Carbon (API) - Architecture

Architecture

Carbon descends from the Toolbox, and as such, is composed of "Managers". Each Manager is a functionally related API, defining sets of data structures and functions to manipulate them. Managers are often interdependent or layered.

Newer parts of Carbon tend to be much more object-oriented in their conception, most of them based on Core Foundation. Some Managers, such as the HIView Manager (a superset of the Control Manager), are implemented in C++, but Carbon remains a C API.

Some examples of Carbon Managers:

• File Manager — manages access to the file system, opening closing, reading and writing files.
• Resource Manager — manages access to resources, which are predefined chunks of data a program may require. Calls File Manager to read and write resources from disk files. Examples of resources include icons, sounds, images, templates for widgets, etc.
• Font Manager — manages fonts. Deprecated (as part of QuickDraw) since Mac OS X v10.4, in favor of Apple Type Services (ATS).
• QuickDraw — 2D graphics primitives. Deprecated since Mac OS X v10.4, in favor of Quartz 2D.
• Carbon Event Manager — converts user and system activity into events that code can recognise and respond to.
• HIObject — a completely new object-oriented API which brings to Carbon an OO model for building GUIs. This is available in Mac OS X v10.2 or later, and gives Carbon programmers some of the tools that Cocoa developers have long been familiar with. Starting with Mac OS X v10.2, HIObject is the base class for all GUI elements in Carbon. HIView is supported by Interface Builder, part of Apple's developer tools. Traditionally GUI architectures of this sort have been left to third-party application frameworks to provide. Starting with Mac OS X v10.4, HIObjects are NSObjects and inherit the ability to be serialized into data streams for transport or saving to disk.
• HITheme — uses QuickDraw and Quartz to render graphical user interface (GUI) elements to the screen. HITheme was introduced in Mac OS X v10.3, and Appearance Manager is a compatibility layer on top of HITheme since that version.
• HIView Manager — manages creation, drawing, hit-testing, and manipulation of controls. Since Mac OS X v10.2, all controls are HIViews. In Mac OS X v10.4, the Control Manager was renamed HIView Manager.
• Window Manager — manages creation, positioning, updating, and manipulation of windows. Since Mac OS X v10.2, windows have a root HIView.
• Menu Manager — manages creation, selection, and manipulation of menus. Since Mac OS X v10.2, menus are HIObjects. Since Mac OS X v10.3, menu content may be drawn using HIViews, and all standard menus use HIViews to draw.