Move Elements Within Diagrams

Any one of the following options enables you to move an element within a diagram. Select an element or group of elements in the diagram view, then:

  • Use the mouse to drag the element to the required position (the cursor switches to the four-arrow icon as shown below)


  • Hold down [Shift] and use the arrow keys to move the element by increments to the required position
  • Use the Left, Right, Up and Down options in the Element | Move submenu
  • Align multiple elements using the Element | Alignment submenu, the Alignment options in the right-click context menu, or the Alignment buttons on the Diagram toolbar.


Confirm Possible Parent Elements

As you organize the elements within a diagram, you can drag any element over another and, provided the dragged element is within and on top of the possible parent, it is always encapsulated by the lower element and moved within the lower element. However, the lower element might not be a valid parent.

You can confirm that a possible parent element is able to accept a selected child element. When you drag the child element over the potential parent, the target element border changes to a dashed line if it can accept the selected element as a child. If the border does not change, the selected element cannot be a child to the target element.



  • The Support for Composite Objects checkbox must be selected on the Objects page of the Options dialog (select the Tools | Options | Objects option). If this option is not selected, the dashed border does not show and the child element cannot be embedded on the parent in the diagram.
  • Both elements must already exist on the diagram; an element border does not change if you drag a potential child element over it from the Toolbox or Project Browser.
  • The child element must have equal or higher z-order placement than the parent; that is, the parent element must be level with or behind the child.
  • The child element borders must be completely within the parent element borders.

For example, if you drag a Signal over a Class, the Class border changes; a Class element can be a parent to a Signal. If you drag a Class element over a Signal element, the Signal border does not change. A Signal cannot be a parent to a Class.

When you embed a child element on its parent, the child element becomes part of the parent element hierarchy in the Project Browser. Similarly, if you drag the child element out of the parent, the child element becomes independent and is no longer embedded in the parent element hierarchy.