|
Eclipse Platform Release 3.1 |
|||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectorg.eclipse.core.runtime.content.BinarySignatureDescriber
A content describer for binary formats that present some simple signature at a known, fixed offset.
This executable extension supports three parameters:
"signature", "offset" and "required", the first one being mandatory.
If the
":-"
method is used, then the value is treated as the
"signature".
The "signature" parameter is a sequence of hex codes, one for each byte in the signature. For example, "CA FE BA BE" would be a signature for Java class files.
The "offset" parameter is an integer indicating the offset where the signature's first byte is found.
The "required" parameter is a boolean (default is " true") indicating whether the absence of a signature should deem the contents validity status as IContentDescriber.INVALID or IContentDescriber.INDETERMINATE.
This class is not intended to be subclassed or instantiated by clients,
only to be referenced by the "describer" configuration element in
extensions to the org.eclipse.core.runtime.contentTypes
extension point.
Field Summary |
---|
Fields inherited from interface org.eclipse.core.runtime.content.IContentDescriber |
---|
INDETERMINATE, INVALID, VALID |
Constructor Summary | |
---|---|
BinarySignatureDescriber()
|
Method Summary | |
---|---|
int |
describe(InputStream contents,
IContentDescription description)
Tries to fill a description for the given contents. |
QualifiedName[] |
getSupportedOptions()
Returns the properties supported by this describer. |
void |
setInitializationData(IConfigurationElement config,
String propertyName,
Object data)
This method is called by the implementation of the method IConfigurationElement.createExecutableExtension
on a newly constructed extension, passing it its relevant configuration
information. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
public BinarySignatureDescriber()
Method Detail |
public int describe(InputStream contents, IContentDescription description) throws IOException
IContentDescriber
int
indicating whether the given stream of
bytes represents a valid sample for its corresponding content type.
If no content description is provided, this method should perform
content type validation.
The input stream must be kept open, and any IOExceptions while reading the stream should flow to the caller.
describe
in interface IContentDescriber
contents
- the contents to be examineddescription
- a description to be filled in, or null
if
only content type validation is to be performed
VALID
INVALID
INDETERMINATE
IOException
- if an I/O error occursIContentDescription
,
IContentDescriber.VALID
,
IContentDescriber.INVALID
,
IContentDescriber.INDETERMINATE
public QualifiedName[] getSupportedOptions()
IContentDescriber
getSupportedOptions
in interface IContentDescriber
IContentDescriber.describe(java.io.InputStream, org.eclipse.core.runtime.content.IContentDescription)
public void setInitializationData(IConfigurationElement config, String propertyName, Object data) throws CoreException
IExecutableExtension
IConfigurationElement.createExecutableExtension
on a newly constructed extension, passing it its relevant configuration
information. Most executable extensions only make use of the first
two call arguments.
Regular executable extensions specify their Java implementation class name as an attribute of the configuration element for the extension. For example
<action run="com.example.BaseAction"/>In the above example, this method would be called with a reference to the
<action>
element (first argument), and
"run"
as the name of the attribute that defined
this executable extension (second argument).
The last parameter is for the specific use of extension adapters and is typically not used by regular executable extensions.
There are two supported ways of associating additional adapter-specific data with the configuration in a way that is transparent to the extension point implementor:
(1) by specifying adapter data as part of the implementation
class attribute value. The Java class name can be followed
by a ":" separator, followed by any adapter data in string
form. For example, if the extension point specifies an attribute
"run"
to contain the name of the extension implementation,
an adapter can be configured as
<action run="com.example.ExternalAdapter:./cmds/util.exe -opt 3"/>
(2) by converting the attribute used to specify the executable extension to a child element of the original configuration element, and specifying the adapter data in the form of xml markup. Using this form, the example above would become
<action> <run class="com.xyz.ExternalAdapter"> <parameter name="exec" value="./cmds/util.exe"/> <parameter name="opt" value="3"/> </run > </action>
Form (2) will typically only be used for extension points that anticipate the majority of extensions configured into it will in fact be in the form of adapters.
In either case, the specified adapter class is instantiated using its 0-argument public constructor. The adapter data is passed as the last argument of this method. The data argument is defined as Object. It can have the following values:
null
, if no adapter data was suppliedString
Hashtable
containing the actual
parameter names and values (both String
s)
setInitializationData
in interface IExecutableExtension
config
- the configuration element used to trigger this execution.
It can be queried by the executable extension for specific
configuration propertiespropertyName
- the name of an attribute of the configuration element
used on the createExecutableExtension(String)
call. This
argument can be used in the cases where a single configuration element
is used to define multiple executable extensions.data
- adapter data in the form of a String
,
a Hashtable
, or null
.
CoreException
- if error(s) detected during initialization processingIConfigurationElement.createExecutableExtension(String)
|
Eclipse Platform Release 3.1 |
|||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
Guidelines for using Eclipse APIs.
Copyright (c) IBM Corp. and others 2000, 2005. All rights reserved.