react app

react-app/node_modules/react/lib/getNodeForCharacterOffset.js

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+/**
+ * Copyright 2013-2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule getNodeForCharacterOffset
+ */
+
+'use strict';
+
+/**
+ * Given any node return the first leaf node without children.
+ *
+ * @param {DOMElement|DOMTextNode} node
+ * @return {DOMElement|DOMTextNode}
+ */
+function getLeafNode(node) {
+  while (node && node.firstChild) {
+    node = node.firstChild;
+  }
+  return node;
+}
+
+/**
+ * Get the next sibling within a container. This will walk up the
+ * DOM if a node's siblings have been exhausted.
+ *
+ * @param {DOMElement|DOMTextNode} node
+ * @return {?DOMElement|DOMTextNode}
+ */
+function getSiblingNode(node) {
+  while (node) {
+    if (node.nextSibling) {
+      return node.nextSibling;
+    }
+    node = node.parentNode;
+  }
+}
+
+/**
+ * Get object describing the nodes which contain characters at offset.
+ *
+ * @param {DOMElement|DOMTextNode} root
+ * @param {number} offset
+ * @return {?object}
+ */
+function getNodeForCharacterOffset(root, offset) {
+  var node = getLeafNode(root);
+  var nodeStart = 0;
+  var nodeEnd = 0;
+
+  while (node) {
+    if (node.nodeType === 3) {
+      nodeEnd = nodeStart + node.textContent.length;
+
+      if (nodeStart <= offset && nodeEnd >= offset) {
+        return {
+          node: node,
+          offset: offset - nodeStart
+        };
+      }
+
+      nodeStart = nodeEnd;
+    }
+
+    node = getLeafNode(getSiblingNode(node));
+  }
+}
+
+module.exports = getNodeForCharacterOffset;