feat: added option to copy legend text (#10294)

* feat: added option to copy legend text

* chore: added test for legend copy action

* chore: updated legend styles

* chore: added check icon when legend copied

* chore: added copytoclipboard hook

* chore: removed copytoclipboard options

frontend/src/hooks/useCopyToClipboard.ts

@@ -0,0 +1,61 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+
+const DEFAULT_COPIED_RESET_MS = 2000;
+
+export interface UseCopyToClipboardOptions {
+	/** How long (ms) to keep "copied" state before resetting. Default 2000. */
+	copiedResetMs?: number;
+}
+
+export type ID = number | string | null;
+
+export interface UseCopyToClipboardReturn {
+	/** Copy text to clipboard. Pass an optional id to track which item was copied (e.g. seriesIndex). */
+	copyToClipboard: (text: string, id?: ID) => void;
+	/** True when something was just copied and still within the reset threshold. */
+	isCopied: boolean;
+	/** The id passed to the last successful copy, or null after reset. Use to show "copied" state for a specific item (e.g. copiedId === item.seriesIndex). */
+	id: ID;
+}
+
+export function useCopyToClipboard(
+	options: UseCopyToClipboardOptions = {},
+): UseCopyToClipboardReturn {
+	const { copiedResetMs = DEFAULT_COPIED_RESET_MS } = options;
+	const [state, setState] = useState<{ isCopied: boolean; id: ID }>({
+		isCopied: false,
+		id: null,
+	});
+	const timeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+	useEffect(() => {
+		return (): void => {
+			if (timeoutRef.current) {
+				clearTimeout(timeoutRef.current);
+				timeoutRef.current = null;
+			}
+		};
+	}, []);
+
+	const copyToClipboard = useCallback(
+		(text: string, id?: ID): void => {
+			navigator.clipboard.writeText(text).then(() => {
+				if (timeoutRef.current) {
+					clearTimeout(timeoutRef.current);
+				}
+				setState({ isCopied: true, id: id ?? null });
+				timeoutRef.current = setTimeout(() => {
+					setState({ isCopied: false, id: null });
+					timeoutRef.current = null;
+				}, copiedResetMs);
+			});
+		},
+		[copiedResetMs],
+	);
+
+	return {
+		copyToClipboard,
+		isCopied: state.isCopied,
+		id: state.id,
+	};
+}

frontend/src/lib/uPlotV2/components/Legend/Legend.styles.scss

@@ -128,6 +128,15 @@
 		opacity: 1;
 	}
 
+	.legend-item-label-trigger {
+		display: flex;
+		align-items: center;
+		gap: 6px;
+		flex: 1;
+		min-width: 0;
+		cursor: pointer;
+	}
+
 	.legend-marker {
 		border-width: 2px;
 		border-radius: 50%;
@@ -157,10 +166,34 @@
 		text-overflow: ellipsis;
 		white-space: nowrap;
 		min-width: 0;
+		user-select: none;
+	}
+
+	.legend-copy-button {
+		display: none;
+		align-items: center;
+		justify-content: center;
+		flex-shrink: 0;
+		padding: 2px;
+		margin: 0;
+		border: none;
+		color: var(--bg-vanilla-400);
+		cursor: pointer;
+		border-radius: 4px;
+		opacity: 1;
+		transition: opacity 0.15s ease, color 0.15s ease;
+
+		&:hover {
+			color: var(--bg-vanilla-100);
+		}
 	}
 
 	&:hover {
 		background: rgba(255, 255, 255, 0.05);
+		.legend-copy-button {
+			display: flex;
+			opacity: 1;
+		}
 	}
 }
 
@@ -172,4 +205,17 @@
 			}
 		}
 	}
+
+	.legend-item {
+		&:hover {
+			background: rgba(0, 0, 0, 0.05);
+		}
+		.legend-copy-button {
+			color: var(--bg-ink-400);
+
+			&:hover {
+				color: var(--bg-ink-500);
+			}
+		}
+	}
 }

frontend/src/lib/uPlotV2/components/Legend/Legend.tsx

@@ -2,8 +2,10 @@ import { useCallback, useMemo, useRef, useState } from 'react';
 import { VirtuosoGrid } from 'react-virtuoso';
 import { Input, Tooltip as AntdTooltip } from 'antd';
 import cx from 'classnames';
+import { useCopyToClipboard } from 'hooks/useCopyToClipboard';
 import { LegendItem } from 'lib/uPlotV2/config/types';
 import useLegendsSync from 'lib/uPlotV2/hooks/useLegendsSync';
+import { Check, Copy } from 'lucide-react';
 
 import { useLegendActions } from '../../hooks/useLegendActions';
 import { LegendPosition, LegendProps } from '../types';
@@ -32,6 +34,7 @@ export default function Legend({
 	});
 	const legendContainerRef = useRef<HTMLDivElement | null>(null);
 	const [legendSearchQuery, setLegendSearchQuery] = useState('');
+	const { copyToClipboard, id: copiedId } = useCopyToClipboard();
 
 	const legendItems = useMemo(() => Object.values(legendItemsMap), [
 		legendItemsMap,
@@ -59,26 +62,53 @@ export default function Legend({
 		);
 	}, [position, legendSearchQuery, legendItems]);
 
