import { ExcalidrawLinearElement, ExcalidrawBindableElement, NonDeleted, NonDeletedExcalidrawElement, PointBinding, ExcalidrawElement, ElementsMap, NonDeletedSceneElementsMap, } from "./types"; import { getElementAtPosition } from "../scene"; import { AppState } from "../types"; import { isBindableElement, isBindingElement, isLinearElement, } from "./typeChecks"; import { bindingBorderTest, distanceToBindableElement, maxBindingGap, determineFocusDistance, intersectElementWithLine, determineFocusPoint, } from "./collision"; import { mutateElement } from "./mutateElement"; import Scene from "../scene/Scene"; import { LinearElementEditor } from "./linearElementEditor"; import { arrayToMap, tupleToCoors } from "../utils"; import { KEYS } from "../keys"; import { getBoundTextElement, handleBindTextResize } from "./textElement"; export type SuggestedBinding = | NonDeleted | SuggestedPointBinding; export type SuggestedPointBinding = [ NonDeleted, "start" | "end" | "both", NonDeleted, ]; export const shouldEnableBindingForPointerEvent = ( event: React.PointerEvent, ) => { return !event[KEYS.CTRL_OR_CMD]; }; export const isBindingEnabled = (appState: AppState): boolean => { return appState.isBindingEnabled; }; const getNonDeletedElements = ( scene: Scene, ids: readonly ExcalidrawElement["id"][], ): NonDeleted[] => { const result: NonDeleted[] = []; ids.forEach((id) => { const element = scene.getNonDeletedElement(id); if (element != null) { result.push(element); } }); return result; }; export const bindOrUnbindLinearElement = ( linearElement: NonDeleted, startBindingElement: ExcalidrawBindableElement | null | "keep", endBindingElement: ExcalidrawBindableElement | null | "keep", elementsMap: NonDeletedSceneElementsMap, ): void => { const boundToElementIds: Set = new Set(); const unboundFromElementIds: Set = new Set(); bindOrUnbindLinearElementEdge( linearElement, startBindingElement, endBindingElement, "start", boundToElementIds, unboundFromElementIds, elementsMap, ); bindOrUnbindLinearElementEdge( linearElement, endBindingElement, startBindingElement, "end", boundToElementIds, unboundFromElementIds, elementsMap, ); const onlyUnbound = Array.from(unboundFromElementIds).filter( (id) => !boundToElementIds.has(id), ); getNonDeletedElements(Scene.getScene(linearElement)!, onlyUnbound).forEach( (element) => { mutateElement(element, { boundElements: element.boundElements?.filter( (element) => element.type !== "arrow" || element.id !== linearElement.id, ), }); }, ); }; const bindOrUnbindLinearElementEdge = ( linearElement: NonDeleted, bindableElement: ExcalidrawBindableElement | null | "keep", otherEdgeBindableElement: ExcalidrawBindableElement | null | "keep", startOrEnd: "start" | "end", // Is mutated boundToElementIds: Set, // Is mutated unboundFromElementIds: Set, elementsMap: NonDeletedSceneElementsMap, ): void => { if (bindableElement !== "keep") { if (bindableElement != null) { // Don't bind if we're trying to bind or are already bound to the same // element on the other edge already ("start" edge takes precedence). if ( otherEdgeBindableElement == null || (otherEdgeBindableElement === "keep" ? !isLinearElementSimpleAndAlreadyBoundOnOppositeEdge( linearElement, bindableElement, startOrEnd, ) : startOrEnd === "start" || otherEdgeBindableElement.id !== bindableElement.id) ) { bindLinearElement( linearElement, bindableElement, startOrEnd, elementsMap, ); boundToElementIds.add(bindableElement.id); } } else { const unbound = unbindLinearElement(linearElement, startOrEnd); if (unbound != null) { unboundFromElementIds.add(unbound); } } } }; export const bindOrUnbindSelectedElements = ( selectedElements: NonDeleted[], elements: readonly ExcalidrawElement[], elementsMap: NonDeletedSceneElementsMap, ): void => { selectedElements.forEach((selectedElement) => { if (isBindingElement(selectedElement)) { bindOrUnbindLinearElement( selectedElement, getElligibleElementForBindingElement( selectedElement, "start", elements, elementsMap, ), getElligibleElementForBindingElement( selectedElement, "end", elements, elementsMap, ), elementsMap, ); } else if (isBindableElement(selectedElement)) { maybeBindBindableElement(selectedElement, elementsMap); } }); }; const maybeBindBindableElement = ( bindableElement: NonDeleted, elementsMap: