The resource lookup algorithm searches a specified resource data base and returns the value for the resource binding whose resource name is the closest match to a given complete resource name and class. The intent of the lookup algorithm is to formalize an intuitive notion of the closest match.
Precedence is given to a match which begins higher in the parent-child contact hierarchy. This allows a resource binding with a partial name to define a resource value shared by all members of a window subtree. For example, suppose the resource database contained the following resource bindings:
| Resource Name | Resource Value |
|---|---|
(mail * background)
| 'red
|
(* reply background)
| 'blue
|
Suppose an application program searched by using the following complete resource name:
(mail screen-1 reply background)
then the closest matching value returned would be 'red.
Precedence is given to the more specific match. A name match is more specific than a class match. Either a name or class match is more specific than a wildcard match. For example, suppose the resource database contained the following resource bindings:
| Resource Name | Resource Value |
|---|---|
(mail * background)
| 'red
|
(mail * fill)
| 'blue
|
Suppose an application program searched by using the following complete resource name and complete resource class:
(mail screen-1 reply background)
(application root button fill)
then the closest matching value returned would be 'red
. However, suppose the resource database contained the following
resource bindings:
| Resource Name | Resource Value |
|---|---|
(mail * background)
| 'red
|
(mail * button background)
| 'blue
|
then the closest matching value returned would be 'blue
.