Add error feedback text when attempting to draw self-intersecting ways

data/core.yaml

@@ -837,6 +837,10 @@ en:
     out: Zoom Out
   cannot_zoom: "Cannot zoom out further in current mode."
   full_screen: Toggle Full Screen
+  self_intersection:
+    error:
+      lines: Lines cannot cross over themselves.
+      areas: Areas cannot cross over themselves.
   QA:
     osmose:
       title: Osmose Issue

dist/locales/en.json

@@ -1047,6 +1047,12 @@
         },
         "cannot_zoom": "Cannot zoom out further in current mode.",
         "full_screen": "Toggle Full Screen",
+        "self_intersection": {
+            "error": {
+                "lines": "Lines cannot cross over themselves.",
+                "areas": "Areas cannot cross over themselves."
+            }
+        },
         "QA": {
             "osmose": {
                 "title": "Osmose Issue",

modules/behavior/draw_way.js

@@ -1,3 +1,5 @@
+import { dispatch as d3_dispatch } from 'd3-dispatch';
+
 import {
     event as d3_event,
     select as d3_select
@@ -12,10 +14,13 @@ import { geoChooseEdge, geoHasSelfIntersections } from '../geo';
 import { modeBrowse } from '../modes/browse';
 import { modeSelect } from '../modes/select';
 import { osmNode } from '../osm/node';
+import { utilRebind } from '../util/rebind';
 import { utilKeybinding } from '../util';
 
 export function behaviorDrawWay(context, wayID, index, mode, startGraph, baselineGraph) {
 
+    var dispatch = d3_dispatch('rejectedSelfIntersection');
+
     var _origWay = context.entity(wayID);
 
     var _annotation = t((_origWay.isDegenerate() ?
@@ -281,6 +286,7 @@ export function behaviorDrawWay(context, wayID, index, mode, startGraph, baselin
     // Accept the current position of the drawing node and continue drawing.
     drawWay.add = function(loc, d) {
         if ((d && d.properties && d.properties.nope) || context.surface().classed('nope')) {
+            dispatch.call('rejectedSelfIntersection', this);
             return;   // can't click here
         }
 
@@ -308,6 +314,7 @@ export function behaviorDrawWay(context, wayID, index, mode, startGraph, baselin
     // Connect the way to an existing way.
     drawWay.addWay = function(loc, edge, d) {
         if ((d && d.properties && d.properties.nope) || context.surface().classed('nope')) {
+            dispatch.call('rejectedSelfIntersection', this);
             return;   // can't click here
         }
 
@@ -332,6 +339,7 @@ export function behaviorDrawWay(context, wayID, index, mode, startGraph, baselin
     // Connect the way to an existing node and continue drawing.
     drawWay.addNode = function(node, d) {
         if ((d && d.properties && d.properties.nope) || context.surface().classed('nope')) {
+            dispatch.call('rejectedSelfIntersection', this);
             return;   // can't click here
         }
 
@@ -417,5 +425,5 @@ export function behaviorDrawWay(context, wayID, index, mode, startGraph, baselin
     };
 
 
-    return drawWay;
+    return utilRebind(drawWay, dispatch, 'on');
 }

modules/modes/draw_area.js

@@ -1,5 +1,6 @@
 import { t } from '../util/locale';
 import { behaviorDrawWay } from '../behavior/draw_way';
+import { uiFlash } from '../ui/flash';
 
 
 export function modeDrawArea(context, wayID, startGraph, baselineGraph, button) {
@@ -16,7 +17,11 @@ export function modeDrawArea(context, wayID, startGraph, baselineGraph, button)
         var way = context.entity(wayID);
 
         behavior = behaviorDrawWay(context, wayID, undefined, mode, startGraph, baselineGraph)
-            .tail(t('modes.draw_area.tail'));
+            .tail(t('modes.draw_area.tail'))
+            .on('rejectedSelfIntersection.modeDrawArea', function() {
+                uiFlash()
+                    .text(t('self_intersection.error.areas'))();
+            });
 
         var addNode = behavior.addNode;
 

modules/modes/draw_line.js

@@ -1,5 +1,6 @@
 import { t } from '../util/locale';
 import { behaviorDrawWay } from '../behavior/draw_way';
+import { uiFlash } from '../ui/flash';
 
 
 export function modeDrawLine(context, wayID, startGraph, baselineGraph, button, affix, continuing) {
@@ -20,7 +21,11 @@ export function modeDrawLine(context, wayID, startGraph, baselineGraph, button,
         var headID = (affix === 'prefix') ? way.first() : way.last();
 
         behavior = behaviorDrawWay(context, wayID, index, mode, startGraph, baselineGraph)
-            .tail(t('modes.draw_line.tail'));
+            .tail(t('modes.draw_line.tail'))
+            .on('rejectedSelfIntersection.modeDrawLine', function() {
+                uiFlash()
+                    .text(t('self_intersection.error.lines'))();
+            });
 
         var addNode = behavior.addNode;
         behavior.addNode = function(node, d) {