Merge pull request #1497 from ckeditor/t/ot-followups

Other: Moved error logging from debug tools to OT code.
Other: Aligned `Schema#getValidRanges` results to changes in `AttributeOperation`.
Other: Unified `RemoveOperation` and `ReinsertOperation` to have just one `MoveOperation`.
Other: Simplified `LiveRange#event:change` second parameter which is now an object containing `Position` not an `Operation`.
Internal: Operational transformations refactor followups. 
Internal: Additional improvements for the new OT algorithms.
Internal: Added relations to better solve cases in undo.
Internal: Improved cloning mechanism inside `WrapOperation`.
Internal: Improved `model.Range#getTransformedByMergeOperation`.
Internal: Other improvements in OT algorithms.
Internal: Improvements in docs.

Closes #1468. Closes #1464. Closes #1467. Closes #1460. Closes #1461. Closes #1462. Closes #1463. Closes #1475. Closes #1479.

BREAKING CHANGE: `LiveRange#event:change` second parameter is now an object containing property `deletionPosition`. It can be `model.Position` instance, if the range was moved to the graveyard root. The position is equal to the position from which nodes were removed. Otherwise, it is set to `null`.

BREAKING CHANGE: `Schema#getValidRanges` will return only flat ranges now. If an attribute is allowed on some nodes and in those nodes children, multiple "nested" ranges will be returned.

BREAKING CHANGE: `Schema#getValidRanges` is a generator now.

src/dev-utils/enableenginedebug.js

@@ -25,7 +25,6 @@ import MoveOperation from '../model/operation/moveoperation';
 import NoOperation from '../model/operation/nooperation';
 import RenameOperation from '../model/operation/renameoperation';
 import RootAttributeOperation from '../model/operation/rootattributeoperation';
-import transform from '../model/operation/transform';
 import Model from '../model/model';
 import ModelDocument from '../model/document';
 import ModelDocumentFragment from '../model/documentfragment';
@@ -349,24 +348,6 @@ function enableLoggingTools() {
 			`"${ this.key }": ${ JSON.stringify( this.oldValue ) } -> ${ JSON.stringify( this.newValue ) }, ${ this.root.rootName }`;
 	} );
 
-	const _transformTransform = transform.transform;
-
-	sandbox.mock( transform, 'transform', function( a, b, context ) {
-		let results;
-
-		try {
-			results = _transformTransform( a, b, context );
-		} catch ( e ) {
-			logger.error( 'Error during operation transformation!' );
-			logger.error( a.toString() + ( context.isStrong ? ' (important)' : '' ) );
-			logger.error( b.toString() + ( context.isStrong ? '' : ' (important)' ) );
-
-			throw e;
-		}
-
-		return results;
-	} );
-
 	sandbox.mock( ViewText.prototype, 'toString', function() {
 		return `#${ this.data }`;
 	} );

src/model/documentselection.js

@@ -750,14 +750,14 @@ class LiveSelection extends Selection {
 
 		const liveRange = LiveRange.createFromRange( range );
 
-		liveRange.on( 'change:range', ( evt, oldRange, operation ) => {
+		liveRange.on( 'change:range', ( evt, oldRange, data ) => {
 			this._hasChangedRange = true;
 
 			// If `LiveRange` is in whole moved to the graveyard, save necessary data. It will be fixed on `Model#applyOperation` event.
 			if ( liveRange.root == this._document.graveyard ) {
 				this._fixGraveyardRangesData.push( {
 					liveRange,
-					sourcePosition: operation.sourcePosition
+					sourcePosition: data.deletionPosition
 				} );
 			}
 		} );

src/model/liverange.js

@@ -86,9 +86,7 @@ export default class LiveRange extends Range {
 	 * @param {Object} data Object with additional information about the change. Those parameters are passed from
 	 * {@link module:engine/model/document~Document#event:change document change event}.
 	 * @param {String} data.type Change type.
-	 * @param {module:engine/model/batch~Batch} data.batch Batch which changed the live range.
-	 * @param {module:engine/model/range~Range} data.range Range containing the result of applied change.
-	 * @param {module:engine/model/position~Position} data.sourcePosition Source position for move, remove and reinsert change types.
+	 * @param {module:engine/model/position~Position|null} deletionPosition Source position for move, remove and reinsert change types.
 	 */
 
