AutoCAD 2008 User's
Guide > Create and Modify
Objects > Create and Use
Blocks (Symbols) > Add Dynamic Behavior
to Blocks > Add Dynamic Elements
to Blocks > Use Actions with
Dynamic Blocks >
Use a Stretch Action in a Dynamic Block
In a dynamic block reference, a stretch action causes objects to move and stretch a specified distance in a specified location.
In a dynamic block definition, you can associate a stretch action with any of the following parameters:
After associating a stretch action with a parameter, you specify a stretch frame for the stretch action. You then select the objects for the stretch action's selection set. The stretch frame determines how the objects within or crossed by the frame are edited in the block reference. The behavior is similar to specifying a crossing selection window with the STRETCH command.
In the following example, the stretch frame is indicated by the dashed line, and the selection set has a haloed effect. The top circle, while enclosed by the stretch frame, is not included in the selection set, so the top circle won't move. The bottom circle is entirely enclosed in the stretch frame and included in the selection set, so the bottom circle will move. The rectangle is crossed by the stretch frame and included in the selection set, so the rectangle will stretch.
In a dynamic block reference, if you change the value of a parameter associated with a stretch action through a grip or the Properties palette, it may affect the key point on the parameter associated with the stretch action. If the key point is affected, the geometry in the stretch action's selection set will move.
Specify the Distance Type Property for a Stretch Action
When a stretch action is associated with an XY parameter, the stretch action has an override property called Distance Type. This property specifies whether the distance applied to the move is the parameter's X value, Y value, or X an Y coordinate value from the parameter's base point.
For example, you specify X Distance as the Distance Type for a stretch action in a dynamic block definition. In a drawing, when you try to edit the block reference by dragging the key point only along the Y axis, the associated geometry does not move because you've added the Distance Type override allowing only a move on the X axis.
