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- /**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md.
- */
- /**
- * @module engine/model/utils/deletecontent
- */
- import LivePosition from '../liveposition';
- import Range from '../range';
- import DocumentSelection from '../documentselection';
- /**
- * Deletes content of the selection and merge siblings. The resulting selection is always collapsed.
- *
- * **Note:** Use {@link module:engine/model/model~Model#deleteContent} instead of this function.
- * This function is only exposed to be reusable in algorithms
- * which change the {@link module:engine/model/model~Model#deleteContent}
- * method's behavior.
- *
- * @param {module:engine/model/model~Model} model The model in context of which the insertion
- * should be performed.
- * @param {module:engine/model/selection~Selection|module:engine/model/documentselection~DocumentSelection} selection
- * Selection of which the content should be deleted.
- * @param {module:engine/model/batch~Batch} batch Batch to which the operations will be added.
- * @param {Object} [options]
- * @param {Boolean} [options.leaveUnmerged=false] Whether to merge elements after removing the content of the selection.
- *
- * For example `<heading>x[x</heading><paragraph>y]y</paragraph>` will become:
- *
- * * `<heading>x^y</heading>` with the option disabled (`leaveUnmerged == false`)
- * * `<heading>x^</heading><paragraph>y</paragraph>` with enabled (`leaveUnmerged == true`).
- *
- * Note: {@link module:engine/model/schema~Schema#isObject object} and {@link module:engine/model/schema~Schema#isLimit limit}
- * elements will not be merged.
- *
- * @param {Boolean} [options.doNotResetEntireContent=false] Whether to skip replacing the entire content with a
- * paragraph when the entire content was selected.
- *
- * For example `<heading>[x</heading><paragraph>y]</paragraph>` will become:
- *
- * * `<paragraph>^</paragraph>` with the option disabled (`doNotResetEntireContent == false`)
- * * `<heading>^</heading>` with enabled (`doNotResetEntireContent == true`).
- *
- * @param {Boolean} [options.doNotAutoparagraph=false] Whether to create a paragraph if after content deletion selection is moved
- * to a place where text cannot be inserted.
- *
- * For example `<paragraph>x</paragraph>[<image src="foo.jpg"></image>]` will become:
- *
- * * `<paragraph>x</paragraph><paragraph>[]</paragraph>` with the option disabled (`doNotAutoparagraph == false`)
- * * `<paragraph>x[]</paragraph>` with the option enabled (`doNotAutoparagraph == true`).
- *
- * **Note:** if there is no valid position for the selection, the paragraph will always be created:
- *
- * `[<image src="foo.jpg"></image>]` -> `<paragraph>[]</paragraph>`.
- */
- export default function deleteContent( model, selection, options = {} ) {
- if ( selection.isCollapsed ) {
- return;
- }
- const selRange = selection.getFirstRange();
- // If the selection is already removed, don't do anything.
- if ( selRange.root.rootName == '$graveyard' ) {
- return;
- }
- const schema = model.schema;
- model.change( writer => {
- // 1. Replace the entire content with paragraph.
- // See: https://github.com/ckeditor/ckeditor5-engine/issues/1012#issuecomment-315017594.
- if ( !options.doNotResetEntireContent && shouldEntireContentBeReplacedWithParagraph( schema, selection ) ) {
- replaceEntireContentWithParagraph( writer, selection, schema );
- return;
- }
- const startPos = selRange.start;
- const endPos = LivePosition.fromPosition( selRange.end, 'toNext' );
- // 2. Remove the content if there is any.
- if ( !selRange.start.isTouching( selRange.end ) ) {
- writer.remove( selRange );
- }
- // 3. Merge elements in the right branch to the elements in the left branch.
- // The only reasonable (in terms of data and selection correctness) case in which we need to do that is:
- //
- // <heading type=1>Fo[</heading><paragraph>]ar</paragraph> => <heading type=1>Fo^ar</heading>
- //
- // However, the algorithm supports also merging deeper structures (up to the depth of the shallower branch),
- // as it's hard to imagine what should actually be the default behavior. Usually, specific features will
- // want to override that behavior anyway.
- if ( !options.leaveUnmerged ) {
- mergeBranches( writer, startPos, endPos );
- // TMP this will be replaced with a postfixer.
- // We need to check and strip disallowed attributes in all nested nodes because after merge
- // some attributes could end up in a path where are disallowed.
- //
- // e.g. bold is disallowed for <H1>
- // <h1>Fo{o</h1><p>b}a<b>r</b><p> -> <h1>Fo{}a<b>r</b><h1> -> <h1>Fo{}ar<h1>.
- schema.removeDisallowedAttributes( startPos.parent.getChildren(), writer );
- }
- collapseSelectionAt( writer, selection, startPos );
- // 4. Add a paragraph to set selection in it.
- // Check if a text is allowed in the new container. If not, try to create a new paragraph (if it's allowed here).
- if ( shouldAutoparagraph( schema, startPos ) ) {
- // If auto-paragraphing is off, find the closest valid selection range and collapse the selection there.
- // If there is no valid selection range, create paragraph anyway and set selection there.
