/** * @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 table/tablenavigation */ import Plugin from '@ckeditor/ckeditor5-core/src/plugin'; import { getSelectedTableCells, getTableCellsContainingSelection } from './utils'; import { findAncestor } from './commands/utils'; import TableWalker from './tablewalker'; import Rect from '@ckeditor/ckeditor5-utils/src/dom/rect'; import ModelRange from '@ckeditor/ckeditor5-engine/src/model/range'; import TreeWalker from '@ckeditor/ckeditor5-engine/src/model/treewalker'; import { keyCodes } from '@ckeditor/ckeditor5-utils/src/keyboard'; import priorities from '@ckeditor/ckeditor5-utils/src/priorities'; /** * This plugin enables a keyboard navigation for tables. * It is loaded automatically by the {@link module:table/table~Table} plugin. * * @extends module:core/plugin~Plugin */ export default class TableNavigation extends Plugin { /** * @inheritDoc */ static get pluginName() { return 'TableNavigation'; } /** * @inheritDoc */ init() { const view = this.editor.editing.view; const viewDocument = view.document; // Handle Tab key navigation. this.editor.keystrokes.set( 'Tab', ( ...args ) => this._handleTabOnSelectedTable( ...args ), { priority: 'low' } ); this.editor.keystrokes.set( 'Tab', this._getTabHandler( true ), { priority: 'low' } ); this.editor.keystrokes.set( 'Shift+Tab', this._getTabHandler( false ), { priority: 'low' } ); // Note: This listener has the "high+1" priority because we would like to avoid collisions with other features // (like Widgets), which take over the keydown events with the "high" priority. Table navigation takes precedence // over Widgets in that matter (widget arrow handler stops propagation of event if object element was selected // but getNearestSelectionRange didn't returned any range). this.listenTo( viewDocument, 'keydown', ( ...args ) => this._onKeydown( ...args ), { priority: priorities.get( 'high' ) + 1 } ); } /** * Handles {@link module:engine/view/document~Document#event:keydown keydown} events for the Tab key executed * when the table widget is selected. * * @private * @param {module:utils/eventinfo~EventInfo} eventInfo * @param {module:engine/view/observer/domeventdata~DomEventData} domEventData */ _handleTabOnSelectedTable( domEventData, cancel ) { const editor = this.editor; const selection = editor.model.document.selection; if ( !selection.isCollapsed && selection.rangeCount === 1 && selection.getFirstRange().isFlat ) { const selectedElement = selection.getSelectedElement(); if ( !selectedElement || !selectedElement.is( 'table' ) ) { return; } cancel(); editor.model.change( writer => { writer.setSelection( writer.createRangeIn( selectedElement.getChild( 0 ).getChild( 0 ) ) ); } ); } } /** * Returns a handler for {@link module:engine/view/document~Document#event:keydown keydown} events for the Tab key executed * inside table cell. * * @private * @param {Boolean} isForward Whether this handler will move the selection to the next or the previous cell. */ _getTabHandler( isForward ) { const editor = this.editor; return ( domEventData, cancel ) => { const selection = editor.model.document.selection; const tableCell = getTableCellsContainingSelection( selection )[ 0 ]; if ( !tableCell ) { return; } cancel(); const tableRow = tableCell.parent; const table = tableRow.parent; const currentRowIndex = table.getChildIndex( tableRow ); const currentCellIndex = tableRow.getChildIndex( tableCell ); const isFirstCellInRow = currentCellIndex === 0; if ( !isForward && isFirstCellInRow && currentRowIndex === 0 ) { // It's the first cell of the table - don't do anything (stay in the current position). return; } const isLastCellInRow = currentCellIndex === tableRow.childCount - 1; const isLastRow = currentRowIndex === table.childCount - 1; if ( isForward && isLastRow && isLastCellInRow ) { editor.execute( 'insertTableRowBelow' ); // Check if the command actually added a row. If `insertTableRowBelow` execution didn't add a row (because it was disabled // or it got overwritten) do not change the selection. if ( currentRowIndex === table.childCount - 1 ) { return; } } let cellToFocus; // Move to first cell in next row. if ( isForward && isLastCellInRow ) { const nextRow = table.getChild( currentRowIndex + 1 ); cellToFocus = nextRow.getChild( 0 ); } // Move to last cell in a previous row. else if ( !isForward && isFirstCellInRow ) { const previousRow = table.getChild( currentRowIndex - 1 ); cellToFocus = previousRow.getChild( previousRow.childCount - 1 ); } // Move to next/previous cell. else { cellToFocus = tableRow.getChild( currentCellIndex + ( isForward ? 