commodities.library Reference

Comprehensive function reference for commodities.library, synthesised from the AmigaOS NDK 3.2 Release 4 (Autodocs/AG/commodities).

This page documents 26 functions of commodities.library. Each function entry follows the canonical autodoc format. struct Name, union Name, enum Name are clickable links to the type definition in the types reference.

Function index

ActivateCxObj()

ActivateCxObj -- change the activation state of a commodity object. (V36)

Synopsis

previous = ActivateCxObj(co,true); D0 A0 D0

LONG ActivateCxObj(CxObj *,LONG);

Function

Commodity objects of all types maintain an activation state. If an object is "active", then it performs its particular action whenever a commodity message arrives. If the object is "inactive" no action is taken, and the message goes on to its next destination.

All objects are created in the "active" state except brokers
which are created "inactive". Thus, after you create your
broker and hang a tree of objects off of it, you must remember
to use this function to activate it. This causes it to divert all
messages to your tree of objects.

This function activates 'co' if 'true' is different than 0. and
deactivates it otherwise. The previous activation state is
returned.

Inputs

co - the commodity object to affect (may be NULL) true - 0 to deactivate the object, anything else to activate it

Results

previous - the previous activation state: 0 if the object was inactive or if 'co' was NULL, anything else if the object was active

See also

CxBroker()

AddIEvents()

AddIEvents -- add input events to commodities' input stream. (V36)

Synopsis

AddIEvents(events) A0

VOID AddIEvents(struct InputEvent*);

Function

This function adds a null-terminated linked list of input events to the input stream processed by commodities. It is a touch easier than using the input device directly.

The contents of the input events are copied into commodity messages,
so they may be disposed of as soon as this call returns.

The messages are initially routed to the first broker in
commodities' object list.

Inputs

events - the list of input events to add (may be NULL)

Bugs

Prior to V40, this function did not copy the data pointed to by ie_EventAddress for any events of type IECLASS_NEWPOINTERPOS.

See also

FreeIEvents()

AttachCxObj()

AttachCxObj -- attach a commodity object to the end of an existing list of objects. (V36)

Synopsis

AttachCxObj(headObj,co); A0 A1

VOID AttachCxObj(CxObj *,CxObj *);

Function

Adds 'co' to the list of objects pointed to by 'headObj'. The new object is added at the end of the list.

Inputs

headObj - pointer to a list of objects. If this value is NULL, then the entire tree of objects pointed to by 'co' is deleted and becomes invalid. co - the object to add to the list (may be NULL)

Results

If 'co' is NULL, this function will record that fact in the internal accumulated error of 'headObj'. This error record can be retrieved using CxObjError() and cleared using ClearCxObjError().

Bugs

Until V38, passing a NULL 'headObj' parameter would cause low-memory access and unpredictable results.

See also

CxObjError(), ClearCxObjError()

ClearCxObjError()

ClearCxObjError -- clear the accumulated error value of a commodity object. (V36)

Synopsis

ClearCxObjError(co); A0

VOID ClearCxObjError(CxObj *);

Function

This function clears the accumulated error value of commodity object 'co'.

It is unwise to do this to a filter if COERR_BADFILTER is set.
This will fool commodities into thinking the filter is OK. Set
another valid filter, or leave the error value alone.

Inputs

co - the object to affect (may be NULL)

See also

CxObjError()

CreateCxObj()

CreateCxObj -- create a new commodity object. (V36)

Synopsis

co = CreateCxObj(type,arg1,arg2); D0 D0 A0 A1

CxObj *CreateCxObj(ULONG,LONG,LONG);

Function

This function creates a commodity object of type 'type'. It is not proper to call this function directly. Each object creation routine except CxBroker() is defined as a macro in These are independently documented.

All functions which operate on a commodity object are made with
a reference to the thirty-two bit value returned by this function
(or by CxBroker()).

Inputs

type - the type of object to create as defined in arg1 - first argument, meaning depends on 'type' arg2 - second argument, meaning depends on 'type'

Results

co - a pointer to the new object or NULL if it could not be created. A NULL return indicates typically a lack of system memory. Minor problems in creating an object, such as providing a bad filter description to amiga.lib/CxFilter(), typically don't cause failure, but are recorded in an internal error field in the new object which can be accessed via CxObjError().