NonDeletedSceneElementsMap, ): void => { getElligibleElementsForBindableElementAndWhere( bindableElement, elementsMap, ).forEach(([linearElement, where]) => bindOrUnbindLinearElement( linearElement, where === "end" ? "keep" : bindableElement, where === "start" ? "keep" : bindableElement, elementsMap, ), ); }; export const maybeBindLinearElement = ( linearElement: NonDeleted, appState: AppState, scene: Scene, pointerCoords: { x: number; y: number }, elementsMap: NonDeletedSceneElementsMap, ): void => { if (appState.startBoundElement != null) { bindLinearElement( linearElement, appState.startBoundElement, "start", elementsMap, ); } const hoveredElement = getHoveredElementForBinding( pointerCoords, scene.getNonDeletedElements(), elementsMap, ); if ( hoveredElement != null && !isLinearElementSimpleAndAlreadyBoundOnOppositeEdge( linearElement, hoveredElement, "end", ) ) { bindLinearElement(linearElement, hoveredElement, "end", elementsMap); } }; export const bindLinearElement = ( linearElement: NonDeleted, hoveredElement: ExcalidrawBindableElement, startOrEnd: "start" | "end", elementsMap: NonDeletedSceneElementsMap, ): void => { mutateElement(linearElement, { [startOrEnd === "start" ? "startBinding" : "endBinding"]: { elementId: hoveredElement.id, ...calculateFocusAndGap( linearElement, hoveredElement, startOrEnd, elementsMap, ), } as PointBinding, }); const boundElementsMap = arrayToMap(hoveredElement.boundElements || []); if (!boundElementsMap.has(linearElement.id)) { mutateElement(hoveredElement, { boundElements: (hoveredElement.boundElements || []).concat({ id: linearElement.id, type: "arrow", }), }); } }; // Don't bind both ends of a simple segment const isLinearElementSimpleAndAlreadyBoundOnOppositeEdge = ( linearElement: NonDeleted, bindableElement: ExcalidrawBindableElement, startOrEnd: "start" | "end", ): boolean => { const otherBinding = linearElement[startOrEnd === "start" ? "endBinding" : "startBinding"]; return isLinearElementSimpleAndAlreadyBound( linearElement, otherBinding?.elementId, bindableElement, ); }; export const isLinearElementSimpleAndAlreadyBound = ( linearElement: NonDeleted, alreadyBoundToId: ExcalidrawBindableElement["id"] | undefined, bindableElement: ExcalidrawBindableElement, ): boolean => { return ( alreadyBoundToId === bindableElement.id && linearElement.points.length < 3 ); }; export const unbindLinearElements = ( elements: NonDeleted[], elementsMap: NonDeletedSceneElementsMap, ): void => { elements.forEach((element) => { if (isBindingElement(element)) { bindOrUnbindLinearElement(element, null, null, elementsMap); } }); }; const unbindLinearElement = ( linearElement: NonDeleted, startOrEnd: "start" | "end", ): ExcalidrawBindableElement["id"] | null => { const field = startOrEnd === "start" ? "startBinding" : "endBinding"; const binding = linearElement[field]; if (binding == null) { return null; } mutateElement(linearElement, { [field]: null }); return binding.elementId; }; export const getHoveredElementForBinding = ( pointerCoords: { x: number; y: number; }, elements: readonly NonDeletedExcalidrawElement[], elementsMap: NonDeletedSceneElementsMap, ): NonDeleted | null => { const hoveredElement = getElementAtPosition( elements, (element) => isBindableElement(element, false) && bindingBorderTest(element, pointerCoords, elementsMap), ); return hoveredElement as NonDeleted | null; }; const calculateFocusAndGap = ( linearElement: NonDeleted, hoveredElement: ExcalidrawBindableElement, startOrEnd: "start" | "end", elementsMap: NonDeletedSceneElementsMap, ): { focus: number; gap: number } => { const direction = startOrEnd === "start" ? -1 : 1; const edgePointIndex = direction === -1 ? 