// Return the value, looking up any indirect ref.
public int GetValue(MHEngine engine)
{
if (m_fIsDirect)
{
return(m_nDirect);
}
else
{
MHUnion result = new MHUnion();
MHRoot pBase = engine.FindObject(m_Indirect);
pBase.GetVariableValue(result, engine);
// From my reading of the MHEG documents implicit conversion is only
// performed when assigning variables. Nevertheless the Channel 4
// Teletext assumes that implicit conversion takes place here as well.
if (result.Type == MHUnion.U_String)
{
// Implicit conversion of string to integer.
return(Convert.ToInt32(result.String.ToString()));
}
else
{
result.CheckType(MHUnion.U_Int);
return(result.Int);
}
}
}
public MHRoot FindObject(MHObjectRef oRef, bool failOnNotFound)
{
// It should match either the application or the scene.
MHGroup pSearch = null;
MHGroup pScene = CurrentScene();
MHGroup pApp = CurrentApp();
if (pScene != null && GetPathName(pScene.ObjectIdentifier.GroupId) == GetPathName(oRef.GroupId))
{
pSearch = pScene;
}
else if (pApp != null && GetPathName(pApp.ObjectIdentifier.GroupId) == GetPathName(oRef.GroupId))
{
pSearch = pApp;
}
if (pSearch != null)
{
MHRoot pItem = pSearch.FindByObjectNo(oRef.ObjectNo);
if (pItem != null)
{
return(pItem);
}
}
if (failOnNotFound)
{
// I've seen at least one case where MHEG code has quite deliberately referred to
// an object that may or may not exist at a particular time.
// Another case was a call to CallActionSlot with an object reference variable
// that had been initialised to zero.
Logging.Log(Logging.MHLogWarning, "Reference " + oRef.ObjectNo + " not found");
throw new MHEGException("FindObject failed");
}
return(null); // If we don't generate an error.
}
// Return the value, looking up any indirect ref.
public void GetValue(MHOctetString str, MHEngine engine)
{
if (m_fIsDirect)
{
str.Copy(m_Direct);
}
else
{
MHUnion result = new MHUnion();
MHRoot pBase = engine.FindObject(m_Indirect);
pBase.GetVariableValue(result, engine);
// From my reading of the MHEG documents implicit conversion is only
// performed when assigning variables. Nevertheless the Channel 4
// Teletext assumes that implicit conversion takes place here as well.
if (result.Type == MHUnion.U_Int)
{
// Implicit conversion of string to integer.
MHOctetString s = new MHOctetString("" + result.Int);
str.Copy(s);
}
else
{
result.CheckType(MHUnion.U_String);
str.Copy(result.String);
}
}
}
public void PutBefore(MHRoot p, MHRoot pRef)
{
int nPos = CurrentApp().FindOnStack(p);
if (nPos == -1)
{
return; // If it's not there do nothing
}
MHVisible pVis = (MHVisible)p; // Can now safely cast it.
int nRef = CurrentApp().FindOnStack(pRef);
if (nRef == -1)
{
return; // If the reference visible isn't there do nothing.
}
CurrentApp().DisplayStack.RemoveAt(nPos);
if (nRef >= nPos)
{
nRef--; // The position of the reference may have shifted
}
CurrentApp().DisplayStack.InsertAt(pVis, nRef + 1);
// Redraw the area occupied by the moved item. We might be able to reduce
// the area to be redrawn by looking at the way it is affected by other items
// in the stack. We could also see whether it's currently active.
Redraw(pVis.GetVisibleArea()); // Request a redraw
}
public void EventTriggered(MHRoot pSource, int ev, MHUnion evData)
{
Logging.Log(Logging.MHLogLinks, "Event - " + MHLink.EventTypeToString(ev) + " from " + pSource.ObjectIdentifier.Printable());
switch (ev)
{
case MHRoot.EventFirstItemPresented:
case MHRoot.EventHeadItems:
case MHRoot.EventHighlightOff:
case MHRoot.EventHighlightOn:
case MHRoot.EventIsAvailable:
case MHRoot.EventIsDeleted:
case MHRoot.EventIsDeselected:
case MHRoot.EventIsRunning:
case MHRoot.EventIsSelected:
case MHRoot.EventIsStopped:
case MHRoot.EventItemDeselected:
case MHRoot.EventItemSelected:
case MHRoot.EventLastItemPresented:
case MHRoot.EventTailItems:
case MHRoot.EventTestEvent:
case MHRoot.EventTokenMovedFrom:
case MHRoot.EventTokenMovedTo:
// Synchronous events. Fire any links that are waiting.
// The UK MHEG describes this as the preferred interpretation. We are checking the link
// at the time we generate the event rather than queuing the synchronous events until
// this elementary action is complete. That matters if we are processing an elementary action
// which will activate or deactivate links.
CheckLinks(pSource.ObjectIdentifier, ev, evData);
break;
case MHRoot.EventAnchorFired:
case MHRoot.EventAsyncStopped:
case MHRoot.EventContentAvailable:
case MHRoot.EventCounterTrigger:
case MHRoot.EventCursorEnter:
case MHRoot.EventCursorLeave:
case MHRoot.EventEngineEvent:
case MHRoot.EventEntryFieldFull:
case MHRoot.EventInteractionCompleted:
case MHRoot.EventStreamEvent:
case MHRoot.EventStreamPlaying:
case MHRoot.EventStreamStopped:
case MHRoot.EventTimerFired:
case MHRoot.EventUserInput:
case MHRoot.EventFocusMoved: // UK MHEG. Generated by HyperText class
case MHRoot.EventSliderValueChanged: // UK MHEG. Generated by Slider class
{
// Asynchronous events. Add to the event queue.
