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asIScriptContext Class Referenceabstract

The interface to the virtual machine. More...

## Public Member Functions
Memory management
virtual int | AddRef () const =0
| Increase reference counter. More...
virtual int | Release () const =0
| Decrease reference counter. More...
Miscellaneous
virtual asIScriptEngine * | GetEngine () const =0
| Returns a pointer to the engine. More...
Execution
virtual int | Prepare (asIScriptFunction *func)=0
| Prepares the context for execution of the function. More...
virtual int | Unprepare ()=0
| Frees resources held by the context. More...
virtual int | Execute ()=0
| Executes the prepared function. More...
virtual int | Abort ()=0
| Aborts the execution. More...
virtual int | Suspend ()=0
| Suspends the execution, which can then be resumed by calling Execute again. More...
virtual asEContextState | GetState () const =0
| Returns the state of the context. More...
virtual int | PushState ()=0
| Backups the current state to prepare the context for a nested call. More...
virtual int | PopState ()=0
| Restores the state to resume previous script execution. More...
virtual bool | IsNested (asUINT *nestCount=0) const =0
| Returns true if the context has any nested calls. More...
Object pointer for calling class methods
virtual int | SetObject (void *obj)=0
| Sets the object for a class method call. More...
Arguments
virtual int | SetArgByte (asUINT arg, asBYTE value)=0
| Sets an 8-bit argument value. More...
virtual int | SetArgWord (asUINT arg, asWORD value)=0
| Sets a 16-bit argument value. More...
virtual int | SetArgDWord (asUINT arg, asDWORD value)=0
| Sets a 32-bit integer argument value. More...
virtual int | SetArgQWord (asUINT arg, asQWORD value)=0
| Sets a 64-bit integer argument value. More...
virtual int | SetArgFloat (asUINT arg, float value)=0
| Sets a float argument value. More...
virtual int | SetArgDouble (asUINT arg, double value)=0
| Sets a double argument value. More...
virtual int | SetArgAddress (asUINT arg, void *addr)=0
| Sets the address of a reference or handle argument. More...
virtual int | SetArgObject (asUINT arg, void *obj)=0
| Sets the object argument value. More...
virtual int | SetArgVarType (asUINT arg, void *ptr, int typeId)=0
| Sets the variable argument value and type. More...
virtual void * | GetAddressOfArg (asUINT arg)=0
| Returns a pointer to the argument for assignment. More...
Return value
virtual asBYTE | GetReturnByte ()=0
| Returns the 8-bit return value. More...
virtual asWORD | GetReturnWord ()=0
| Returns the 16-bit return value. More...
virtual asDWORD | GetReturnDWord ()=0
| Returns the 32-bit return value. More...
virtual asQWORD | GetReturnQWord ()=0
| Returns the 64-bit return value. More...
virtual float | GetReturnFloat ()=0
| Returns the float return value. More...
virtual double | GetReturnDouble ()=0
| Returns the double return value. More...
virtual void * | GetReturnAddress ()=0
| Returns the address for a reference or handle return type. More...
virtual void * | GetReturnObject ()=0
| Return a pointer to the returned object. More...
virtual void * | GetAddressOfReturnValue ()=0
| Returns the address of the returned value. More...
Exception handling
virtual int | SetException (const char *info, bool allowCatch=true)=0
| Sets an exception, which aborts the execution. More...
virtual int | GetExceptionLineNumber (int *column=0, const char **sectionName=0)=0
| Returns the line number where the exception occurred. More...
virtual asIScriptFunction * | GetExceptionFunction ()=0
| Returns the function where the exception occurred. More...
virtual const char * | GetExceptionString ()=0
| Returns the exception string text. More...
virtual bool | WillExceptionBeCaught ()=0
| Determine if the current exception will be caught by the script. More...
virtual int | SetExceptionCallback (asSFuncPtr callback, void *obj, int callConv)=0
| Sets an exception callback function. The function will be called if a script exception occurs. More...
virtual void | ClearExceptionCallback ()=0
| Removes the registered callback. More...
Debugging
virtual int | SetLineCallback (asSFuncPtr callback, void *obj, int callConv)=0
| Sets a line callback function. The function will be called for each executed script statement. More...
virtual void | ClearLineCallback ()=0
| Removes the registered callback. More...
virtual asUINT | GetCallstackSize () const =0
| Returns the size of the callstack, i.e. the number of functions that have yet to complete. More...
virtual asIScriptFunction * | GetFunction (asUINT stackLevel=0)=0
| Returns the function at the specified callstack level. More...
virtual int | GetLineNumber (asUINT stackLevel=0, int *column=0, const char **sectionName=0)=0
| Returns the line number at the specified callstack level. More...
virtual int | GetVarCount (asUINT stackLevel=0)=0
| Returns the number of local variables at the specified callstack level. More...
virtual const char * | GetVarName (asUINT varIndex, asUINT stackLevel=0)=0
| Returns the name of local variable at the specified callstack level. More...
virtual const char * | GetVarDeclaration (asUINT varIndex, asUINT stackLevel=0, bool includeNamespace=false)=0
| Returns the declaration of a local variable at the specified callstack level. More...
virtual int | GetVarTypeId (asUINT varIndex, asUINT stackLevel=0)=0
| Returns the type id of a local variable at the specified callstack level. More...
virtual void * | GetAddressOfVar (asUINT varIndex, asUINT stackLevel=0)=0
| Returns a pointer to a local variable at the specified callstack level. More...
virtual bool | IsVarInScope (asUINT varIndex, asUINT stackLevel=0)=0
| Informs whether the variable is in scope at the current program position. More...
virtual int | GetThisTypeId (asUINT stackLevel=0)=0
| Returns the type id of the object, if a class method is being executed. More...
virtual void * | GetThisPointer (asUINT stackLevel=0)=0
| Returns a pointer to the object, if a class method is being executed. More...
virtual asIScriptFunction * | GetSystemFunction ()=0
| Returns the registered function that is currently being called by the context. More...
User data
virtual void * | SetUserData (void *data, asPWORD type=0)=0
| Register the memory address of some user data. More...
virtual void * | GetUserData (asPWORD type=0) const =0
| Returns the address of the previously registered user data. More...

