Link.cpp

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/* Link.cpp

   Copyright (C)  David C. J. Matthews 2004, 2008  dm at prolingua.co.uk

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   Or, point your browser to http://www.gnu.org/copyleft/gpl.html

*/

#include "Link.h"
#include "Ingredients.h"
#include "Root.h"
#include "BaseClasses.h"
#include "ParseNode.h"
#include "ASN1Codes.h"
#include "Actions.h"
#include "Engine.h"
#include "Logging.h"

MHLink::MHLink()
{
    m_EventData.m_Type = MHUnion::U_None;
}

void MHLink::Initialise(MHParseNode *p, MHEngine *engine)
{
    MHIngredient::Initialise(p, engine);
    // The link condition is encoded differently in the binary and text representations.
    MHParseNode *pLinkCond = p->GetNamedArg(C_LINK_CONDITION);
    if (pLinkCond) { // Only in binary.
        m_EventSource.Initialise(pLinkCond->GetArgN(0), engine); // Event source
        m_nEventType = (enum EventType)pLinkCond->GetArgN(1)->GetEnumValue(); // Event type
        // The event data is optional and type-dependent.
        if (pLinkCond->GetArgCount() >= 3) {
            MHParseNode *pEventData = pLinkCond->GetArgN(2);
            switch (pEventData->m_nNodeType) {
            case MHParseNode::PNBool: m_EventData.m_fBoolVal = pEventData->GetBoolValue(); m_EventData.m_Type = MHUnion::U_Bool; break;
            case MHParseNode::PNInt: m_EventData.m_nIntVal = pEventData->GetIntValue(); m_EventData.m_Type = MHUnion::U_Int; break;
            case MHParseNode::PNString: pEventData->GetStringValue(m_EventData.m_StrVal); m_EventData.m_Type = MHUnion::U_String; break;
            default: pEventData->Failure("Unknown type of event data");
            }
        }
    }
    else { // Only in text.
        MHParseNode *pEventSource = p->GetNamedArg(P_EVENT_SOURCE); // Event source
        if (! pEventSource) p->Failure("Missing :EventSource");
        m_EventSource.Initialise(pEventSource->GetArgN(0), engine);
        MHParseNode *pEventType = p->GetNamedArg(P_EVENT_TYPE); // Event type
        if (! pEventType) p->Failure("Missing :EventType");
        m_nEventType = (enum EventType)pEventType->GetArgN(0)->GetEnumValue();
        MHParseNode *pEventData = p->GetNamedArg(P_EVENT_DATA); // Event data - optional
        if (pEventData) {
            MHParseNode *pEventDataArg = pEventData->GetArgN(0);
            switch (pEventDataArg->m_nNodeType) {
            case MHParseNode::PNBool: m_EventData.m_fBoolVal = pEventDataArg->GetBoolValue(); m_EventData.m_Type = MHUnion::U_Bool; break;
            case MHParseNode::PNInt: m_EventData.m_nIntVal = pEventDataArg->GetIntValue(); m_EventData.m_Type = MHUnion::U_Int; break;
            case MHParseNode::PNString: pEventDataArg->GetStringValue(m_EventData.m_StrVal); m_EventData.m_Type = MHUnion::U_String; break;
            default: pEventDataArg->Failure("Unknown type of event data");
            }
        }
    }

    MHParseNode *pLinkEffect = p->GetNamedArg(C_LINK_EFFECT);
    m_LinkEffect.Initialise(pLinkEffect, engine);
}

static const char *rchEventType[] =
{
    "IsAvailable",
    "ContentAvailable",
    "IsDeleted",
    "IsRunning",
    "IsStopped",
    "UserInput",
    "AnchorFired",
    "TimerFired",
    "AsyncStopped",
    "InteractionCompleted",
    "TokenMovedFrom",
    "TokenMovedTo",
    "StreamEvent",
    "StreamPlaying",
    "StreamStopped",
    "CounterTrigger",
    "HighlightOn",
    "HighlightOff",
    "CursorEnter",
    "CursorLeave",
    "IsSelected",
    "IsDeselected",
    "TestEvent",
    "FirstItemPresented",
    "LastItemPresented",
    "HeadItems",
    "TailItems",
    "ItemSelected",
    "ItemDeselected",
    "EntryFieldFull",
    "EngineEvent",
    "FocusMoved",
    "SliderValueChanged"
};

