react app

react-app/node_modules/react/lib/ReactDOMSelection.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 ReactDOMSelection
+ */
+
+'use strict';
+
+var ExecutionEnvironment = require("./ExecutionEnvironment");
+
+var getNodeForCharacterOffset = require("./getNodeForCharacterOffset");
+var getTextContentAccessor = require("./getTextContentAccessor");
+
+/**
+ * While `isCollapsed` is available on the Selection object and `collapsed`
+ * is available on the Range object, IE11 sometimes gets them wrong.
+ * If the anchor/focus nodes and offsets are the same, the range is collapsed.
+ */
+function isCollapsed(anchorNode, anchorOffset, focusNode, focusOffset) {
+  return anchorNode === focusNode && anchorOffset === focusOffset;
+}
+
+/**
+ * Get the appropriate anchor and focus node/offset pairs for IE.
+ *
+ * The catch here is that IE's selection API doesn't provide information
+ * about whether the selection is forward or backward, so we have to
+ * behave as though it's always forward.
+ *
+ * IE text differs from modern selection in that it behaves as though
+ * block elements end with a new line. This means character offsets will
+ * differ between the two APIs.
+ *
+ * @param {DOMElement} node
+ * @return {object}
+ */
+function getIEOffsets(node) {
+  var selection = document.selection;
+  var selectedRange = selection.createRange();
+  var selectedLength = selectedRange.text.length;
+
+  // Duplicate selection so we can move range without breaking user selection.
+  var fromStart = selectedRange.duplicate();
+  fromStart.moveToElementText(node);
+  fromStart.setEndPoint('EndToStart', selectedRange);
+
+  var startOffset = fromStart.text.length;
+  var endOffset = startOffset + selectedLength;
+
+  return {
+    start: startOffset,
+    end: endOffset
+  };
+}
+
+/**
+ * @param {DOMElement} node
+ * @return {?object}
+ */
+function getModernOffsets(node) {
+  var selection = window.getSelection && window.getSelection();
+
+  if (!selection || selection.rangeCount === 0) {
+    return null;
+  }
+
+  var anchorNode = selection.anchorNode;
+  var anchorOffset = selection.anchorOffset;
+  var focusNode = selection.focusNode;
+  var focusOffset = selection.focusOffset;
+
+  var currentRange = selection.getRangeAt(0);
+
+  // If the node and offset values are the same, the selection is collapsed.
+  // `Selection.isCollapsed` is available natively, but IE sometimes gets
+  // this value wrong.
+  var isSelectionCollapsed = isCollapsed(
+    selection.anchorNode,
+    selection.anchorOffset,
+    selection.focusNode,
+    selection.focusOffset
+  );
+
+  var rangeLength = isSelectionCollapsed ? 0 : currentRange.toString().length;
+
+  var tempRange = currentRange.cloneRange();
+  tempRange.selectNodeContents(node);
+  tempRange.setEnd(currentRange.startContainer, currentRange.startOffset);
+
+  var isTempRangeCollapsed = isCollapsed(
+    tempRange.startContainer,
+    tempRange.startOffset,
+    tempRange.endContainer,
+    tempRange.endOffset
+  );
+
+  var start = isTempRangeCollapsed ? 0 : tempRange.toString().length;
+  var end = start + rangeLength;
+
+  // Detect whether the selection is backward.
+  var detectionRange = document.createRange();
+  detectionRange.setStart(anchorNode, anchorOffset);
+  detectionRange.setEnd(focusNode, focusOffset);
+  var isBackward = detectionRange.collapsed;
+
+  return {
+    start: isBackward ? end : start,
+    end: isBackward ? start : end
+  };
+}
+
+/**
+ * @param {DOMElement|DOMTextNode} node
+ * @param {object} offsets
+ */
+function setIEOffsets(node, offsets) {
+  var range = document.selection.createRange().duplicate();
+  var start, end;
+
+  if (typeof offsets.end === 'undefined') {
+    start = offsets.start;
+    end = start;
+  } else if (offsets.start > offsets.end) {
+    start = offsets.end;
+    end = offsets.start;
+  } else {
+    start = offsets.start;
+    end = offsets.end;
+  }
+
+  range.moveToElementText(node);
+  range.moveStart('character', start);
+  range.setEndPoint('EndToStart', range);
+  range.moveEnd('character', end - start);
+  range.select();
+}
+
+/**
+ * In modern non-IE browsers, we can support both forward and backward
+ * selections.
+ *
+ * Note: IE10+ supports the Selection object, but it does not support
+ * the `extend` method, which means that even in modern IE, it's not possible
+ * to programatically create a backward selection. Thus, for all IE
+ * versions, we use the old IE API to create our selections.
+ *
+ * @param {DOMElement|DOMTextNode} node
+ * @param {object} offsets
+ */
+function setModernOffsets(node, offsets) {
+  if (!window.getSelection) {
+    return;
+  }
+
+  var selection = window.getSelection();
+  var length = node[getTextContentAccessor()].length;
+  var start = Math.min(offsets.start, length);
+  var end = typeof offsets.end === 'undefined' ?
+            start : Math.min(offsets.end, length);
+
+  // IE 11 uses modern selection, but doesn't support the extend method.
+  // Flip backward selections, so we can set with a single range.
+  if (!selection.extend && start > end) {
+    var temp = end;
+    end = start;
+    start = temp;
+  }
+
+  var startMarker = getNodeForCharacterOffset(node, start);
+  var endMarker = getNodeForCharacterOffset(node, end);
+
+  if (startMarker && endMarker) {
+    var range = document.createRange();
+    range.setStart(startMarker.node, startMarker.offset);
+    selection.removeAllRanges();
+
+    if (start > end) {
+      selection.addRange(range);
+      selection.extend(endMarker.node, endMarker.offset);
+    } else {
+      range.setEnd(endMarker.node, endMarker.offset);
+      selection.addRange(range);
+    }
+  }
+}
+
+var useIEOffsets = (
+  ExecutionEnvironment.canUseDOM &&
+  'selection' in document &&
+  !('getSelection' in window)
+);
+
+var ReactDOMSelection = {
+  /**
+   * @param {DOMElement} node
+   */
+  getOffsets: useIEOffsets ? getIEOffsets : getModernOffsets,
+
+  /**
+   * @param {DOMElement|DOMTextNode} node
+   * @param {object} offsets
+   */
+  setOffsets: useIEOffsets ? setIEOffsets : setModernOffsets
+};
+
+module.exports = ReactDOMSelection;