line decorations for first and last line

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

@@ -74,9 +74,17 @@ export class LinesDecorationsOverlay extends DedupOverlay {
 		let r: DecorationToRender[] = [], rLen = 0;
 		for (let i = 0, len = decorations.length; i < len; i++) {
 			const d = decorations[i];
-			const linesDecorationsClassName = d.options.linesDecorationsClassName;
-			if (linesDecorationsClassName) {
-				r[rLen++] = new DecorationToRender(d.range.startLineNumber, d.range.endLineNumber, linesDecorationsClassName);
+			const linesDecorations = d.options.linesDecorationsClassName;
+			if (linesDecorations) {
+				r[rLen++] = new DecorationToRender(d.range.startLineNumber, d.range.endLineNumber, linesDecorations);
+			}
+			const firstLineDecorationsClassName = d.options.firstLineDecorationsClassName;
+			if (firstLineDecorationsClassName) {
+				r[rLen++] = new DecorationToRender(d.range.startLineNumber, d.range.startLineNumber, firstLineDecorationsClassName);
+			}
+			const lastLineDecorationsClassName = d.options.lastLineDecorationsClassName;
+			if (lastLineDecorationsClassName) {
+				r[rLen++] = new DecorationToRender(d.range.endLineNumber, d.range.endLineNumber, lastLineDecorationsClassName);
 			}
 		}
 		return r;

src/vs/editor/common/model.ts

@@ -123,6 +123,14 @@ export interface IModelDecorationOptions {
 	 * If set, the decoration will be rendered in the lines decorations with this CSS class name.
 	 */
 	linesDecorationsClassName?: string | null;
+	/**
+	 * If set, the decoration will be rendered for first line of the range in the lines decorations with this CSS class name.
+	 */
+	firstLineDecorationsClassName?: string | null;
+	/**
+	 * If set, the decoration will be rendered for last line of the range in the lines decorations for last line with this CSS class name.
+	 */
+	lastLineDecorationsClassName?: string | null;
 	/**
 	 * If set, the decoration will be rendered in the margin (covering its full width) with this CSS class name.
 	 */

src/vs/editor/common/model/textModel.ts

@@ -3053,6 +3053,8 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 	readonly minimap: ModelDecorationMinimapOptions | null;
 	readonly glyphMarginClassName: string | null;
 	readonly linesDecorationsClassName: string | null;
+	readonly firstLineDecorationsClassName: string | null;
+	readonly lastLineDecorationsClassName: string | null;
 	readonly marginClassName: string | null;
 	readonly inlineClassName: string | null;
 	readonly inlineClassNameAffectsLetterSpacing: boolean;
@@ -3072,6 +3074,8 @@ export class ModelDecorationOptions implements model.IModelDecorationOptions {
 		this.minimap = options.minimap ? new ModelDecorationMinimapOptions(options.minimap) : null;
 		this.glyphMarginClassName = options.glyphMarginClassName ? cleanClassName(options.glyphMarginClassName) : null;
 		this.linesDecorationsClassName = options.linesDecorationsClassName ? cleanClassName(options.linesDecorationsClassName) : null;
+		this.firstLineDecorationsClassName = options.firstLineDecorationsClassName ? cleanClassName(options.firstLineDecorationsClassName) : null;
+		this.lastLineDecorationsClassName = options.lastLineDecorationsClassName ? cleanClassName(options.lastLineDecorationsClassName) : null;
 		this.marginClassName = options.marginClassName ? cleanClassName(options.marginClassName) : null;
 		this.inlineClassName = options.inlineClassName ? cleanClassName(options.inlineClassName) : null;
 		this.inlineClassNameAffectsLetterSpacing = options.inlineClassNameAffectsLetterSpacing || false;

src/vs/editor/contrib/folding/foldingDecorations.ts

@@ -13,7 +13,8 @@ export class FoldingDecorationProvider implements IDecorationProvider {
 	private static readonly COLLAPSED_VISUAL_DECORATION = ModelDecorationOptions.register({
 		stickiness: TrackedRangeStickiness.NeverGrowsWhenTypingAtEdges,
 		afterContentClassName: 'inline-folded',
-		linesDecorationsClassName: 'codicon codicon-chevron-right'
+		isWholeLine: true,
+		firstLineDecorationsClassName: 'codicon codicon-chevron-right'
 	});
 
 	private static readonly COLLAPSED_HIGHLIGHTED_VISUAL_DECORATION = ModelDecorationOptions.register({
@@ -21,16 +22,19 @@ export class FoldingDecorationProvider implements IDecorationProvider {
 		afterContentClassName: 'inline-folded',
 		className: 'folded-background',
 		isWholeLine: true,
-		linesDecorationsClassName: 'codicon codicon-chevron-right'
+		firstLineDecorationsClassName: 'codicon codicon-chevron-right'
 	});
 
 	private static readonly EXPANDED_AUTO_HIDE_VISUAL_DECORATION = ModelDecorationOptions.register({
 		stickiness: TrackedRangeStickiness.NeverGrowsWhenTypingAtEdges,
-		linesDecorationsClassName: 'codicon codicon-chevron-down'
+		isWholeLine: true,
+		firstLineDecorationsClassName: 'codicon codicon-chevron-down'
 	});
 
 	private static readonly EXPANDED_VISUAL_DECORATION = ModelDecorationOptions.register({
 		stickiness: TrackedRangeStickiness.NeverGrowsWhenTypingAtEdges,
+		isWholeLine: true,
+		firstLineDecorationsClassName: 'codicon codicon-chevron-down alwaysShowFoldIcons'
 	});
 
 	private static readonly HIDDEN_RANGE_DECORATION = ModelDecorationOptions.register({

src/vs/monaco.d.ts

@@ -1369,6 +1369,14 @@ declare namespace monaco.editor {
 		 * If set, the decoration will be rendered in the lines decorations with this CSS class name.
 		 */
 		linesDecorationsClassName?: string | null;
+		/**
+		 * If set, the decoration will be rendered for first line of the range in the lines decorations with this CSS class name.
+		 */
+		firstLineDecorationsClassName?: string | null;
+		/**
+		 * If set, the decoration will be rendered for last line of the range in the lines decorations for last line with this CSS class name.
+		 */
+		lastLineDecorationsClassName?: string | null;
 		/**
 		 * If set, the decoration will be rendered in the margin (covering its full width) with this CSS class name.
 		 */