Package org.eclipse.core.runtime.content

Interface IContentDescription

public interface IContentDescription
A content description object contains information about the nature of arbitrary data.

A content description object will always include the content type for the examined contents, and may also include information on:

  1. charset;
  2. byte order mark;
  3. other custom properties provided by third-party plug-ins.

Content describers provided by plug-ins will fill in most of the properties in a content description object, except for the content type, what is done by the platform. After a content description is filled in by a content interpreter, it is marked as immutable by the platform, so calling any of the mutator methods defined in this interface will cause an IllegalStateException to be thrown.

Default values for properties can be contributed by plug-ins as part of the content type definition markup.

This interface is not intended to be implemented by clients.

Since:
3.0
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final QualifiedName[]
    ALL
    Options constant meaning that all properties should be described.
    static final byte[]
    BOM_UTF_16BE
    Constant that identifies the Byte-Order-Mark for contents encoded with the UTF-16 Big Endian character encoding scheme.
    static final byte[]
    BOM_UTF_16LE
    Constant that identifies the Byte-Order-Mark for contents encoded with the UTF-16 Little Endian character encoding scheme.
    static final byte[]
    BOM_UTF_8
    Constant that identifies the Byte-Order-Mark for contents encoded with the UTF-8 character encoding scheme.
    static final QualifiedName
    BYTE_ORDER_MARK
    Key for the "byte order mark" property.
    static final QualifiedName
    CHARSET
    Key for the "charset" property.

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    getCharset()
    Returns the charset name to be used when reading the contents described by this object.
    IContentType
    getContentType()
    Returns the content type detected.
    Object
    getProperty(QualifiedName key)
    Returns the value of custom property set by the content describer, or the default value for the property, if one has been defined.
    boolean
    isRequested(QualifiedName key)
    Returns whether the given property is requested to be described.
    void
    setProperty(QualifiedName key, Object value)
    Sets the given property to the given value.

  • Field Details

    • CHARSET

      static final QualifiedName CHARSET
      Key for the "charset" property.

    • BYTE_ORDER_MARK

      static final QualifiedName BYTE_ORDER_MARK
      Key for the "byte order mark" property. This property is only meaningful when describing byte streams.

    • ALL

      static final QualifiedName[] ALL
      Options constant meaning that all properties should be described.

    • BOM_UTF_8

      static final byte[] BOM_UTF_8
      Constant that identifies the Byte-Order-Mark for contents encoded with the UTF-8 character encoding scheme.

    • BOM_UTF_16BE

      static final byte[] BOM_UTF_16BE
      Constant that identifies the Byte-Order-Mark for contents encoded with the UTF-16 Big Endian character encoding scheme.

    • BOM_UTF_16LE

      static final byte[] BOM_UTF_16LE
      Constant that identifies the Byte-Order-Mark for contents encoded with the UTF-16 Little Endian character encoding scheme.

  • Method Details

    • isRequested

      boolean isRequested(QualifiedName key)
      Returns whether the given property is requested to be described. This method is intended to allow content describers to determine which properties should be described.
      Parameters:
      key - a key for the property to be verified
      Returns:
      true if the property is to be described, false otherwise

    • getCharset

      String getCharset()
      Returns the charset name to be used when reading the contents described by this object.

      If a Unicode byte order mark has been found (the BYTE_ORDER_MARK property has been set), a corresponding charset name will be returned (e.g. "UTF-8", "UTF-16"). Otherwise, the value of the CHARSET property will be returned.

      Returns:
      a charset name, or null

    • getContentType

      IContentType getContentType()
      Returns the content type detected. Returns null if the content type could not be determined.
      Returns:
      the corresponding content type, or null

    • getProperty

      Object getProperty(QualifiedName key)
      Returns the value of custom property set by the content describer, or the default value for the property, if one has been defined.

      The qualifier part of the property name must be the unique identifier of the declaring plug-in (e.g. "com.example.plugin").

      Parameters:
      key - the property key
      Returns:
      the property value, or null, if the property is not found

    • setProperty

      void setProperty(QualifiedName key, Object value)
      Sets the given property to the given value.

      The qualifier part of the property name must be the unique identifier of the declaring plug-in (e.g. "com.example.plugin").

      This method should not be called by clients other than content describers. An attempt to set a property from other contexts will cause an IllegalStateException to be thrown.

      Parameters:
      key - the qualified name of the property
      value - the property value, or null, if the property is to be removed
      Throws:
      IllegalStateException - if called after this description has been filled in