Alter implementation. Need to see if projection.translate is required

modules/actions/flip.js

@@ -6,49 +6,29 @@ Only operates on "area" ways
 export function actionFlip(wayId, isVertical, projection) {
 
     return function (graph) {
-        var targetWay = graph.entity(wayId);
+        const targetWay = graph.entity(wayId);
         // If the way is not an area, we will not process it
         if (!targetWay.isArea()) {
             // return input graph without changes
             return graph;
         }
-        // Obtain all of the nodes on the way
-        var nodesAndRects = _(targetWay.nodes)
+        // Get the bounding rectangle of the area
+        const boundingRect = targetWay.extent(graph).rectangle();
+        // rectangle returned as [ lon (x) top left, lat (y) top left, lon (x) bottom right, lat (y) bottom right]
+        // Obtain the left/top lonlat and the right/bottom
+        const leftOrTop = isVertical ? boundingRect[1] : boundingRect[0];
+        const rightOrBottom = isVertical ? boundingRect[3] : boundingRect[2];
+        // Determine the mid-point that we will flip on
+        const midPoint = leftOrTop + (rightOrBottom - leftOrTop);
+
+        // Obtain all of the nodes on the way, iterate over them to translate then aggreate up
+        return _(targetWay.nodes)
             .map(function (nodeId) {
                 return graph.entity(nodeId);
             })
-            // and their rectangles
             .map(function (node) {
-                return {
-                    node: node,
-                    rect: node.extent().rectangle()
-                };
-            });
-        // Obtain the left/top lonlat
-        // rectangle returned as [ lon (x) top left, lat (y) top left, lon (x) bottom right, lat (y) bottom right]
-        var leftOrTop = nodesAndRects
-            .map(function (nodeAndRect) {
-                return nodeAndRect.rect;
-            })
-            .minBy(function (rect) {
-                return isVertical ? rect[1] : rect[0];
-            });
-        // Now the same for right/bottom
-        var rightOrBottom = nodesAndRects
-            .map(function (nodeAndRect) {
-                return nodeAndRect.rect;
-            })
-            .minBy(function (rect) {
-                return isVertical ? rect[3] : rect[2];
-            });
-        // Determine the mid-point that we will flip on
-        var midPoint = rightOrBottom - leftOrTop;
-        // Iterate and aggregate
-        return nodesAndRects
-            .map(function (nodeAndRect) {
                 // Get distance from midPoint
-                var node = nodeAndRect.node;
-                var delta = isVertical ?
+                const delta = isVertical ?
                     node.loc[1] - midPoint :
                     node.loc[0] - midPoint;
                 return isVertical ?

modules/operations/flip.js

@@ -7,7 +7,7 @@ export function operationFlip(selectedIDs, context) {
 
     var operation = function() {
         context.perform(
-            actionFlip(entityId),
+            actionFlip(entityId, false, context.projection),
             t('operations.flip.annotation')
         );
     };