only allow zoom by mouse wheel or selection when time axis is available

pdb-js/src/app/plot.service.ts

@@ -93,14 +93,11 @@ export class PlotType {
   }
   
   compatible(others: Array<PlotType>) : boolean {
-    var result = true;
-    var other : PlotType;
-    
     var xAxisTypes = new Set([this.xAxis]);
     var yAxisTypes = new Set([this.yAxis]);
   
     for(var i = 0; i < others.length; i++){
-      other = others[i];
+      var other = others[i];
       xAxisTypes.add(other.xAxis);
       yAxisTypes.add(other.yAxis);
     }
@@ -129,6 +126,24 @@ export enum DataType {
     Other
 }
 
+export class AxesTypes {
+  x : Set<DataType>;
+  y : Set<DataType>;
+  
+  constructor(x: Set<DataType>, y : Set<DataType>) {
+    this.x = x;
+    this.y = y;
+  }
+  
+  hasXAxis(type : DataType){
+    return this.x.has(type);
+  }
+  
+  hasYAxis(type : DataType){
+    return this.y.has(type);
+  }
+}
+
 export class Suggestion {
   value: string;
   newQuery: string;