chore(*): refactor code about expand/collapse

Author: ddincheva

projects/igniteui-angular/src/lib/grids/columns/column-group.component.ts

@@ -303,12 +303,6 @@ export class IgxColumnGroupComponent extends IgxColumnComponent implements After
 
     set width(val) { }
 
-    private setExpandCollapseState() {
-        this.children.filter(col => (col.visibleOnCollapse !== undefined)).forEach(c =>  {
-            c.hidden = this._expand ? c.visibleOnCollapse : !c.visibleOnCollapse;
-        });
-    }
-
     // constructor(public gridAPI: GridBaseAPIService<IgxGridBaseDirective & IGridDataBindable>, public cdr: ChangeDetectorRef) {
     //     // D.P. constructor duplication due to es6 compilation, might be obsolete in the future
     //     super(gridAPI, cdr);

projects/igniteui-angular/src/lib/grids/columns/column.component.ts

@@ -1751,6 +1751,16 @@ export class IgxColumnComponent implements AfterContentInit {
         this.calcPixelWidth = parseInt(this._calcWidth, 10);
     }
 
+    /**
+     * @hidden
+     * @internal
+     */
+    protected setExpandCollapseState() {
+        this.children.filter(col => (col.visibleOnCollapse !== undefined)).forEach(c =>  {
+            c.hidden = this._expand ? c.visibleOnCollapse : !c.visibleOnCollapse;
+        });
+    }
+
     /**
      *@hidden
     */