| org.netbeans.spi.queries |
|
Permits query implementations to be registered.
A query is implemented by creating an instance of its implementation
interface and registering it to default lookup. Queriers should normally not
need to see these interfaces directly since there is a matching utility class
which aggregates and prioritizes the results automatically. The utility class in
the API can also insulate clients from changes in the SPI.
It is expected that only a small number of implementations of a given query
interface are actually registered at once, so the critical path for answering it
should be relatively short. Where a large number of modules are
able to supply information for a query following a common structure, and it is
possible to quickly determine which one would know the answer, a multiplexing
implementation of the query interface may be registered which can reroute
requests directly to a proper implementation of some secondary interface (again
registered in default lookup). This technique permits the SPI to be very
flexible while keeping a typical API method call fast. For an example, note that
only one instance of
ProjectFactory
is
necessary to support all Ant-based projects: each project type is defined using
an
AntBasedProjectType,
and the
singleton multiplexer delegates appropriately based on the project type ID found
in nbproject/project.xml in the project directory. Therefore adding
a new Ant-based project type should not increase the time required to recognize a
particular Ant-based project on disk.
|
| Java Source File Name | Type | Comment |
| CollocationQueryImplementation.java | Interface | A query which should typically be provided by a VCS to give information
about whether some files can be considered part of one logical directory tree.
This should be treated as a heuristic, useful when deciding whether to use
absolute or relative links between path locations.
The file names might refer to nonexistent files. |
| FileBuiltQueryImplementation.java | Interface | Test whether a file can be considered to be built (up to date). |
| FileEncodingQueryImplementation.java | Class | Information about encoding of a file.
A default implementations are registered by the
org.netbeans.modules.projectapi module which firstly looks up the
implementation of this interface in the DataObject lookup. |
| SharabilityQueryImplementation.java | Interface | Determine whether files should be shared (for example in a VCS) or are intended
to be unshared.
Could be implemented e.g. |
| VisibilityQueryImplementation.java | Interface | Determine whether files should be hidden in views presented to the user.
Global lookup is used to find all instances of VisibilityQueryImplementation.
Threading note: implementors should avoid acquiring locks that might be held
by other threads. |