Snap immediately on starting a sketch. r=ahocevar (closes #2039)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@9270 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/Snapping.js

@@ -298,6 +298,7 @@ OpenLayers.Control.Snapping = OpenLayers.Class(OpenLayers.Control, {
         if(activated) {
             if(this.layer && this.layer.events) {
                 this.layer.events.on({
+                    sketchstarted: this.onSketchModified,
                     sketchmodified: this.onSketchModified,
                     vertexmodified: this.onVertexModified,
                     scope: this
@@ -317,6 +318,7 @@ OpenLayers.Control.Snapping = OpenLayers.Class(OpenLayers.Control, {
         if(deactivated) {
             if(this.layer && this.layer.events) {
                 this.layer.events.un({
+                    sketchstarted: this.onSketchModified,
                     sketchmodified: this.onSketchModified,
                     vertexmodified: this.onVertexModified,
                     scope: this

tests/Control/Snapping.html

@@ -175,7 +175,7 @@
     
     function test_snapping(t) {
         
-        t.plan(33);
+        t.plan(46);
         
         var map = new OpenLayers.Map("map", {
             resolutions: [1],
@@ -298,7 +298,29 @@
         // unsnap & reset        
         drag(-100, -50);
         control.greedy = true;
-        events = [];
+        events = [];        
+        
+        // demonstrate snapping on sketchstarted
+        var p = new OpenLayers.Geometry.Point(0, 1);
+        layer1.events.triggerEvent("sketchstarted", {
+            vertex: p,
+            feature: new OpenLayers.Feature.Vector(p)
+        });
+        t.eq(events.length, 2, "[sketchstarted] 2 events triggered");
+        t.eq(events[0].type, "beforesnap", "[sketchstarted] beforesnap triggered");
+        t.eq(events[0].snapType, "node", "[sketchstarted] beforesnap triggered for node");
+        t.ok(events[0].point === p, "[sketchstarted] beforesnap triggered with vertex");
+        t.eq(events[0].x, 0, "[sketchstarted] beforesnap triggered correct x");
+        t.eq(events[0].y, 0, "[sketchstarted] beforesnap triggered with correct y");
+        t.eq(events[1].type, "snap", "[sketchstarted] snap triggered");
+        t.eq(events[1].snapType, "node", "[sketchstarted] snap triggered for node");
+        t.ok(events[1].point === p, "[sketchstarted] snap triggered with point");
+        t.eq(events[1].distance, 1, "[sketchstarted] snap triggered correct distance");
+        t.ok(events[1].layer === layer1, "[sketchstarted] snap triggered with correct target layer");
+        t.eq(p.x, 0, "[sketchstarted] vertex x modified");
+        t.eq(p.y, 0, "[sketchstarted] vertex y modified");
+        // reset
+        events = [];        
         
         map.destroy();