Introduced context for OT. Refactored: History, RemoveOperation, OT and other.

src/conversion/modelconversiondispatcher.js

@@ -224,7 +224,7 @@ export default class ModelConversionDispatcher {
 			}
 
 			// Check if inserted content contains a marker.
-			if ( range.containsRange( markerRange ) || range.isEqual( markerRange ) ) {
+			if ( range.containsRange( markerRange, true ) ) {
 				this.convertMarker( 'addMarker', marker.name, markerRange );
 			}
 		}

src/dev-utils/enableenginedebug.js

@@ -287,7 +287,7 @@ function enableLoggingTools() {
 		const range = ModelRange.createFromPositionAndShift( this.sourcePosition, this.howMany );
 
 		return getClassName( this ) + `( ${ this.baseVersion } ): ` +
-			`${ range } -> ${ this.targetPosition }`;
+			`${ range } -> ${ this.targetPosition }${ this.isSticky ? ' (sticky)' : '' }`;
 	};
 
 	NoOperation.prototype.toString = function() {
@@ -334,15 +334,15 @@ function enableLoggingTools() {
 
 	const _deltaTransformTransform = deltaTransform.transform;
 
-	deltaTransform.transform = function( a, b, isAMoreImportantThanB ) {
+	deltaTransform.transform = function( a, b, context ) {
 		let results;
 
 		try {
-			results = _deltaTransformTransform( a, b, isAMoreImportantThanB );
+			results = _deltaTransformTransform( a, b, context );
 		} catch ( e ) {
 			logger.error( 'Error during delta transformation!' );
-			logger.error( a.toString() + ( isAMoreImportantThanB ? ' (important)' : '' ) );
-			logger.error( b.toString() + ( isAMoreImportantThanB ? '' : ' (important)' ) );
+			logger.error( a.toString() + ( context.isStrong ? ' (important)' : '' ) );
+			logger.error( b.toString() + ( context.isStrong ? '' : ' (important)' ) );
 
 			throw e;
 		}
@@ -351,7 +351,7 @@ function enableLoggingTools() {
 			results[ i ]._saveHistory( {
 				before: a,
 				transformedBy: b,
-				wasImportant: !!isAMoreImportantThanB,
+				wasImportant: !!context.isStrong,
 				resultIndex: i,
 				resultsTotal: results.length
 			} );

src/model/delta/attributedelta.js

@@ -12,6 +12,7 @@ import DeltaFactory from './deltafactory';
 import { register } from '../batch';
 import AttributeOperation from '../operation/attributeoperation';
 import RootAttributeOperation from '../operation/rootattributeoperation';
+import NoOperation from '../operation/nooperation';
 import Position from '../position';
 import Range from '../range';
 
@@ -65,6 +66,10 @@ export default class AttributeDelta extends Delta {
 		let end = null;
 
 		for ( const operation of this.operations ) {
+			if ( operation instanceof NoOperation ) {
+				continue;
+			}
+
 			if ( start === null || start.isAfter( operation.range.start ) ) {
 				start = operation.range.start;
 			}
@@ -104,13 +109,6 @@ export default class AttributeDelta extends Delta {
 	static get className() {
 		return 'engine.model.delta.AttributeDelta';
 	}
-
-	/**
-	 * @inheritDoc
-	 */
-	static get _priority() {
-		return 20;
-	}
 }
 
 /**

src/model/delta/delta.js

@@ -162,18 +162,6 @@ export default class Delta {
 	static get className() {
 		return 'engine.model.delta.Delta';
 	}
-
-	/**
-	 * Delta priority. Used in {@link module:engine/model/delta/transform~transform delta transformations}. Delta with the higher
-	 * priority will be treated as more important when resolving transformation conflicts. If deltas have same
-	 * priority, other factors will be used to determine which delta is more important.
-	 *
-	 * @private
-	 * @type {Number}
-	 */
-	static get _priority() {
-		return 0;
-	}
 }
 
 DeltaFactory.register( Delta );

src/model/delta/insertdelta.js

@@ -75,13 +75,6 @@ export default class InsertDelta extends Delta {
 	static get className() {
 		return 'engine.model.delta.InsertDelta';
 	}
-
-	/**
-	 * @inheritDoc
-	 */
-	static get _priority() {
-		return 20;
-	}
 }
 
 /**

src/model/delta/mergedelta.js

@@ -40,19 +40,6 @@ export default class MergeDelta extends Delta {
 		return this._removeOperation ? this._removeOperation.sourcePosition : null;
 	}
 
