Provides a content formatter add-on for an ITextViewer.
A content formatter changes the formatting of a document region while
preserving and correctly updating the positions of the document.
Package Specification
IContentFormatter defines the concept of a text formatter. It
collaborates with content type specific formatting stratgies (IFormattingStrategy)
which for a given document region format the subregion with the matching
content type. The package contains a default implementation of IContentFormatter
(ContentFormatter).
Additionally, an implementation of IContentFormatter is provided
for text edit based formatting strategies. This implementation only accepts formatting strategies
implementing the extension interface IFormattingStrategyExtension. These formatting strategies are required to
handle the position updating of the document. To facilitate the work with these text edit based formatting strategies, a default implementation called ContextBasedFormattingStrategy
is provided. Formatting strategies inheriting from this class are text edit based and behave context dependent. Depending on the formatting context that is passed
to the content formatter, different preferences and modes can be used to format different parts of a document.
To set up a proper working text edit based content formatter, the following steps are needed:
- Create an instance of IFormattingContext. The default implementation FormattingContext already
provides support for the conversion of preferences from a preference store to a map and vice versa. The method getPreferenceKeys
usually has to be overridden to return the appropriate keys of the preferences used during the formatting process. Then register a map of preferences
with the formatting context by calling setProperty(String, Object) with the property identifier FormattingContextProperties.CONTEXT_PREFERENCES.
- Create an instance of the text edit based content formatter class MultiPassContentFormatter. The document partitioning and its associated
default content type have to be passed to the constructor. This information is needed since the content formatter is able to format documents
according to arbitrary partitionings and default content types.
- Register the formatting strategies for the content types that have to be formatted. If a formatting strategy is
registered as master strategy, it is automatically associated with the default content type of the specified partitioning.
If the formatting strategy is registered as slave strategy, it is associated with the indicated content type during the registration.
Note that the master strategy can also be registered as a slave strategy for a content type other than the default content type.
- Specify the proper formatting mode:
- For whole document formatting set the property CONTEXT_DOCUMENT of the created formatting context to true. This is
equivalent to setting
CONTEXT_REGION
with a region spanning the whole document.
- For multiple region formatting set the property
CONTEXT_REGION
of the formatting context. Note that
the content formatter automatically aligns the region to a block selected region, and if the region spans
multiple partitions, it also completes eventual partitions covered only partially by the region.
- For explicit formatting of a partition with the formatting strategy registered for a certain content type use the
property CONTEXT_PARTITION. Note that the region denoted by this property must correspond to a partition relative
to the specified partitioning in the document to be formatted. The content type of this property overrides the content type of the partition
in the document.
- Call the method MultiPassContentFormatter#format(IDocument, IFormattingContext) with the created formatting context
and the document to be formatted.