feature: allow unsetting color theme values in settings (#213512)

* allow null value

* allow unsetting color

* undo change

* delete color

* undo changes

* remove unused code

* unset right map

* add function to create nullable color schema

* use nullable schema

* undo change

* fix nullable object

* use default value

* update both schemas on timeout

* simplifications & polish

---------

Co-authored-by: Martin Aeschlimann 

Author: SimonSiefke

src/vs/platform/theme/common/colorUtils.ts

@@ -11,6 +11,7 @@ import { IJSONSchema, IJSONSchemaMap } from 'vs/base/common/jsonSchema';
 import { IJSONContributionRegistry, Extensions as JSONExtensions } from 'vs/platform/jsonschemas/common/jsonContributionRegistry';
 import * as platform from 'vs/platform/registry/common/platform';
 import { IColorTheme } from 'vs/platform/theme/common/themeService';
+import * as nls from 'vs/nls';
 
 //  ------ API types
 
@@ -79,6 +80,8 @@ export const Extensions = {
 	ColorContribution: 'base.contributions.colors'
 };
 
+export const DEFAULT_COLOR_CONFIG_VALUE = 'default';
+
 export interface IColorRegistry {
 
 	readonly onDidChangeSchema: Event<void>;
@@ -141,9 +144,14 @@ class ColorRegistry implements IColorRegistry {
 		}
 		if (needsTransparency) {
 			propertySchema.pattern = '^#(?:(?[0-9a-fA-f]{3}[0-9a-eA-E])|(?:[0-9a-fA-F]{6}(?:(?![fF]{2})(?:[0-9a-fA-F]{2}))))?$';
-			propertySchema.patternErrorMessage = 'This color must be transparent or it will obscure content';
+			propertySchema.patternErrorMessage = nls.localize('transparecyRequired', 'This color must be transparent or it will obscure content');
 		}
-		this.colorSchema.properties[id] = propertySchema;
+		this.colorSchema.properties[id] = {
+			oneOf: [
+				propertySchema,
+				{ type: 'string', const: DEFAULT_COLOR_CONFIG_VALUE, description: nls.localize('useDefault', 'Use the default color.') }
+			]
+		};
 		this.colorReferenceSchema.enum.push(id);
 		this.colorReferenceSchema.enumDescriptions.push(description);
 
@@ -319,6 +327,7 @@ const schemaRegistry = platform.Registry.as(JSONExten
 schemaRegistry.registerSchema(workbenchColorsSchemaId, colorRegistry.getColorSchema());
 
 const delayer = new RunOnceScheduler(() => schemaRegistry.notifySchemaChanged(workbenchColorsSchemaId), 200);
+
 colorRegistry.onDidChangeSchema(() => {
 	if (!delayer.isScheduled()) {
 		delayer.schedule();

src/vs/workbench/services/themes/common/colorThemeData.ts

@@ -11,7 +11,7 @@ import { convertSettings } from 'vs/workbench/services/themes/common/themeCompat
 import * as nls from 'vs/nls';
 import * as types from 'vs/base/common/types';
 import * as resources from 'vs/base/common/resources';
-import { Extensions as ColorRegistryExtensions, IColorRegistry, ColorIdentifier, editorBackground, editorForeground } from 'vs/platform/theme/common/colorRegistry';
+import { Extensions as ColorRegistryExtensions, IColorRegistry, ColorIdentifier, editorBackground, editorForeground, DEFAULT_COLOR_CONFIG_VALUE } from 'vs/platform/theme/common/colorRegistry';
 import { ITokenStyle, getThemeTypeSelector } from 'vs/platform/theme/common/themeService';
 import { Registry } from 'vs/platform/registry/common/platform';
 import { getParseErrorMessage } from 'vs/base/common/jsonErrorMessages';
@@ -372,7 +372,9 @@ export class ColorThemeData implements IWorkbenchColorTheme {
 	private overwriteCustomColors(colors: IColorCustomizations) {
 		for (const id in colors) {
 			const colorVal = colors[id];
-			if (typeof colorVal === 'string') {
+			if (colorVal === DEFAULT_COLOR_CONFIG_VALUE) {
+				delete this.colorMap[id];
+			} else if (typeof colorVal === 'string') {
 				this.customColorMap[id] = Color.fromHex(colorVal);
 			}
 		}
@@ -716,8 +718,10 @@ async function _loadColorTheme(extensionResourceLoaderService: IExtensionResourc
 			}
 			// new JSON color themes format
 			for (const colorId in colors) {
-				const colorHex = colors[colorId];
-				if (typeof colorHex === 'string') { // ignore colors tht are null
+				const colorVal = colors[colorId];
+				if (colorVal === DEFAULT_COLOR_CONFIG_VALUE) {
+					delete result.colors[colorId];
+				} else if (typeof colorVal === 'string') { // ignore colors that are null
 					result.colors[colorId] = Color.fromHex(colors[colorId]);
 				}
 			}