Support theming of active line number

src/vs/editor/browser/viewParts/lineNumbers/lineNumbers.ts

@@ -6,7 +6,7 @@
 'use strict';
 
 import 'vs/css!./lineNumbers';
-import { editorLineNumbers } from 'vs/editor/common/view/editorColorRegistry';
+import { editorLineNumbers, editorActiveLineNumber } from 'vs/editor/common/view/editorColorRegistry';
 import { registerThemingParticipant } from 'vs/platform/theme/common/themeService';
 import * as platform from 'vs/base/common/platform';
 import { DynamicViewOverlay } from 'vs/editor/browser/view/dynamicViewOverlay';
@@ -175,4 +175,8 @@ registerThemingParticipant((theme, collector) => {
 	if (lineNumbers) {
 		collector.addRule(`.monaco-editor .line-numbers { color: ${lineNumbers}; }`);
 	}
+	const activeLineNumber = theme.getColor(editorActiveLineNumber);
+	if (activeLineNumber) {
+		collector.addRule(`.monaco-editor .current-line-margin ~ .line-numbers { color: ${activeLineNumber}; }`);
+	}
 });

src/vs/editor/common/view/editorColorRegistry.ts

@@ -19,6 +19,7 @@ export const editorCursorBackground = registerColor('editorCursor.background', n
 export const editorWhitespaces = registerColor('editorWhitespace.foreground', { dark: '#e3e4e229', light: '#33333333', hc: '#e3e4e229' }, nls.localize('editorWhitespaces', 'Color of whitespace characters in the editor.'));
 export const editorIndentGuides = registerColor('editorIndentGuide.background', { dark: editorWhitespaces, light: editorWhitespaces, hc: editorWhitespaces }, nls.localize('editorIndentGuides', 'Color of the editor indentation guides.'));
 export const editorLineNumbers = registerColor('editorLineNumber.foreground', { dark: '#5A5A5A', light: '#2B91AF', hc: Color.white }, nls.localize('editorLineNumbers', 'Color of editor line numbers.'));
+export const editorActiveLineNumber = registerColor('editorActiveLineNumber.foreground', { dark: null, light: null, hc: null }, nls.localize('editorActiveLineNumber', 'Color of editor active line number'));
 export const editorRuler = registerColor('editorRuler.foreground', { dark: '#5A5A5A', light: Color.lightgrey, hc: Color.white }, nls.localize('editorRuler', 'Color of the editor rulers.'));
 
 export const editorCodeLensForeground = registerColor('editorCodeLens.foreground', { dark: '#999999', light: '#999999', hc: '#999999' }, nls.localize('editorCodeLensForeground', 'Foreground color of editor code lenses'));