+	const handleCopyLegendItem = useCallback(
+		(e: React.MouseEvent, seriesIndex: number, label: string): void => {
+			e.stopPropagation();
+			copyToClipboard(label, seriesIndex);
+		},
+		[copyToClipboard],
+	);
+
 	const renderLegendItem = useCallback(
-		(item: LegendItem): JSX.Element => (
-			<AntdTooltip key={item.seriesIndex} title={item.label}>
+		(item: LegendItem): JSX.Element => {
+			const isCopied = copiedId === item.seriesIndex;
+			return (
 				<div
+					key={item.seriesIndex}
 					data-legend-item-id={item.seriesIndex}
 					className={cx('legend-item', `legend-item-${position.toLowerCase()}`, {
 						'legend-item-off': !item.show,
 						'legend-item-focused': focusedSeriesIndex === item.seriesIndex,
 					})}
 				>
-					<div
-						className="legend-marker"
-						style={{ borderColor: String(item.color) }}
-						data-is-legend-marker={true}
-					/>
-					<span className="legend-label">{item.label}</span>
+					<AntdTooltip title={item.label}>
+						<div className="legend-item-label-trigger">
+							<div
+								className="legend-marker"
+								style={{ borderColor: String(item.color) }}
+								data-is-legend-marker={true}
+							/>
+							<span className="legend-label">{item.label}</span>
+						</div>
+					</AntdTooltip>
+					<AntdTooltip title={isCopied ? 'Copied' : 'Copy'}>
+						<button
+							type="button"
+							className="legend-copy-button"
+							onClick={(e): void =>
+								handleCopyLegendItem(e, item.seriesIndex, item.label ?? '')
+							}
+							aria-label={`Copy ${item.label}`}
+							data-testid="legend-copy"
+						>
+							{isCopied ? <Check size={12} /> : <Copy size={12} />}
+						</button>
+					</AntdTooltip>
 				</div>
-			</AntdTooltip>
-		),
-		[focusedSeriesIndex, position],
+			);
+		},
+		[copiedId, focusedSeriesIndex, handleCopyLegendItem, position],
 	);
 
 	const isEmptyState = useMemo(() => {

frontend/src/lib/uPlotV2/components/__tests__/Legend.test.tsx

@@ -1,5 +1,11 @@
 import React from 'react';
-import { render, RenderResult, screen } from '@testing-library/react';
+import {
+	fireEvent,
+	render,
+	RenderResult,
+	screen,
+	within,
+} from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { LegendItem } from 'lib/uPlotV2/config/types';
 import useLegendsSync from 'lib/uPlotV2/hooks/useLegendsSync';
@@ -8,6 +14,9 @@ import { useLegendActions } from '../../hooks/useLegendActions';
 import Legend from '../Legend/Legend';
 import { LegendPosition } from '../types';
 
+const mockWriteText = jest.fn().mockResolvedValue(undefined);
+let clipboardSpy: jest.SpyInstance | undefined;
+
 jest.mock('react-virtuoso', () => ({
 	VirtuosoGrid: ({
 		data,
@@ -39,6 +48,15 @@ const mockUseLegendActions = useLegendActions as jest.MockedFunction<
 >;
 
 describe('Legend', () => {
+	beforeAll(() => {
+		// JSDOM does not define navigator.clipboard; add it so we can spy on writeText
+		Object.defineProperty(navigator, 'clipboard', {
+			value: { writeText: () => Promise.resolve() },
+			writable: true,
+			configurable: true,
+		});
+	});
+
 	const baseLegendItemsMap = {
 		0: {
 			seriesIndex: 0,
@@ -70,6 +88,11 @@ describe('Legend', () => {
 		onLegendMouseMove = jest.fn();
 		onLegendMouseLeave = jest.fn();
 		onFocusSeries = jest.fn();
+		mockWriteText.mockClear();
+
+		clipboardSpy = jest
+			.spyOn(navigator.clipboard, 'writeText')
+			.mockImplementation(mockWriteText);
 
 		mockUseLegendsSync.mockReturnValue({
 			legendItemsMap: baseLegendItemsMap,
@@ -86,6 +109,7 @@ describe('Legend', () => {
 	});
 
 	afterEach(() => {
+		clipboardSpy?.mockRestore();
 		jest.clearAllMocks();
 	});
 
@@ -210,4 +234,47 @@ describe('Legend', () => {
 			expect(onLegendMouseLeave).toHaveBeenCalledTimes(1);
 		});
 	});
+
+	describe('copy action', () => {
+		it('copies the legend label to clipboard when copy button is clicked', () => {
+			renderLegend(LegendPosition.RIGHT);
+
+			const firstLegendItem = document.querySelector(
+				'[data-legend-item-id="0"]',
+			) as HTMLElement;
+			const copyButton = within(firstLegendItem).getByTestId('legend-copy');
+
+			fireEvent.click(copyButton);
+
+			expect(mockWriteText).toHaveBeenCalledTimes(1);
+			expect(mockWriteText).toHaveBeenCalledWith('A');
+		});
+
+		it('copies the correct label when copy is clicked on a different legend item', () => {
+			renderLegend(LegendPosition.RIGHT);
+
+			const thirdLegendItem = document.querySelector(
+				'[data-legend-item-id="2"]',
+			) as HTMLElement;
+			const copyButton = within(thirdLegendItem).getByTestId('legend-copy');
+
+			fireEvent.click(copyButton);
+
+			expect(mockWriteText).toHaveBeenCalledTimes(1);
+			expect(mockWriteText).toHaveBeenCalledWith('C');
+		});
+
+		it('does not call onLegendClick when copy button is clicked', () => {
+			renderLegend(LegendPosition.RIGHT);
+
+			const firstLegendItem = document.querySelector(
+				'[data-legend-item-id="0"]',
+			) as HTMLElement;
+			const copyButton = within(firstLegendItem).getByTestId('legend-copy');
+
+			fireEvent.click(copyButton);
+
+			expect(onLegendClick).not.toHaveBeenCalled();
+		});
+	});
 });