0 : linearElement.points.length - 1; const adjacentPointIndex = edgePointIndex - direction; const edgePoint = LinearElementEditor.getPointAtIndexGlobalCoordinates( linearElement, edgePointIndex, elementsMap, ); const adjacentPoint = LinearElementEditor.getPointAtIndexGlobalCoordinates( linearElement, adjacentPointIndex, elementsMap, ); return { focus: determineFocusDistance( hoveredElement, adjacentPoint, edgePoint, elementsMap, ), gap: Math.max( 1, distanceToBindableElement(hoveredElement, edgePoint, elementsMap), ), }; }; // Supports translating, rotating and scaling `changedElement` with bound // linear elements. // Because scaling involves moving the focus points as well, it is // done before the `changedElement` is updated, and the `newSize` is passed // in explicitly. export const updateBoundElements = ( changedElement: NonDeletedExcalidrawElement, elementsMap: ElementsMap, options?: { simultaneouslyUpdated?: readonly ExcalidrawElement[]; newSize?: { width: number; height: number }; }, ) => { const boundLinearElements = (changedElement.boundElements ?? []).filter( (el) => el.type === "arrow", ); if (boundLinearElements.length === 0) { return; } const { newSize, simultaneouslyUpdated } = options ?? {}; const simultaneouslyUpdatedElementIds = getSimultaneouslyUpdatedElementIds( simultaneouslyUpdated, ); const scene = Scene.getScene(changedElement)!; getNonDeletedElements( scene, boundLinearElements.map((el) => el.id), ).forEach((element) => { if (!isLinearElement(element)) { return; } const bindableElement = changedElement as ExcalidrawBindableElement; // In case the boundElements are stale if (!doesNeedUpdate(element, bindableElement)) { return; } const startBinding = maybeCalculateNewGapWhenScaling( bindableElement, element.startBinding, newSize, ); const endBinding = maybeCalculateNewGapWhenScaling( bindableElement, element.endBinding, newSize, ); // `linearElement` is being moved/scaled already, just update the binding if (simultaneouslyUpdatedElementIds.has(element.id)) { mutateElement(element, { startBinding, endBinding }); return; } updateBoundPoint( element, "start", startBinding, changedElement as ExcalidrawBindableElement, elementsMap, ); updateBoundPoint( element, "end", endBinding, changedElement as ExcalidrawBindableElement, elementsMap, ); const boundText = getBoundTextElement( element, scene.getNonDeletedElementsMap(), ); if (boundText) { handleBindTextResize(element, scene.getNonDeletedElementsMap(), false); } }); }; const doesNeedUpdate = ( boundElement: NonDeleted, changedElement: ExcalidrawBindableElement, ) => { return ( boundElement.startBinding?.elementId === changedElement.id || boundElement.endBinding?.elementId === changedElement.id ); }; const getSimultaneouslyUpdatedElementIds = ( simultaneouslyUpdated: readonly ExcalidrawElement[] | undefined, ): Set => { return new Set((simultaneouslyUpdated || []).map((element) => element.id)); }; const updateBoundPoint = ( linearElement: NonDeleted, startOrEnd: "start" | "end", binding: PointBinding | null | undefined, changedElement: ExcalidrawBindableElement, elementsMap: ElementsMap, ): void => { if ( binding == null || // We only need to update the other end if this is a 2 point line element (binding.elementId !== changedElement.id && linearElement.points.length > 2) ) { return; } const bindingElement = Scene.getScene(linearElement)!.getElement( binding.elementId, ) as ExcalidrawBindableElement | null; if (bindingElement == null) { // We're not cleaning up after deleted elements atm., so handle this case return; } const direction = startOrEnd === "start" ? -1 : 1; const edgePointIndex = direction === -1 ? 0 : linearElement.points.length - 1; const adjacentPointIndex = edgePointIndex - direction; const adjacentPoint = LinearElementEditor.getPointAtIndexGlobalCoordinates( linearElement, adjacentPointIndex, elementsMap, ); const focusPointAbsolute = determineFocusPoint( bindingElement, binding.focus, adjacentPoint, elementsMap, ); let newEdgePoint; // The linear element was not originally pointing inside the bound shape, // we can point directly at the focus point if (binding.gap === 0) { newEdgePoint = focusPointAbsolute; } else { const intersections = intersectElementWithLine( bindingElement, adjacentPoint, focusPointAbsolute, binding.gap, elementsMap, ); if (intersections.length === 0) { // This should never happen, since focusPoint should always be // inside the element, but just in case, bail out newEdgePoint = focusPointAbsolute; } else { // Guaranteed to intersect because focusPoint is always inside the shape newEdgePoint = intersections[0]; } } LinearElementEditor.movePoints( linearElement, [ { index: edgePointIndex, point: LinearElementEditor.pointFromAbsoluteCoords( linearElement, newEdgePoint, elementsMap, ), }, ], { [startOrEnd === "start" ? "startBinding" : "endBinding"]: binding }, ); }; const maybeCalculateNewGapWhenScaling = ( changedElement: ExcalidrawBindableElement, currentBinding: PointBinding | null | undefined, newSize: { width: number; height: number } | undefined, ): PointBinding | null | undefined => { if (currentBinding == null || newSize == null) { return currentBinding; } const { gap, focus, elementId } = currentBinding; const { width: newWidth, height: newHeight } = newSize; const { width, height } = changedElement; const newGap = Math.max( 1, Math.min( maxBindingGap(changedElement, newWidth, newHeight), gap * (newWidth < newHeight ? newWidth / width : newHeight / height), ), ); return { elementId, gap: newGap, focus }; }; // TODO: this is a bottleneck, optimise export const getEligibleElementsForBinding = ( selectedElements: NonDeleted[], elements: readonly ExcalidrawElement[], elementsMap: NonDeletedSceneElementsMap, ): SuggestedBinding[] => { const includedElementIds = new Set(selectedElements.map(({ id }) => id)); return selectedElements.flatMap((selectedElement) => isBindingElement(selectedElement, false) ? (getElligibleElementsForBindingElement( selectedElement as NonDeleted, elements, elementsMap, ).filter( (element) => !includedElementIds.has(element.id), ) as SuggestedBinding[]) : isBindableElement(selectedElement, false) ? getElligibleElementsForBindableElementAndWhere( selectedElement, elementsMap, ).filter((binding) => !includedElementIds.has(binding[0].id)) : [], ); }; const getElligibleElementsForBindingElement = ( linearElement: NonDeleted, elements: readonly ExcalidrawElement[], elementsMap: NonDeletedSceneElementsMap, ): NonDeleted[] => { return [ getElligibleElementForBindingElement( linearElement, "start", elements, elementsMap, ), getElligibleElementForBindingElement( linearElement, "end", elements, elementsMap, ), ].filter( (element): element is NonDeleted => element != null, ); }; const getElligibleElementForBindingElement = ( linearElement: NonDeleted, startOrEnd: "start" | "end", elements: readonly ExcalidrawElement[], elementsMap: NonDeletedSceneElementsMap, ): NonDeleted | null => { return getHoveredElementForBinding( getLinearElementEdgeCoors(linearElement, startOrEnd, elementsMap), elements, elementsMap, ); }; const getLinearElementEdgeCoors = ( linearElement: NonDeleted, startOrEnd: "start" | "end", elementsMap: NonDeletedSceneElementsMap, ): { x: number; y: number } => { const index = startOrEnd === "start" ? 0 : -1; return tupleToCoors( LinearElementEditor.getPointAtIndexGlobalCoordinates( linearElement, index, elementsMap, ), ); }; const getElligibleElementsForBindableElementAndWhere = ( bindableElement: NonDeleted, elementsMap: NonDeletedSceneElementsMap, ): SuggestedPointBinding[] => { const scene = Scene.getScene(bindableElement)!; return scene .getNonDeletedElements() .map((element) => { if (!isBindingElement(element, false)) { return null; } const canBindStart = isLinearElementEligibleForNewBindingByBindable( element, "start", bindableElement, elementsMap, ); const canBindEnd = isLinearElementEligibleForNewBindingByBindable( element, "end", bindableElement, elementsMap, ); if (!canBindStart && !canBindEnd) { return null; } return [ element, canBindStart && canBindEnd ? "both" : canBindStart ? "start" : "end", bindableElement, ]; }) .filter((maybeElement) => maybeElement != null) as SuggestedPointBinding[]; }; const isLinearElementEligibleForNewBindingByBindable = ( linearElement: NonDeleted, startOrEnd: "start" | "end", bindableElement: NonDeleted, elementsMap: NonDeletedSceneElementsMap, ): boolean => { const existingBinding = linearElement[startOrEnd === "start" ? "startBinding" : "endBinding"]; return ( existingBinding == null && !isLinearElementSimpleAndAlreadyBoundOnOppositeEdge( linearElement, bindableElement, startOrEnd, ) && bindingBorderTest( bindableElement, getLinearElementEdgeCoors(linearElement, startOrEnd, elementsMap), elementsMap, ) ); }; // We need to: // 1: Update elements not selected to point to duplicated elements // 2: Update duplicated elements to point to other duplicated elements export const fixBindingsAfterDuplication = ( sceneElements: readonly ExcalidrawElement[], oldElements: readonly ExcalidrawElement[], oldIdToDuplicatedId: Map, // There are three copying mechanisms: Copy-paste, duplication and alt-drag. // Only when alt-dragging the