LibreOffice » sw
Writer application code.
Exact history was lost before Sept. 18th, 2000, but old source code comments show that Writer core dates back until at least November 1990.
There is a good overview documentation of basic architecture of Writer core in the OOo wiki:
Writer specific WhichIds are defined in sw/inc/hintids.hxx.
The details below are mainly about details missing from the Wiki pages.
The central class for a document is SwDoc, which represents a document.
A lot of the functionality is split out into separate Manager classes, each of which implements some IDocument* interface; there are SwDoc::getIDocument*() methods to retrieve the managers.
However there are still too many members and methods in this class, many of which could be moved to some Manager or other...
Basically a (fancy) array of SwNode pointers. There are special subclasses of SwNode (SwStartNode and SwEndNode) which are used to encode a nested tree structure into the flat array; the range of nodes from SwStartNode to its corresponding SwEndNode is sometimes called a "section" (but is not necessarily what the high-level document model calls a "Section"; that is just one of the possibilities).
The SwNodes contains the following top-level sections:
1. Empty 2. Footnote content 3. Frame / Header / Footer content 4. Deleted Change Tracking content 5. Body content
The Undo/Redo information is stored in a sw::UndoManager member of SwDoc, which implements the IDocumentUndoRedo interface. Its members include a SwNodes array containing the document content that is currently not in the actual document but required for Undo/Redo, and a stack of SwUndo actions, each of which represents one user-visible Undo/Redo step.
There are also ListActions which internally contain several individual SwUndo actions; these are created by the StartUndo/EndUndo wrapper methods.
The sub-structure of paragraphs is stored in the SwpHintsArray member SwTextNode::m_pSwpHints. There is a base class SwTextAttr with numerous subclasses; the SwTextAttr has a start and end index and a SfxPoolItem to store the actual formatting attribute.
There are several sub-categories of SwTextAttr:
- formatting attributes: Character Styles (SwTextCharFormat, RES_TXTATR_CHARFMT) and Automatic Styles (no special class, RES_TXTATR_AUTOFMT): these are handled by SwpHintsArray::BuildPortions and MergePortions, which create non-overlapping portions of formatting attributes.
- nesting attributes: Hyperlinks (SwTextINetFormat, RES_TXTATR_INETFMT), Ruby (SwTextRuby, RES_TXTATR_CJK_RUBY) and Meta/MetaField (SwTextMeta, RES_TXTATR_META/RES_TXTATR_METAFIELD): these maintain a properly nested tree structure. The Meta/Metafield are "special" because they have both start/end and a dummy character at the start.
- misc. attributes: Reference Marks, ToX Marks
- attributes without end: Fields, Footnotes, Flys (AS_CHAR) These all have a corresponding dummy character in the paragraph text, which is a placeholder for the "expansion" of the attribute, e.g. field content.
There are multiple model classes involved for fields:
- enum SwFieldIds enumerates the different types of fields. - SwFieldType contains some shared stuff for all fields of a type. There are many subclasses of SwFieldType, one for each different type of field. For most types of fields there is one shared instance of this per type, which is created in DocumentFieldsManager::InitFieldTypes() but for some there are more than one, and they are dynamically created, see DocumentFieldsManager::InsertFieldType(). An example for the latter are variable fields (SwFieldIds::GetExp/SwFieldIds::SetExp), with one SwFieldType per variable. - SwXFieldMaster is the UNO wrapper of a field type. It is a SwClient registered at the SwFieldType. Its life-cycle is determined by UNO clients outside of sw; it will get disposed when the SwFieldType dies. - SwFormatField is the SfxPoolItem of a field. The SwFormatField is a SwClient registered at its SwFieldType. The SwFormatField owns the SwField of the field. - SwField contains the core logic of a field. The SwField is owned by the SwFormatField of the field. There are many subclasses of SwField, one for each different type of field. Note that there are not many places that can Expand the field to its correct value, since for example page number fields require a View with an up to date layout; therefore the correct expansion is cached. - SwTextField is the text attribute of a field. It owns the SwFormatField of the field (like all text attributes). - SwXTextField is the UNO wrapper object of a field. It is a SwClient registered at the SwFormatField. Its life-cycle is determined by UNO clients outside of sw; it will get disposed when the SwFormatField dies.