react-dnd-html5-backend
Version:
HTML5 backend for React DnD
571 lines (570 loc) • 25.4 kB
JavaScript
function _defineProperty(obj, key, value) {
if (key in obj) {
Object.defineProperty(obj, key, {
value: value,
enumerable: true,
configurable: true,
writable: true
});
} else {
obj[key] = value;
}
return obj;
}
function _objectSpread(target) {
for(var i = 1; i < arguments.length; i++){
var source = arguments[i] != null ? arguments[i] : {};
var ownKeys = Object.keys(source);
if (typeof Object.getOwnPropertySymbols === 'function') {
ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function(sym) {
return Object.getOwnPropertyDescriptor(source, sym).enumerable;
}));
}
ownKeys.forEach(function(key) {
_defineProperty(target, key, source[key]);
});
}
return target;
}
import { EnterLeaveCounter } from './EnterLeaveCounter.js';
import { createNativeDragSource, matchNativeItemType } from './NativeDragSources/index.js';
import * as NativeTypes from './NativeTypes.js';
import { getDragPreviewOffset, getEventClientOffset, getNodeClientOffset } from './OffsetUtils.js';
import { OptionsReader } from './OptionsReader.js';
export class HTML5BackendImpl {
/**
* Generate profiling statistics for the HTML5Backend.
*/ profile() {
var ref, ref1;
return {
sourcePreviewNodes: this.sourcePreviewNodes.size,
sourcePreviewNodeOptions: this.sourcePreviewNodeOptions.size,
sourceNodeOptions: this.sourceNodeOptions.size,
sourceNodes: this.sourceNodes.size,
dragStartSourceIds: ((ref = this.dragStartSourceIds) === null || ref === void 0 ? void 0 : ref.length) || 0,
dropTargetIds: this.dropTargetIds.length,
dragEnterTargetIds: this.dragEnterTargetIds.length,
dragOverTargetIds: ((ref1 = this.dragOverTargetIds) === null || ref1 === void 0 ? void 0 : ref1.length) || 0
};
}
// public for test
get window() {
return this.options.window;
}
get document() {
return this.options.document;
}
/**
* Get the root element to use for event subscriptions
*/ get rootElement() {
return this.options.rootElement;
}
setup() {
const root = this.rootElement;
if (root === undefined) {
return;
}
if (root.__isReactDndBackendSetUp) {
throw new Error('Cannot have two HTML5 backends at the same time.');
}
root.__isReactDndBackendSetUp = true;
this.addEventListeners(root);
}
teardown() {
const root = this.rootElement;
if (root === undefined) {
return;
}
root.__isReactDndBackendSetUp = false;
this.removeEventListeners(this.rootElement);
this.clearCurrentDragSourceNode();
if (this.asyncEndDragFrameId) {
var ref;
(ref = this.window) === null || ref === void 0 ? void 0 : ref.cancelAnimationFrame(this.asyncEndDragFrameId);
}
}
connectDragPreview(sourceId, node, options) {
this.sourcePreviewNodeOptions.set(sourceId, options);
this.sourcePreviewNodes.set(sourceId, node);
return ()=>{
this.sourcePreviewNodes.delete(sourceId);
this.sourcePreviewNodeOptions.delete(sourceId);
};
}
connectDragSource(sourceId, node, options) {
this.sourceNodes.set(sourceId, node);
this.sourceNodeOptions.set(sourceId, options);
const handleDragStart = (e)=>this.handleDragStart(e, sourceId)
;
const handleSelectStart = (e)=>this.handleSelectStart(e)
;
node.setAttribute('draggable', 'true');
node.addEventListener('dragstart', handleDragStart);
node.addEventListener('selectstart', handleSelectStart);
return ()=>{
this.sourceNodes.delete(sourceId);
this.sourceNodeOptions.delete(sourceId);
node.removeEventListener('dragstart', handleDragStart);
node.removeEventListener('selectstart', handleSelectStart);
node.setAttribute('draggable', 'false');
};
}
connectDropTarget(targetId, node) {
const handleDragEnter = (e)=>this.handleDragEnter(e, targetId)
;
const handleDragOver = (e)=>this.handleDragOver(e, targetId)
;
const handleDrop = (e)=>this.handleDrop(e, targetId)
;
node.addEventListener('dragenter', handleDragEnter);