- const validSelectionRange = schema.getNearestSelectionRange( startPos );
- if ( options.doNotAutoparagraph && validSelectionRange ) {
- collapseSelectionAt( writer, selection, validSelectionRange );
- } else {
- insertParagraph( writer, startPos, selection );
- }
- }
- endPos.detach();
- } );
- }
- // This function is a result of reaching the Ballmer's peak for just the right amount of time.
- // Even I had troubles documenting it after a while and after reading it again I couldn't believe that it really works.
- function mergeBranches( writer, startPos, endPos ) {
- const startParent = startPos.parent;
- const endParent = endPos.parent;
- // If both positions ended up in the same parent, then there's nothing more to merge:
- // <$root><p>x[]</p><p>{}y</p></$root> => <$root><p>xy</p>[]{}</$root>
- if ( startParent == endParent ) {
- return;
- }
- // If one of the positions is a limit element, then there's nothing to merge because we don't want to cross the limit boundaries.
- if ( writer.model.schema.isLimit( startParent ) || writer.model.schema.isLimit( endParent ) ) {
- return;
- }
- // Check if operations we'll need to do won't need to cross object or limit boundaries.
- // E.g., we can't merge endParent into startParent in this case:
- // <limit><startParent>x[]</startParent></limit><endParent>{}</endParent>
- if ( !checkCanBeMerged( startPos, endPos, writer.model.schema ) ) {
- return;
- }
- // Remember next positions to merge. For example:
- // <a><b>x[]</b></a><c><d>{}y</d></c>
- // will become:
- // <a><b>xy</b>[]</a><c>{}</c>
- startPos = writer.createPositionAfter( startParent );
- endPos = writer.createPositionBefore( endParent );
- if ( !endPos.isEqual( startPos ) ) {
- // In this case, before we merge, we need to move `endParent` to the `startPos`:
- // <a><b>x[]</b></a><c><d>{}y</d></c>
- // becomes:
- // <a><b>x</b>[]<d>y</d></a><c>{}</c>
- writer.insert( endParent, startPos );
- }
- // Merge two siblings:
- // <a>x</a>[]<b>y</b> -> <a>xy</a> (the usual case)
- // <a><b>x</b>[]<d>y</d></a><c></c> -> <a><b>xy</b>[]</a><c></c> (this is the "move parent" case shown above)
- writer.merge( startPos );
- // Remove empty end ancestors:
- // <a>fo[o</a><b><a><c>bar]</c></a></b>
- // becomes:
- // <a>fo[]</a><b><a>{}</a></b>
- // So we can remove <a> and <b>.
- while ( endPos.parent.isEmpty ) {
- const parentToRemove = endPos.parent;
- endPos = writer.createPositionBefore( parentToRemove );
- writer.remove( parentToRemove );
- }
- // Continue merging next level.
- mergeBranches( writer, startPos, endPos );
- }
- function shouldAutoparagraph( schema, position ) {
- const isTextAllowed = schema.checkChild( position, '$text' );
- const isParagraphAllowed = schema.checkChild( position, 'paragraph' );
- return !isTextAllowed && isParagraphAllowed;
- }
- // Check if parents of two positions can be merged by checking if there are no limit/object
- // boundaries between those two positions.
- //
- // E.g. in <bQ><p>x[]</p></bQ><widget><caption>{}</caption></widget>
- // we'll check <p>, <bQ>, <widget> and <caption>.
- // Usually, widget and caption are marked as objects/limits in the schema, so in this case merging will be blocked.
- function checkCanBeMerged( leftPos, rightPos, schema ) {
- const rangeToCheck = new Range( leftPos, rightPos );
- for ( const value of rangeToCheck.getWalker() ) {
- if ( schema.isLimit( value.item ) ) {
- return false;
- }
- }
- return true;
- }
- function insertParagraph( writer, position, selection ) {
- const paragraph = writer.createElement( 'paragraph' );
- writer.insert( paragraph, position );
- collapseSelectionAt( writer, selection, writer.createPositionAt( paragraph, 0 ) );
- }
- function replaceEntireContentWithParagraph( writer, selection ) {
- const limitElement = writer.model.schema.getLimitElement( selection );
- writer.remove( writer.createRangeIn( limitElement ) );
- insertParagraph( writer, writer.createPositionAt( limitElement, 0 ), selection );
- }
- // We want to replace the entire content with a paragraph when:
- // * the entire content is selected,
- // * selection contains at least two elements,
- // * whether the paragraph is allowed in schema in the common ancestor.
- function shouldEntireContentBeReplacedWithParagraph( schema, selection ) {
- const limitElement = schema.getLimitElement( selection );
- if ( !selection.containsEntireContent( limitElement ) ) {
- return false;
- }
- const range = selection.getFirstRange();
- if ( range.start.parent == range.end.parent ) {
- return false;
- }
- return schema.checkChild( limitElement, 'paragraph' );
- }
- // Helper function that sets the selection. Depending whether given `selection` is a document selection or not,
- // uses a different method to set it.
- function collapseSelectionAt( writer, selection, positionOrRange ) {
- if ( selection instanceof DocumentSelection ) {
- writer.setSelection( positionOrRange );
- } else {
- selection.setTo( positionOrRange );
- }
- }
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