Files
standardnotes-app-web/packages/blocks-editor/src/Lexical/Plugins/DraggableBlockPlugin/index.tsx
2022-12-23 22:22:19 +05:30

527 lines
14 KiB
TypeScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
*/
import {$createListNode, $isListNode} from '@lexical/list';
import {useLexicalComposerContext} from '@lexical/react/LexicalComposerContext';
import {eventFiles} from '@lexical/rich-text';
import {mergeRegister} from '@lexical/utils';
import {
$getNearestNodeFromDOMNode,
$getNodeByKey,
$getRoot,
COMMAND_PRIORITY_HIGH,
COMMAND_PRIORITY_LOW,
DRAGOVER_COMMAND,
DROP_COMMAND,
LexicalEditor,
LexicalNode,
} from 'lexical';
import {
DragEvent as ReactDragEvent,
TouchEvent,
useCallback,
useEffect,
useRef,
useState,
} from 'react';
import {createPortal} from 'react-dom';
import {BlockIcon} from '@standardnotes/icons';
import {isHTMLElement} from '../../Utils/guard';
import {Point} from '../../Utils/point';
import {ContainsPointReturn, Rect} from '../../Utils/rect';
const DRAGGABLE_BLOCK_MENU_LEFT_SPACE = -2;
const TARGET_LINE_HALF_HEIGHT = 2;
const DRAGGABLE_BLOCK_MENU_CLASSNAME = 'draggable-block-menu';
const DRAG_DATA_FORMAT = 'application/x-lexical-drag-block';
const TEXT_BOX_HORIZONTAL_PADDING = 24;
const Downward = 1;
const Upward = -1;
const Indeterminate = 0;
let prevIndex = Infinity;
function getCurrentIndex(keysLength: number): number {
if (keysLength === 0) {
return Infinity;
}
if (prevIndex >= 0 && prevIndex < keysLength) {
return prevIndex;
}
return Math.floor(keysLength / 2);
}
function getTopLevelNodeKeys(editor: LexicalEditor): string[] {
return editor.getEditorState().read(() => $getRoot().getChildrenKeys());
}
function elementContainingEventLocation(
anchorElem: HTMLElement,
element: HTMLElement,
eventLocation: Point,
): {contains: ContainsPointReturn; element: HTMLElement} {
const anchorElementRect = anchorElem.getBoundingClientRect();
const elementDomRect = Rect.fromDOM(element);
const {marginTop, marginBottom} = window.getComputedStyle(element);
const rect = elementDomRect.generateNewRect({
bottom: elementDomRect.bottom + parseFloat(marginBottom),
left: anchorElementRect.left,
right: anchorElementRect.right,
top: elementDomRect.top - parseFloat(marginTop),
});
const children = Array.from(element.children);
const shouldRecurseIntoChildren = ['UL', 'OL', 'LI'].includes(
element.tagName,
);
if (shouldRecurseIntoChildren) {
for (const child of children) {
const isLeaf = child.children.length === 0;
if (isLeaf) {
continue;
}
const childResult = elementContainingEventLocation(
anchorElem,
child as HTMLElement,
eventLocation,
);
if (childResult.contains.result) {
return childResult;
}
}
}
return {contains: rect.contains(eventLocation), element: element};
}
function getBlockElement(
anchorElem: HTMLElement,
editor: LexicalEditor,
eventLocation: Point,
): HTMLElement | null {
const topLevelNodeKeys = getTopLevelNodeKeys(editor);
let blockElem: HTMLElement | null = null;
editor.getEditorState().read(() => {
let index = getCurrentIndex(topLevelNodeKeys.length);
let direction = Indeterminate;
while (index >= 0 && index < topLevelNodeKeys.length) {
const key = topLevelNodeKeys[index];
const elem = editor.getElementByKey(key);
if (elem === null) {
break;
}
const {contains, element} = elementContainingEventLocation(
anchorElem,
elem,
eventLocation,
);
if (contains.result) {
blockElem = element;
prevIndex = index;
break;
}
if (direction === Indeterminate) {
if (contains.reason.isOnTopSide) {
direction = Upward;
} else if (contains.reason.isOnBottomSide) {
direction = Downward;
} else {
// stop search block element
direction = Infinity;
}
}
index += direction;
}
});
return blockElem;
}
function isOnMenu(element: HTMLElement): boolean {
return !!element.closest(`.${DRAGGABLE_BLOCK_MENU_CLASSNAME}`);
}
function setMenuPosition(
targetElem: HTMLElement | null,
floatingElem: HTMLElement,
anchorElem: HTMLElement,
) {
if (!targetElem) {
floatingElem.style.opacity = '0';
return;
}
const targetRect = targetElem.getBoundingClientRect();
const targetStyle = window.getComputedStyle(targetElem);
