planning

node_modules/react-dnd/lib/internals/TargetConnector.js

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+import { shallowEqual } from '@react-dnd/shallowequal';
+import { wrapConnectorHooks } from './wrapConnectorHooks';
+import { isRef } from './isRef';
+export class TargetConnector {
+    hooks = wrapConnectorHooks({
+        dropTarget: (node, options) => {
+            this.clearDropTarget();
+            this.dropTargetOptions = options;
+            if (isRef(node)) {
+                this.dropTargetRef = node;
+            }
+            else {
+                this.dropTargetNode = node;
+            }
+            this.reconnect();
+        },
+    });
+    handlerId = null;
+    // The drop target may either be attached via ref or connect function
+    dropTargetRef = null;
+    dropTargetNode;
+    dropTargetOptionsInternal = null;
+    unsubscribeDropTarget;
+    lastConnectedHandlerId = null;
+    lastConnectedDropTarget = null;
+    lastConnectedDropTargetOptions = null;
+    backend;
+    constructor(backend) {
+        this.backend = backend;
+    }
+    get connectTarget() {
+        return this.dropTarget;
+    }
+    reconnect() {
+        // if nothing has changed then don't resubscribe
+        const didChange = this.didHandlerIdChange() ||
+            this.didDropTargetChange() ||
+            this.didOptionsChange();
+        if (didChange) {
+            this.disconnectDropTarget();
+        }
+        const dropTarget = this.dropTarget;
+        if (!this.handlerId) {
+            return;
+        }
+        if (!dropTarget) {
+            this.lastConnectedDropTarget = dropTarget;
+            return;
+        }
+        if (didChange) {
+            this.lastConnectedHandlerId = this.handlerId;
+            this.lastConnectedDropTarget = dropTarget;
+            this.lastConnectedDropTargetOptions = this.dropTargetOptions;
+            this.unsubscribeDropTarget = this.backend.connectDropTarget(this.handlerId, dropTarget, this.dropTargetOptions);
+        }
+    }
+    receiveHandlerId(newHandlerId) {
+        if (newHandlerId === this.handlerId) {
+            return;
+        }
+        this.handlerId = newHandlerId;
+        this.reconnect();
+    }
+    get dropTargetOptions() {
+        return this.dropTargetOptionsInternal;
+    }
+    set dropTargetOptions(options) {
+        this.dropTargetOptionsInternal = options;
+    }
+    didHandlerIdChange() {
+        return this.lastConnectedHandlerId !== this.handlerId;
+    }
+    didDropTargetChange() {
+        return this.lastConnectedDropTarget !== this.dropTarget;
+    }
+    didOptionsChange() {
+        return !shallowEqual(this.lastConnectedDropTargetOptions, this.dropTargetOptions);
+    }
+    disconnectDropTarget() {
+        if (this.unsubscribeDropTarget) {
+            this.unsubscribeDropTarget();
+            this.unsubscribeDropTarget = undefined;
+        }
+    }
+    get dropTarget() {
+        return (this.dropTargetNode || (this.dropTargetRef && this.dropTargetRef.current));
+    }
+    clearDropTarget() {
+        this.dropTargetRef = null;
+        this.dropTargetNode = null;
+    }
+}