Use React's 'TouchHistoryMath' module

src/apis/PanResponder/TouchHistoryMath.js

@@ -1,124 +0,0 @@
-/* eslint-disable */
-/**
- * Copyright (c) 2015-present, Facebook, Inc.
- * All rights reserved.
- */
-
-"use strict";
-
-var TouchHistoryMath = {
-  /**
-   * This code is optimized and not intended to look beautiful. This allows
-   * computing of touch centroids that have moved after `touchesChangedAfter`
-   * timeStamp. You can compute the current centroid involving all touches
-   * moves after `touchesChangedAfter`, or you can compute the previous
-   * centroid of all touches that were moved after `touchesChangedAfter`.
-   *
-   * @param {TouchHistoryMath} touchHistory Standard Responder touch track
-   * data.
-   * @param {number} touchesChangedAfter timeStamp after which moved touches
-   * are considered "actively moving" - not just "active".
-   * @param {boolean} isXAxis Consider `x` dimension vs. `y` dimension.
-   * @param {boolean} ofCurrent Compute current centroid for actively moving
-   * touches vs. previous centroid of now actively moving touches.
-   * @return {number} value of centroid in specified dimension.
-   */
-  centroidDimension: function(touchHistory, touchesChangedAfter, isXAxis, ofCurrent) {
-    var touchBank = touchHistory.touchBank;
-    var total = 0;
-    var count = 0;
-
-    var oneTouchData = touchHistory.numberActiveTouches === 1 ?
-      touchHistory.touchBank[touchHistory.indexOfSingleActiveTouch] : null;
-
-    if (oneTouchData !== null) {
-      if (oneTouchData.touchActive && oneTouchData.currentTimeStamp > touchesChangedAfter) {
-        total += ofCurrent && isXAxis ? oneTouchData.currentPageX :
-          ofCurrent && !isXAxis ? oneTouchData.currentPageY :
-          !ofCurrent && isXAxis ? oneTouchData.previousPageX :
-          oneTouchData.previousPageY;
-        count = 1;
-      }
-    } else {
-      for (var i = 0; i < touchBank.length; i++) {
-        var touchTrack = touchBank[i];
-        if (touchTrack !== null &&
-            touchTrack !== undefined &&
-            touchTrack.touchActive &&
-            touchTrack.currentTimeStamp >= touchesChangedAfter) {
-          var toAdd;  // Yuck, program temporarily in invalid state.
-          if (ofCurrent && isXAxis) {
-            toAdd = touchTrack.currentPageX;
-          } else if (ofCurrent && !isXAxis) {
-            toAdd = touchTrack.currentPageY;
-          } else if (!ofCurrent && isXAxis) {
-            toAdd = touchTrack.previousPageX;
-          } else {
-            toAdd = touchTrack.previousPageY;
-          }
-          total += toAdd;
-          count++;
-        }
-      }
-    }
-    return count > 0 ? total / count : TouchHistoryMath.noCentroid;
-  },
-
-  currentCentroidXOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
-    return TouchHistoryMath.centroidDimension(
-      touchHistory,
-      touchesChangedAfter,
-      true,  // isXAxis
-      true   // ofCurrent
-    );
-  },
-
-  currentCentroidYOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
-    return TouchHistoryMath.centroidDimension(
-      touchHistory,
-      touchesChangedAfter,
-      false,  // isXAxis
-      true    // ofCurrent
-    );
-  },
-
-  previousCentroidXOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
-    return TouchHistoryMath.centroidDimension(
-      touchHistory,
-      touchesChangedAfter,
-      true,  // isXAxis
-      false  // ofCurrent
-    );
-  },
-
-  previousCentroidYOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
-    return TouchHistoryMath.centroidDimension(
-      touchHistory,
-      touchesChangedAfter,
-      false,  // isXAxis
-      false   // ofCurrent
-    );
-  },
-
-  currentCentroidX: function(touchHistory) {
-    return TouchHistoryMath.centroidDimension(
-      touchHistory,
-      0,     // touchesChangedAfter
-      true,  // isXAxis
-      true   // ofCurrent
-    );
-  },
-
-  currentCentroidY: function(touchHistory) {
-    return TouchHistoryMath.centroidDimension(
-      touchHistory,
-      0,     // touchesChangedAfter
-      false,  // isXAxis
-      true    // ofCurrent
-    );
-  },
-
-  noCentroid: -1,
-};
-
-module.exports = TouchHistoryMath;

src/apis/PanResponder/index.js

@@ -7,7 +7,7 @@
 "use strict";
 
 import normalizeNativeEvent from '../../modules/normalizeNativeEvent';
-var TouchHistoryMath = require('./TouchHistoryMath');
+var TouchHistoryMath = require('react/lib/TouchHistoryMath');
 
 var currentCentroidXOfTouchesChangedAfter =
   TouchHistoryMath.currentCentroidXOfTouchesChangedAfter;