48 Specifiers

A specifier is an object used to keep track of a property whose value should vary according to display context, a window, a frame, or device. The value of many built-in properties, such as the font, foreground, background, and such properties of a face and variables such as modeline-shadow-thickness and top-toolbar-height, is actually a specifier object. The specifier object, in turn, is “instanced” in a particular situation to yield the real value of the property in the current context.

• Introduction to Specifiers: Specifiers provide a clean way for display and other properties to vary (under user control) in a wide variety of contexts.
• Simple Specifier Usage: Getting started with specifiers.
• Specifiers In-Depth: Gory details about specifier innards.
• Specifier Instancing: Instancing means obtaining the ``value'' of a specifier in a particular context.
• Specifier Types: Specifiers come in different flavors.
• Adding Specifications: Specifications control a specifier's ``value'' by giving conditions under which a particular value is valid.
• Retrieving Specifications: Querying a specifier's specifications.
• Specifier Tag Functions: Working with specifier tags.
• Specifier Instancing Functions Functions to instance a specifier.
• Specifier Examples: Making all this stuff clearer.
• Creating Specifiers: Creating specifiers for your own use.
• Specifier Validation Functions Validating the components of a specifier.
• Other Specification Functions Other ways of working with specifications.