Add component for ShapeIndicators (#4083)

This PR adds a component for `ShapeIndicators` to the UI component
overrides. It moves the "select tool" state logic up to the new
`TldrawShapeIndicators` component.

### Change type

- [ ] `bugfix`
- [x] `improvement`
- [ ] `feature`
- [x] `api`
- [ ] `other`

### Release notes

- Added new `ShapeIndicators` component to `components` object.
- Added new `TldrawShapeIndicators` component.

apps/examples/src/examples/exploded/ExplodedExample.tsx

@@ -9,6 +9,7 @@ import {
 	TldrawScribble,
 	TldrawSelectionBackground,
 	TldrawSelectionForeground,
+	TldrawShapeIndicators,
 	TldrawUi,
 	defaultBindingUtils,
 	defaultEditorAssetUrls,
@@ -24,6 +25,7 @@ import 'tldraw/tldraw.css'
 // [1]
 const defaultComponents = {
 	Scribble: TldrawScribble,
+	ShapeIndicators: TldrawShapeIndicators,
 	CollaboratorScribble: TldrawScribble,
 	SelectionForeground: TldrawSelectionForeground,
 	SelectionBackground: TldrawSelectionBackground,

packages/editor/api-report.md

@@ -653,6 +653,9 @@ export function DefaultSelectionForeground({ bounds, rotation }: TLSelectionFore
 // @public (undocumented)
 export const DefaultShapeIndicator: NamedExoticComponent<TLShapeIndicatorProps>;
 
+// @public (undocumented)
+export const DefaultShapeIndicators: NamedExoticComponent<object>;
+
 // @public (undocumented)
 export function DefaultSnapIndicator({ className, line, zoom }: TLSnapIndicatorProps): JSX_2.Element;
 
@@ -1772,7 +1775,7 @@ export function openWindow(url: string, target?: string): void;
 // @internal (undocumented)
 export function OptionalErrorBoundary({ children, fallback, ...props }: Omit<TLErrorBoundaryProps, 'fallback'> & {
     fallback: TLErrorFallbackComponent;
-}): JSX_2.Element;
+}): boolean | JSX_2.Element | Iterable<React_3.ReactNode> | null | number | string | undefined;
 
 // @public (undocumented)
 export type OptionalKeys<T, K extends keyof T> = Omit<T, K> & Partial<Pick<T, K>>;
@@ -2669,6 +2672,8 @@ export interface TLEditorComponents {
     // (undocumented)
     ShapeIndicatorErrorFallback?: TLShapeIndicatorErrorFallbackComponent;
     // (undocumented)
+    ShapeIndicators?: ComponentType | null;
+    // (undocumented)
     SnapIndicator?: ComponentType<TLSnapIndicatorProps> | null;
     // (undocumented)
     Spinner?: ComponentType | null;

packages/editor/src/index.ts

@@ -96,6 +96,7 @@ export {
 	type TLShapeIndicatorProps,
 } from './lib/components/default-components/DefaultShapeIndicator'
 export { type TLShapeIndicatorErrorFallbackComponent } from './lib/components/default-components/DefaultShapeIndicatorErrorFallback'
+export { DefaultShapeIndicators } from './lib/components/default-components/DefaultShapeIndicators'
 export {
 	DefaultSnapIndicator,
 	type TLSnapIndicatorProps,

packages/editor/src/lib/TldrawEditor.tsx

@@ -453,7 +453,7 @@ function Layout({ children, onMount }: { children: ReactNode; onMount?: TLOnMoun
 	useForceUpdate()
 	useOnMount(onMount)
 
-	return <>{children}</>
+	return children
 }
 
 function Crash({ crashingError }: { crashingError: unknown }): null {

packages/editor/src/lib/components/ErrorBoundary.tsx

@@ -46,7 +46,7 @@ export function OptionalErrorBoundary({
 	fallback: TLErrorFallbackComponent
 }) {
 	if (fallback === null) {
-		return <>{children}</>
+		return children
 	}
 
 	return (

packages/editor/src/lib/components/LiveCollaborators.tsx

@@ -9,13 +9,7 @@ import { usePresence } from '../hooks/usePresence'
 
 export const LiveCollaborators = track(function Collaborators() {
 	const peerIds = usePeerIds()
-	return (
-		<>
-			{peerIds.map((id) => (
-				<CollaboratorGuard key={id} collaboratorId={id} />
-			))}
-		</>
-	)
+	return peerIds.map((id) => <CollaboratorGuard key={id} collaboratorId={id} />)
 })
 
 const CollaboratorGuard = track(function CollaboratorGuard({

packages/editor/src/lib/components/default-components/DefaultCanvas.tsx

@@ -33,7 +33,7 @@ export interface TLCanvasComponentProps {
 export function DefaultCanvas({ className }: TLCanvasComponentProps) {
 	const editor = useEditor()
 
