Relax the availability rules for rotation and reflection operations

(closes #4237)

New rules:
- Rotation available if at least 2 unique nodes in selectedIDs
- Reflection available if at least 3 unique nodes in selectedIDs

modules/modes/rotate.js

@@ -1,10 +1,9 @@
 import * as d3 from 'd3';
 import { d3keybinding } from '../lib/d3.keybinding.js';
 import { t } from '../util/locale';
-
-import { actionRotate } from '../actions/index';
-import { behaviorEdit } from '../behavior/index';
-
+import { actionRotate } from '../actions';
+import { behaviorEdit } from '../behavior';
+import { geoInterp } from '../geo';
 import {
     modeBrowse,
     modeSelect
@@ -17,7 +16,7 @@ import {
     operationOrthogonalize,
     operationReflectLong,
     operationReflectShort
-} from '../operations/index';
+} from '../operations';
 
 import {
     polygonHull as d3polygonHull,
@@ -71,7 +70,13 @@ export function modeRotate(context, entityIDs) {
             var nodes = utilGetAllNodes(entityIDs, context.graph()),
                 points = nodes.map(function(n) { return projection(n.loc); });
 
-            pivot = d3polygonCentroid(d3polygonHull(points));
+            if (points.length === 1) {  // degenerate case
+                pivot = points[0];
+            } else if (points.length === 2) {
+                pivot = geoInterp(points[0], points[1], 0.5);
+            } else {
+                pivot = d3polygonCentroid(d3polygonHull(points));
+            }
             prevAngle = undefined;
         }
 

modules/operations/reflect.js

@@ -1,8 +1,9 @@
 import _ from 'lodash';
 import { t } from '../util/locale';
-import { actionReflect } from '../actions/index';
-import { behaviorOperation } from '../behavior/index';
-import { geoExtent } from '../geo/index';
+import { actionReflect } from '../actions';
+import { behaviorOperation } from '../behavior';
+import { geoExtent } from '../geo';
+import { utilGetAllNodes } from '../util';
 
 
 export function operationReflectShort(selectedIDs, context) {
@@ -31,13 +32,8 @@ export function operationReflect(selectedIDs, context, axis) {
 
 
     operation.available = function() {
-        return _.some(selectedIDs, hasArea);
-
-        function hasArea(id) {
-            var entity = context.entity(id);
-            return (entity.type === 'way' && entity.isClosed()) ||
-                (entity.type ==='relation' && entity.isMultipolygon());
-        }
+        var nodes = utilGetAllNodes(selectedIDs, context.graph());
+        return _.uniqBy(nodes, function(n) { return n.loc; }).length >= 3;
     };
 
 

modules/operations/rotate.js

@@ -1,8 +1,9 @@
 import _ from 'lodash';
 import { t } from '../util/locale';
-import { behaviorOperation } from '../behavior/index';
-import { geoExtent } from '../geo/index';
-import { modeRotate } from '../modes/index';
+import { behaviorOperation } from '../behavior';
+import { geoExtent } from '../geo';
+import { modeRotate } from '../modes';
+import { utilGetAllNodes } from '../util';
 
 
 export function operationRotate(selectedIDs, context) {
@@ -18,13 +19,8 @@ export function operationRotate(selectedIDs, context) {
 
 
     operation.available = function() {
-        return _.some(selectedIDs, hasArea);
-
-        function hasArea(id) {
-            var entity = context.entity(id);
-            return (entity.type === 'way' && entity.isClosed()) ||
-                (entity.type ==='relation' && entity.isMultipolygon());
-        }
+        var nodes = utilGetAllNodes(selectedIDs, context.graph());
+        return _.uniqBy(nodes, function(n) { return n.loc; }).length >= 2;
     };