added scroll direction option

src/index.ts

@@ -82,6 +82,7 @@ const DEFAULT_OPTIONS: Options = {
         keyEvent: KeyEvent.SHIFT,
         panStep: DEFAULT_SCROLL_PAN_STEP,
         orientation: ScrollPanOrientation.HORIZONTAL,
+        direction: ScrollPanDirection.BOTH,
       },
     },
   },
@@ -608,11 +609,25 @@ abstract class ChartwerkPod<T extends TimeSerie, O extends Options> {
       .text('No data points');
   }
 
+  private disableScrollForward(event: any): boolean {
+    return event.sourceEvent.wheelDelta > 0
+        && this.options.zoomEvents.scroll.pan.direction === ScrollPanDirection.FORWARD;
+  }
+
+  private disableScrollBackward(event: any): boolean {
+    return event.sourceEvent.wheelDelta < 0
+        && this.options.zoomEvents.scroll.pan.direction === ScrollPanDirection.BACKWARD;
+  }
+
   protected onPanning(): void {
     const event = this.d3.event;
     if(event.sourceEvent === null || event.sourceEvent === undefined) {
       return;
     }
+    if (event.sourceEvent.type === 'wheel'
+        && (this.disableScrollBackward(event) || this.disableScrollForward(event))) {
+      return;
+    }
     this.rescaleMetricAndAxis(event);
 
     if(this.options.eventsCallbacks !== undefined && this.options.eventsCallbacks.panning !== undefined) {

src/types.ts

@@ -85,6 +85,7 @@ export type Options = {
         keyEvent?: KeyEvent;
         panStep?: number;
         orientation?: ScrollPanOrientation;
+        direction?: ScrollPanDirection;
       },
     },
   }
@@ -140,6 +141,11 @@ export enum ScrollPanOrientation {
   VERTICAL = 'vertical',
   HORIZONTAL = 'horizontal',
 }
+export enum ScrollPanDirection  {
+  FORWARD = 'forward',
+  BACKWARD = 'backward',
+  BOTH = 'both',
+}
 export enum AxisFormat {
   TIME = 'time',
   NUMERIC = 'numeric',
@@ -177,4 +183,4 @@ export type SvgElParams = {
   width: number,
   xScale: d3.ScaleLinear<number, number>,
   yScale: d3.ScaleLinear<number, number>,
-}
+}