Rewrite ckeditor5-page-break to TypeScript.

.gitignore

@@ -39,6 +39,7 @@ packages/ckeditor5-engine/src/**/*.js
 packages/ckeditor5-enter/src/**/*.js
 packages/ckeditor5-essentials/src/**/*.js
 packages/ckeditor5-list/src/**/*.js
+packages/ckeditor5-page-break/src/**/*.js
 packages/ckeditor5-paragraph/src/**/*.js
 packages/ckeditor5-paste-from-office/src/**/*.js
 packages/ckeditor5-select-all/src/**/*.js

packages/ckeditor5-page-break/package.json

@@ -10,7 +10,7 @@
     "ckeditor5-plugin",
     "ckeditor5-dll"
   ],
-  "main": "src/index.js",
+  "main": "src/index.ts",
   "dependencies": {
     "ckeditor5": "^35.4.0"
   },
@@ -26,6 +26,7 @@
     "@ckeditor/ckeditor5-theme-lark": "^35.4.0",
     "@ckeditor/ckeditor5-ui": "^35.4.0",
     "@ckeditor/ckeditor5-widget": "^35.4.0",
+    "typescript": "^4.8.4",
     "webpack": "^5.58.1",
     "webpack-cli": "^4.9.0"
   },
@@ -44,13 +45,16 @@
   },
   "files": [
     "lang",
-    "src",
+    "src/**/*.js",
+    "src/**/*.d.ts",
     "theme",
     "build",
     "ckeditor5-metadata.json",
     "CHANGELOG.md"
   ],
   "scripts": {
-    "dll:build": "webpack"
+    "dll:build": "webpack",
+    "build": "tsc -p ./tsconfig.release.json",
+    "postversion": "npm run build"
   }
 }

packages/ckeditor5-page-break/src/index.ts

@@ -0,0 +1,12 @@
+/**
+ * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module page-break
+ */
+
+export { default as PageBreak } from './pagebreak';
+export { default as PageBreakEditing } from './pagebreakediting';
+export { default as PageBreakUI } from './pagebreakui';

packages/ckeditor5-page-break/src/pagebreak.ts

@@ -0,0 +1,43 @@
+/**
+ * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module page-break/pagebreak
+ */
+
+import { Plugin, type PluginDependencies } from 'ckeditor5/src/core';
+import { Widget } from 'ckeditor5/src/widget';
+
+import PageBreakEditing from './pagebreakediting';
+import PageBreakUI from './pagebreakui';
+
+/**
+ * The page break feature.
+ *
+ * It provides the possibility to insert a page break into the rich-text editor.
+ *
+ * For a detailed overview, check the {@glink features/page-break Page break feature} documentation.
+ */
+export default class PageBreak extends Plugin {
+	/**
+	 * @inheritDoc
+	 */
+	public static get requires(): PluginDependencies {
+		return [ PageBreakEditing, PageBreakUI, Widget ];
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public static get pluginName(): 'PageBreak' {
+		return 'PageBreak';
+	}
+}
+
+declare module '@ckeditor/ckeditor5-core' {
+	interface PluginsMap {
+		[ PageBreak.pluginName ]: PageBreak;
+	}
+}