See also

CxObjError(), CxFilter(), CxSender(), CxSignal(), CxTranslate(), CxDebug(), CxCustom(), CxBroker()

CxBroker()

CxBroker -- create a commodity broker. (V36)

Synopsis

broker = CxBroker(nb,error); D0 A0 D0

CxObj *CxBroker(struct NewBroker*,LONG *);

Function

This function creates a broker from the specification found in the NewBroker structure pointed to by 'nb'. The purpose and meaning of the fields of the NewBroker structure are described below. Also see for more info.

struct NewBroker
{
    BYTE            nb_Version;
    STRPTR          nb_Name;
    STRPTR          nb_Title;
    STRPTR          nb_Descr;
    WORD            nb_Unique;
    WORD            nb_Flags;
    BYTE            nb_Pri;
    struct MsgPort *nb_Port;
    WORD            nb_ReservedChannel;
};

nb_Version
This is the way that future versions of commodities can identify
which version of the NewBroker structure you are using. This should be
set to NB_VERSION as defined in <libraries/commodities.h>

nb_Name
This is the name of the broker. This name is used to find the broker
in commodities' object list and is the name shown in the listview
gadget of the Exchange program. The name string is copied in the
broker object upon creation so it can be discarded right after
CxBroker() returns. The maximum length of the name string is defined
by a constant in <libraries/commodities.h>.

nb_Title, nb_Descr
These are two strings which appear to the user in the Exchange
program and describe the application the broker is representing.
Note that these strings are copied into the broker object so they
can be discarded right after CxBroker() returns. The maximum length
of these strings that will be recognized are defined by constants in
<libraries/commodities.h>.

nb_Unique
This field indicates what should happen if a broker of the same name
(nb_Name) already exists in commodities' object list. Constants
in <libraries/commodities.h> allow the caller to specify whether
another broker is to be created, and whether any existing broker of
the same name should be notified that an attempt at creating a
duplicate has been made.

nb_Pri
This specifies with what priority the new broker is to be inserted
within commodities' object list. Higher priority nodes appear
earlier in a list. It is strongly recommended that the ToolTypes
environment of an application be used to allow the end-user to set
the priority of the broker.

Inputs

nb - an initialized NewBroker structure error - a pointer to a longword where to store a failure code (may be NULL)

Results

broker - a pointer to the broker object or NULL upon failure. If the 'error' pointer is not NULL, a further diagnostic code is placed at that address. Error codes are defined in and include:

        CBERR_OK
        No problems; broker created OK.

        CBERR_SYSERR
        System problems, not your fault, sign of low memory.

        CBERR_DUP
        The nb_Unique field specified that only one broker of
        'nb_Name' should be allowed, and one already exists.

        CBERR_VERSION
        The version specified in 'nb_Version' is unknown to the
        library.

See also

SetCxObjPri()

CxMsgData()

CxMsgData -- obtain a pointer to a commodity message's data area. (V36)

Synopsis

data = CxMsgData(cxm); D0 A0

APTR CxMsgData(struct CxMsg*);

Function

Most commodity messages contain meaningful data such as an InputEvent structure. This function returns a pointer to this data.

You may get a commodity message from a synchronous (custom object) or
asynchronous (sender object) source. In the second case, 'data' is
not valid after you have replied to the message.

Inputs

cxm - the commodity message to get the data pointer from (may be NULL)

Results

data - a pointer to the message's data, or NULL if 'cxm' is NULL. The meaning of the data varies depending on which kind of object is being inspected.

Bugs

Until V38, passing a NULL 'cxm' parameter would cause low-memory access and unpredictable results.

Until V40, whenever the data pointer is a (struct InputEvent), the
ie_EventAddress field of these structures was not reliable whenever
the message was generated by a sender object.

See also

CxSender(), CxCustom()

CxMsgID()

CxMsgID -- obtain the ID of a commodity message. (V36)

Synopsis

id = CxMsgID(cxm); D0 A0

LONG CxMsgID(struct CxMsg*);

Function

This function returns the value associated with the cause or source of the commodity message 'cxm'. Values are provided by the application when a sender or custom object is created.

Inputs

cxm - the commodity message to inquire about (must NOT be NULL)

Results

id - if not specified by the application, the ID value of a commodity message will be 0. It is suggested that using non-zero values in your program as a rule may identify some possible errors.

See also

CxSender(), CxCustom()

CxMsgType()

CxMsgType -- obtain the type of a commodity message. (V36)

Synopsis

type = CxMsgType(cxm); D0 A0

ULONG CxMsgType(struct CxMsg*);

Function

This function returns the type of a commodity message. Possible values of 'type' are defined in . Most commodity messages are of type CXM_IEVENT.

