fix(simple-combo): new approach selectionChanging event when input value changes

Author: georgianastasov

projects/igniteui-angular/src/lib/simple-combo/simple-combo.component.spec.ts

@@ -1557,7 +1557,7 @@ describe('IgxSimpleCombo', () => {
             expect(spy).toHaveBeenCalledTimes(1);
         }));
 
-        it('should emit selectionChanging event when input value changes and input loses focus', () => {
+        it('should emit selectionChanging event when input value changes', () => {
             spyOn(combo.selectionChanging, 'emit').and.callThrough();
             fixture.detectChanges();
 
@@ -1591,7 +1591,7 @@ describe('IgxSimpleCombo', () => {
                 },
                 newSelection: undefined,
                 owner: combo,
-                displayText: "",
+                displayText: "z",
                 cancel: false
             });
         });

projects/igniteui-angular/src/lib/simple-combo/simple-combo.component.ts

@@ -292,7 +292,19 @@ export class IgxSimpleComboComponent extends IgxComboBaseDirective implements Co
             this.filterValue = '';
         }
         if (super.selection.length) {
-            this.clearSelection();
+            const args: ISimpleComboSelectionChangingEventArgs = {
+                newValue: undefined,
+                oldValue: this.selectedItem,
+                newSelection: undefined,
+                oldSelection: this.selection,
+                displayText: typeof event === 'string' ? event : event?.target?.value,
+                owner: this,
+                cancel: false
+            };
+            this.selectionChanging.emit(args);
+            if (!args.cancel) {
+                this.selectionService.select_items(this.id, [], true);
+            }
         }
         // when filtering the focused item should be the first item or the currently selected item
         if (!this.dropdown.focusedItem || this.dropdown.focusedItem.id !== this.dropdown.items[0].id) {