1 : -1 ) ); } editor.model.change( writer => { writer.setSelection( writer.createRangeIn( cellToFocus ) ); } ); }; } /** * Handles {@link module:engine/view/document~Document#event:keydown keydown} events. * * @private * @param {module:utils/eventinfo~EventInfo} eventInfo * @param {module:engine/view/observer/domeventdata~DomEventData} domEventData */ _onKeydown( eventInfo, domEventData ) { const isLtrContent = this.editor.locale.contentLanguageDirection === 'ltr'; const keyCode = domEventData.keyCode; let wasHandled = false; // Checks if the keys were handled and then prevents the default event behaviour and stops // the propagation. if ( isArrowKeyCode( keyCode ) ) { wasHandled = this._handleArrowKeys( getDirectionFromKeyCode( keyCode, isLtrContent ) ); } if ( wasHandled ) { domEventData.preventDefault(); eventInfo.stop(); } } /** * Handles arrow keys. * * @private * @param {'left'|'up'|'right'|'down'} direction The direction of the arrow key. * @returns {Boolean|undefined} Returns `true` if key was handled. */ _handleArrowKeys( direction ) { const model = this.editor.model; const selection = model.document.selection; const isForward = [ 'right', 'down' ].includes( direction ); // In case one or more table cells are selected (from outside), // move the selection to a cell adjacent to the selected table fragment. const selectedCells = getSelectedTableCells( selection ); if ( selectedCells.length ) { const tableCell = isForward ? selectedCells[ selectedCells.length - 1 ] : selectedCells[ 0 ]; this._navigateFromCellInDirection( tableCell, direction ); return true; } // Abort if we're not in a table. const tableCell = findAncestor( 'tableCell', selection.focus ); if ( !tableCell ) { return; } const cellRange = model.createRangeIn( tableCell ); // Let's check if the selection is at the beginning/end of the cell. if ( this._isSelectionAtCellEdge( cellRange, selection, isForward ) ) { this._navigateFromCellInDirection( tableCell, direction ); return true; } // If there isn't any $text position between cell edge and selection then we shall move the selection to next cell. const textRange = this._findTextRangeFromSelection( cellRange, selection, isForward ); if ( !textRange ) { this._navigateFromCellInDirection( tableCell, direction ); return true; } // If the navigation is horizontal then we have no more custom cases. if ( [ 'left', 'right' ].includes( direction ) ) { return; } // If the range is a single line then move the selection to the beginning/end of a cell content. // // We can't move the selection directly to the another cell because of dual position at the end/beginning // of wrapped line (it's at the same time at the end of one line and at the start of the next line). if ( this._isSingleLineRange( textRange, isForward ) ) { model.change( writer => { writer.setSelection( isForward ? cellRange.end : cellRange.start ); } ); return true; } } /** * Returns `true` if `selection` is at `cellRange` edge according to navigation `direction`. * * @private * @param {module:engine/model/range~Range} cellRange The bounding cell range. * @param {module:engine/model/selection~Selection} selection The current selection. * @param {Boolean} isForward The expected navigation direction. * @returns {Boolean} */ _isSelectionAtCellEdge( cellRange, selection, isForward ) { const model = this.editor.model; const schema = this.editor.model.schema; const focus = isForward ? selection.getLastPosition() : selection.getFirstPosition(); // If the current limit element is not table cell we are for sure not at the cell edge. // Also `modifySelection` will not let us out of it. if ( !schema.getLimitElement( focus ).is( 'tableCell' ) ) { return false; } const probe = model.createSelection( focus ); model.modifySelection( probe, { direction: isForward ? 'forward' : 'backward' } ); // If there was no change in the focus position, then it's not possible to move the selection there. return focus.isEqual( probe.focus ); } /** * Returns a range from beginning/end of range up to selection closest position. * Returns `null` if resulting range can't contain text element (according to schema). * * @private * @param {module:engine/model/range~Range} range Current table cell content range. * @param {module:engine/model/selection~Selection} selection The current selection. * @param {Boolean} isForward The expected navigation direction. * @returns {module:engine/model/range~Range|null} */ _findTextRangeFromSelection( range, selection, isForward ) { if ( isForward ) { const position = selection.getLastPosition(); const lastRangePosition = this._getNearestVisibleTextPosition( range, 'backward' ); if ( !lastRangePosition || position.compareWith( lastRangePosition ) != 'before' ) { return null; } return new ModelRange( position, lastRangePosition ); } else { const position = selection.getFirstPosition(); const firstRangePosition = this._getNearestVisibleTextPosition( range, 'forward' ); if ( !firstRangePosition || position.compareWith( firstRangePosition ) != 'after' ) { return null; } return new ModelRange( firstRangePosition, position ); } } /** * Basing on provided `boundaries` range, finds first/last (depending on `direction`) element * that can contain `$text` (according to schema) and