new "duplicates" act as the "old", while // the "old" elements act as the "new copy" - essentially working reverse // to the other two. duplicatesServeAsOld?: "duplicatesServeAsOld" | undefined, ): void => { // First collect all the binding/bindable elements, so we only update // each once, regardless of whether they were duplicated or not. const allBoundElementIds: Set = new Set(); const allBindableElementIds: Set = new Set(); const shouldReverseRoles = duplicatesServeAsOld === "duplicatesServeAsOld"; oldElements.forEach((oldElement) => { const { boundElements } = oldElement; if (boundElements != null && boundElements.length > 0) { boundElements.forEach((boundElement) => { if (shouldReverseRoles && !oldIdToDuplicatedId.has(boundElement.id)) { allBoundElementIds.add(boundElement.id); } }); allBindableElementIds.add(oldIdToDuplicatedId.get(oldElement.id)!); } if (isBindingElement(oldElement)) { if (oldElement.startBinding != null) { const { elementId } = oldElement.startBinding; if (shouldReverseRoles && !oldIdToDuplicatedId.has(elementId)) { allBindableElementIds.add(elementId); } } if (oldElement.endBinding != null) { const { elementId } = oldElement.endBinding; if (shouldReverseRoles && !oldIdToDuplicatedId.has(elementId)) { allBindableElementIds.add(elementId); } } if (oldElement.startBinding != null || oldElement.endBinding != null) { allBoundElementIds.add(oldIdToDuplicatedId.get(oldElement.id)!); } } }); // Update the linear elements ( sceneElements.filter(({ id }) => allBoundElementIds.has(id), ) as ExcalidrawLinearElement[] ).forEach((element) => { const { startBinding, endBinding } = element; mutateElement(element, { startBinding: newBindingAfterDuplication( startBinding, oldIdToDuplicatedId, ), endBinding: newBindingAfterDuplication(endBinding, oldIdToDuplicatedId), }); }); // Update the bindable shapes sceneElements .filter(({ id }) => allBindableElementIds.has(id)) .forEach((bindableElement) => { const { boundElements } = bindableElement; if (boundElements != null && boundElements.length > 0) { mutateElement(bindableElement, { boundElements: boundElements.map((boundElement) => oldIdToDuplicatedId.has(boundElement.id) ? { id: oldIdToDuplicatedId.get(boundElement.id)!, type: boundElement.type, } : boundElement, ), }); } }); }; const newBindingAfterDuplication = ( binding: PointBinding | null, oldIdToDuplicatedId: Map, ): PointBinding | null => { if (binding == null) { return null; } const { elementId, focus, gap } = binding; return { focus, gap, elementId: oldIdToDuplicatedId.get(elementId) ?? elementId, }; }; export const fixBindingsAfterDeletion = ( sceneElements: readonly ExcalidrawElement[], deletedElements: readonly ExcalidrawElement[], ): void => { const deletedElementIds = new Set( deletedElements.map((element) => element.id), ); // non-deleted which bindings need to be updated const affectedElements: Set = new Set(); deletedElements.forEach((deletedElement) => { if (isBindableElement(deletedElement)) { deletedElement.boundElements?.forEach((element) => { if (!deletedElementIds.has(element.id)) { affectedElements.add(element.id); } }); } else if (isBindingElement(deletedElement)) { if (deletedElement.startBinding) { affectedElements.add(deletedElement.startBinding.elementId); } if (deletedElement.endBinding) { affectedElements.add(deletedElement.endBinding.elementId); } } }); sceneElements .filter(({ id }) => affectedElements.has(id)) .forEach((element) => { if (isBindableElement(element)) { mutateElement(element, { boundElements: newBoundElementsAfterDeletion( element.boundElements, deletedElementIds, ), }); } else if (isBindingElement(element)) { mutateElement(element, { startBinding: newBindingAfterDeletion( element.startBinding, deletedElementIds, ), endBinding: newBindingAfterDeletion( element.endBinding, deletedElementIds, ), }); } }); }; const newBindingAfterDeletion = ( binding: PointBinding | null, deletedElementIds: Set, ): PointBinding | null => { if (binding == null || deletedElementIds.has(binding.elementId)) { return null; } return binding; }; const newBoundElementsAfterDeletion = ( boundElements: ExcalidrawElement["boundElements"], deletedElementIds: Set, ) => { if (!boundElements) { return null; } return boundElements.filter((ele) => !deletedElementIds.has(ele.id)); };