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iHTML Library Services

Language Modules

The iHTML library language services provide data structures and functions for managing and interacting with the system's back-end language modules.

Types

IHLanguage

Synopsis

The high-level interface to a language module.

Definition

typedef struct ih_language_rec IHLanguage;
struct ih_language_rec {

  /* The interface functions for this language.  Must always be set. */
  IHLanguageFunc* Fn;

  /* Version information */
  int Version;
  int Revision;
  int Submake;
  char* BuildDate;

  /* ASCII name of this language */
  char* Name;

  /* The total size in bytes of this language's IHLangEnv structure. */
  int LangEnvSize;
};

See Also

IHLanguageFunc, LanguageInit, Language Services.

This structure defines the entire public interface to an externally loaded language module. It is returned by the language's initialization function, and includes fields indicating the name and version of the module, as well as a pointer to the module's function table.

IHLanguageFunc

Synopsis

The functional interface to a language module.

Definition

typedef struct ih_language_func_rec {
  void              (*Term) IH_PROTO((IHLanguage* language));
  IHLangEnv*        (*AllocLangEnv)      IH_PROTO((IHLangEnv* le));
  void              (*FreeLangEnv)       IH_PROTO((IHLangEnv* le));
  int               (*ExecLangEnv)       IH_PROTO((IHLangEnv* le,
					           IHModuleInfo* main));
  void              (*StopLangEnv)       IH_PROTO((IHLangEnv* le,
					           IHModuleInfo* main));
  IHModuleInfo*     (*AllocModule)       IH_PROTO((IHModuleInfo* mi));
  void              (*FreeModule)        IH_PROTO((IHModuleInfo* mi));
  IHEmbeddedInfo*   (*AllocEmbedded)     IH_PROTO((IHEmbeddedInfo* ei));
  void              (*FreeEmbedded)      IH_PROTO((IHEmbeddedInfo* ei));
  int               (*ExecEmbedded)      IH_PROTO((IHEmbeddedInfo* ei));
  void              (*StopEmbedded)      IH_PROTO((IHEmbeddedInfo* ei));
  int               (*HandleEvent)       IH_PROTO((IHLangEnv* env,
					           IHEvent* event));
  HTMLNode          (*IHMarkup_HeadNode) IH_PROTO((IHMarkup markup));
  HTMLNode          (*IHMarkup_TailNode) IH_PROTO((IHMarkup markup));
  void              (*IHMarkup_SetHead)  IH_PROTO((IHMarkup markup,
						   HTMLNode node));
  void              (*IHMarkup_Ref)      IH_PROTO((IHMarkup markup));
  void              (*IHMarkup_Deref)    IH_PROTO((IHMarkup markup));
} IHLanguageFunc;

See Also

IHLanguage, Language Services.

This structure contains a language module's functional interface. It is composed of pointers to the various functions the module implements, used by the iHTML Library to make calls into the module.

LanguageInit

Synopsis

Language initialization function.

Definition

typedef IHLanguage* (LanguageInit) IH_PROTO((static char* browser,
                                             static char* language));

Parameters

(static char*) browser

The name of the browser executable, as it was invoked.

(static char*) language

The name of the language that is being loaded.

See Also

IHLanguage, Language Services.

This is the type of a language module's initialization function, which is called to initialize the language upon loading it, and get the language's public interface. This entry point is the only public symbol defined by a dynamically loaded module, and most be globally visible as IHTML_language, where language is the (case-sensitive!) name of the module. If that symbol is not found, the generic symbol IHTMLinterface will be tried instead.

Functions

IH_AllocWidget

Synopsis

IHWidgetObj IH_AllocWidget(IHGlobalInfo* gi, IHDocument doc, IHLangEnv* langenv, IHWidgetObj par, IHWidgetRep rep, IHMemberValue* init)

Arguments

(IHGlobalInfo*) gi

iHTML library context making widget.

(IHDocument) doc

Browser-side document that widget is associated with.

(IHLangEnv*) doc

Language context in which to allocate widget.

(IHWidgetObj) par

Widget this is a child of, or NULL if it is a top-level widget.

(IHWidgetRep) rep

Browser-side widget representation, or NULL.

(const IHMemberValue*) init

The initial values of the new widget's members. This is an array of IHMemberValue structures, which is terminated with a member of IWM_NULL_ID.

Return

(IHWidgetObj) The newly created language-side widget.

See Also

IHGlobalInfo, IHDocument, IHLangEnv, IHWidgetObj, IHWidgetRep, IHMemberValue, BR_AllocWidget()

Creates a new language widget object. Similar to BR_AllocWidget(), except that a specific IHWidgetRep can be supplied for this object to use; otherwise, it will allocate its own from the browser.

IH_CleanHTMLNode

Synopsis

void IH_CleanHTMLNode(HTMLNode node)

Arguments

(HTMLNode) node

The browser-side node to clean.

Return

nothing.

See Also

HTMLNode

Cleans any interface information that has been associated with the given HTMLNode before deallocating it. This routine must be called when freeing any HTMLNodes owned by the interface, e.g. when freeing nodes in BR_FreeMarkup().

IH_DerefMarkup

Synopsis

void IH_DerefMarkup(IHLanguage* lang, IHMarkup markup)

Arguments

(IHLanguage*) lang

The language that made this markup object.

(IHMarkup) markup

The language-side object to dereference.

Return

nothing.

