: <p>f^|oo</p> -> <p>fbar|oo</p>
- * - sticks to next node: <p>f^|oo</p> -> <p>fbar|oo</p>
- * - sticks to previous node: <p>f|^oo</p> -> <p>f|baroo</p>
- *
- *
- * Move. Position is at | and range [oo] is moved to position ^:
- *
- * - sticks to none: <p>f|[oo]</p><p>b^ar</p> -> <p>f|</p><p>booar</p>
- * - sticks to none: <p>f[oo]|</p><p>b^ar</p> -> <p>f|</p><p>booar</p>
- *
- * - sticks to next node: <p>f|[oo]</p><p>b^ar</p> -> <p>f</p><p>b|ooar</p>
- * - sticks to next node: <p>f[oo]|</p><p>b^ar</p> -> <p>f|</p><p>booar</p>
- *
- * - sticks to previous node: <p>f|[oo]</p><p>b^ar</p> -> <p>f|</p><p>booar</p>
- * - sticks to previous node: <p>f[oo]|</p><p>b^ar</p> -> <p>f</p><p>boo|ar</p>
- *
- * @typedef {String} module:engine/model/position~PositionStickiness
- */
- /**
- * Returns a text node at the given position.
- *
- * This is a helper function optimized to reuse the position parent instance for performance reasons.
- *
- * Normally, you should use {@link module:engine/model/position~Position#textNode `Position#textNode`}.
- * If you start hitting performance issues with {@link module:engine/model/position~Position#parent `Position#parent`}
- * check if your algorithm does not access it multiple times (which can happen directly or indirectly via other position properties).
- *
- * See https://github.com/ckeditor/ckeditor5/issues/6579.
- *
- * See also:
- *
- * * {@link module:engine/model/position~getNodeAfterPosition}
- * * {@link module:engine/model/position~getNodeBeforePosition}
- *
- * @param {module:engine/model/position~Position} position
- * @param {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment} positionParent The parent of the
- * given position.
- * @returns {module:engine/model/text~Text|null}
- */
- export function getTextNodeAtPosition( position, positionParent ) {
- const node = positionParent.getChild( positionParent.offsetToIndex( position.offset ) );
- if ( node && node.is( '$text' ) && node.startOffset < position.offset ) {
- return node;
- }
- return null;
- }
- /**
- * Returns the node after the given position.
- *
- * This is a helper function optimized to reuse the position parent instance and the calculation of the text node at the
- * specific position for performance reasons.
- *
- * Normally, you should use {@link module:engine/model/position~Position#nodeAfter `Position#nodeAfter`}.
- * If you start hitting performance issues with {@link module:engine/model/position~Position#parent `Position#parent`} and/or
- * {@link module:engine/model/position~Position#textNode `Position#textNode`}
- * check if your algorithm does not access those properties multiple times
- * (which can happen directly or indirectly via other position properties).
- *
- * See https://github.com/ckeditor/ckeditor5/issues/6579 and https://github.com/ckeditor/ckeditor5/issues/6582.
- *
- * See also:
- *
- * * {@link module:engine/model/position~getTextNodeAtPosition}
- * * {@link module:engine/model/position~getNodeBeforePosition}
- *
- * @param {module:engine/model/position~Position} position
- * @param {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment} positionParent The parent of the
- * given position.
- * @param {module:engine/model/text~Text|null} textNode Text node at the given position.
- * @returns {module:engine/model/node~Node|null}
- */
- export function getNodeAfterPosition( position, positionParent, textNode ) {
- if ( textNode !== null ) {
- return null;
- }
- return positionParent.getChild( positionParent.offsetToIndex( position.offset ) );
- }
- /**
- * Returns the node before the given position.
- *
- * Refer to {@link module:engine/model/position~getNodeBeforePosition} for documentation on when to use this util method.
- *
- * See also:
- *
- * * {@link module:engine/model/position~getTextNodeAtPosition}
- * * {@link module:engine/model/position~getNodeAfterPosition}
- *
- * @param {module:engine/model/position~Position} position
- * @param {module:engine/model/element~Element|module:engine/model/documentfragment~DocumentFragment} positionParent The parent of the
- * given position.
- * @param {module:engine/model/text~Text|null} textNode Text node at the given position.
- * @returns {module:engine/model/node~Node|null}
- */
- export function getNodeBeforePosition( position, positionParent, textNode ) {
- if ( textNode !== null ) {
- return null;
- }
- return positionParent.getChild( positionParent.offsetToIndex( position.offset ) - 1 );
- }
|