Grouping Objects
Grouping is a fundamentally useful, natural feeling and rather common mechanism. Design Intuition, by the way, kicks it up a notch.
How do I create a Group?
Select the objects you wish to group BY CLICKING ON EACH ONE WHILE HOLDING DOWN THE SHIFT KEY, OR BY CLICK-DRAGGING A SELECTION RECTANGLE AROUND THE DESIRED OBJECTS. Open the Layout Inspector. You'll see that the Group button is enabled. Click it to group the objects you selected. A new object appears that encloses your selected objects. You can also use the contextual popup menu, which appears when you right-click in the design window (or if your mouse only has one button, hold the Control key down when you click).
This new object has dimensions, and in many ways, is just lke any other object. It does, however, have certain characteristics that make it more powerful.
How is a Group different from other objects?
When you alter a group's size, the size of the objects contained inside it scale accordingly. The attributes of a group's objects are resolved in context, meaning that their values change in relation to the dimensions of the group object.
Even though objects may be members of a group, you can still control the values and visibility of their dimensions independently. Of course, if you change the dimension of an object within a group such that it grows outside the group's boundaries, the group object dimensions will change to accommodate the change in the member object.
Smart Objects are Groups that can't be ungrouped
A Smart Object is a group, with one important difference: it cannot be ungrouped. This is because Smart Objects pretty much always contain authored attributes, added for a variety of reasons. Ungrouping the Smart Object would discard these extra attributes, which would cause the components of the (former) Smart Object to behave very badly.
How do I alter a Smart Object?
One reason you might want to alter a Smart Object is to add or remove an object.
To do this: open the Smart Object's file by triple-clicking on it in the Library (alternatively, after dragging a Smart Object into a design, it will be listed in the File:Open Recent hierarchal menu item -- you can select it there to open it). Add or remove the object. Then save the file using the File:Save In Library menu item, using a new file name.
Another limitation
You cannot group an object from one group with an object from another. Any particular object must be contained by exactly one group.
