Inside Macintosh: QuickDraw GX Objects /

Chapter 2 - Shape Objects / About Shape Objects

Default Shapes

When you first create a shape of a given shape type, QuickDraw GX provides an initial value for each property; those initial values define the starting characteristics of the shape. The shape QuickDraw GX creates is a copy of the default shape for that shape type (such as a line, rectangle, or glyph). There is one default shape for each shape type. These are the default properties:

• No geometry. All applicable values and counts are set to 0.
• A shape fill that depends on the shape type:
  • The default empty shape has no fill.
  • The default point, line, and curve shapes have open-frame fill.
  • The default rectangle, polygon, path, full, bitmap, and picture shapes have even-odd fill.
  • The default text, glyph, and layout shapes have winding fill.

• A nil style reference, which is equivalent to a reference to the default style object.
  See the chapter "Style Objects" in this book for a description of the default style object. Graphic shapes all share a single common default style; each different type of typographic shape (text, glyph, and layout) uses its own default style.
• A nil ink reference, which is equivalent to a reference to the default ink object. See the chapter "Ink Objects" in this book for a description of the default ink object. All shapes except bitmaps share a common default ink object.
• A nil transform reference, which is equivalent to a reference to the default transform object. See the chapter "Transform Objects" in this book for a description of the default transform object. All shapes share a common default transform, with the exception of the picture shape, which has its own default transform.
• No attributes set (except for bitmap, picture, and layout shapes, which have the gxMapTransformShape attribute set).
• An owner count of 1.
• An empty tag list.

After creating the shape, you can change its characteristics to customize it; for example, you can give it a specific geometry. Or, if you want to create several shapes with the same customized characteristics, you can change the default shape itself to suit your purposes. If you do this, each shape that you create thereafter has the customized characteristics. See the section "Getting and Setting the Default Shape Objects" beginning on page 2-23, and the section "Resetting a Shape Object's Properties to Their Default Values" beginning on page 2-31, for more information.