Improved balloon positioning when there is more than one stack in the rotator

package.json

@@ -16,6 +16,7 @@
     "lodash-es": "^4.17.10"
   },
   "devDependencies": {
+    "@ckeditor/ckeditor5-block-quote": "^11.1.2",
     "@ckeditor/ckeditor5-clipboard": "^12.0.1",
     "@ckeditor/ckeditor5-editor-classic": "^12.1.3",
     "@ckeditor/ckeditor5-enter": "^11.0.4",

src/linkui.js

@@ -414,6 +414,7 @@ export default class LinkUI extends Plugin {
 		const editor = this.editor;
 
 		this.stopListening( editor.ui, 'update' );
+		this.stopListening( this._balloon, 'change:visibleView' );
 
 		// Make sure the focus always gets back to the editable _before_ removing the focused form view.
 		// Doing otherwise causes issues in some browsers. See https://github.com/ckeditor/ckeditor5-link/issues/193.
@@ -441,7 +442,7 @@ export default class LinkUI extends Plugin {
 		let prevSelectedLink = this._getSelectedLinkElement();
 		let prevSelectionParent = getSelectionParent();
 
-		this.listenTo( editor.ui, 'update', () => {
+		const update = () => {
 			const selectedLink = this._getSelectedLinkElement();
 			const selectionParent = getSelectionParent();
 
@@ -460,9 +461,10 @@ export default class LinkUI extends Plugin {
 				this._hideUI();
 			}
 			// Update the position of the panel when:
+			//  * link panel is in the visible stack
 			//  * the selection remains in the original link element,
 			//  * there was no link element in the first place, i.e. creating a new link
-			else {
+			else if ( this._isUIVisible ) {
 				// If still in a link element, simply update the position of the balloon.
 				// If there was no link (e.g. inserting one), the balloon must be moved
 				// to the new position in the editing view (a new native DOM range).
@@ -471,13 +473,16 @@ export default class LinkUI extends Plugin {
 
 			prevSelectedLink = selectedLink;
 			prevSelectionParent = selectionParent;
-		} );
+		};
 
 		function getSelectionParent() {
 			return viewDocument.selection.focus.getAncestors()
 				.reverse()
 				.find( node => node.is( 'element' ) );
 		}
+
+		this.listenTo( editor.ui, 'update', update );
+		this.listenTo( this._balloon, 'change:visibleView', update );
 	}
 
 	/**

tests/linkui.js

@@ -12,6 +12,7 @@ import { setData as setModelData } from '@ckeditor/ckeditor5-engine/src/dev-util
 import { getData as getViewData } from '@ckeditor/ckeditor5-engine/src/dev-utils/view';
 
 import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
+import BlockQuote from '@ckeditor/ckeditor5-block-quote/src/blockquote';
 import LinkEditing from '../src/linkediting';
 import LinkUI from '../src/linkui';
 import LinkFormView from '../src/ui/linkformview';
@@ -33,7 +34,7 @@ describe( 'LinkUI', () => {
 
 		return ClassicTestEditor
 			.create( editorElement, {
-				plugins: [ LinkEditing, LinkUI, Paragraph ]
+				plugins: [ LinkEditing, LinkUI, Paragraph, BlockQuote ]
 			} )
 			.then( newEditor => {
 				editor = newEditor;
@@ -269,6 +270,42 @@ describe( 'LinkUI', () => {
 			expect( balloon.visibleView ).to.equal( formView );
 		} );
 
+		// https://github.com/ckeditor/ckeditor5-link/issues/242.
+		it( 'should update balloon position when is switched in rotator to a visible panel', () => {
+			setModelData( editor.model, '<paragraph>fo<$text linkHref="foo">o[] b</$text>ar</paragraph>' );
+			linkUIFeature._showUI();
+
+			const customView = new View();
+			const linkViewElement = editor.editing.view.document.getRoot().getChild( 0 ).getChild( 1 );
+			const linkDomElement = editor.editing.view.domConverter.mapViewToDom( linkViewElement );
+
+			expect( balloon.visibleView ).to.equal( actionsView );
+			expect( balloon.view.pin.lastCall.args[ 0 ].target ).to.equal( linkDomElement );
+
+			balloon.add( {
+				stackId: 'custom',
+				view: customView,
+				position: { target: {} }
+			} );
+
+			balloon.showStack( 'custom' );
+
+			expect( balloon.visibleView ).to.equal( customView );
+			expect( balloon.hasView( actionsView ) ).to.equal( true );
+
+			editor.execute( 'blockQuote' );
+			balloon.showStack( 'main' );
+
+			expect( balloon.visibleView ).to.equal( actionsView );
+			expect( balloon.hasView( customView ) ).to.equal( true );
+			expect( balloon.view.pin.lastCall.args[ 0 ].target ).to.not.equal( linkDomElement );
+
+			const newLinkViewElement = editor.editing.view.document.getRoot().getChild( 0 ).getChild( 0 ).getChild( 1 );
+			const newLinkDomElement = editor.editing.view.domConverter.mapViewToDom( newLinkViewElement );
+
+			expect( balloon.view.pin.lastCall.args[ 0 ].target ).to.equal( newLinkDomElement );
+		} );
+
 		describe( 'response to ui#update', () => {
 			let view, viewDocument;
 
@@ -337,6 +374,31 @@ describe( 'LinkUI', () => {
 				} );
 			} );
 
+			it( 'not update the position when is in not visible stack', () => {
+				setModelData( editor.model, '<paragraph><$text linkHref="url">f[]oo</$text></paragraph>' );
+
+				linkUIFeature._showUI();
+
+				const customView = new View();
+
+				balloon.add( {
+					stackId: 'custom',
+					view: customView,
+					position: { target: {} }
+				} );
+
+				balloon.showStack( 'custom' );
+
+				expect( balloon.visibleView ).to.equal( customView );
+				expect( balloon.hasView( actionsView ) ).to.equal( true );
+
+				const spy = testUtils.sinon.spy( balloon, 'updatePosition' );
+
+				editor.ui.fire( 'update' );
+
+				sinon.assert.notCalled( spy );
+			} );
+
 			// https://github.com/ckeditor/ckeditor5-link/issues/113
 			it( 'hides of the panel – editing a link, then the selection moved out of the link', () => {
 				setModelData( editor.model, '<paragraph><$text linkHref="url">f[]oo</$text>bar</paragraph>' );