Additional small fixes.

Author: MKirova

projects/igniteui-angular/src/lib/grids/pivot-grid/pivot-header-row.component.ts

@@ -56,7 +56,8 @@ export class IgxPivotHeaderRowComponent extends IgxGridHeaderRowComponent {
     }
 
     public onDimDragEnter(event, dimension: PivotDimensionType) {
-        const typeMismatch = dimension !== undefined ? this.grid.pivotConfiguration.values.find(x => x.member === event.dragChip.id) : null;
+        const typeMismatch = dimension !== undefined ? this.grid.pivotConfiguration.values.find(x => x.member === event.dragChip.id) :
+        !this.grid.pivotConfiguration.values.find(x => x.member === event.dragChip.id);
         if (typeMismatch) {
             // cannot drag between dimensions and value
             return;
@@ -69,7 +70,8 @@ export class IgxPivotHeaderRowComponent extends IgxGridHeaderRowComponent {
 
     public onAreaDragEnter(event, area, dimension: PivotDimensionType) {
         const dragId = event.detail.owner.element.nativeElement.parentElement.id;
-        const typeMismatch = dimension !== undefined ? this.grid.pivotConfiguration.values.find(x => x.member === dragId) : null;
+        const typeMismatch = dimension !== undefined ? this.grid.pivotConfiguration.values.find(x => x.member === dragId) :
+        !this.grid.pivotConfiguration.values.find(x => x.member === dragId);
         if (typeMismatch) {
             // cannot drag between dimensions and value
             return;
@@ -94,11 +96,12 @@ export class IgxPivotHeaderRowComponent extends IgxGridHeaderRowComponent {
         const chipsArray = area.chipsList.toArray();
         const chipIndex = chipsArray.indexOf(event.owner) !== -1 ? chipsArray.indexOf(event.owner) : chipsArray.length;
         const newDim = currentDim.find(x => x.member === dragId);
-        const dragChipIndex = chipsArray.indexOf(event.dragChip || event.dragData.chip);
-        currentDim.splice(dragChipIndex, 1);
-        currentDim.splice(dragChipIndex > chipIndex ? chipIndex : chipIndex - 1, 0, newDim);
-
-        this.grid.setupColumns();
+        if (newDim) {
+            const dragChipIndex = chipsArray.indexOf(event.dragChip || event.dragData.chip);
+            currentDim.splice(dragChipIndex, 1);
+            currentDim.splice(dragChipIndex > chipIndex ? chipIndex : chipIndex - 1, 0, newDim);
+            this.grid.setupColumns();
+        }
     }
 
     public onDimDrop(event, area, dimension: PivotDimensionType) {
@@ -123,14 +126,18 @@ export class IgxPivotHeaderRowComponent extends IgxGridHeaderRowComponent {
             const newDim = Object.assign({}, dim);
             newDim.enabled = true;
             currentDim.splice(chipIndex, 0, newDim);
-            this.grid.setupColumns();
+
         } else {
             // chip from same collection, reordered.
             const newDim = currentDim.find(x => x.fieldName === dragId);
             const dragChipIndex = chipsArray.indexOf(event.dragChip || event.dragData.chip);
             currentDim.splice(dragChipIndex, 1);
             currentDim.splice(dragChipIndex > chipIndex ? chipIndex : chipIndex - 1, 0, newDim);
         }
+        if (dimension === PivotDimensionType.Column) {
+            // if columns have changed need to regenerate columns.
+            this.grid.setupColumns();
+        }
         this.grid.pipeTrigger++;
     }
 }