A LevelCache provides access to level definitions. More...

Classes
struct	LevelDefinitionStyleBase
	Base class for style that is used by a level. More...

struct	LevelDefinitionColor
	Represents a color used by a level. More...

struct	LevelDefinitionLineStyle
	Represents a line style used by a level. More...

struct	LevelDefinitionIdBase
	Represents a style used by a level. More...

struct	LevelDefinitionMaterial
	Represents a material used by a level. More...

struct	LevelDefinitionPlotStyle
	Represents a PlotStyleID used by a level. More...

struct	LevelHandle
	Read-only access to a level definition. More...

struct	EditLevelHandle
	Read-write access to a level definition. More...

struct	LevelCache
	A level cache holds level definitions. More...

struct	PersistentLevelCache
	Abstract base class for persistent LevelCaches that support Write. More...

struct	FileLevelCache
	A FileLevelCache contains the level definitions for a file. More...

struct	DgnAttachmentLevelCache
	Provides access to levels used by elements in a referenced model. More...

struct	LevelUtils

Macros
#define	LEVEL_NAME_DISPLAY_FORMAT_STRING L"N"
	Level Display Name Format Defines. More...

#define	LEVEL_CODE_DISPLAY_FORMAT_STRING L"C"

#define	LEVEL_DESCRIPTION_DISPLAY_FORMAT_STRING L"D"

#define	LEVEL_NAME_DISPLAY_FORMAT L'N'
	Level Display Name Format Values. More...

#define	LEVEL_CODE_DISPLAY_FORMAT L'C'

#define	LEVEL_DESCRIPTION_DISPLAY_FORMAT L'D'

#define	LEVEL_ID_DISPLAY_FORMAT L'I'

Typedefs
typedef bset< byte >::iterator	T_LevelIdToDefinitionMapIterator

typedef RefCountedPtr < FileLevelCache >	FileLevelCachePtr
	Smart pointer wrapper for FileLevelCache. More...

typedef bvector < FileLevelCachePtr >	T_LevelCachePtrVector

Enumerations
enum	LevelCacheErrorCode { None = BSISUCCESS, Error = BSIERROR, TableIsReadOnly = 2, LevelIsReadOnly = 4, LevelNameIsNull = 7, LevelNameIsInvalid = 8, LevelNameIsDuplicate = 9, LevelIsUsed = 11, LevelCodeIsDuplicate = 23, LevelIdIsDuplicate = 46, LibraryLevelNotEditable = 49, CannotFindLevel = 56, LevelTableIntegrityFailure = 59, DgnAttachmentNotResolved = 60, LevelNullId = 92, NoLevels = 1000, AttachmentSharesFileLevelCache = 1001 }
	Error codes returned by LevelCache function. More...

enum	EditPropertiesChangeWrite { Always = 0, IfNewChangesOnly = 1, Never = 2 }
	Controls Change writing for LevelCache EditProperties method. More...

Detailed Description

A LevelCache provides access to level definitions.

DgnFile::GetLevelCacheR accesses the level definitions of a file. Levels are stored in a level table. A DgnFile has a FileLevelCache to provide access to the information in its level table.

FileLevelCache::GetLevel accesses the definition of a level. Every element in a file is associated with a level. The Elm_hdr.level member of an element is the internal LevelId of the level in the file that contains the element. (Example)

LevelHandle accesses the attributes of a level. Level attributes tell you if elements on the level should be displayed, what the element by-level symbology is for that level, and so on. (Example)

FileLevelCache::CreateLevel allows you to create a new level. (Example)

EditLevelHandle allows you to modify the attributes of an existing level. You can only get a EditLevelHandle from a FileLevelCache to which you have read-write access.

DgnAttachment::GetAttachmentLevelCache accesses level definition overrides for a reference attachment. When one model is referenced into another, the elements in the referenced model refer to levels in the file that contains that referenced model. A reference attachment can override the definition of some or all of the referenced levels. A DgnAttachmentLevelCache provides access to both levels that were overridden by the attachment and levels that are defined by the referenced file.

FileLevelCache and DgnAttachmentLevelCache are both derived from LevelCache. LevelCache defines the basic level look-up and iteration functions that are common to both kinds of level cache. Only FileLevelCache provides functions to create or remove levels or to modify level attributes.

Collections and Iterators

See Iterate levels in a level cache

Example Code

See LevelCache Code Samples

A LevelCache collaborates with DgnFile and DgnModel to keep track of which levels are actually used by elements. A level is used if:

A graphic element (including element of a shared cell definition) is on the level,
Individual segments of a Multi-line element are on the level,
Individual segments of a Multi-line Style are on the level,
A reference attachment is on the level,
A dimension style has its "Dimension Line Level Override" on the level.

Macro Definition Documentation

#define LEVEL_CODE_DISPLAY_FORMAT L'C'

#define LEVEL_CODE_DISPLAY_FORMAT_STRING L"C"

#define LEVEL_DESCRIPTION_DISPLAY_FORMAT L'D'

#define LEVEL_DESCRIPTION_DISPLAY_FORMAT_STRING L"D"

#define LEVEL_ID_DISPLAY_FORMAT L'I'

#define LEVEL_NAME_DISPLAY_FORMAT L'N'

Level Display Name Format Values.

#define LEVEL_NAME_DISPLAY_FORMAT_STRING L"N"

Level Display Name Format Defines.

Typedef Documentation

typedef RefCountedPtr<FileLevelCache> FileLevelCachePtr

Smart pointer wrapper for FileLevelCache.

typedef bvector<FileLevelCachePtr> T_LevelCachePtrVector

typedef bset<byte>::iterator T_LevelIdToDefinitionMapIterator

Enumeration Type Documentation

enum EditPropertiesChangeWrite

strong

Controls Change writing for LevelCache EditProperties method.

Enumerator
Always	Write changes to the file regardless of whether there were pre-existing changes.
IfNewChangesOnly	Write changes to the file only if there were previously no unsaved changes.
Never	Don't write changes to the file.

enum LevelCacheErrorCode

strong

Error codes returned by LevelCache function.

Enumerator
None	Success.
Error	An unspecified error.
TableIsReadOnly	The level cache is marked as read-only.
LevelIsReadOnly	The level is read-only.
LevelNameIsNull	The level name cannot be NULL.
LevelNameIsInvalid	The name contains invalid characters. See LevelUtils::ContainsInvalidCharacters.
LevelNameIsDuplicate	The name is already used by a level in this cache.
LevelIsUsed	The level is in use.
LevelCodeIsDuplicate	The LevelCode is already used by a level in this cache.
LevelIdIsDuplicate	The LevelId is already used by a level in this cache.
LibraryLevelNotEditable	The level is in a library, and cannot be edited.
CannotFindLevel	Cannot find level.
LevelTableIntegrityFailure	Integrity check failure.
DgnAttachmentNotResolved	Attempt to query a FileLevelCache for a DgnAttachment that is not resolved (not found or not read).
LevelNullId	A level element with levelId - LEVEL_NULL_ID is in the level table element descriptor and that level definition is ignored.
NoLevels	There are no levels in the LevelCache.
AttachmentSharesFileLevelCache	An attempt was made to Write the LevelCache associated with a DgnAttachment that shares the FileLevelCache for the root model.

Classes

Macros