## Detailed Description

The script context provides the interface for a single script execution. The object stores the call stack where the local variables used by the execution are kept, however it doesn't keep copies of global variables as these are stored in the asIScriptModule, and only referenced by the context.

The value stored in a global variable is shared between all contexts, as they all refer to the same memory. This means that the global variables outlive the execution of a script, and will keep their values between executions.

It is seldom necessary to maintain more than one script context at a time, with the only exceptions being when a script calls an application function that in turn calls another script before returning, and if multiple scripts are running in parallel.

Try to avoid associating a unique context with each object that may need to call scripts. Instead keep a shared pool of contexts that can be requested by the objects on a need-to basis.

## Member Function Documentation

virtual int asIScriptContext::Abort | ( |  | ) |
| pure virtual

Returns
  A negative value on error.

Return values

  asERROR | Invalid context object.

Aborts the current execution of a script.

If the call to Abort is done from within a function called by the script, it will only take effect after that function returns.

virtual int asIScriptContext::AddRef | ( |  | ) | const
| pure virtual

Returns
  The number of references to this object.

Call this method when storing an additional reference to the object. Remember that the first reference that is received from asIScriptEngine::CreateContext is already accounted for.

virtual void asIScriptContext::ClearExceptionCallback | ( |  | ) |
| pure virtual

Removes a previously registered callback.

virtual void asIScriptContext::ClearLineCallback | ( |  | ) |
| pure virtual

Removes a previously registered callback.

virtual int asIScriptContext::Execute | ( |  | ) |
| pure virtual

Returns
  A negative value on error, or one of asEContextState.

Return values

  asCONTEXT_NOT_PREPARED | The context is not prepared or it is not in suspended state.
  asEXECUTION_ABORTED | The execution was aborted with a call to Abort.
  asEXECUTION_SUSPENDED | The execution was suspended with a call to Suspend.
  asEXECUTION_FINISHED | The execution finished successfully.
  asEXECUTION_EXCEPTION | The execution ended with an exception.

Executes the prepared function until the script returns. If the execution was previously suspended the function resumes where it left of.

Note that if the script freezes, e.g. if trapped in a never ending loop, you may call Abort from another thread to stop execution.

If the function returns asEXECUTION_EXCEPTION, use the GetExceptionString, GetExceptionFunction, and GetExceptionLineNumber to obtain more information on the exception and where it occurred.

See Also
  Calling a script function

virtual void* asIScriptContext::GetAddressOfArg | ( | asUINT | arg | ) |
| pure virtual

Parameters

  [in] | arg | The argument index.

