Merge pull request #168 from nasa/mct80

[Plot] Dates show 1970 when there is no data

platform/features/plot/src/SubPlot.js

@@ -64,6 +64,16 @@ define(
             this.updateTicks();
         }
 
+        /**
+         * Tests whether this subplot has domain data to show for the current pan/zoom level. Absence of domain data
+         * implies that there is no range data displayed either
+         * @returns {boolean} true if domain data exists for the current pan/zoom level
+         */
+        SubPlot.prototype.hasDomainData = function() {
+            return this.panZoomStack
+                && this.panZoomStack.getDimensions()[0] > 0;
+        };
+
         // Utility function for filtering out empty strings.
         function isNonEmpty(v) {
             return typeof v === 'string' && v !== "";
@@ -253,7 +263,10 @@ define(
             this.hovering = true;
             this.subPlotBounds = $event.target.getBoundingClientRect();
             this.mousePosition = this.toMousePosition($event);
+            //If there is a domain to display, show hover coordinates, otherwise hover coordinates are meaningless
+            if (this.hasDomainData()) {
                 this.updateHoverCoordinates();
+            }
             if (this.marqueeStart) {
                 this.updateMarqueeBox();
             }

platform/features/plot/src/elements/PlotTickGenerator.js

@@ -53,7 +53,8 @@ define(
 
             for (i = 0; i < count; i += 1) {
                 result.push({
-                    label: format(i * step + start)
+                    //If data to show, display label for each tick line, otherwise show lines but suppress labels.
+                    label: span > 0 ? format(i * step + start) : ''
                 });
             }
 

platform/features/plot/test/SubPlotSpec.js

@@ -157,6 +157,15 @@ define(
                 );
             });
 
+            it ("indicates when there is domain data shown", function () {
+                expect(subplot.hasDomainData()).toEqual(true);
+            });
+
+            it ("indicates when there is no domain data shown", function () {
+                mockPanZoomStack.getDimensions.andReturn([0,0]);
+                expect(subplot.hasDomainData()).toEqual(false);
+            });
+            
             it("disallows marquee zoom when start and end Marquee is at the same position", function () {
                 expect(mockPanZoomStack.pushPanZoom).not.toHaveBeenCalled();