-	const { Background, SvgDefs } = useEditorComponents()
+	const { Background, SvgDefs, ShapeIndicators } = useEditorComponents()
 
 	const rCanvas = useRef<HTMLDivElement>(null)
 	const rHtmlLayer = useRef<HTMLDivElement>(null)
@@ -161,7 +161,7 @@ export function DefaultCanvas({ className }: TLCanvasComponentProps) {
 						<BrushWrapper />
 						<ScribbleWrapper />
 						<ZoomBrushWrapper />
-						<ShapeIndicators />
+						{ShapeIndicators && <ShapeIndicators />}
 						<HintedShapeIndicator />
 						<SnapIndicatorWrapper />
 						<SelectionForegroundWrapper />
@@ -201,18 +201,9 @@ function ScribbleWrapper() {
 
 	if (!(Scribble && scribbles.length)) return null
 
-	return (
-		<>
-			{scribbles.map((scribble) => (
-				<Scribble
-					key={scribble.id}
-					className="tl-user-scribble"
-					scribble={scribble}
-					zoom={zoomLevel}
-				/>
-			))}
-		</>
-	)
+	return scribbles.map((scribble) => (
+		<Scribble key={scribble.id} className="tl-user-scribble" scribble={scribble} zoom={zoomLevel} />
+	))
 }
 
 function BrushWrapper() {
@@ -243,13 +234,9 @@ function SnapIndicatorWrapper() {
 
 	if (!(SnapIndicator && lines.length > 0)) return null
 
-	return (
-		<>
-			{lines.map((line) => (
-				<SnapIndicator key={line.id} className="tl-user-snapline" line={line} zoom={zoomLevel} />
-			))}
-		</>
-	)
+	return lines.map((line) => (
+		<SnapIndicator key={line.id} className="tl-user-snapline" line={line} zoom={zoomLevel} />
+	))
 }
 
 function HandlesWrapper() {
@@ -388,16 +375,12 @@ function ShapesWithSVGs() {
 		[editor]
 	)
 
-	return (
-		<>
-			{renderingShapes.map((result) => (
-				<Fragment key={result.id + '_fragment'}>
-					<Shape {...result} dprMultiple={dprMultiple} />
-					<DebugSvgCopy id={result.id} />
-				</Fragment>
-			))}
-		</>
-	)
+	return renderingShapes.map((result) => (
+		<Fragment key={result.id + '_fragment'}>
+			<Shape {...result} dprMultiple={dprMultiple} />
+			<DebugSvgCopy id={result.id} />
+		</Fragment>
+	))
 }
 function ReflowIfNeeded() {
 	const editor = useEditor()
@@ -448,70 +431,6 @@ function ShapesToDisplay() {
 	)
 }
 
-function ShapeIndicators() {
-	const editor = useEditor()
-	const renderingShapes = useValue('rendering shapes', () => editor.getRenderingShapes(), [editor])
-	const rPreviousSelectedShapeIds = useRef<Set<TLShapeId>>(new Set())
-	const idsToDisplay = useValue(
-		'should display selected ids',
-		() => {
-			// todo: move to tldraw selected ids wrappe
-			const prev = rPreviousSelectedShapeIds.current
-			const next = new Set<TLShapeId>()
-			if (
-				editor.isInAny(
-					'select.idle',
-					'select.brushing',
-					'select.scribble_brushing',
-					'select.editing_shape',
-					'select.pointing_shape',
-					'select.pointing_selection',
-					'select.pointing_handle'
-				) &&
-				!editor.getInstanceState().isChangingStyle
-			) {
-				const selected = editor.getSelectedShapeIds()
-				for (const id of selected) {
-					next.add(id)
-				}
-				if (editor.isInAny('select.idle', 'select.editing_shape')) {
-					const instanceState = editor.getInstanceState()
-					if (instanceState.isHoveringCanvas && !instanceState.isCoarsePointer) {
-						const hovered = editor.getHoveredShapeId()
-						if (hovered) next.add(hovered)
-					}
-				}
-			}
-
-			if (prev.size !== next.size) {
-				rPreviousSelectedShapeIds.current = next
-				return next
-			}
-
-			for (const id of next) {
-				if (!prev.has(id)) {
-					rPreviousSelectedShapeIds.current = next
-					return next
-				}
-			}
-
-			return prev
-		},
-		[editor]
-	)
-
-	const { ShapeIndicator } = useEditorComponents()
-	if (!ShapeIndicator) return null
-
-	return (
-		<>
-			{renderingShapes.map(({ id }) => (
-				<ShapeIndicator key={id + '_indicator'} shapeId={id} hidden={!idsToDisplay.has(id)} />
-			))}
-		</>
-	)
-}
-
 function HintedShapeIndicator() {
 	const editor = useEditor()
 	const { ShapeIndicator } = useEditorComponents()
@@ -521,13 +440,9 @@ function HintedShapeIndicator() {
 	if (!ids.length) return null
 	if (!ShapeIndicator) return null
 