node.addEventListener('dragover', handleDragOver);
node.addEventListener('drop', handleDrop);
return ()=>{
node.removeEventListener('dragenter', handleDragEnter);
node.removeEventListener('dragover', handleDragOver);
node.removeEventListener('drop', handleDrop);
};
}
addEventListeners(target) {
// SSR Fix (https://github.com/react-dnd/react-dnd/pull/813
if (!target.addEventListener) {
return;
}
target.addEventListener('dragstart', this.handleTopDragStart);
target.addEventListener('dragstart', this.handleTopDragStartCapture, true);
target.addEventListener('dragend', this.handleTopDragEndCapture, true);
target.addEventListener('dragenter', this.handleTopDragEnter);
target.addEventListener('dragenter', this.handleTopDragEnterCapture, true);
target.addEventListener('dragleave', this.handleTopDragLeaveCapture, true);
target.addEventListener('dragover', this.handleTopDragOver);
target.addEventListener('dragover', this.handleTopDragOverCapture, true);
target.addEventListener('drop', this.handleTopDrop);
target.addEventListener('drop', this.handleTopDropCapture, true);
}
removeEventListeners(target) {
// SSR Fix (https://github.com/react-dnd/react-dnd/pull/813
if (!target.removeEventListener) {
return;
}
target.removeEventListener('dragstart', this.handleTopDragStart);
target.removeEventListener('dragstart', this.handleTopDragStartCapture, true);
target.removeEventListener('dragend', this.handleTopDragEndCapture, true);
target.removeEventListener('dragenter', this.handleTopDragEnter);
target.removeEventListener('dragenter', this.handleTopDragEnterCapture, true);
target.removeEventListener('dragleave', this.handleTopDragLeaveCapture, true);
target.removeEventListener('dragover', this.handleTopDragOver);
target.removeEventListener('dragover', this.handleTopDragOverCapture, true);
target.removeEventListener('drop', this.handleTopDrop);
target.removeEventListener('drop', this.handleTopDropCapture, true);
}
getCurrentSourceNodeOptions() {
const sourceId = this.monitor.getSourceId();
const sourceNodeOptions = this.sourceNodeOptions.get(sourceId);
return _objectSpread({
dropEffect: this.altKeyPressed ? 'copy' : 'move'
}, sourceNodeOptions || {});
}
getCurrentDropEffect() {
if (this.isDraggingNativeItem()) {
// It makes more sense to default to 'copy' for native resources
return 'copy';
}
return this.getCurrentSourceNodeOptions().dropEffect;
}
getCurrentSourcePreviewNodeOptions() {
const sourceId = this.monitor.getSourceId();
const sourcePreviewNodeOptions = this.sourcePreviewNodeOptions.get(sourceId);
return _objectSpread({
anchorX: 0.5,
anchorY: 0.5,
captureDraggingState: false
}, sourcePreviewNodeOptions || {});
}
isDraggingNativeItem() {
const itemType = this.monitor.getItemType();
return Object.keys(NativeTypes).some((key)=>NativeTypes[key] === itemType
);
}
beginDragNativeItem(type, dataTransfer) {
this.clearCurrentDragSourceNode();
this.currentNativeSource = createNativeDragSource(type, dataTransfer);
this.currentNativeHandle = this.registry.addSource(type, this.currentNativeSource);
this.actions.beginDrag([
this.currentNativeHandle
]);
}
setCurrentDragSourceNode(node) {
this.clearCurrentDragSourceNode();
this.currentDragSourceNode = node;
// A timeout of > 0 is necessary to resolve Firefox issue referenced
// See:
// * https://github.com/react-dnd/react-dnd/pull/928
// * https://github.com/react-dnd/react-dnd/issues/869
const MOUSE_MOVE_TIMEOUT = 1000;
// Receiving a mouse event in the middle of a dragging operation
// means it has ended and the drag source node disappeared from DOM,
// so the browser didn't dispatch the dragend event.
//
// We need to wait before we start listening for mousemove events.
// This is needed because the drag preview needs to be drawn or else it fires an 'mousemove' event
// immediately in some browsers.
