msg.h

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// $Id: msg.h 751 2006-03-31 15:43:49Z alex $
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=================================XARAHEADEREND============================
 */
/*
 * */ 

// This file contains a hierarchy of messages and broadcast macros 

#ifndef INC_MSG
#define INC_MSG        

#include "dlgtypes.h"
#include "errors.h"

class Operation;

// Place the CC_IMPLEMENT_DYNAMIC macros in pump.cpp if you like

/********************************************************************************************

>   class Msg: public CCObject

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Purpose:    The base Msg class from which all messages must be derived 
    SeeAlso:    -

********************************************************************************************/

class Msg: public CCObject
{
    CC_DECLARE_DYNAMIC(Msg); 
    Msg() { }
    Msg(const Msg & msg) { }
};

/********************************************************************************************

>   class OpMsg: public Msg

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Purpose:    This message is sent whenever something happens to an operation
    SeeAlso:    -

********************************************************************************************/

class OpMsg: public Msg
{
    CC_DECLARE_DYNAMIC(OpMsg);
public:

    enum OpMsgType
    {
        BEGIN,          // An operation is about to be performed
        END,            // An operation has successfully ended
        BEFORE_UNDO,    // Sent prior to the operation being undone
        AFTER_UNDO,     // Sent after the operation has been undone
        BEFORE_REDO,    // Sent prior to the operation being redone
        AFTER_REDO      // Sent after the operation has been redone
    };

    OpMsgType MsgType;  // The message type
    Operation* pOp;     // A pointer to the operation, can be NULL 

    OpMsg(Operation* pOperation, OpMsgType TypeMsg)
      : MsgType(TypeMsg), pOp(pOperation)
        { /* empty */ }
};


/********************************************************************************************

>   class DialogMsg: public Msg

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Purpose:    A DialogMsg is sent whenever the user interacts with the gadgets in
                a dialog box, It is only sensible to send this message to DialogOp objects.

                ** Important **
                
                When processing the DialogMessage you should always use the IS_OUR_DIALOG_MSG
                macro. In normal circumstances this will return TRUE if the DlgWndID of 
                the message is the same as the DialogOps window ID. However sometimes it 
                is neccessary to send a DialogMsg to all DialogOps. For example when Camelot is
                dying we need to send a DIM_CANCEL to all open dialogs. The IS_DIALOG_MSG macro
                provides clever handling to ensure that all open DialogOps receive this message.
                in this situation the DlgWndID will be NULL. So when handling the DIM_CANCEL
                message you should not assume that DlgWndID is a valid window identifier. 

                after processing the dialog message you should always 
                
                return(DLG_EAT_IF_HUNGRY(DlgMsg)); 
                
                The DLG_EAT_IF_HUNGRY macro will return EAT_MSG if the message should not be
                sent on to other dialogOps and OK if it should.


                Syntax of constructor is:
                DialogMsg(CWindowID DlgID, CDlgMessage Msg, CGadgetID Gadget, INT32 LongParam=0)


                  
    SeeAlso:    IS_OUR_DIALOG_MSG
    SeeAlso:    EAT_IF_HUNGRY

********************************************************************************************/

class DialogMsg: public Msg
{
    CC_DECLARE_DYNAMIC(DialogMsg); 
public:
    CWindowID   DlgWndID;
    CDlgMessage DlgMsg;
    CGadgetID   GadgetID;
    UINT_PTR    DlgMsgParam;        // Message specific data will be placed in here
                                    // Note: if more complex data needs to be stored in the
                                    //       future this field ought to become a pointer
                                    //       to a struct which holds the data (rather than
                                    //       adding huge structs into this class).
    CDlgResID PageID;               // Only relevent for tabbed dialogs. Specifies which page
                                    // (in the tabbed dialog) generated the message. If the dialog
                                    // itself sent the message then this will be 0.

    DialogMsg(CWindowID DlgID, CDlgMessage Msg, CGadgetID Gadget, UINT_PTR LongParam=0, CDlgResID Pageid=0): 
        DlgWndID(DlgID), DlgMsg(Msg), GadgetID(Gadget), DlgMsgParam(LongParam), PageID(Pageid)
    {
    }
    DialogMsg(const DialogMsg & msg) :
        DlgWndID(msg.DlgWndID), DlgMsg(msg.DlgMsg), GadgetID(msg.GadgetID), DlgMsgParam(msg.DlgMsgParam), PageID(msg.PageID) { } // copy constructor
        
};



/********************************************************************************************

>   class DeathMsg: public Msg

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    29/3/94
    Purpose:    This message is sent just before camelot's death. 
                When a long-life operation receives this message it should tidy-up then call
                End(). 
    SeeAlso:    -

********************************************************************************************/

class DeathMsg: public Msg
{
    CC_DECLARE_DYNAMIC(DeathMsg); 
    DeathMsg() { }
};

/********************************************************************************************

>   MsgResult BROADCAST_TO_ALL(Msg) 

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Inputs:     -
    Outputs:    -


    Returns:    A value of OK or EAT_MSG indicates that the message was successfully sent to the 
                MessageHandler objects. i.e. the MessageHandlers Message functions
                all returned either OK, or EAT_MSG. 

                OK means that message got sent to all specified MessageHandlers and all of them
                return OK. This does not imply than anyone acted on the message of course.

                EAT_MSG means that a handler processed the message and didn't want it to be
                passed on. 

