14Styles

Many objects in an office document have formatting properties. A formatting property influences the visual representation of an object but it does not contribute to the content or structure of the document. Examples of formatting properties are:

�        Font family

�        Font size

�        Font color

�        Page margins

In the OpenDocument format, formatting properties are only stored within styles. This differs to the user interface of typical office applications, where formatting properties may be assigned to an object directly, or indirectly by applying a style to the object. Assigning formatting properties to an object directly has the same effect as assigning an unnamed style with the same properties to that object. Therefore, user interface styles remain unchanged conceptually in the OpenDocument file format, while formatting properties assigned directly to an object are assumed to be unnamed styles. In order to use unnamed styles, they are assigned a name and therefore become automatic styles.

There are two main reasons for using styles to store formatting properties:

1.   The format and layout of the document get separated from the document content.

2.   If two or more objects have the same formatting properties and styles assigned, the formatting properties that are assigned to the objects directly can be represented by a single automatic style for all objects. This saves disk space and allows styles to integrate seamlessly into the overall document style.

Within this chapter, the various style types are explained.