const floatingElemRect = floatingElem.getBoundingClientRect();
const anchorElementRect = anchorElem.getBoundingClientRect();
const top =
targetRect.top +
(parseInt(targetStyle.lineHeight, 10) - floatingElemRect.height) / 2 -
anchorElementRect.top;
const left = DRAGGABLE_BLOCK_MENU_LEFT_SPACE;
floatingElem.style.opacity = '1';
floatingElem.style.transform = `translate(${left}px, ${top}px)`;
}
function setDragImage(
dataTransfer: DataTransfer,
draggableBlockElem: HTMLElement,
) {
const {transform} = draggableBlockElem.style;
// Remove dragImage borders
draggableBlockElem.style.transform = 'translateZ(0)';
dataTransfer.setDragImage(draggableBlockElem, 0, 0);
setTimeout(() => {
draggableBlockElem.style.transform = transform;
});
}
function setTargetLine(
targetLineElem: HTMLElement,
targetBlockElem: HTMLElement,
mouseY: number,
anchorElem: HTMLElement,
) {
const targetStyle = window.getComputedStyle(targetBlockElem);
const {top: targetBlockElemTop, height: targetBlockElemHeight} =
targetBlockElem.getBoundingClientRect();
const {top: anchorTop, width: anchorWidth} =
anchorElem.getBoundingClientRect();
let lineTop = targetBlockElemTop;
// At the bottom of the target
if (mouseY - targetBlockElemTop > targetBlockElemHeight / 2) {
lineTop += targetBlockElemHeight + parseFloat(targetStyle.marginBottom);
} else {
lineTop -= parseFloat(targetStyle.marginTop);
}
const top = lineTop - anchorTop - TARGET_LINE_HALF_HEIGHT;
const left = TEXT_BOX_HORIZONTAL_PADDING - DRAGGABLE_BLOCK_MENU_LEFT_SPACE;
targetLineElem.style.transform = `translate(${left}px, ${top}px)`;
targetLineElem.style.width = `${
anchorWidth -
(TEXT_BOX_HORIZONTAL_PADDING - DRAGGABLE_BLOCK_MENU_LEFT_SPACE) * 2
}px`;
targetLineElem.style.opacity = '.6';
}
function hideTargetLine(targetLineElem: HTMLElement | null) {
if (targetLineElem) {
targetLineElem.style.opacity = '0';
}
}
function useDraggableBlockMenu(
editor: LexicalEditor,
anchorElem: HTMLElement,
isEditable: boolean,
): JSX.Element {
const scrollerElem = anchorElem.parentElement;
const menuRef = useRef<HTMLDivElement>(null);
const targetLineRef = useRef<HTMLDivElement>(null);
const [draggableBlockElem, setDraggableBlockElem] =
useState<HTMLElement | null>(null);
const dragDataRef = useRef<string | null>(null);
useEffect(() => {
function onMouseMove(event: MouseEvent) {
const target = event.target;
if (!isHTMLElement(target)) {
setDraggableBlockElem(null);
return;
}
if (isOnMenu(target)) {
return;
}
const _draggableBlockElem = getBlockElement(
anchorElem,
editor,
new Point(event.clientX, event.clientY),
);
setDraggableBlockElem(_draggableBlockElem);
}
function onMouseLeave() {
setDraggableBlockElem(null);
}
scrollerElem?.addEventListener('mousemove', onMouseMove);
scrollerElem?.addEventListener('mouseleave', onMouseLeave);
return () => {
scrollerElem?.removeEventListener('mousemove', onMouseMove);
scrollerElem?.removeEventListener('mouseleave', onMouseLeave);
};
}, [scrollerElem, anchorElem, editor]);
useEffect(() => {
if (menuRef.current) {
setMenuPosition(draggableBlockElem, menuRef.current, anchorElem);
}
}, [anchorElem, draggableBlockElem]);
const insertDraggedNode = useCallback(
(
draggedNode: LexicalNode,
targetNode: LexicalNode,
targetBlockElem: HTMLElement,
pageY: number,
) => {
let nodeToInsert = draggedNode;
const targetParent = targetNode.getParent();
const sourceParent = draggedNode.getParent();
if ($isListNode(sourceParent) && !$isListNode(targetParent)) {
const newList = $createListNode(sourceParent.getListType());
newList.append(draggedNode);
nodeToInsert = newList;
}
const {top, height} = targetBlockElem.getBoundingClientRect();
const shouldInsertAfter = pageY - top > height / 2;
if (shouldInsertAfter) {
targetNode.insertAfter(nodeToInsert);
} else {
targetNode.insertBefore(nodeToInsert);
}
},
[],
);
useEffect(() => {
function onDragover(event: DragEvent): boolean {
const [isFileTransfer] = eventFiles(event);
if (isFileTransfer) {
return false;
}
const {pageY, target} = event;
if (!isHTMLElement(target)) {
return false;
}
const targetBlockElem = getBlockElement(
anchorElem,