packages/ckeditor5-page-break/src/pagebreakcommand.ts

@@ -0,0 +1,74 @@
+/**
+ * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module page-break/pagebreakcommand
+ */
+
+import { Command } from 'ckeditor5/src/core';
+import { findOptimalInsertionRange } from 'ckeditor5/src/widget';
+import type { DocumentSelection, Element, Model, Schema } from 'ckeditor5/src/engine';
+
+/**
+ * The page break command.
+ *
+ * The command is registered by {@link module:page-break/pagebreakediting~PageBreakEditing} as `'pageBreak'`.
+ *
+ * To insert a page break at the current selection, execute the command:
+ *
+ *		editor.execute( 'pageBreak' );
+ */
+export default class PageBreakCommand extends Command {
+	/**
+	 * @inheritDoc
+	 */
+	public override refresh(): void {
+		const model = this.editor.model;
+		const schema = model.schema;
+		const selection = model.document.selection;
+
+		this.isEnabled = isPageBreakAllowedInParent( selection, schema, model );
+	}
+
+	/**
+	 * Executes the command.
+	 *
+	 * @fires execute
+	 */
+	public override execute(): void {
+		const model = this.editor.model;
+
+		model.change( writer => {
+			const pageBreakElement = writer.createElement( 'pageBreak' );
+
+			model.insertObject( pageBreakElement, null, null, {
+				setSelection: 'after'
+			} );
+		} );
+	}
+}
+
+/**
+ * Checks if a page break is allowed by the schema in the optimal insertion parent.
+ */
+function isPageBreakAllowedInParent( selection: DocumentSelection, schema: Schema, model: Model ): boolean {
+	const parent = getInsertPageBreakParent( selection, model );
+
+	return schema.checkChild( parent, 'pageBreak' );
+}
+
+/**
+ * Returns a node that will be used to insert a page break with `model.insertContent` to check if the page break can be placed there.
+ */
+function getInsertPageBreakParent( selection: DocumentSelection, model: Model ): Element {
+	const insertionRange = findOptimalInsertionRange( selection, model );
+	const parent = insertionRange.start.parent;
+
+	if ( parent.isEmpty && !parent.is( 'element', '$root' ) ) {
+		return parent.parent as Element;
+	}
+
+	return parent as Element;
+}

packages/ckeditor5-page-break/src/pagebreakediting.ts

@@ -0,0 +1,140 @@
+/**
+ * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module page-break/pagebreakediting
+ */
+
+import { Plugin } from 'ckeditor5/src/core';
+import { toWidget } from 'ckeditor5/src/widget';
+import type { DowncastWriter, ViewElement } from 'ckeditor5/src/engine';
+
+import PageBreakCommand from './pagebreakcommand';
+
+import '../theme/pagebreak.css';
+
+/**
+ * The page break editing feature.
+ */
+export default class PageBreakEditing extends Plugin {
+	/**
+	 * @inheritDoc
+	 */
+	public static get pluginName(): 'PageBreakEditing' {
+		return 'PageBreakEditing';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public init(): void {
+		const editor = this.editor;
+		const schema = editor.model.schema;
+		const t = editor.t;
+		const conversion = editor.conversion;
+
+		schema.register( 'pageBreak', {
+			inheritAllFrom: '$blockObject'
+		} );
+
+		conversion.for( 'dataDowncast' ).elementToStructure( {
+			model: 'pageBreak',
+			view: ( modelElement, { writer } ) => {
+				const divElement = writer.createContainerElement( 'div',
+					{
+						class: 'page-break',
+						// If user has no `.ck-content` styles, it should always break a page during print.
+						style: 'page-break-after: always'
+					},
+					// For a rationale of using span inside a div see:
+					// https://github.com/ckeditor/ckeditor5-page-break/pull/1#discussion_r328934062.
+					writer.createContainerElement( 'span', {
+						style: 'display: none'
+					} )
+				);
+
+				return divElement;
+			}
+		} );
+
+		conversion.for( 'editingDowncast' ).elementToStructure( {
+			model: 'pageBreak',
+			view: ( modelElement, { writer } ) => {
+				const label = t( 'Page break' );
+				const viewWrapper = writer.createContainerElement( 'div' );
+				const viewLabelElement = writer.createRawElement(
+					'span',
+					{ class: 'page-break__label' },
+					function( domElement ) {
+						domElement.innerText = t( 'Page break' );
+					}
+				);
+
+				writer.addClass( 'page-break', viewWrapper );
+				writer.insert( writer.createPositionAt( viewWrapper, 0 ), viewLabelElement );
+
+				return toPageBreakWidget( viewWrapper, writer, label );
+			}
+		} );
+
+		conversion.for( 'upcast' )
+			.elementToElement( {
+				view: element => {
+					// For upcast conversion it's enough if we check for element style and verify if it's empty
+					// or contains only hidden span element.
+
+					const hasPageBreakBefore = element.getStyle( 'page-break-before' ) == 'always';
+					const hasPageBreakAfter = element.getStyle( 'page-break-after' ) == 'always';
+
+					if ( !hasPageBreakBefore && !hasPageBreakAfter ) {
+						return null;
+					}
+
+					// The "page break" div accepts only single child or no child at all.
+					if ( element.childCount == 1 ) {
+						const viewSpan = element.getChild( 0 );
+
+						// The child must be the "span" element that is not displayed.
+						if ( !viewSpan!.is( 'element', 'span' ) || viewSpan.getStyle( 'display' ) != 'none' ) {
+							return null;
+						}
+					} else if ( element.childCount > 1 ) {
+						return null;
+					}
+
+					return { name: true };
+				},
+				model: 'pageBreak',
+
+				// This conversion must be checked before <br> conversion because some editors use
+				// <br style="page-break-before:always"> as a page break marker.
+				converterPriority: 'high'
+			} );
+
+		editor.commands.add( 'pageBreak', new PageBreakCommand( editor ) );
+	}
+}
+
+/**
+ * Converts a given {@link module:engine/view/element~Element} to a page break widget:
+ * * Adds a {@link module:engine/view/element~Element#_setCustomProperty custom property} allowing to
+ *   recognize the page break widget element.
+ * * Calls the {@link module:widget/utils~toWidget} function with the proper element's label creator.
+ */
+function toPageBreakWidget( viewElement: ViewElement, writer: DowncastWriter, label: string ): ViewElement {
+	writer.setCustomProperty( 'pageBreak', true, viewElement );
+
+	return toWidget( viewElement, writer, { label } );
+}
+
+declare module '@ckeditor/ckeditor5-core' {
+	interface CommandsMap {
+		pageBreak: PageBreakCommand;
+	}
+
+	interface PluginsMap {
+		[ PageBreakEditing.pluginName ]: PageBreakEditing;
+	}
+}