Returns
  A pointer to the argument on the stack.

This method returns a pointer to the argument on the stack for assignment. For object handles, you should increment the reference counter. For object values, you should pass a pointer to a copy of the object.

virtual void* asIScriptContext::GetAddressOfReturnValue | ( |  | ) |
| pure virtual

Returns
  A pointer to the return value returned from the script function, or 0 on error.

virtual void* asIScriptContext::GetAddressOfVar | ( | asUINT | varIndex,
|  | asUINT | stackLevel = `0`
| ) |  |
| pure virtual

Parameters

  [in] | varIndex | The index of the variable.
  [in] | stackLevel | The index on the call stack.

Returns
  A pointer to the variable.

Returns a pointer to the variable, so that its value can be read and written. The address is valid until the script function returns.

Note that object variables may not be initalized at all moments, thus you must verify if the address returned points to a null pointer, before you try to dereference it.

virtual asUINT asIScriptContext::GetCallstackSize | ( |  | ) | const
| pure virtual

Returns
  The number of functions on the call stack, including the current function.

This methods returns the size of the callstack. It can be used to enumerate the callstack in order to generate a detailed report when an exception occurs, or for debugging running scripts.

virtual asIScriptEngine* asIScriptContext::GetEngine | ( |  | ) | const
| pure virtual

Returns
  A pointer to the engine.

virtual asIScriptFunction* asIScriptContext::GetExceptionFunction | ( |  | ) |
| pure virtual

Returns
  The function where the exception occurred.

virtual int asIScriptContext::GetExceptionLineNumber | ( | int * | column = `0`,
|  | const char ** | sectionName = `0`
| ) |  |
| pure virtual

Parameters

  [out] | column | The variable will receive the column number.
  [out] | sectionName | The variable will receive the name of the script section.

Returns
  The line number where the exception occurred.

This method returns the line number where the exception ocurred. The line number is relative to the script section where the function was implemented.

Observe that the returned sectionName can be null, e.g. if the function in which the exception occurred was a generated stub function.

virtual const char* asIScriptContext::GetExceptionString | ( |  | ) |
| pure virtual

Returns
  A null terminated string describing the exception that occurred.

virtual asIScriptFunction* asIScriptContext::GetFunction | ( | asUINT | stackLevel = `0` | ) |
| pure virtual

Parameters

  [in] | stackLevel | The index on the call stack.

Returns
  The function descriptor on the call stack referred to by the index.

Index 0 refers to the current function, index 1 to the calling function, and so on. The highest index is the originating function that the application called.

The returned value will be null if the stackLevel is invalid, or if the requested stack level doesn't have a defined function. The latter scenario happens when the engine performs a nested call internally, e.g. to call a constructor for a script object indirectly created.

If the application performs a nested call, then the returned value will give the application registered function that was called by the previous script.

See Also
  PushState

virtual int asIScriptContext::GetLineNumber | ( | asUINT | stackLevel = `0`,
|  | int * | column = `0`,
|  | const char ** | sectionName = `0`
| ) |  |
| pure virtual

Parameters

  [in] | stackLevel | The index on the call stack.
  [out] | column | The variable will receive the column number.
  [out] | sectionName | The variable will receive the name of the script section.

Returns
  The line number for the call stack level referred to by the index.

This function returns the line number, and optionally the column number and the name of the script section where the program is current at.

The sectionName pointer will point to an internal buffer, so do not deallocate it. If the function doesn't have any debug info sectionName will be set to null.

virtual void* asIScriptContext::GetReturnAddress | ( |  | ) |
| pure virtual

Returns
  The address value returned from the script function, or 0 on error.

The method doesn't increase the reference counter with this call, so if you store the pointer of a reference counted object you need to increase the reference manually otherwise the object will be released when the context is released or reused.

virtual asBYTE asIScriptContext::GetReturnByte | ( |  | ) |
| pure virtual

Returns
  The 1 byte value returned from the script function, or 0 on error.

virtual double asIScriptContext::GetReturnDouble | ( |  | ) |
| pure virtual

Returns
  The double value returned from the script function, or 0 on error.

virtual asDWORD asIScriptContext::GetReturnDWord | ( |  | ) |
| pure virtual

Returns
  The 4 byte value returned from the script function, or 0 on error.

virtual float asIScriptContext::GetReturnFloat | ( |  | ) |
| pure virtual

Returns
  The float value returned from the script function, or 0 on error.

virtual void* asIScriptContext::GetReturnObject | ( |  | ) |
| pure virtual

Returns
  A pointer to the object returned from the script function, or 0 on error.

