allow premove in analysis to alleviate network lag

ui/analyse/src/analyse.js

@@ -28,7 +28,7 @@ module.exports = function(steps, analysis) {
     nextPath.forEach(function(p) {
       for (i = 0, nb = tree.length; i < nb; i++) {
         var step = tree[i];
-        if (p.ply == step.ply) {
+        if (p.ply === step.ply) {
           if (p.variation) {
             tree = step.variations[p.variation - 1];
             break;
@@ -38,11 +38,9 @@ module.exports = function(steps, analysis) {
     });
     if (curStep) {
       curStep.variations = curStep.variations || [];
-      if (curStep.san === step.san) return nextPath;
+      if (curStep.san === step.san) return false;;
       for (var i = 0; i < curStep.variations.length; i++) {
-        if (curStep.variations[i][0].san === step.san) {
-          return treePath.withVariation(nextPath, i + 1);
-        }
+        if (curStep.variations[i][0].san === step.san) return false;
       }
       curStep.variations.push([step]);
       return treePath.withVariation(nextPath, curStep.variations.length);

ui/analyse/src/ctrl.js

@@ -1,4 +1,5 @@
 var chessground = require('chessground');
+var opposite = chessground.util.opposite;
 var data = require('./data');
 var analyse = require('./analyse');
 var ground = require('./ground');
@@ -72,7 +73,6 @@ module.exports = function(opts) {
     this.vm.cgConfig = config;
     if (!this.chessground)
       this.chessground = ground.make(this.data, config, userMove);
-    this.chessground.stop();
     this.chessground.set(config);
     if (opts.onChange) opts.onChange(config.fen, this.vm.path);
   }.bind(this);
@@ -116,11 +116,21 @@ module.exports = function(opts) {
     };
     if (prom) move.promotion = prom;
     this.socket.sendAnaMove(move);
+    this.chessground.set({
+      turnColor: this.chessground.data.movable.color,
+      movable: {
+        color: opposite(this.chessground.data.movable.color)
+      }
+    });
+    console.log(this.chessground.data);
   }.bind(this);
 
   this.addStep = function(step, path) {
-    this.userJump(this.analyse.addStep(step, treePath.read(path)));
+    var newPath = this.analyse.addStep(step, treePath.read(path));
+    if (!newPath) return;
+    this.jump(newPath);
     m.redraw();
+    this.chessground.playPremove();
   }.bind(this);
 
   this.reset = function() {

ui/analyse/src/ground.js

@@ -17,7 +17,7 @@ function makeConfig(data, config, onMove) {
       }
     },
     premovable: {
-      enabled: false
+      enabled: true
     },
     drawable: {
       enabled: true