[performance] faster Tree expand - eclipse.platform.swt#901

move setExpanded() after expanding the children

eclipse-platform/eclipse.platform.swt#901

Author: EcljpseB0T

bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java

@@ -1836,9 +1836,6 @@ protected void internalExpandToLevel(Widget widget, int level) {
 				return;
 			}
 			createChildren(widget, false);
-			if (widget instanceof Item) {
-				setExpanded((Item) widget, true);
-			}
 			if (level == ALL_LEVELS || level > 1) {
 				Item[] children = getChildren(widget);
 				if (children != null) {
@@ -1849,6 +1846,9 @@ protected void internalExpandToLevel(Widget widget, int level) {
 					}
 				}
 			}
+			if (widget instanceof Item) {
+				setExpanded((Item) widget, true);
+			}
 		}
 	}