The method doesn't increase the reference counter with this call, so if you store the pointer of a reference counted object you need to increase the reference manually otherwise the object will be released when the context is released or reused.

virtual asQWORD asIScriptContext::GetReturnQWord | ( |  | ) |
| pure virtual

Returns
  The 8 byte value returned from the script function, or 0 on error.

virtual asWORD asIScriptContext::GetReturnWord | ( |  | ) |
| pure virtual

Returns
  The 2 byte value returned from the script function, or 0 on error.

virtual asEContextState asIScriptContext::GetState | ( |  | ) | const
| pure virtual

Returns
  The current state of the context.

virtual asIScriptFunction* asIScriptContext::GetSystemFunction | ( |  | ) |
| pure virtual

Returns
  Returns the registered function that is currently being called, or null if no registered function is being called at the moment.

virtual void* asIScriptContext::GetThisPointer | ( | asUINT | stackLevel = `0` | ) |
| pure virtual

Parameters

  [in] | stackLevel | The index on the call stack.

Returns
  Returns a pointer to the object if it is a class method.

virtual int asIScriptContext::GetThisTypeId | ( | asUINT | stackLevel = `0` | ) |
| pure virtual

Parameters

  [in] | stackLevel | The index on the call stack.

Returns
  Returns the type id of the object if it is a class method.

virtual void* asIScriptContext::GetUserData | ( | asPWORD | type = `0` | ) | const
| pure virtual

Parameters

  [in] | type | An identifier specifying the user data to set.

Returns
  The pointer to the user data.

virtual int asIScriptContext::GetVarCount | ( | asUINT | stackLevel = `0` | ) |
| pure virtual

Parameters

  [in] | stackLevel | The index on the call stack.

Returns
  The number of variables in the function on the call stack level. Or negative value on error.

Return values

  asINVALID_ARG | The stackLevel is invalid.

Returns the number of declared variables, including the parameters, in the function on the stack.

virtual const char* asIScriptContext::GetVarDeclaration | ( | asUINT | varIndex,
|  | asUINT | stackLevel = `0`,
|  | bool | includeNamespace = `false`
| ) |  |
| pure virtual

Parameters

  [in] | varIndex | The index of the variable.
  [in] | stackLevel | The index on the call stack.
  [in] | includeNamespace | Set to true if the namespace should be included in the declaration.

Returns
  A null terminated string with the declaration of the variable.

virtual const char* asIScriptContext::GetVarName | ( | asUINT | varIndex,
|  | asUINT | stackLevel = `0`
| ) |  |
| pure virtual

Parameters

  [in] | varIndex | The index of the variable.
  [in] | stackLevel | The index on the call stack.

Returns
  A null terminated string with the name of the variable.

virtual int asIScriptContext::GetVarTypeId | ( | asUINT | varIndex,
|  | asUINT | stackLevel = `0`
| ) |  |
| pure virtual

Parameters

  [in] | varIndex | The index of the variable.
  [in] | stackLevel | The index on the call stack.

Returns
  The type id of the variable, or a negative value on error.

Return values

  asINVALID_ARG | The index or stack level is invalid.

virtual bool asIScriptContext::IsNested | ( | asUINT * | nestCount = `0` | ) | const
| pure virtual

Parameters

  [out] | nestCount | This argument receives the nesting level.

Returns
  true if there are any nested calls.

virtual bool asIScriptContext::IsVarInScope | ( | asUINT | varIndex,
|  | asUINT | stackLevel = `0`
| ) |  |
| pure virtual

Parameters

  [in] | varIndex | The index of the variable.
  [in] | stackLevel | The index on the call stack.

Returns
  True if variable is in scope.

This method can be used to determine if a variable is currently visible from the current program position. This is especially useful if multiple variables with the same name is declared in different scopes.

virtual int asIScriptContext::PopState | ( |  | ) |
| pure virtual

Returns
  A negative value on error.

Return values

  asERROR | The state couldn't be restored.

virtual int asIScriptContext::Prepare | ( | asIScriptFunction * | func | ) |
| pure virtual

Parameters

  [in] | func | The id of the function/method that will be executed.

Returns
  A negative value on error.