is visible in the view. * * @param {module:engine/model/range~Range} boundaries The range to find position in. * @param {'forward'|'backward'} direction Search direction. * @returns {module:engine/model/position~Position|null} Nearest selection range or `null` if one cannot be found. */ _getNearestVisibleTextPosition( boundaries, direction ) { const schema = this.editor.model.schema; const mapper = this.editor.editing.mapper; const startPosition = direction == 'forward' ? boundaries.start : boundaries.end; const treeWalker = new TreeWalker( { direction, boundaries, startPosition } ); for ( const { nextPosition, item } of treeWalker ) { if ( schema.checkChild( nextPosition, '$text' ) ) { const viewElement = mapper.toViewElement( item ); if ( viewElement && !viewElement.hasClass( 'ck-hidden' ) ) { return nextPosition; } } } return null; } /** * Checks if the `modelRange` renders to a single line in the DOM. * * @private * @param {module:engine/model/range~Range} modelRange Current table cell content range. * @param {Boolean} isForward The expected navigation direction. * @returns {Boolean} */ _isSingleLineRange( modelRange, isForward ) { const editing = this.editor.editing; const domConverter = editing.view.domConverter; if ( isForward && !modelRange.start.isAtEnd ) { // Wrapped lines contain exactly the same position at the end of current line // and at the beginning of next line. That position's client rect is at the end // of current line. In case of caret at first position of the last line that 'dual' // position would be detected as it's not the last line. modelRange = new ModelRange( modelRange.start.getShiftedBy( 1 ), modelRange.end ); } const viewRange = editing.mapper.toViewRange( modelRange ); const domRange = domConverter.viewRangeToDom( viewRange ); const rects = Rect.getDomRangeRects( domRange ); let boundaryVerticalPosition; for ( const rect of rects ) { if ( boundaryVerticalPosition === undefined ) { boundaryVerticalPosition = Math.round( rect.bottom ); continue; } // Let's check if this rect is in new line. if ( Math.round( rect.top ) >= boundaryVerticalPosition ) { return false; } boundaryVerticalPosition = Math.max( boundaryVerticalPosition, Math.round( rect.bottom ) ); } return true; } /** * Moves the selection from the given table cell in the specified direction. * * @private * @param {module:engine/model/element~Element} tableCell The table cell to start the selection navigation. * @param {'left'|'up'|'right'|'down'} direction Direction in which selection should move. */ _navigateFromCellInDirection( tableCell, direction ) { const model = this.editor.model; const table = findAncestor( 'table', tableCell ); const tableMap = [ ...new TableWalker( table, { includeSpanned: true } ) ]; const { row: lastRow, column: lastColumn } = tableMap[ tableMap.length - 1 ]; const currentCellInfo = tableMap.find( ( { cell } ) => cell == tableCell ); let { row, column } = currentCellInfo; switch ( direction ) { case 'left': column--; break; case 'up': row--; break; case 'right': column += currentCellInfo.colspan || 1; break; case 'down': row += currentCellInfo.rowspan || 1; break; } const isOutsideVertically = row < 0 || row > lastRow; const isBeforeFirstCell = column < 0 && row <= 0; const isAfterLastCell = column > lastColumn && row >= lastRow; // Note that if the last table cell is row-spanned then isAfterLastCell will never be true but we don't know // if user was navigating on the last row or not, so let's allow him to stay in the table. if ( isOutsideVertically || isBeforeFirstCell || isAfterLastCell ) { model.change( writer => { writer.setSelection( writer.createRangeOn( table ) ); } ); return; } if ( column < 0 ) { column = lastColumn; row--; } else if ( column > lastColumn ) { column = 0; row++; } const cellToSelect = tableMap.find( cellInfo => cellInfo.row == row && cellInfo.column == column ).cell; const isForward = [ 'right', 'down' ].includes( direction ); const positionToSelect = model.createPositionAt( cellToSelect, isForward ? 0 : 'end' ); model.change( writer => { writer.setSelection( positionToSelect ); } ); } } // Returns 'true' if provided key code represents one of the arrow keys. // // @private // @param {Number} keyCode // @returns {Boolean} function isArrowKeyCode( keyCode ) { return keyCode == keyCodes.arrowright || keyCode == keyCodes.arrowleft || keyCode == keyCodes.arrowup || keyCode == keyCodes.arrowdown; } // Returns direction name from `keyCode`. // // @private // @param {Number} keyCode // @param {Boolean} isLtrContent The content language direction. // @returns {'left'|'up'|'right'|'down'} Arrow direction. function getDirectionFromKeyCode( keyCode, isLtrContent ) { switch ( keyCode ) { case keyCodes.arrowleft: return isLtrContent ? 'left' : 'right'; case keyCodes.arrowright: return isLtrContent ? 'right' : 'left'; case keyCodes.arrowup: return 'up'; case keyCodes.arrowdown: return 'down'; } }