MHAsynchEvent pEvent = new MHAsynchEvent();
pEvent.EventSource = pSource;
pEvent.EventType = ev;
pEvent.EventData = evData;
m_EventQueue.Add(pEvent);
} break;
}
}
public void SendToBack(MHRoot p)
{
int nPos = CurrentApp().FindOnStack(p);
if (nPos == -1)
{
return; // If it's not there do nothing
}
MHVisible pVis = (MHVisible)p; // Can now safely cast it.
CurrentApp().DisplayStack.RemoveAt(nPos); // Remove it from its present posn
CurrentApp().DisplayStack.InsertAt(pVis, 0); // Put it on the bottom.
Redraw(pVis.GetVisibleArea()); // Request a redraw
}
// Functions to alter the Z-order.
public void BringToFront(MHRoot p)
{
int nPos = CurrentApp().FindOnStack(p);
if (nPos == -1)
{
return; // If it's not there do nothing
}
MHVisible pVis = (MHVisible)p; // Can now safely cast it.
CurrentApp().DisplayStack.RemoveAt(nPos); // Remove it from its present posn
CurrentApp().DisplayStack.Append((MHVisible)pVis); // Push it on the top.
Redraw(pVis.GetVisibleArea()); // Request a redraw
}
// Return the value, looking up any indirect ref.
public void GetValue(MHContentRef reference, MHEngine engine)
{
if (m_fIsDirect)
{
reference.Copy(m_Direct);
}
else
{
MHUnion result = new MHUnion();
MHRoot pBase = engine.FindObject(m_Indirect);
pBase.GetVariableValue(result, engine);
result.CheckType(MHUnion.U_ContentRef);
reference.Copy(result.ContentRef);
}
}
// Return the value, looking up any indirect ref.
public bool GetValue(MHEngine engine)
{
if (m_fIsDirect)
{
return(m_fDirect);
}
else
{
MHUnion result = new MHUnion();
MHRoot pBase = engine.FindObject(m_Indirect);
pBase.GetVariableValue(result, engine);
result.CheckType(MHUnion.U_Bool);
return(result.Bool);
}
}
public void PutBehind(MHRoot p, MHRoot pRef)
{
int nPos = CurrentApp().FindOnStack(p);
if (nPos == -1)
{
return; // If it's not there do nothing
}
int nRef = CurrentApp().FindOnStack(pRef);
if (nRef == -1)
{
return; // If the reference visible isn't there do nothing.
}
MHVisible pVis = (MHVisible)p; // Can now safely cast it.
CurrentApp().DisplayStack.RemoveAt(nPos);
if (nRef >= nPos)
{
nRef--; // The position of the reference may have shifted
}
CurrentApp().DisplayStack.InsertAt((MHVisible)pVis, nRef); // Shift the reference and anything above up.
Redraw(pVis.GetVisibleArea()); // Request a redraw
}
public virtual void GetBoxSize(MHRoot pWidthDest, MHRoot HeightDest)
{
InvalidAction("GetBoxSize");
}
public virtual void PutBefore(MHRoot pRef, MHEngine engine)
{
InvalidAction("PutBefore");
}
public virtual void GetListSize(MHRoot pResult, MHEngine engine)
{
InvalidAction("GetListSize");
}
public virtual void GetPosition(MHRoot pXPosN, MHRoot pYPosN)
{
InvalidAction("GetPosition");
}
public virtual void DelItem(MHRoot pItem, MHEngine engine)
{
InvalidAction("GetCellItem");
}
public virtual void GetFirstItem(MHRoot pResult, MHEngine engine)
{
InvalidAction("GetFirstItem");
}
// Actions on ListGroups
public virtual void AddItem(int nIndex, MHRoot pItem, MHEngine engine)
{
InvalidAction("GetCellItem");
}
// Called when an event is triggered. Either queues the event or finds a link that matches.
public void EventTriggered(MHRoot pSource, int eventType)
{
EventTriggered(pSource, eventType, new MHUnion());
}
public virtual void GetFillColour(MHRoot pResult)
{
InvalidAction("GetFillColour");
}
public virtual void GetLineWidth(MHRoot pResult)
{
InvalidAction("GetLineWidth");
}
public virtual void PutBehind(MHRoot pRef, MHEngine engine)
{
InvalidAction("PutBehind");
}
public virtual void GetBitmapDecodeOffset(MHRoot pXOffset, MHRoot pYOffset)
{
InvalidAction("GetBitmapDecodeOffset");
}
// This isn't an MHEG action as such but is used as part of the implementation of "Clone"
public virtual void MakeClone(MHRoot target, MHRoot reference, MHEngine engine)
{
InvalidAction("MakeClone");
}
public virtual void GetLineStyle(MHRoot pResult)
{
InvalidAction("GetLineStyle");
}
// Actions on Text objects
public virtual void GetTextData(MHRoot pDestination, MHEngine engine)
{
InvalidAction("GetTextData");
}
public virtual void GetVideoDecodeOffset(MHRoot pXOffset, MHRoot pYOffset, MHEngine engine)
{
InvalidAction("GetVideoDecodeOffset");
}
public virtual void GetTokenPosition(MHRoot pResult, MHEngine engine)
{
InvalidAction("GetTokenPosition");
}
