feat(igxTreeGrid): Adds always expanded state to pinned rows #6640

Author: 3phase

projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.html

@@ -85,7 +85,7 @@
                     <igx-tree-grid-row [gridID]="id" [index]="rowIndex" [treeRow]="rowData" #row>
                     </igx-tree-grid-row>
                 </ng-template>
-                <ng-container [igxTemplateOutlet]="record_template" [igxTemplateOutletContext]="getContext(rowData, rowIndex)">
+                <ng-container [igxTemplateOutlet]="record_template" [igxTemplateOutletContext]="getContext(rowData, rowIndex, true)">
                 </ng-container>
             </ng-container>
         </ng-template>

projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.ts

@@ -561,6 +561,7 @@ export class IgxTreeGridComponent extends IgxGridBaseDirective implements GridTy
         if (this.gridAPI.grid) {
             this.notifyChanges(true);
         }
+        this.cdr.detectChanges();
     }
 
     /**
@@ -646,7 +647,11 @@ export class IgxTreeGridComponent extends IgxGridBaseDirective implements GridTy
     /**
     * @hidden
     */
-    public getContext(rowData: any, rowIndex: Number): any {
+    public getContext(rowData: any, rowIndex: number, pinned?: boolean): any {
+        if (pinned && !this.isRowPinningToTop) {
+            rowIndex = rowIndex + this.dataView.length;
+        }
+        rowIndex = !pinned && this.isRowPinningToTop ? rowIndex + this.pinnedRecords.length : rowIndex;
         return {
             $implicit: rowData,
             index: rowIndex,

projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.pipes.ts

@@ -168,7 +168,11 @@ export class IgxTreeGridFlatteningPipe implements PipeTransform {
                 data.push(hierarchicalRecord);
             }
 
-            hierarchicalRecord.expanded = this.gridAPI.get_row_expansion_state(hierarchicalRecord);
+            const pinnedRow = this.gridAPI.get_row_by_key(hierarchicalRecord.rowID) !== undefined ? 
+                    this.gridAPI.get_row_by_key(hierarchicalRecord.rowID).pinned :
+                    false;
+
+            hierarchicalRecord.expanded = this.gridAPI.get_row_expansion_state(hierarchicalRecord) || pinnedRow;
 
             this.updateNonProcessedRecordExpansion(grid, hierarchicalRecord);