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

pdb-js/src/app/plot-view/plot-view.component.ts

@@ -1,4 +1,5 @@
 import { Component, OnInit, Output, EventEmitter } from '@angular/core';
+import { DataType, AxesTypes  } from '../plot.service';
 
 @Component({
   selector: 'pdb-plot-view',
@@ -16,6 +17,8 @@ export class PlotViewComponent implements OnInit {
 
   imageUrl : string;
   
+  axes: AxesTypes;
+  
   @Output()
   zoomRange : EventEmitter<SelectionRange> = new EventEmitter<SelectionRange>();
   
@@ -89,7 +92,7 @@ export class PlotViewComponent implements OnInit {
     //console.log("dragStart inPlot: " + this.isInPlot(event));
     
     event.preventDefault();
-    if (event.buttons == 1 && this.isInPlot(event)) {
+    if (event.buttons == 1 && this.isInPlot(event) && this.axes.hasXAxis(DataType.Time)) {
       const pos = this.positionInImage(event);
       this.in_drag_mode = true;
       this.drag_start_x = pos.x;
@@ -157,7 +160,7 @@ export class PlotViewComponent implements OnInit {
   }
   
   zoomByScroll(event) {
-    if (this.isInImage(event) && event.deltaY != 0) {
+    if (this.isInImage(event) && event.deltaY != 0 && this.axes.hasXAxis(DataType.Time)) {
       this.in_drag_mode = false;
       this.hideZoomInSlider();