//
// See:
// * https://github.com/react-dnd/react-dnd/pull/928
// * https://github.com/react-dnd/react-dnd/issues/869
//
this.mouseMoveTimeoutTimer = setTimeout(()=>{
var ref;
return (ref = this.rootElement) === null || ref === void 0 ? void 0 : ref.addEventListener('mousemove', this.endDragIfSourceWasRemovedFromDOM, true);
}, MOUSE_MOVE_TIMEOUT);
}
clearCurrentDragSourceNode() {
if (this.currentDragSourceNode) {
this.currentDragSourceNode = null;
if (this.rootElement) {
var ref;
(ref = this.window) === null || ref === void 0 ? void 0 : ref.clearTimeout(this.mouseMoveTimeoutTimer || undefined);
this.rootElement.removeEventListener('mousemove', this.endDragIfSourceWasRemovedFromDOM, true);
}
this.mouseMoveTimeoutTimer = null;
return true;
}
return false;
}
handleDragStart(e, sourceId) {
if (e.defaultPrevented) {
return;
}
if (!this.dragStartSourceIds) {
this.dragStartSourceIds = [];
}
this.dragStartSourceIds.unshift(sourceId);
}
handleDragEnter(_e, targetId) {
this.dragEnterTargetIds.unshift(targetId);
}
handleDragOver(_e, targetId) {
if (this.dragOverTargetIds === null) {
this.dragOverTargetIds = [];
}
this.dragOverTargetIds.unshift(targetId);
}
handleDrop(_e, targetId) {
this.dropTargetIds.unshift(targetId);
}
constructor(manager, globalContext, options){
this.sourcePreviewNodes = new Map();
this.sourcePreviewNodeOptions = new Map();
this.sourceNodes = new Map();
this.sourceNodeOptions = new Map();
this.dragStartSourceIds = null;
this.dropTargetIds = [];
this.dragEnterTargetIds = [];
this.currentNativeSource = null;
this.currentNativeHandle = null;
this.currentDragSourceNode = null;
this.altKeyPressed = false;
this.mouseMoveTimeoutTimer = null;
this.asyncEndDragFrameId = null;
this.dragOverTargetIds = null;
this.lastClientOffset = null;
this.hoverRafId = null;
this.getSourceClientOffset = (sourceId)=>{
const source = this.sourceNodes.get(sourceId);
return source && getNodeClientOffset(source) || null;
};
this.endDragNativeItem = ()=>{
if (!this.isDraggingNativeItem()) {
return;
}
this.actions.endDrag();
if (this.currentNativeHandle) {
this.registry.removeSource(this.currentNativeHandle);
}
this.currentNativeHandle = null;
this.currentNativeSource = null;
};
this.isNodeInDocument = (node)=>{
// Check the node either in the main document or in the current context
return Boolean(node && this.document && this.document.body && this.document.body.contains(node));
};
this.endDragIfSourceWasRemovedFromDOM = ()=>{
const node = this.currentDragSourceNode;
if (node == null || this.isNodeInDocument(node)) {
return;
}
if (this.clearCurrentDragSourceNode() && this.monitor.isDragging()) {
this.actions.endDrag();
}
this.cancelHover();
};
this.scheduleHover = (dragOverTargetIds)=>{
if (this.hoverRafId === null && typeof requestAnimationFrame !== 'undefined') {
this.hoverRafId = requestAnimationFrame(()=>{
if (this.monitor.isDragging()) {
this.actions.hover(dragOverTargetIds || [], {
clientOffset: this.lastClientOffset
});
}
this.hoverRafId = null;
});
}
};
this.cancelHover = ()=>{
if (this.hoverRafId !== null && typeof cancelAnimationFrame !== 'undefined') {
cancelAnimationFrame(this.hoverRafId);
this.hoverRafId = null;
}
};
this.handleTopDragStartCapture = ()=>{
this.clearCurrentDragSourceNode();
this.dragStartSourceIds = [];
};
this.handleTopDragStart = (e)=>{
if (e.defaultPrevented) {
return;
}
const { dragStartSourceIds } = this;
this.dragStartSourceIds = null;
const clientOffset = getEventClientOffset(e);
// Avoid crashing if we missed a drop event or our previous drag died
if (this.monitor.isDragging()) {
this.actions.endDrag();
this.cancelHover();
}
// Don't publish the source just yet (see why below)
this.actions.beginDrag(dragStartSourceIds || [], {
publishSource: false,
getSourceClientOffset: this.getSourceClientOffset,
clientOffset
});
const { dataTransfer } = e;
const nativeType = matchNativeItemType(dataTransfer);
if (this.monitor.isDragging()) {
if (dataTransfer && typeof dataTransfer.setDragImage === 'function') {
// Use custom drag image if user specifies it.