See Also

HTMLNode, IHMarkup, IHLanguage,

Decrements the number of pointer references on the given IHMarkup. The IHMarkup or any HTMLNode nodes owned by it can not be relied upon to exist after this call.

IH_FreeWidget

Synopsis

void IH_FreeWidget(IHLangEnv* langenv,IHWidgetObj widget)

Arguments

(IHLangEnv*) doc

Language context in which widget exists.

(IHWidgetObj) widget

Widget to deallocate

Return

nothing.

See Also

IHLangEnv, IHWidgetObj

Deallocates a previously allocated language-side widget, freeing all resources that were originally allocated along with it.

IH_GetWidgetMembers

Synopsis

void IH_GetWidgetMembers(IHLangEnv* langenv, IHWidgetObj widget, IHMemberValue* values)

Arguments

(IHLangEnv*) doc

Language context in which widget exists.

(IHWidgetObj) widget

Widget to examine.

(const IHMemberValue*) value

The widget member values to get. This is an array of IHMemberValue structures, which is terminated with a member of IWM_NULL_ID; each value in the array is a pointer to the place in member in which the widget's value should be stored.

Return

nothing.

See Also

IHLangEnv, IHWidgetObj, IHMemberValue, BR_SetWidgetMembers()

Retrieves the values of the given widget's member attributes. The argument values is an array of IHMemberValue structures, terminated with a member of IWM_NULL_ID.

IH_HandleEvent

Synopsis

void IH_HandleEvent(IHEvent* event)

Arguments

(IHEvent*) event

An event to process.

Return

nothing.

See Also

IHEvent

Send the given event off to the language module that can handle it.

IH_HeadMarkupNode

Synopsis

HTMLNode IH_HeadMarkupNode(IHLanguage* lang, IHMarkup markup)

Arguments

(IHLanguage*) lang

The language that made this markup node.

(IHMarkup) markup

The language-side node to look at.

Return

(HTMLNode) The first node in the tree owned by markup

See Also

HTMLNode, IHMarkup, IHLanguage,

This routine returns the first HTMLNode that is owned and being managed by the language-side tree markup.

IH_ImportLanguage

Synopsis

IHLanguage* IH_ImportLanguage(IHContentType* type)

Arguments

(IHContentType*) type

The content type that the important language needs to handle.

Return

(IHLanguage*) A handle on the requested language.

See Also

IHLanguage, IHContentType

Loads an external language module, links it into the browser, and returns its public interface. The language is found by looking through an internally generated list of available languages, searching for one that implements the given content type. Once one is found, an external module named "impl" is hunted for in the path for that name'd language. The module is then loaded and initialized, and the interface to it returned.

If a language implementing the given content type has already been loaded, its interface is immediately returned, instead.

IH_RefMarkup

Synopsis

void IH_RefMarkup(IHLanguage* lang, IHMarkup markup)

Arguments

(IHLanguage*) lang

The language that made this markup object.

(IHMarkup) markup

The language-side object to reference.

Return

nothing.

See Also

HTMLNode, IHMarkup, IHLanguage,

Adds a pointer reference to the given IHMarkup. This is used when linking HTMLNode trees together, to indicate links between trees with different owners.

IH_ReleaseLanguage

Synopsis

void IH_ReleaseLanguage(IHLanguage* lang)

Arguments

(IHLanguage*) lang

A previously important language interface.

Return

nothing.

See Also

IHLanguage, IH_ImportLanguage,

Releases a handle in the given language interface, as returned previously by IH_ImportLanguage(). Every IH_ImportLanguage() call that returns a non-NULL value must be matched with exactly one IH_ReleaseLanguage() call, when the language is no longer needed.

IH_SetMarkupHead

Synopsis

void IH_SetMarkupHead(IHLanguage* lang, IHMarkup markup, HTMLNode node)

Arguments

(IHLanguage*) lang

The language that made this markup object.

(IHMarkup) markup

The language-side object to set.

(HTMLNode) node

The new head of the language-side tree.

Return

nothing.

See Also

HTMLNode, IHMarkup, IHLanguage,

Informs that IHMarkup that it has a new head node. This is called when deleting a tree of nodes, to make sure that the head node saved by the IHMarkup is kept up to date. If NULL, this IHMarkup does not own any more nodes.

IH_SetWidgetMembers

Synopsis

void IH_SetWidgetMembers(IHLangEnv* langenv, IHWidgetObj widget, IHMemberValue* values)

Arguments

(IHLangEnv*) doc

Language context in which widget exists.

(IHWidgetObj) widget

Widget to modify.

(const IHMemberValue*) value

The widget member values to set. This is an array of IHMemberValue structures, which is terminated with a member of IWM_NULL_ID.

Return

nothing.

See Also

IHLangEnv, IHWidgetObj, IHMemberValue, BR_SetWidgetMembers()

Sets the values of the given widget's member attributes. The argument values is an array of IHMemberValue structures, terminated with a member of IWM_NULL_ID.

IH_TailMarkupNode

Synopsis

HTMLNode IH_TailMarkupNode(IHLanguage* lang, IHMarkup markup)

Arguments

(IHLanguage*) lang

The language that made this markup node.

(IHMarkup) markup

The language-side node to look at.

Return

(HTMLNode) The last node in the tree owned by markup

See Also

HTMLNode, IHMarkup, IHLanguage,

This routine returns the last HTMLNode that is owned and being managed by the language-side tree markup.