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.
}
protected MHGroup ParseProgram(byte[] text)
{
if (text.Length == 0)
{
return(null);
}
IMHParser parser = null;
MHParseNode pTree = null;
MHGroup pRes = null;
// Look at the first byte to decide whether this is text or binary. Binary
// files will begin with 0xA0 or 0xA1, text files with white space, comment ('/')
// or curly bracket.
// This is only there for testing: all downloaded objects will be in ASN1
byte ch = text[0];
if (ch >= 128)
{
parser = new MHParseBinary(text);
}
else
{
parser = new MHParseText(text);
}
// Parse the binary or text.
pTree = parser.Parse();
switch (pTree.GetTagNo())
{ // The parse node should be a tagged item.
case ASN1Codes.C_APPLICATION: pRes = new MHApplication(); break;
case ASN1Codes.C_SCENE: pRes = new MHScene(); break;
default: pTree.Failure("Expected Application or Scene"); break; // throws exception.
}
pRes.Initialise(pTree, this); // Convert the parse tree.
return(pRes);
}
public void TransitionToScene(MHObjectRef target)
{
int i;
if (m_fInTransition)
{
// TransitionTo is not allowed in OnStartUp or OnCloseDown actions.
Logging.Log(Logging.MHLogWarning, "TransitionTo during transition - ignoring");
return;
}
if (target.GroupId.Size == 0)
{
return; // No file name.
}
string csPath = GetPathName(target.GroupId);
// Check that the file exists before we commit to the transition.
byte[] text;
if (!m_Context.GetCarouselData(csPath, out text))
{
return;
}
// Parse and run the file.
MHGroup pProgram = ParseProgram(text);
if (pProgram.IsApp)
{
throw new MHEGException("Expected a scene");
}
// Clear the action queue of anything pending.
m_ActionStack.Clear();
// At this point we have managed to load the scene.
// Deactivate any non-shared ingredients in the application.
MHApplication pApp = CurrentApp();
for (i = pApp.Items.Size; i > 0; i--)
{
MHIngredient pItem = pApp.Items.GetAt(i - 1);
if (!pItem.IsShared())
{
pItem.Deactivation(this); // This does not remove them from the display stack.
}
}
m_fInTransition = true; // TransitionTo etc are not allowed.
if (pApp.CurrentScene != null)
{
pApp.CurrentScene.Deactivation(this); // This may involve a call to RunActions
pApp.CurrentScene.Destruction(this);
}
// Everything that belongs to the previous scene should have been removed from the display stack.
// At this point we may have added actions to the queue as a result of synchronous
// events during the deactivation.
// Remove any events from the asynch event queue unless they derive from
// the application itself or a shared ingredient.
List <MHAsynchEvent> removeEvents = new List <MHAsynchEvent>();
foreach (MHAsynchEvent e in m_EventQueue)
{
if (!e.EventSource.IsShared())
{
removeEvents.Add(e);
}
}
foreach (MHAsynchEvent e in removeEvents)
{
m_EventQueue.Remove(e);
}
// Can now actually delete the old scene.
if (pApp.CurrentScene != null)
{
pApp.CurrentScene = null;
}
// Switch to the new scene.
CurrentApp().CurrentScene = (MHScene)pProgram;
SetInputRegister(CurrentScene().EventReg);
m_redrawRegion = new Region(new Rectangle(0, 0, CurrentScene().SceneCoordX, CurrentScene().SceneCoordY)); // Redraw the whole screen
if ((Logging.GetLoggingLevel() & Logging.MHLogScenes) != 0)
{ // Print it so we know what's going on.
pProgram.Print(Logging.GetLoggingStream(), 0);
}
pProgram.Preparation(this);
pProgram.Activation(this);
m_fInTransition = false; // The transition is complete
}