Inputs

cxm - the commodity message to inquire about (must NOT be NULL)

Results

type - the type of the commodity message, possible values are defined in

CxObjError()

CxObjError -- obtain a commodity object's accumulated error. (V36)

Synopsis

error = CxObjError(co); D0 A0

LONG CxObjError(CxObj *);

Function

When a function acting on an object fails, it records the failure in the object. This function returns the accumulated error value. The values are represented by flag bits defined in . Several errors may be recorded by multiple bits in 'error'.

The currently defined errors are:

COERR_ISNULL
  The value of parameter 'co' was in fact NULL. This error
  means "the problem with the object you inquire about is
  that it failed to be created."

COERR_NULLATTACH
  Using the commodities' list manipulation functions, an attempt was
  made to add a NULL object to the list belonging to 'co'. This allows
  a line of code as follows to exist in an error-tolerant program:

    AttachCxObj(filter,CxSender(myport,MY_ID));

COERR_BADFILTER
  The most recent filter specification for a filter object
  was faulty. This happens if no sense can be made out of a
  description string, or if an input expression (IX) has an
  invalid format or version byte. When this bit is set in a
  filter's error field, the filter will match nothing, but this
  is not the proper way to "turn off" a filter, use ActivateCxObj().

COERR_BADTYPE
  A type specific operation, such as SetFilterIX(), was called
  for object 'co', but 'co' isn't of the proper type.

Inputs

co - the commodity object to get the accumulated error from (may be NULL)

Results

error - the accumulated error, or 0 if 'co' is NULL

See also

SetFilter(), SetFilterIX(), AttachCxObj(), ActivateCxObj(), ClearCxObjError()

CxObjType()

CxObjType -- obtain the type of a commodity object. (V36)

Synopsis

type = CxObjType(co); D0 A0

ULONG CxObjType(CxObj *);

Function

This function should not really be necessary. It returns the type of a commodity object, which you should already know, since you created it in the first place.

Inputs

co - the commodity object to inquire about (may be NULL)

Results

type - the type of the commodity object, possible values are defined in . Returns CX_INVALID if 'co' is NULL.

See also

CreateCxObj()

DeleteCxObj()

DeleteCxObj -- delete a commmodity object. (V36)

Synopsis

DeleteCxObj(co); A0

VOID DeleteCxObj(CxObj *);

Function

Deletes a commodity object of any type. If the object is linked into a list, it is first removed. Note that the handle 'co' is invalid after this function is called.

Also note that deleting an object which has other objects attached
to it may be undesirable. Use the function DeleteCxObjAll()
to delete an entire sub-tree of objects.

Inputs

co - the commodity object to delete (may be NULL)

See also

DeleteCxObjAll()

DeleteCxObjAll()

DeleteCxObjAll -- recursively delete a tree of commodity objects. (V36)

Synopsis

DeleteCxObjAll(co); A0

VOID DeleteCxObjAll(CxObj *);

Function

This function deletes the commodity object 'co', and recursively deletes all objects attached to it, and the objects attached to them, etc.

If 'co' is linked into a list, it is first removed. Note
that the handle 'co' is invalid after this function is called.

This function is useful when an application exits: most
applications can clean up completely by deleting the
entire sub-tree of objects starting at their broker.

Inputs

co - the first commodity object to delete (may be NULL)

See also

DeleteCxObj()

DisposeCxMsg()

DisposeCxMsg -- delete a commodity message. (V36)

Synopsis

DisposeCxMsg(cxm); A0

VOID DisposeCxMsg(struct CxMsg*);

Function

This function eliminates the commodity message pointed to by 'cxm'. Can be used to 'swallow' input events by disposing of every commodity message of type CXM_IEVENT.

This function can only be called from within a custom object running
on the input handler's context. It cannot be called from code running
on a commodities' context, such as when receiving a CXM_IEVENT message
from a sender object. CxMsg sent to a commodity program from a sender
object must be sent back using ReplyMsg().

Inputs

cxm - the commodity message to delete (must NOT be NULL)

DivertCxMsg()

DivertCxMsg -- send a commodity message down an object list. (V36)

Synopsis

DivertCxMsg(cxm,headObj,returnObj); A0 A1 A2

VOID DivertCxMsg(struct CxMsg*,CxObj *,CxObj *);

Function

This function sends the commodity message 'cxm' down the list of objects attached to 'headObj'. The pointer 'returnObj' is first pushed onto the routing stack of 'cxm' so that when the end of the list of 'headObj' is reached the SUCCESSOR of 'returnObj' is the next destination.