-	return (
-		<>
-			{ids.map((id) => (
-				<ShapeIndicator className="tl-user-indicator__hint" shapeId={id} key={id + '_hinting'} />
-			))}
-		</>
-	)
+	return ids.map((id) => (
+		<ShapeIndicator className="tl-user-indicator__hint" shapeId={id} key={id + '_hinting'} />
+	))
 }
 
 function CursorDef() {

packages/editor/src/lib/components/default-components/DefaultShapeIndicators.tsx

@@ -0,0 +1,80 @@
+import { useValue } from '@tldraw/state'
+import { TLShapeId } from '@tldraw/tlschema'
+import { memo, useRef } from 'react'
+import { useEditor } from '../../hooks/useEditor'
+import { useEditorComponents } from '../../hooks/useEditorComponents'
+
+/** @public @react */
+export const DefaultShapeIndicators = memo(function DefaultShapeIndicators() {
+	const editor = useEditor()
+
+	const rPreviousSelectedShapeIds = useRef<Set<TLShapeId>>(new Set())
+
+	const idsToDisplay = useValue(
+		'should display selected ids',
+		() => {
+			const prev = rPreviousSelectedShapeIds.current
+			const next = new Set<TLShapeId>()
+
+			if (
+				// We only show indicators when in the following states...
+				editor.isInAny(
+					'select.idle',
+					'select.brushing',
+					'select.scribble_brushing',
+					'select.editing_shape',
+					'select.pointing_shape',
+					'select.pointing_selection',
+					'select.pointing_handle'
+				) &&
+				// ...but we hide indicators when we've just changed a style (so that the user can see the change)
+				!editor.getInstanceState().isChangingStyle
+			) {
+				// We always want to show indicators for the selected shapes, if any
+				const selected = editor.getSelectedShapeIds()
+				for (const id of selected) {
+					next.add(id)
+				}
+
+				// If we're idle or editing a shape, we want to also show an indicator for the hovered shape, if any
+				if (editor.isInAny('select.idle', 'select.editing_shape')) {
+					const instanceState = editor.getInstanceState()
+					if (instanceState.isHoveringCanvas && !instanceState.isCoarsePointer) {
+						const hovered = editor.getHoveredShapeId()
+						if (hovered) next.add(hovered)
+					}
+				}
+			}
+
+			// Ok, has anything changed?
+
+			// If the number of items in the set is different, then the selection has changed. This catches most changes.
+			if (prev.size !== next.size) {
+				rPreviousSelectedShapeIds.current = next
+				return next
+			}
+
+			// If any of the new ids are not in the previous set, then the selection has changed
+			for (const id of next) {
+				if (!prev.has(id)) {
+					rPreviousSelectedShapeIds.current = next
+					return next
+				}
+			}
+
+			// If nothing has changed, then return the previous value
+			return prev
+		},
+		[editor]
+	)
+
+	// Show indicators only for the shapes that are currently being rendered (ie that are on screen)
+	const renderingShapes = useValue('rendering shapes', () => editor.getRenderingShapes(), [editor])
+
+	const { ShapeIndicator } = useEditorComponents()
+	if (!ShapeIndicator) return null
+
+	return renderingShapes.map(({ id }) => (
+		<ShapeIndicator key={id + '_indicator'} shapeId={id} hidden={!idsToDisplay.has(id)} />
+	))
+})

packages/editor/src/lib/hooks/useEditorComponents.tsx

@@ -39,6 +39,7 @@ import {
 	DefaultShapeIndicatorErrorFallback,
 	TLShapeIndicatorErrorFallbackComponent,
 } from '../components/default-components/DefaultShapeIndicatorErrorFallback'
+import { DefaultShapeIndicators } from '../components/default-components/DefaultShapeIndicators'
 import {
 	DefaultSnapIndicator,
 	TLSnapIndicatorProps,
@@ -53,6 +54,7 @@ export interface TLEditorComponents {
 	SvgDefs?: ComponentType | null
 	Brush?: ComponentType<TLBrushProps> | null
 	ZoomBrush?: ComponentType<TLBrushProps> | null
+	ShapeIndicators?: ComponentType | null
 	ShapeIndicator?: ComponentType<TLShapeIndicatorProps> | null
 	Cursor?: ComponentType<TLCursorProps> | null
 	Canvas?: ComponentType<TLCanvasComponentProps> | null
@@ -114,6 +116,7 @@ export function EditorComponentsProvider({
 			Spinner: DefaultSpinner,
 			SelectionBackground: DefaultSelectionBackground,
 			SelectionForeground: DefaultSelectionForeground,
+			ShapeIndicators: DefaultShapeIndicators,
 			ShapeIndicator: DefaultShapeIndicator,
 			OnTheCanvas: null,
 			InFrontOfTheCanvas: null,

