remove indexChanged event registration

src/ui/SolidityLocals.js

@@ -28,27 +28,19 @@ class SolidityLocals {
   }
 
   init () {
-    this.parent.event.register('indexChanged', this, (index) => {
+    this.parent.event.register('sourceLocationChanged', this, (sourceLocation) => {
       var warningDiv = this.view.querySelector('#warning')
       warningDiv.innerHTML = ''
-      if (index < 0) {
-        warningDiv.innerHTML = 'invalid step index'
-        return
-      }
-
-      if (this.parent.currentStepIndex !== index) return
-
-      this.parent.event.register('sourceLocationChanged', this, (sourceLocation) => {
       this.traceManager.waterfall([
         this.traceManager.getStackAt,
         this.traceManager.getMemoryAt],
-          index,
+        this.parent.currentStepIndex,
         (error, result) => {
           if (!error) {
             var stack = result[0].value
             var memory = result[1].value
             try {
-                var locals = localDecoder.solidityLocals(index, this.internalTreeCall, stack, memory, sourceLocation)
+              var locals = localDecoder.solidityLocals(this.parent.currentStepIndex, this.internalTreeCall, stack, memory, sourceLocation)
               this.basicPanel.update(locals)
             } catch (e) {
               warningDiv.innerHTML = e.message
@@ -56,7 +48,6 @@ class SolidityLocals {
           }
         })
     })
-    })
   }
 }