packages/ckeditor5-page-break/src/pagebreakui.ts

@@ -0,0 +1,61 @@
+/**
+ * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module page-break/pagebreakui
+ */
+
+import { Plugin } from 'ckeditor5/src/core';
+import { ButtonView } from 'ckeditor5/src/ui';
+
+import pageBreakIcon from '../theme/icons/pagebreak.svg';
+
+/**
+ * The page break UI plugin.
+ */
+export default class PageBreakUI extends Plugin {
+	/**
+	 * @inheritDoc
+	 */
+	public static get pluginName(): 'PageBreakUI' {
+		return 'PageBreakUI';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public init(): void {
+		const editor = this.editor;
+		const t = editor.t;
+
+		// Add pageBreak button to feature components.
+		editor.ui.componentFactory.add( 'pageBreak', locale => {
+			const command = editor.commands.get( 'pageBreak' )!;
+			const view = new ButtonView( locale );
+
+			view.set( {
+				label: t( 'Page break' ),
+				icon: pageBreakIcon,
+				tooltip: true
+			} );
+
+			view.bind( 'isEnabled' ).to( command, 'isEnabled' );
+
+			// Execute command.
+			this.listenTo( view, 'execute', () => {
+				editor.execute( 'pageBreak' );
+				editor.editing.view.focus();
+			} );
+
+			return view;
+		} );
+	}
+}
+
+declare module '@ckeditor/ckeditor5-core' {
+	interface PluginsMap {
+		[ PageBreakUI.pluginName ]: PageBreakUI;
+	}
+}

packages/ckeditor5-page-break/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "ckeditor5/tsconfig.json",
+  "include": [
+    "src",
+    "../../typings"
+  ]
+}

packages/ckeditor5-page-break/tsconfig.release.json

@@ -0,0 +1,10 @@
+{
+  "extends": "../../tsconfig.release.json",
+  "include": [
+    "./src/",
+    "../../typings/"
+  ],
+  "exclude": [
+    "./tests/"
+  ]
+}