Implement new functionality

modules/actions/straighten.js

@@ -1,4 +1,5 @@
 import { actionDeleteNode } from './delete_node';
+import _difference from 'lodash-es/difference';
 
 import {
     geoVecInterp,
@@ -9,20 +10,47 @@ import {
 /*
  * Based on https://github.com/openstreetmap/potlatch2/net/systemeD/potlatch2/tools/Straighten.as
  */
-export function actionStraighten(wayId, projection) {
+export function actionStraighten(wayIds, projection) {
 
     function positionAlongWay(n, s, e) {
         return ((n[0] - s[0]) * (e[0] - s[0]) + (n[1] - s[1]) * (e[1] - s[1])) /
                 (Math.pow(e[0] - s[0], 2) + Math.pow(e[1] - s[1], 2));
     }
 
+    // Return all ways as a continuous, ordered array of nodes
+    var getAllNodes = function(graph) {
+        var nodes = [],
+            startNodes = [],
+            endNodes = [],
+            ways = {};
+
+        for (var i = 0; i < wayIds.length; i++) {
+            var way = graph.entity(wayIds[i]);
+                nodes = graph.childNodes(way);
+                ways[nodes[0].id] = nodes;
+                startNodes.push(nodes[0]);
+                endNodes.push(nodes[nodes.length-1]);
+        }
+
+        var startNode = _difference(startNodes, endNodes)[0],
+            endNode = _difference(endNodes, startNodes)[0];
+
+        nodes = ways[startNode.id];
+
+        while (nodes[nodes.length-1] !== endNode) {
+            var lastNode = nodes[nodes.length-1];
+                nodes = nodes.concat(ways[lastNode.id]);
+        }
+
+        return nodes;
+    };
+
 
     var action = function(graph, t) {
         if (t === null || !isFinite(t)) t = 1;
         t = Math.min(Math.max(+t, 0), 1);
 
-        var way = graph.entity(wayId),
-            nodes = graph.childNodes(way),
+        var nodes = getAllNodes(graph),
             points = nodes.map(function(n) { return projection(n.loc); }),
             startPoint = points[0],
             endPoint = points[points.length-1],
@@ -64,8 +92,7 @@ export function actionStraighten(wayId, projection) {
 
     action.disabled = function(graph) {
         // check way isn't too bendy
-        var way = graph.entity(wayId),
-            nodes = graph.childNodes(way),
+        var nodes = getAllNodes(graph),
             points = nodes.map(function(n) { return projection(n.loc); }),
             startPoint = points[0],
             endPoint = points[points.length-1],

modules/operations/straighten.js

@@ -1,4 +1,5 @@
 import _uniq from 'lodash-es/uniq';
+import _difference from 'lodash-es/difference';
 
 import { t } from '../util/locale';
 import { actionStraighten } from '../actions/index';
@@ -6,8 +7,7 @@ import { behaviorOperation } from '../behavior/index';
 
 
 export function operationStraighten(selectedIDs, context) {
-    var entityId = selectedIDs[0],
-        action = actionStraighten(entityId, context.projection);
+    var action = actionStraighten(selectedIDs, context.projection);
 
 
     function operation() {
@@ -16,18 +16,41 @@ export function operationStraighten(selectedIDs, context) {
 
 
     operation.available = function() {
-        var entity = context.entity(entityId);
-        return selectedIDs.length === 1 &&
-            entity.type === 'way' &&
-            !entity.isClosed() &&
-            _uniq(entity.nodes).length > 2;
+        var nodes = [],
+            startNodes = [],
+            endNodes = [];
+
+        for (var i = 0; i < selectedIDs.length; i++) {
+            if (!context.hasEntity(selectedIDs[i])) return false;
+
+            var entity = context.entity(selectedIDs[i]);
+
+            if (entity.type !== 'way' ||
+                entity.isClosed()) {
+                return false;
+            }
+
+            nodes = nodes.concat(entity.nodes);
+            startNodes.push(entity.nodes[0]);
+            endNodes.push(entity.nodes[entity.nodes.length-1]);
+        }
+
+        if (_uniq(nodes).length <= 2) return false;
+
+        // Ensure all ways are connected (i.e. only one unique start point and one unique end point)
+        if (_difference(startNodes, endNodes).length !== 1 ||
+            _difference(endNodes, startNodes).length !== 1) return false;
+
+        return true;
     };
 
 
     operation.disabled = function() {
         var reason;
-        if (context.hasHiddenConnections(entityId)) {
-            reason = 'connected_to_hidden';
+        for (var i = 0; i < selectedIDs.length; i++) {
+            if (context.hasHiddenConnections(selectedIDs[i])) {
+                reason = 'connected_to_hidden';
+            }
         }
         return action.disabled(context.graph()) || reason;
     };