// If child drag source refuses drag but parent agrees,
// use parent's node as drag image. Neither works in IE though.
const sourceId = this.monitor.getSourceId();
const sourceNode = this.sourceNodes.get(sourceId);
const dragPreview = this.sourcePreviewNodes.get(sourceId) || sourceNode;
if (dragPreview) {
const { anchorX , anchorY , offsetX , offsetY } = this.getCurrentSourcePreviewNodeOptions();
const anchorPoint = {
anchorX,
anchorY
};
const offsetPoint = {
offsetX,
offsetY
};
const dragPreviewOffset = getDragPreviewOffset(sourceNode, dragPreview, clientOffset, anchorPoint, offsetPoint);
dataTransfer.setDragImage(dragPreview, dragPreviewOffset.x, dragPreviewOffset.y);
}
}
try {
// Firefox won't drag without setting data
dataTransfer === null || dataTransfer === void 0 ? void 0 : dataTransfer.setData('application/json', {});
} catch (err) {
// IE doesn't support MIME types in setData
}
// Store drag source node so we can check whether
// it is removed from DOM and trigger endDrag manually.
this.setCurrentDragSourceNode(e.target);
// Now we are ready to publish the drag source.. or are we not?
const { captureDraggingState } = this.getCurrentSourcePreviewNodeOptions();
if (!captureDraggingState) {
// Usually we want to publish it in the next tick so that browser
// is able to screenshot the current (not yet dragging) state.
//
// It also neatly avoids a situation where render() returns null
// in the same tick for the source element, and browser freaks out.
setTimeout(()=>this.actions.publishDragSource()
, 0);
} else {
// In some cases the user may want to override this behavior, e.g.
// to work around IE not supporting custom drag previews.
//
// When using a custom drag layer, the only way to prevent
// the default drag preview from drawing in IE is to screenshot
// the dragging state in which the node itself has zero opacity
// and height. In this case, though, returning null from render()
// will abruptly end the dragging, which is not obvious.
//
// This is the reason such behavior is strictly opt-in.
this.actions.publishDragSource();
}
} else if (nativeType) {
// A native item (such as URL) dragged from inside the document
this.beginDragNativeItem(nativeType);
} else if (dataTransfer && !dataTransfer.types && (e.target && !e.target.hasAttribute || !e.target.hasAttribute('draggable'))) {
// Looks like a Safari bug: dataTransfer.types is null, but there was no draggable.
// Just let it drag. It's a native type (URL or text) and will be picked up in
// dragenter handler.
return;
} else {
// If by this time no drag source reacted, tell browser not to drag.
e.preventDefault();
}
};
this.handleTopDragEndCapture = ()=>{
if (this.clearCurrentDragSourceNode() && this.monitor.isDragging()) {
// Firefox can dispatch this event in an infinite loop
// if dragend handler does something like showing an alert.
// Only proceed if we have not handled it already.
this.actions.endDrag();
}
this.cancelHover();
};
this.handleTopDragEnterCapture = (e)=>{
this.dragEnterTargetIds = [];
if (this.isDraggingNativeItem()) {
var ref;
(ref = this.currentNativeSource) === null || ref === void 0 ? void 0 : ref.loadDataTransfer(e.dataTransfer);
}
const isFirstEnter = this.enterLeaveCounter.enter(e.target);
if (!isFirstEnter || this.monitor.isDragging()) {
return;
}
const { dataTransfer } = e;
const nativeType = matchNativeItemType(dataTransfer);
if (nativeType) {
// A native item (such as file or URL) dragged from outside the document
this.beginDragNativeItem(nativeType, dataTransfer);
}
};
this.handleTopDragEnter = (e)=>{
const { dragEnterTargetIds } = this;
this.dragEnterTargetIds = [];
if (!this.monitor.isDragging()) {
// This is probably a native item type we don't understand.
return;
}
this.altKeyPressed = e.altKey;
// If the target changes position as the result of `dragenter`, `dragover` might still
// get dispatched despite target being no longer there. The easy solution is to check
// whether there actually is a target before firing `hover`.