// Look up the event type. Returns zero if it doesn't match.
int MHLink::GetEventType(const char *str)
{
    for (int i = 0; i < (int)(sizeof(rchEventType)/sizeof(rchEventType[0])); i++) {
        if (strcasecmp(str, rchEventType[i]) == 0) return (i+1); // Numbered from 1
    }
    return 0;
}

QString MHLink::EventTypeToString(enum EventType ev)
{
    if (ev > 0 && ev <= (int)(sizeof(rchEventType)/sizeof(rchEventType[0]))) return rchEventType[ev-1];
    else return QString("Unknown event %1").arg(ev);
}

void MHLink::PrintMe(FILE *fd, int nTabs) const
{
    PrintTabs(fd, nTabs);
    fprintf(fd, "{:Link"); MHIngredient::PrintMe(fd, nTabs+1);
    PrintTabs(fd, nTabs+1); fprintf(fd, ":EventSource "); m_EventSource.PrintMe(fd, nTabs+1); fprintf(fd, "\n");
    MHASSERT(m_nEventType > 0 && m_nEventType <= (int)(sizeof(rchEventType)/sizeof(rchEventType[0])));
    PrintTabs(fd, nTabs+1); fprintf(fd, ":EventType %s\n", rchEventType[m_nEventType-1]);
    // The event data is optional and its format depends on the event type.
    switch (m_EventData.m_Type) {
    case MHUnion::U_Bool: PrintTabs(fd, nTabs+1); fprintf(fd, ":EventData %s\n", m_EventData.m_fBoolVal ? "true" : "false"); break;
    case MHUnion::U_Int: PrintTabs(fd, nTabs+1); fprintf(fd, ":EventData %d\n", m_EventData.m_nIntVal); break;
    case MHUnion::U_String: PrintTabs(fd, nTabs+1); fprintf(fd, ":EventData"); m_EventData.m_StrVal.PrintMe(fd, nTabs); fprintf(fd, "\n"); break;
    default: break; // None and others 
    }
    PrintTabs(fd, nTabs+1); fprintf(fd, ":LinkEffect (\n");
    m_LinkEffect.PrintMe(fd, nTabs+2);
    PrintTabs(fd, nTabs+1); fprintf(fd, ")\n");
    PrintTabs(fd, nTabs); fprintf(fd, "}\n");
}

// Activation.
void MHLink::Activation(MHEngine *engine)
{
    if (m_fRunning) return;
    MHIngredient::Activation(engine);
    m_fRunning = true;
    engine->AddLink(this);
    engine->EventTriggered(this, EventIsRunning);
}

void MHLink::Deactivation(MHEngine *engine)
{
    if (! m_fRunning) return;
    engine->RemoveLink(this);
    MHIngredient::Deactivation(engine);
}

// Activate or deactivate the link.
void MHLink::Activate(bool fActivate, MHEngine *engine)
{
    if (fActivate) {
        if (! m_fRunning) Activation(engine);
    }
    else {
        if (m_fRunning) Deactivation(engine);
    }
}

// Check this link to see if the event matches the requirements.  If the link does not specify
// any event data the link fires whatever the value of the data.
void MHLink::MatchEvent(const MHObjectRef &sourceRefRef, enum EventType ev, const MHUnion &evData, MHEngine *engine)
{
    if (m_fRunning && m_nEventType == ev && sourceRefRef.Equal(m_EventSource, engine)) { // Source and event type match.
        bool fMatch = false;
        switch (m_EventData.m_Type) {
        case MHUnion::U_None: fMatch = true; break; // No data specified - always matches.
        case MHUnion::U_Bool:
            fMatch = evData.m_Type == MHUnion::U_Bool && evData.m_fBoolVal == m_EventData.m_fBoolVal; break;
        case MHUnion::U_Int:
            fMatch = evData.m_Type == MHUnion::U_Int && evData.m_nIntVal == m_EventData.m_nIntVal; break;
        case MHUnion::U_String:
            fMatch = evData.m_Type == MHUnion::U_String && evData.m_StrVal.Equal(m_EventData.m_StrVal); break;
        default: fMatch = false; break;
        }
        // Fire the link
        if (fMatch) {
            MHLOG(MHLogLinks, QString("Link fired - %1").arg(m_ObjectReference.Printable()));
            engine->AddActions(m_LinkEffect);
        }
    }
}

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