 	/**
@@ -145,18 +143,28 @@ function transform( operation ) {
 	const result = Range.createFromRanges( ranges );
 	const boundariesChanged = !result.isEqual( this );
 	const contentChanged = doesOperationChangeRangeContent( this, operation );
+	let deletionPosition = null;
 
 	if ( boundariesChanged ) {
+		if ( result.root.rootName == '$graveyard' ) {
+			if ( operation.type == 'remove' ) {
+				deletionPosition = operation.sourcePosition;
+			} else {
+				// Merge operation.
+				deletionPosition = operation.deletionPosition;
+			}
+		}
+
 		// If range boundaries have changed, fire `change:range` event.
 		const oldRange = Range.createFromRange( this );
 
 		this.start = result.start;
 		this.end = result.end;
 
-		this.fire( 'change:range', oldRange, operation );
+		this.fire( 'change:range', oldRange, { deletionPosition } );
 	} else if ( contentChanged ) {
 		// If range boundaries have not changed, but there was change inside the range, fire `change:content` event.
-		this.fire( 'change:content', Range.createFromRange( this ), operation );
+		this.fire( 'change:content', Range.createFromRange( this ), { deletionPosition } );
 	}
 }
 

src/model/operation/detachoperation.js

@@ -60,7 +60,6 @@ export default class DetachOperation extends Operation {
 		if ( this.sourcePosition.root.document ) {
 			/**
 			 * Cannot detach document node.
-			 * Use {@link module:engine/model/operation/removeoperation~RemoveOperation remove operation} instead.
 			 *
 			 * @error detach-operation-on-document-node
 			 */

src/model/operation/insertoperation.js

@@ -10,7 +10,7 @@
 import Operation from './operation';
 import Position from '../position';
 import NodeList from '../nodelist';
-import RemoveOperation from './removeoperation';
+import MoveOperation from './moveoperation';
 import { _insert, _normalizeNodes } from './utils';
 import Text from '../text';
 import Element from '../element';
@@ -87,13 +87,13 @@ export default class InsertOperation extends Operation {
 	/**
 	 * See {@link module:engine/model/operation/operation~Operation#getReversed `Operation#getReversed()`}.
 	 *
-	 * @returns {module:engine/model/operation/removeoperation~RemoveOperation}
+	 * @returns {module:engine/model/operation/moveoperation~MoveOperation}
 	 */
 	getReversed() {
 		const graveyard = this.position.root.document.graveyard;
 		const gyPosition = new Position( graveyard, [ 0 ] );
 
-		return new RemoveOperation( this.position, this.nodes.maxOffset, gyPosition, this.baseVersion + 1 );
+		return new MoveOperation( this.position, this.nodes.maxOffset, gyPosition, this.baseVersion + 1 );
 	}
 
 	/**

src/model/operation/moveoperation.js

@@ -64,6 +64,12 @@ export default class MoveOperation extends Operation {
 	 * @inheritDoc
 	 */
 	get type() {
+		if ( this.targetPosition.root.rootName == '$graveyard' ) {
+			return 'remove';
+		} else if ( this.sourcePosition.root.rootName == '$graveyard' ) {
+			return 'reinsert';
+		}
+
 		return 'move';
 	}
 

src/model/operation/operationfactory.js

@@ -13,8 +13,6 @@ import MarkerOperation from '../operation/markeroperation';
 import MoveOperation from '../operation/moveoperation';
 import NoOperation from '../operation/nooperation';
 import Operation from '../operation/operation';
-import ReinsertOperation from '../operation/reinsertoperation';
-import RemoveOperation from '../operation/removeoperation';
 import RenameOperation from '../operation/renameoperation';
 import RootAttributeOperation from '../operation/rootattributeoperation';
 import SplitOperation from '../operation/splitoperation';
@@ -29,8 +27,6 @@ operations[ MarkerOperation.className ] = MarkerOperation;
 operations[ MoveOperation.className ] = MoveOperation;
 operations[ NoOperation.className ] = NoOperation;
 operations[ Operation.className ] = Operation;
-operations[ ReinsertOperation.className ] = ReinsertOperation;
-operations[ RemoveOperation.className ] = RemoveOperation;
 operations[ RenameOperation.className ] = RenameOperation;
 operations[ RootAttributeOperation.className ] = RootAttributeOperation;
 operations[ SplitOperation.className ] = SplitOperation;

src/model/operation/splitoperation.js

@@ -43,6 +43,10 @@ export default class SplitOperation extends Operation {
 		this.position.stickiness = 'toNext';
 
 		this.graveyardPosition = graveyardPosition ? Position.createFromPosition( graveyardPosition ) : null;
+
+		if ( this.graveyardPosition ) {
+			this.graveyardPosition.stickiness = 'toNext';
+		}
 	}
 
 	/**