Other (table): Reuse Rect#getBoundingRect() method to calculate ballo…

…on toolbar position.

packages/ckeditor5-table/src/utils/ui/contextualballoon.js

@@ -87,11 +87,7 @@ export function getBalloonCellPositionData( editor ) {
 
 	if ( selection.rangeCount > 1 ) {
 		return {
-			target: () => createBoundingRect( selection.getRanges(), modelRange => {
-				const modelTableCell = getTableCellAtPosition( modelRange.start );
-				const viewTableCell = mapper.toViewElement( modelTableCell );
-				return new Rect( domConverter.viewToDom( viewTableCell ) );
-			} ),
+			target: () => createBoundingRect( selection.getRanges(), editor ),
 			positions: BALLOON_POSITIONS
 		};
 	}
@@ -115,30 +111,19 @@ function getTableCellAtPosition( position ) {
 	return isTableCellSelected ? position.nodeAfter : position.findAncestor( 'tableCell' );
 }
 
-// Returns bounding rect for list of rects.
+// Returns bounding rectangle for given model ranges.
 //
-// @param {Array.<module:utils/dom/rect~Rect>|Array.<*>} list List of `Rect`s or any list to map by `mapFn`.
-// @param {Function} mapFn Mapping function for list elements.
+// @param {Iterable.<module:engine/model/range~Range>} ranges Model ranges that the bounding rect should be returned for.
+// @param {module:core/editor/editor~Editor} editor The editor instance.
 // @returns {module:utils/dom/rect~Rect}
-function createBoundingRect( list, mapFn ) {
-	const rectData = {
-		left: Number.POSITIVE_INFINITY,
-		top: Number.POSITIVE_INFINITY,
-		right: Number.NEGATIVE_INFINITY,
-		bottom: Number.NEGATIVE_INFINITY
-	};
-
-	for ( const item of list ) {
-		const rect = mapFn( item );
-
-		rectData.left = Math.min( rectData.left, rect.left );
-		rectData.top = Math.min( rectData.top, rect.top );
-		rectData.right = Math.max( rectData.right, rect.right );
-		rectData.bottom = Math.max( rectData.bottom, rect.bottom );
-	}
-
-	rectData.width = rectData.right - rectData.left;
-	rectData.height = rectData.bottom - rectData.top;
+function createBoundingRect( ranges, editor ) {
+	const mapper = editor.editing.mapper;
+	const domConverter = editor.editing.view.domConverter;
+	const rects = Array.from( ranges ).map( range => {
+		const modelTableCell = getTableCellAtPosition( range.start );
+		const viewTableCell = mapper.toViewElement( modelTableCell );
+		return new Rect( domConverter.viewToDom( viewTableCell ) );
+	} );
 
-	return new Rect( rectData );
+	return Rect.getBoundingRect( rects );
 }