Fixes #47660: Trigger hover even when the mouse is very close to the content text

src/vs/editor/browser/controller/mouseTarget.ts

@@ -35,6 +35,7 @@ export interface IMarginData {
 
 export interface IEmptyContentData {
 	isAfterLines: boolean;
+	horizontalDistanceToText?: number;
 }
 
 interface IETextRange {
@@ -415,7 +416,13 @@ class HitTestRequest extends BareHitTestRequest {
 }
 
 const EMPTY_CONTENT_AFTER_LINES: IEmptyContentData = { isAfterLines: true };
-const EMPTY_CONTENT_IN_LINES: IEmptyContentData = { isAfterLines: false };
+
+function createEmptyContentDataInLines(horizontalDistanceToText: number): IEmptyContentData {
+	return {
+		isAfterLines: false,
+		horizontalDistanceToText: horizontalDistanceToText
+	};
+}
 
 export class MouseTargetFactory {
 
@@ -639,7 +646,9 @@ export class MouseTargetFactory {
 			if (ElementPath.isStrictChildOfViewLines(request.targetPath)) {
 				const lineNumber = ctx.getLineNumberAtVerticalOffset(request.mouseVerticalOffset);
 				if (ctx.model.getLineLength(lineNumber) === 0) {
-					return request.fulfill(MouseTargetType.CONTENT_EMPTY, new Position(lineNumber, 1), void 0, EMPTY_CONTENT_IN_LINES);
+					const lineWidth = ctx.getLineWidth(lineNumber);
+					const detail = createEmptyContentDataInLines(request.mouseContentHorizontalOffset - lineWidth);
+					return request.fulfill(MouseTargetType.CONTENT_EMPTY, new Position(lineNumber, 1), void 0, detail);
 				}
 			}
 
@@ -713,9 +722,11 @@ export class MouseTargetFactory {
 		if (request.mouseContentHorizontalOffset > lineWidth) {
 			if (browser.isEdge && pos.column === 1) {
 				// See https://github.com/Microsoft/vscode/issues/10875
-				return request.fulfill(MouseTargetType.CONTENT_EMPTY, new Position(lineNumber, ctx.model.getLineMaxColumn(lineNumber)), void 0, EMPTY_CONTENT_IN_LINES);
+				const detail = createEmptyContentDataInLines(request.mouseContentHorizontalOffset - lineWidth);
+				return request.fulfill(MouseTargetType.CONTENT_EMPTY, new Position(lineNumber, ctx.model.getLineMaxColumn(lineNumber)), void 0, detail);
 			}
-			return request.fulfill(MouseTargetType.CONTENT_EMPTY, pos, void 0, EMPTY_CONTENT_IN_LINES);
+			const detail = createEmptyContentDataInLines(request.mouseContentHorizontalOffset - lineWidth);
+			return request.fulfill(MouseTargetType.CONTENT_EMPTY, pos, void 0, detail);
 		}
 
 		const visibleRange = ctx.visibleRangeForPosition2(lineNumber, column);

src/vs/editor/contrib/hover/hover.ts

@@ -23,6 +23,7 @@ import { registerThemingParticipant, IThemeService } from 'vs/platform/theme/com
 import { editorHoverHighlight, editorHoverBackground, editorHoverBorder, textLinkForeground, textCodeBlockBackground } from 'vs/platform/theme/common/colorRegistry';
 import { EditorContextKeys } from 'vs/editor/common/editorContextKeys';
 import { MarkdownRenderer } from 'vs/editor/contrib/markdown/markdownRenderer';
+import { IEmptyContentData } from 'vs/editor/browser/controller/mouseTarget';
 
 export class ModesHoverController implements editorCommon.IEditorContribution {
 
@@ -114,8 +115,8 @@ export class ModesHoverController implements editorCommon.IEditorContribution {
 	}
 
 	private _onEditorMouseMove(mouseEvent: IEditorMouseEvent): void {
-		var targetType = mouseEvent.target.type;
-		var stopKey = platform.isMacintosh ? 'metaKey' : 'ctrlKey';
+		let targetType = mouseEvent.target.type;
+		let stopKey = platform.isMacintosh ? 'metaKey' : 'ctrlKey';
 
 		if (this._isMouseDown && this._hoverClicked && this.contentWidget.isColorPickerVisible()) {
 			return;
@@ -131,6 +132,15 @@ export class ModesHoverController implements editorCommon.IEditorContribution {
 			return;
 		}
 
+		if (targetType === MouseTargetType.CONTENT_EMPTY) {
+			const epsilon = this._editor.getConfiguration().fontInfo.typicalHalfwidthCharacterWidth / 2;
+			const data = <IEmptyContentData>mouseEvent.target.detail;
+			if (data && !data.isAfterLines && typeof data.horizontalDistanceToText === 'number' && data.horizontalDistanceToText < epsilon) {
+				// Let hover kick in even when the mouse is technically in the empty area after a line, given the distance is small enough
+				targetType = MouseTargetType.CONTENT_TEXT;
+			}
+		}
+
 		if (this._editor.getConfiguration().contribInfo.hover && targetType === MouseTargetType.CONTENT_TEXT) {
 			this.glyphWidget.hide();
 			this.contentWidget.startShowingAt(mouseEvent.target.range, false);