editor,
new Point(event.pageX, pageY),
);
const targetLineElem = targetLineRef.current;
if (targetBlockElem === null || targetLineElem === null) {
return false;
}
setTargetLine(targetLineElem, targetBlockElem, pageY, anchorElem);
// Prevent default event to be able to trigger onDrop events
event.preventDefault();
return true;
}
function onDrop(event: DragEvent): boolean {
const [isFileTransfer] = eventFiles(event);
if (isFileTransfer) {
return false;
}
const {target, dataTransfer, pageY} = event;
if (!isHTMLElement(target)) {
return false;
}
const dragData = dataTransfer?.getData(DRAG_DATA_FORMAT) || '';
const draggedNode = $getNodeByKey(dragData);
if (!draggedNode) {
return false;
}
const targetBlockElem = getBlockElement(
anchorElem,
editor,
new Point(event.pageX, pageY),
);
if (!targetBlockElem) {
return false;
}
const targetNode = $getNearestNodeFromDOMNode(targetBlockElem);
if (!targetNode) {
return false;
}
if (targetNode === draggedNode) {
return true;
}
insertDraggedNode(draggedNode, targetNode, targetBlockElem, event.pageY);
setDraggableBlockElem(null);
return true;
}
return mergeRegister(
editor.registerCommand(
DRAGOVER_COMMAND,
(event) => {
return onDragover(event);
},
COMMAND_PRIORITY_LOW,
),
editor.registerCommand(
DROP_COMMAND,
(event) => {
return onDrop(event);
},
COMMAND_PRIORITY_HIGH,
),
);
}, [anchorElem, editor, insertDraggedNode]);
function onDragStart(event: ReactDragEvent<HTMLDivElement>): void {
const dataTransfer = event.dataTransfer;
if (!dataTransfer || !draggableBlockElem) {
return;
}
setDragImage(dataTransfer, draggableBlockElem);
let nodeKey = '';
editor.update(() => {
const node = $getNearestNodeFromDOMNode(draggableBlockElem);
if (node) {
nodeKey = node.getKey();
}
});
dataTransfer.setData(DRAG_DATA_FORMAT, nodeKey);
}
function onDragEnd(): void {
hideTargetLine(targetLineRef.current);
}
function onTouchStart(): void {
if (!draggableBlockElem) {
return;
}
editor.update(() => {
const node = $getNearestNodeFromDOMNode(draggableBlockElem);
if (!node) {
return;
}
const nodeKey = node.getKey();
dragDataRef.current = nodeKey;
});
}
function onTouchMove(event: TouchEvent) {
const {pageX, pageY} = event.targetTouches[0];
const rootElement = editor.getRootElement();
if (rootElement) {
const {top, bottom} = rootElement.getBoundingClientRect();
const scrollOffset = 20;
if (pageY - top < scrollOffset) {
rootElement.scrollTop -= scrollOffset;
} else if (bottom - pageY < scrollOffset) {
rootElement.scrollTop += scrollOffset;
}
}
const targetBlockElem = getBlockElement(
anchorElem,
editor,
new Point(pageX, pageY),
);
const targetLineElem = targetLineRef.current;
if (targetBlockElem === null || targetLineElem === null) {
return;
}
setTargetLine(targetLineElem, targetBlockElem, pageY, anchorElem);
}
function onTouchEnd(event: TouchEvent): void {
hideTargetLine(targetLineRef.current);
editor.update(() => {
const {pageX, pageY} = event.changedTouches[0];
const dragData = dragDataRef.current || '';
const draggedNode = $getNodeByKey(dragData);
if (!draggedNode) {
return;
}
const targetBlockElem = getBlockElement(
anchorElem,
editor,
new Point(pageX, pageY),
);
if (!targetBlockElem) {
return;
}
const targetNode = $getNearestNodeFromDOMNode(targetBlockElem);
if (!targetNode) {
return;
}
if (targetNode === draggedNode) {
return;
}
insertDraggedNode(draggedNode, targetNode, targetBlockElem, pageY);
});
setDraggableBlockElem(null);
}
return createPortal(
<>
<div
className="icon draggable-block-menu"
ref={menuRef}
draggable={true}
onDragStart={onDragStart}
onDragEnd={onDragEnd}
onTouchStart={onTouchStart}
onTouchMove={onTouchMove}
onTouchEnd={onTouchEnd}>
<div className={isEditable ? 'icon' : ''}>
<BlockIcon className="text-text pointer-events-none" />
</div>
</div>
<div className="draggable-block-target-line" ref={targetLineRef} />
</>,
anchorElem,
);
}
export default function DraggableBlockPlugin({
anchorElem = document.body,
}: {
anchorElem?: HTMLElement;
}): JSX.Element {
const [editor] = useLexicalComposerContext();
return useDraggableBlockMenu(editor, anchorElem, editor._editable);
}