For example, when a filter finds a match with a message, the
message is diverted down the filter's list like this:

  DivertCxMsg(cxm,filter,filter);

Inputs

cxm - the commodity message to divert (must NOT be NULL) headObj - the list of objects to divert the message to returnObj - the object to use as a place holder

See also

RouteCxMsg()

EnqueueCxObj()

EnqueueCxObj -- insert a commodity object within a list of objects based on object priority. (V36)

Synopsis

EnqueueCxObj(headObj,co); A0 A1

VOID EnqueueCxObj(CxObj *,CxObj *);

Function

This function puts object 'co' into the list of object 'headObj'. The insertion point is determined by the object's priority. The objects are kept in the list from the highest priority to the lowest. New nodes are inserted in front of the first node with a lower priority. Hence a FIFO queue for nodes of equal priority.

The priority of the commodity object can be set using SetCxObjPri().

Inputs

headObj - pointer to a list of objects. If this value is NULL, then the entire tree of objects pointed to by 'co' is deleted and becomes invalid. co - the object to add to the list (may be NULL)

Results

If 'co' is NULL, this function will record that fact in the internal accumulated error of 'headObj'. This error record can be retrieved using CxObjError() and cleared using ClearCxObjError().

Bugs

Until V38, passing a NULL 'headObj' parameter would cause low-memory access and unpredictable results.

See also

SetCxObjPri(), CxObjError(), ClearCxObjError()

InsertCxObj()

InsertCxObj -- insert a commodity object in a list after a given object. (V36)

Synopsis

InsertCxObj(headObj,co,pred); A0 A1 A2

VOID InsertCxObj(CxObj *,CxObj *,CxObj *);

Function

Adds 'co' to the list of objects pointed to by 'headObj' after object 'pred'.

Inputs

headObj - pointer to a list of objects. If this value is NULL, then the entire tree of objects pointed to by 'co' is deleted and becomes invalid. co - the object to add to the list (may be NULL) pred - the object after which 'co' should be inserted. If this is NULL then 'co' is added to the head of the list.

Results

If 'co' is NULL, this function will record that fact in the internal accumulated error of 'headObj'. This error record can be retrieved using CxObjError() and cleared using ClearCxObjError().

Bugs

Until V38, passing a NULL 'headObj' parameter would cause low-memory access and unpredictable results.

See also

CxObjError(), ClearCxObjError()

InvertKeyMap()

InvertKeyMap -- generate an input event from an ANSI code. (V36)

Synopsis

success = InvertKeyMap(ansiCode,event,km) D0 D0 A0 A1

BOOL InvertKeyMap(ULONG,struct InputEvent*,struct KeyMap*);

Function

This function uses the system call MapANSI() to figure out what InputEvent translates to an ANSI character code 'ansiCode'. The InputEvent pointed to by 'event' is filled in with that information. The KeyMap 'km' is used for the translation, unless it is NULL, in which case the current system default keymap is used.

Inputs

ansiCode - the ANSI code to convert to an input event event - the InputEvent to fill-in km - the keymap to use for the translation, or NULL to use the current system default keymap.

Results

success - TRUE if the translation worked, FALSE otherwise.

Bugs

This function currently handles one-deep dead keys (such as o ). It does not look up the high key map (keystrokes with scan codes greater than 0x40).

Prior to V40, this function was not initializing the ie_SubClass
and ie_TimeStamp fields of the InputEvent structure. A simple work
around to the problem is to clear these values to 0 before making
a call to this function:

    struct InputEvent ie;

        ie.ie_SubClass           = 0;
        ie.ie_TimeStamp.tv_secs  = 0;
        ie.ie_TimeStamp.tv_micro = 0;
        if (InvertKeyMap(ansiCode,&ie,NULL))
        ...

See also

InvertString()

MatchIX()

MatchIX -- see if an input event matches an initialized input expression. (V38)

Synopsis

match = MatchIX(event,ix); D0 A0 A1

BOOL MatchIX(struct InputEvent*,IX *);

Function

This function determines whether an input event matches an initialized input expression. Applications generally do not need to call this function as filter objects will normally provide all the event filtering needed. Nevertheless, MatchIX() can come in handy as it is the same function used to match an event to the various filter objects when an event makes its way through the input network.

Inputs

event - the input event to match against the input expression ix - the input expression for the comparison

Results

match - TRUE if the input event matches the input expression, or FALSE if not

See also

ParseIX()

ParseIX()

ParseIX -- initialize an input expression given a description string. (V36)

Synopsis

failureCode = ParseIX(description,ix); D0 A0 A1

LONG ParseIX(STRPTR,IX *);

Function

Given an input description string and an allocated input expression, sets the fields of the input expression to correspond to the description string.