                A FAIL value indicates that one or more Message handlers returned a FAIL value 
                from their Message functions. In this situation the broadcast function will call 
                InformError describing the first error which occured.  

    Purpose:    The BROADCAST_TO_ALL macro is used to send a message to all MessageHandler objects
                in the system. If any MessageHandler returns a FAIL value then InformError is
                called.

                Usage:

                BROADCAST_TO_ALL(AMsg(p1,p2,p3))
            
    SeeAlso:    BROADCAST_TO_CLASS
    SeeAlso:    MessageHandler::Broadcast

********************************************************************************************/
#define BROADCAST_TO_ALL(Message) \
    MessageHandler::pTmpMsg = new Message, \
        (MessageHandler::pTmpMsg == NULL) ? (FAIL) :    \
    MessageHandler::Broadcast(MessageHandler::pTmpMsg)   \


/********************************************************************************************

>   MsgResult BROADCAST_TO_CLASS(Msg,Class) 

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Inputs:     -
    Outputs:    -
    Returns:    A value of OK or EAT_MSG indicates that the message was successfully sent to the 
                MessageHandler objects. i.e. the MessageHandlers Message functions
                all returned either OK, or EAT_MSG. 

                OK means that message got sent to all specified MessageHandlers and all of them
                return OK. This does not imply than anyone acted on the message of course.

                EAT_MSG means that a handler processed the message and didn't want it to be
                passed on. 

                A FAIL value indicates that one or more Message handlers returned a FAIL value 
                from their Message functions. In this situation the broadcast function will call 
                InformError describing the first error which occured.  
            
    Purpose:    The BROADCAST_TO_ALL macro is used to send a message to all MessageHandler objects
                with a class derived from or equal to Class.  

                
                To send a message to all DialogOp objects

                BROADCAST_TO_CLASS(DialogMsg(p1,p2,p3), DialogOp)

                To send a message to all Operation objects, including DialogOp objects. 

                BROADCAST_TO_CLASS(AMsg(p1,p2,p3), Operation)

    Errors:     -
    SeeAlso:    BROADCAST_TO_ALL
    SeeAlso:    MessageHandler::Broadcast

********************************************************************************************/

#define BROADCAST_TO_CLASS(Message, Class) \
    MessageHandler::pTmpMsg = new Message, \
        (MessageHandler::pTmpMsg == NULL) ? (FAIL) :    \
    MessageHandler::Broadcast(MessageHandler::pTmpMsg, CC_RUNTIME_CLASS(Class))  \

// The following are useful little macros for use in a MessageHandler's message function

/********************************************************************************************

>   IS_OUR_DIALOG_MSG(Message)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Inputs:     Message: Msg* 
    Outputs:    -
    Returns:    -
    Purpose:    This macro for use in DialogOp classes evaluates to TRUE if the Message is
                a DialogMsg for the DialogOp. See DialogMsg for a full description of its
                usage. 
    Errors:     -
    SeeAlso:    DialogMsg
    SeeAlso:    DLG_EAT_IF_HUNGRY

********************************************************************************************/
// Returns TRUE if
//      The DialogOps WindowID != NULL and    // The DialogOp is visible (may not be the case if it's a bar)
//      (The message is a DialogMsg and
//          ((The DialogOps WindowID == The message's Window ID) or
//           (The message's Window ID is NULL)) // A message for all DialogOps
//      ) 
// ** We need all this nonsense so that we can send CANCEL messages sensibly 

#define IS_OUR_DIALOG_MSG(Message)                                          \
    (                                                                       \
        (WindowID != NULL) &&                                               \
            (                                                               \
                ((Message)->IsKindOf(CC_RUNTIME_CLASS(DialogMsg))) &&       \
                    (                                                       \
                        (WindowID == ((DialogMsg*)(Message))->DlgWndID) ||  \
                        ( ((DialogMsg*)(Message))->DlgWndID == NULL)        \
                    )                                                       \
            )                                                               \
    )
#endif 

/********************************************************************************************

>   DLG_EAT_IF_HUNGRY(DialogMsg)


    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    18/4/94
    Inputs:     DialogMsg: The dialog message (DialogMsg)
    Outputs:    -
    Returns:    -
    Purpose:    You should use this macro to return from a DialogOp's Message function after
                a DialogMsg has been processed. See DialogMsg for a full description of its use
                
                return(DLG_EAT_IF_HUNGRY(Msg)); 
                 
    Errors:     -
    SeeAlso:    IS_OUR_DIALOG_MSG

********************************************************************************************/

// If the DlgWndID is NULL then the message should be broadcast to all DialogOps so return OK
// otherwise return EAT_MSG

#define DLG_EAT_IF_HUNGRY(DialogMsg)    \
    ((DialogMsg)->DlgWndID) == NULL ? OK : EAT_MSG 

/********************************************************************************************

>   MESSAGE_IS_A(Message, MsgClass)

    Author:     Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
    Created:    23/3/94
    Inputs:     Message: Msg*
                MsgClass: A class eg. DialogMsg
    Outputs:    -
    Returns:    
    Purpose:    This macro determines if Message is a kind of MsgClass
    Errors:     -
    SeeAlso:    -

********************************************************************************************/


#define MESSAGE_IS_A(Message,MsgClass) \
    (Message->IsKindOf(CC_RUNTIME_CLASS(MsgClass)))

---