-	/**
-	 * @inheritDoc
-	 */
-	getReversed() {
-		const delta = super.getReversed();
-
-		if ( delta.operations.length > 0 ) {
-			delta.operations[ 1 ].isSticky = false;
-		}
-
-		return delta;
-	}
-
 	/**
 	 * Operation in this delta that removes the node after merge position (which will be empty at that point) or
 	 * `null` if the delta has no operations. Note, that after {@link module:engine/model/delta/transform~transform transformation}
@@ -131,7 +118,10 @@ register( 'merge', function( position ) {
 	delta.addOperation( move );
 	this.document.applyOperation( move );
 
-	const remove = new RemoveOperation( position, 1, this.document.version );
+	const graveyard = this.document.graveyard;
+	const gyPosition = new Position( graveyard, [ 0 ] );
+
+	const remove = new RemoveOperation( position, 1, gyPosition, this.document.version );
 	delta.addOperation( remove );
 	this.document.applyOperation( remove );
 

src/model/delta/movedelta.js

@@ -83,13 +83,6 @@ export default class MoveDelta extends Delta {
 	static get className() {
 		return 'engine.model.delta.MoveDelta';
 	}
-
-	/**
-	 * @inheritDoc
-	 */
-	static get _priority() {
-		return 20;
-	}
 }
 
 function addMoveOperation( batch, delta, sourcePosition, howMany, targetPosition ) {

src/model/delta/removedelta.js

@@ -28,8 +28,14 @@ export default class RemoveDelta extends MoveDelta {
 	}
 }
 
-function addRemoveOperation( batch, delta, position, howMany ) {
-	const operation = new RemoveOperation( position, howMany, batch.document.version );
+function addRemoveDelta( batch, position, howMany ) {
+	const delta = new RemoveDelta();
+	batch.addDelta( delta );
+
+	const graveyard = batch.document.graveyard;
+	const gyPosition = new Position( graveyard, [ 0 ] );
+
+	const operation = new RemoveOperation( position, howMany, gyPosition, batch.document.version );
 	delta.addOperation( operation );
 	batch.document.applyOperation( operation );
 }
@@ -42,18 +48,15 @@ function addRemoveOperation( batch, delta, position, howMany ) {
  * @param {module:engine/model/item~Item|module:engine/model/range~Range} itemOrRange Model item or range to remove.
  */
 register( 'remove', function( itemOrRange ) {
-	const delta = new RemoveDelta();
-	this.addDelta( delta );
-
 	if ( itemOrRange instanceof Range ) {
-		// The array is reversed, so the ranges are correct and do not have to be updated.
+		// The array is reversed, so the ranges to remove are in correct order and do not have to be updated.
 		const ranges = itemOrRange.getMinimalFlatRanges().reverse();
 
 		for ( const flat of ranges ) {
-			addRemoveOperation( this, delta, flat.start, flat.end.offset - flat.start.offset );
+			addRemoveDelta( this, flat.start, flat.end.offset - flat.start.offset );
 		}
 	} else {
-		addRemoveOperation( this, delta, Position.createBefore( itemOrRange ), 1 );
+		addRemoveDelta( this, Position.createBefore( itemOrRange ), 1 );
 	}
 
 	return this;

src/model/delta/splitdelta.js

@@ -39,19 +39,6 @@ export default class SplitDelta extends Delta {
 		return this._moveOperation ? this._moveOperation.sourcePosition : null;
 	}
 
-	/**
-	 * @inheritDoc
-	 */
-	getReversed() {
-		const delta = super.getReversed();
-
-		if ( delta.operations.length > 0 ) {
-			delta.operations[ 0 ].isSticky = true;
-		}
-
-		return delta;
-	}
-
 	/**
 	 * Operation in the delta that adds to model an element into which split nodes will be moved, or `null` if
 	 * there are no operations in the delta.
@@ -79,7 +66,7 @@ export default class SplitDelta extends Delta {
 	 * @type {module:engine/model/operation/moveoperation~MoveOperation|null}
 	 */
 	get _moveOperation() {
-		return this.operations[ 1 ] || null;
+		return this.operations[ 1 ] && this.operations[ 1 ] instanceof MoveOperation ? this.operations[ 1 ] : null;
 	}
 
 	/**
@@ -95,13 +82,6 @@ export default class SplitDelta extends Delta {
 	static get className() {
 		return 'engine.model.delta.SplitDelta';
 	}
-
-	/**
-	 * @inheritDoc
-	 */
-	static get _priority() {
-		return 5;
-	}
 }
 
 /**