Inputs

description - the string to parse ix - the input expression to hold the result of the parse

Results

failureCode - 0 if all went well, -1 if tokens after end (code spec) -2 if 'description' was NULL

See also

MatchIX()

RemoveCxObj()

RemoveCxObj -- remove a commodity object from a list. (V36)

Synopsis

RemoveCxObj(co); A0

VOID RemoveCxObj(CxObj *);

Function

This function removes 'co' from any list it may be a part of. Will not crash if 'co' is NULL, or if it has not been inserted in a list.

Inputs

co - the object to remove (may be NULL)

See also

AttachCxObj(), EnqueueCxObj(), InsertCxObj()

RouteCxMsg()

RouteCxMsg -- set the next destination of a commodity message. (V36)

Synopsis

RouteCxMsg(cxm,co); A0 A1

VOID RouteCxMsg(struct CxMsg*,CxObj *);

Function

Establishes the next destination of a commodity message to be 'co', which must be a valid commodity object, and must be linked in ultimately to commodities' object list.

Routing of an object is analogous to a 'goto' in a program.
There is no effect on the message's routing stack.

Inputs

cxm - the commodity message to route (must NOT be NULL) co - the commodity object to route the message to (must NOT be NULL)

See also

DivertCxMsg()

SetCxObjPri()

SetCxObjPri -- set the priority of a commodity object. (V36)

Synopsis

oldPri = SetCxObjPri(co,pri) D0 A0 D0

LONG SetCxObjPri(CxObj *,LONG);

Function

This function sets the priority of a commodity object for the purposes of EnqueueCxObj().

It is strongly recommended that the ToolTypes environment be
utilized to provide end-user control over the priority of
brokers, but application specific ordering of other objects
within their lists is not dictated.

Inputs

co - the commodity object to affect (may be NULL) pri - the object's new priority in the range -128 to +127. A value of 0 is normal.

Results

oldPri - the previous priority of the object or 0 if 'co' was NULL. This value is only returned in V38 and beyond.

Bugs

This function will not reposition an object within its list when its priority changes. To attain the same effect, first remove the object from its list using RemoveCxObj(), set its priority using SetCxObjPri(), and reinsert it in the list using EnqueueCxObj().

See also

EnqueueCxObj()

SetFilter()

SetFilter -- change the matching condition of a commodity filter. (V36)

Synopsis

SetFilter(filter,text); A0 A1

VOID SetFilter(CxObj *,STRPTR);

Function

This function changes the matching condition of a commodity input filter to that described by the input description string 'text'.

Inputs

filter - the filter object to affect (may be NULL) text - the new matching conditions for the filter

Results

The internal error of 'filter' will have the COERR_BADFILTER bit set or cleared depending on the failure or success of this function.

See also

SetFilterIX(), CxObjError()

SetFilterIX()

SetFilterIX -- change the matching condition of a commodity filter. (V36)

Synopsis

SetFilterIX(filter,ix); A0 A1

VOID SetFilterIX(CxObj *,IX *);

Function

This function changes the matching condition of a commodity input filter to that described by the binary input expression pointed by 'ix'.

Input expressions are defined in <libraries/commodities.h>.
It is important to remember that the first field of the input
expression structure must indicate which version of the
input expression structure is being used.

Inputs

filter - the filter object to affect (may be NULL) ix - the new matching conditions for the filter

Results

The internal error of 'filter' will have the COERR_BADFILTER bit set or cleared depending on the failure or success of this function.

See also

SetFilter(), CxObjError()

SetTranslate()

SetTranslate -- replace a translator object's translation list. (V36)

Synopsis

SetTranslate(translator,events); A0 A1

VOID SetTranslate(CxObj *,struct InputEvent*);

Function

This function replaces the translation list of a commodity translator object with the linked list starting at 'events'.

A NULL value for 'events' indicates that the object 'translator'
should swallow all commodity messages that are sent its way.

Note that the input events are not copied into commodities' private
memory, but the value of 'events' is used -- asynchronously to the
application program -- to find a chain of InputEvents in the
application's data space. At the time of translation, each input event
is copied into its own new commodity message.

The above means that no other commodities' user, nor
commodities.library itself will be modifying your list of InputEvents.
On the other hand, your program must not corrupt the input event
chain that has been presented to a translator.

Inputs

translator - the translator object to affect (may be NULL) events - the new input event translation list

See also

CxTranslate()