Merge from master

src/vs/workbench/browser/parts/quickinput/quickInputUtils.ts

@@ -0,0 +1,28 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import 'vs/css!./quickInput';
+import * as dom from 'vs/base/browser/dom';
+import { URI } from 'vs/base/common/uri';
+import { IdGenerator } from 'vs/base/common/idGenerator';
+
+const iconPathToClass = {};
+const iconClassGenerator = new IdGenerator('quick-input-button-icon-');
+
+export function getIconClass(iconPath: { dark: URI; light?: URI; }) {
+	let iconClass: string;
+
+	const key = iconPath.dark.toString();
+	if (iconPathToClass[key]) {
+		iconClass = iconPathToClass[key];
+	} else {
+		iconClass = iconClassGenerator.nextId();
+		dom.createCSSRule(`.${iconClass}`, `background-image: url("${(iconPath.light || iconPath.dark).toString()}")`);
+		dom.createCSSRule(`.vs-dark .${iconClass}, .hc-black .${iconClass}`, `background-image: url("${iconPath.dark.toString()}")`);
+		iconPathToClass[key] = iconClass;
+	}
+
+	return iconClass;
+}