codemirror.mediawiki.js: add Mod-Shift-x

This patch adds a keyboard shortcut `Mod-Shift-x` to toggle between left-to-right (LTR) and right-to-left (RTL) text directions.

Bug: T170001
Change-Id: Ia857ad0b0aff0bb206b45e4d27dee6e91a3effce

resources/dist/codemirror.mediawiki.js

@@ -1 +1 @@
-"use strict";var e=require("ext.CodeMirror.v6"),i=require("ext.CodeMirror.v6.mode.mediawiki");require("ext.CodeMirror.v6.lib");var r=document.getElementById("wpTextbox1"),o=new e(r),t=new URLSearchParams(window.location.search);o.initialize([o.defaultExtensions,i({bidiIsolation:"rtl"===r.dir&&t.get("cm6bidi")})]);
+"use strict";var e=require("ext.CodeMirror.v6"),i=require("ext.CodeMirror.v6.mode.mediawiki");require("ext.CodeMirror.v6.lib");var r=new e(document.getElementById("wpTextbox1")),o=new URLSearchParams(window.location.search);r.initialize([r.defaultExtensions,i({bidiIsolation:o.get("cm6bidi")})]);

src/codemirror.bidiIsolation.js

@@ -28,6 +28,7 @@ const isolate = Decoration.mark( {
 function computeIsolates( view ) {
 	const set = new RangeSetBuilder();
 
+	if ( view.editorAttrs.dir === 'rtl' ) {
 		for ( const { from, to } of view.visibleRanges ) {
 			let startPos = null;
 			syntaxTree( view.state ).iterate( {
@@ -52,6 +53,7 @@ function computeIsolates( view ) {
 				}
 			} );
 		}
+	}
 
 	return set.finish();
 }
@@ -69,6 +71,8 @@ class CodeMirrorBidiIsolation {
 		this.isolates = computeIsolates( view );
 		/** @type {Tree} */
 		this.tree = syntaxTree( view.state );
+		/** @type {Direction} */
+		this.dir = view.textDirection;
 	}
 
 	/**
@@ -76,7 +80,8 @@ class CodeMirrorBidiIsolation {
 	 */
 	update( update ) {
 		if ( update.docChanged || update.viewportChanged ||
-			syntaxTree( update.state ) !== this.tree
+			syntaxTree( update.state ) !== this.tree ||
+			update.view.textDirection !== this.dir
 		) {
 			this.isolates = computeIsolates( update.view );
 			this.tree = syntaxTree( update.state );

src/codemirror.js

@@ -1,4 +1,4 @@
-import { EditorState, Extension } from '@codemirror/state';
+import { EditorState, Extension, Compartment } from '@codemirror/state';
 import {
 	EditorView,
 	drawSelection,
@@ -6,7 +6,8 @@ import {
 	highlightSpecialChars,
 	keymap,
 	rectangularSelection,
-	crosshairCursor
+	crosshairCursor,
+	ViewUpdate
 } from '@codemirror/view';
 import { defaultKeymap, history, historyKeymap } from '@codemirror/commands';
 import { searchKeymap } from '@codemirror/search';
@@ -73,6 +74,12 @@ class CodeMirror {
 		 * @type {CodeMirrorTextSelection}
 		 */
 		this.textSelection = null;
+		/**
+		 * Language direction extension.
+		 *
+		 * @type {Compartment}
+		 */
+		this.dirCompartment = new Compartment();
 	}
 
 	/**
@@ -91,6 +98,7 @@ class CodeMirror {
 			this.heightExtension,
 			this.updateExtension,
 			this.bracketMatchingExtension,
+			this.dirExtension,
 			EditorState.readOnly.of( this.readOnly ),
 			EditorView.domEventHandlers( {
 				blur: () => this.$textarea.triggerHandler( 'blur' ),
@@ -221,9 +229,8 @@ class CodeMirror {
 			} ),
 			// .cm-editor element (contains the whole CodeMirror UI)
 			EditorView.editorAttributes.of( {
-				// Use direction and language of the original textbox.
+				// Use language of the original textbox.
 				// These should be attributes of .cm-editor, not the .cm-content (T359589)
-				dir: this.$textarea.attr( 'dir' ),
 				lang: this.$textarea.attr( 'lang' )
 			} ),
 			// The search panel should use the same direction as the interface language (T359611)
@@ -321,6 +328,29 @@ class CodeMirror {
 		} );
 	}
 
+	get dirExtension() {
+		return [
+			this.dirCompartment.of( EditorView.editorAttributes.of( {
+				// Use direction of the original textbox.
+				// These should be attributes of .cm-editor, not the .cm-content (T359589)
+				dir: this.$textarea.attr( 'dir' )
+			} ) ),
+			keymap.of( [ {
+				key: 'Mod-Shift-x',
+				run: ( view ) => {
+					const dir = this.$textarea.attr( 'dir' ) === 'rtl' ? 'ltr' : 'rtl';
+					this.$textarea.attr( 'dir', dir );
+					view.dispatch( {
+						effects: this.dirCompartment.reconfigure(
+							EditorView.editorAttributes.of( { dir } )
+						)
+					} );
+					return true;
+				}
+			} ] )
+		];
+	}
+
 	/**
 	 * Setup CodeMirror and add it to the DOM. This will hide the original textarea.
 	 *

src/codemirror.mediawiki.js

@@ -8,6 +8,6 @@ const urlParams = new URLSearchParams( window.location.search );
 cm.initialize( [
 	cm.defaultExtensions,
 	mediaWikiLang( {
-		bidiIsolation: textarea.dir === 'rtl' && urlParams.get( 'cm6bidi' )
+		bidiIsolation: urlParams.get( 'cm6bidi' )
 	} )
 ] );