if (dragEnterTargetIds.length > 0) {
this.actions.hover(dragEnterTargetIds, {
clientOffset: getEventClientOffset(e)
});
}
const canDrop = dragEnterTargetIds.some((targetId)=>this.monitor.canDropOnTarget(targetId)
);
if (canDrop) {
// IE requires this to fire dragover events
e.preventDefault();
if (e.dataTransfer) {
e.dataTransfer.dropEffect = this.getCurrentDropEffect();
}
}
};
this.handleTopDragOverCapture = (e)=>{
this.dragOverTargetIds = [];
if (this.isDraggingNativeItem()) {
var ref;
(ref = this.currentNativeSource) === null || ref === void 0 ? void 0 : ref.loadDataTransfer(e.dataTransfer);
}
};
this.handleTopDragOver = (e)=>{
const { dragOverTargetIds } = this;
this.dragOverTargetIds = [];
if (!this.monitor.isDragging()) {
// This is probably a native item type we don't understand.
// Prevent default "drop and blow away the whole document" action.
e.preventDefault();
if (e.dataTransfer) {
e.dataTransfer.dropEffect = 'none';
}
return;
}
this.altKeyPressed = e.altKey;
this.lastClientOffset = getEventClientOffset(e);
this.scheduleHover(dragOverTargetIds);
const canDrop = (dragOverTargetIds || []).some((targetId)=>this.monitor.canDropOnTarget(targetId)
);
if (canDrop) {
// Show user-specified drop effect.
e.preventDefault();
if (e.dataTransfer) {
e.dataTransfer.dropEffect = this.getCurrentDropEffect();
}
} else if (this.isDraggingNativeItem()) {
// Don't show a nice cursor but still prevent default
// "drop and blow away the whole document" action.
e.preventDefault();
} else {
e.preventDefault();
if (e.dataTransfer) {
e.dataTransfer.dropEffect = 'none';
}
}
};
this.handleTopDragLeaveCapture = (e)=>{
if (this.isDraggingNativeItem()) {
e.preventDefault();
}
const isLastLeave = this.enterLeaveCounter.leave(e.target);
if (!isLastLeave) {
return;
}
if (this.isDraggingNativeItem()) {
setTimeout(()=>this.endDragNativeItem()
, 0);
}
this.cancelHover();
};
this.handleTopDropCapture = (e)=>{
this.dropTargetIds = [];
if (this.isDraggingNativeItem()) {
var ref;
e.preventDefault();
(ref = this.currentNativeSource) === null || ref === void 0 ? void 0 : ref.loadDataTransfer(e.dataTransfer);
} else if (matchNativeItemType(e.dataTransfer)) {
// Dragging some elements, like <a> and <img> may still behave like a native drag event,
// even if the current drag event matches a user-defined type.
// Stop the default behavior when we're not expecting a native item to be dropped.
e.preventDefault();
}
this.enterLeaveCounter.reset();
};
this.handleTopDrop = (e)=>{
const { dropTargetIds } = this;
this.dropTargetIds = [];
this.actions.hover(dropTargetIds, {
clientOffset: getEventClientOffset(e)
});
this.actions.drop({
dropEffect: this.getCurrentDropEffect()
});
if (this.isDraggingNativeItem()) {
this.endDragNativeItem();
} else if (this.monitor.isDragging()) {
this.actions.endDrag();
}
this.cancelHover();
};
this.handleSelectStart = (e)=>{
const target = e.target;
// Only IE requires us to explicitly say
// we want drag drop operation to start
if (typeof target.dragDrop !== 'function') {
return;
}
// Inputs and textareas should be selectable
if (target.tagName === 'INPUT' || target.tagName === 'SELECT' || target.tagName === 'TEXTAREA' || target.isContentEditable) {
return;
}
// For other targets, ask IE
// to enable drag and drop
e.preventDefault();
target.dragDrop();
};
this.options = new OptionsReader(globalContext, options);
this.actions = manager.getActions();
this.monitor = manager.getMonitor();
this.registry = manager.getRegistry();
this.enterLeaveCounter = new EnterLeaveCounter(this.isNodeInDocument);
}
}
//# sourceMappingURL=HTML5BackendImpl.js.map