packages/tldraw/api-report.md

@@ -1686,6 +1686,9 @@ export const TldrawSelectionBackground: ({ bounds, rotation }: TLSelectionBackgr
 // @public (undocumented)
 export const TldrawSelectionForeground: MemoExoticComponent<({ bounds, rotation, }: TLSelectionForegroundProps) => JSX_2.Element | null>;
 
+// @public (undocumented)
+export function TldrawShapeIndicators(): JSX_2.Element | null;
+
 // @public (undocumented)
 export const TldrawUi: React_3.NamedExoticComponent<TldrawUiProps>;
 

packages/tldraw/src/index.ts

@@ -10,6 +10,7 @@ export { TldrawHandles } from './lib/canvas/TldrawHandles'
 export { TldrawScribble } from './lib/canvas/TldrawScribble'
 export { TldrawSelectionBackground } from './lib/canvas/TldrawSelectionBackground'
 export { TldrawSelectionForeground } from './lib/canvas/TldrawSelectionForeground'
+export { TldrawShapeIndicators } from './lib/canvas/TldrawShapeIndicators'
 export { defaultBindingUtils } from './lib/defaultBindingUtils'
 export { type TLExternalContentProps } from './lib/defaultExternalContentHandlers'
 export { defaultShapeTools } from './lib/defaultShapeTools'

packages/tldraw/src/lib/Tldraw.tsx

@@ -21,6 +21,7 @@ import { TldrawHandles } from './canvas/TldrawHandles'
 import { TldrawScribble } from './canvas/TldrawScribble'
 import { TldrawSelectionBackground } from './canvas/TldrawSelectionBackground'
 import { TldrawSelectionForeground } from './canvas/TldrawSelectionForeground'
+import { TldrawShapeIndicators } from './canvas/TldrawShapeIndicators'
 import { defaultBindingUtils } from './defaultBindingUtils'
 import {
 	TLExternalContentProps,
@@ -72,6 +73,7 @@ export function Tldraw(props: TldrawProps) {
 	const componentsWithDefault = useMemo(
 		() => ({
 			Scribble: TldrawScribble,
+			ShapeIndicators: TldrawShapeIndicators,
 			CollaboratorScribble: TldrawScribble,
 			SelectionForeground: TldrawSelectionForeground,
 			SelectionBackground: TldrawSelectionBackground,

packages/tldraw/src/lib/canvas/TldrawShapeIndicators.tsx

@@ -0,0 +1,26 @@
+import { DefaultShapeIndicators, useEditor, useValue } from '@tldraw/editor'
+
+/** @public @react */
+export function TldrawShapeIndicators() {
+	const editor = useEditor()
+
+	const isInSelectState = useValue(
+		'is in a valid select state',
+		() => {
+			return editor.isInAny(
+				'select.idle',
+				'select.brushing',
+				'select.scribble_brushing',
+				'select.editing_shape',
+				'select.pointing_shape',
+				'select.pointing_selection',
+				'select.pointing_handle'
+			)
+		},
+		[editor]
+	)
+
+	if (!isInSelectState) return null
+
+	return <DefaultShapeIndicators />
+}

packages/tldraw/src/lib/ui/components/Dialogs.tsx

@@ -47,13 +47,7 @@ const Dialog = ({ id, component: ModalContent, onClose }: TLUiDialog) => {
 function _Dialogs() {
 	const { dialogs } = useDialogs()
 
-	return (
-		<>
-			{dialogs.map((dialog: TLUiDialog) => (
-				<Dialog key={dialog.id} {...dialog} />
-			))}
-		</>
-	)
+	return dialogs.map((dialog: TLUiDialog) => <Dialog key={dialog.id} {...dialog} />)
 }
 
 export const Dialogs = React.memo(_Dialogs)

packages/tldraw/src/lib/ui/components/Toasts.tsx

@@ -83,13 +83,7 @@ function Toast({ toast }: { toast: TLUiToast }) {
 function _Toasts() {
 	const { toasts } = useToasts()
 
-	return (
-		<>
-			{toasts.map((toast) => (
-				<Toast key={toast.id} toast={toast} />
-			))}
-		</>
-	)
+	return toasts.map((toast) => <Toast key={toast.id} toast={toast} />)
 }
 
 export const Toasts = React.memo(_Toasts)