Return values

  asCONTEXT_ACTIVE | The context is still active or suspended.
  asNO_FUNCTION | The function pointer is null.
  asINVALID_ARG | The function is from a different engine than the context.
  asOUT_OF_MEMORY | The context ran out of memory while allocating call stack.

This method prepares the context for executeion of a script function. It allocates the stack space required and reserves space for return value and parameters. The default value for parameters and return value is 0.

See Also
  Calling a script function

virtual int asIScriptContext::PushState | ( |  | ) |
| pure virtual

Returns
  A negative value on error.

Return values

  asERROR | The current context is not active.
  asOUT_OF_MEMORY | Couldn't allocate memory to store state.

This method can be invoked on an active context in order to reuse the context for a nested call, e.g. when a function called by a script needs to call another script before returning. After the method returns with success the method Prepare() shall be invoked to prepare the new execution.

By reusing an active context the application can avoid creating a temporary context, and thus improve the run-time performance.

For each successful call to PushState() the method PopState() must be called to return the state in order to resume the previous script execution.

If PushState() fails, the context was not modified, so the application can just create a different context instead, and when it is done with it the original context can be resumed normally.

virtual int asIScriptContext::Release | ( |  | ) | const
| pure virtual

Returns
  The number of references to this object.

Call this method when you will no longer use the references that you own.

virtual int asIScriptContext::SetArgAddress | ( | asUINT | arg,
|  | void * | addr
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | addr | The address that should be passed in the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a reference or an object handle.

Sets an address argument, e.g. an object handle or a reference.

virtual int asIScriptContext::SetArgByte | ( | asUINT | arg,
|  | asBYTE | value
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | value | The value of the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not an 8-bit value.

Sets a 1 byte argument.

virtual int asIScriptContext::SetArgDouble | ( | asUINT | arg,
|  | double | value
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | value | The value of the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a 64-bit value.

Sets a double argument.

virtual int asIScriptContext::SetArgDWord | ( | asUINT | arg,
|  | asDWORD | value
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | value | The value of the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a 32-bit value.

Sets a 4 byte argument.

virtual int asIScriptContext::SetArgFloat | ( | asUINT | arg,
|  | float | value
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | value | The value of the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a 32-bit value.

Sets a float argument.

virtual int asIScriptContext::SetArgObject | ( | asUINT | arg,
|  | void * | obj
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | obj | A pointer to the object.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not an object or handle.

Sets an object argument. If the argument is an object handle AngelScript will increment the reference for the object. If the argument is an object value AngelScript will make a copy of the object.

virtual int asIScriptContext::SetArgQWord | ( | asUINT | arg,
|  | asQWORD | value
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | value | The value of the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a 64-bit value.

Sets an 8 byte argument.

virtual int asIScriptContext::SetArgVarType | ( | asUINT | arg,
|  | void * | ptr,
|  | int | typeId
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | ptr | A pointer to the value.
  [in] | typeId | The type id of the value.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a variable type.

This method should be used when setting the argument for functions with variable parameter types.

virtual int asIScriptContext::SetArgWord | ( | asUINT | arg,
|  | asWORD | value
| ) |  |
| pure virtual

Parameters

  [in] | arg | The argument index.
  [in] | value | The value of the argument.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asINVALID_ARG | The arg is larger than the number of arguments in the prepared function.
  asINVALID_TYPE | The argument is not a 16-bit value.

Sets a 2 byte argument.

virtual int asIScriptContext::SetException | ( | const char * | info,
|  | bool | allowCatch = `true`
| ) |  |
| pure virtual

Parameters

  [in] | info | A string that describes the exception that occurred.
  [in] | allowCatch | Set to false if the script shouldn't be allowed to catch the exception.

Returns
  A negative value on error.

Return values

  asERROR | The context isn't currently calling an application registered function.

This method sets a script exception in the context. This will only work if the context is currently calling a system function, thus this method can only be used for system functions.

Note that if your system function sets an exception, it should not return any object references because the engine will not release the returned reference.

virtual int asIScriptContext::SetExceptionCallback | ( | asSFuncPtr | callback,
|  | void * | obj,
|  | int | callConv
| ) |  |
| pure virtual

Parameters

  [in] | callback | The callback function/method that should be called upon an exception.
  [in] | obj | The object pointer on which the callback is called.
  [in] | callConv | The calling convention of the callback function/method.

Returns
  A negative value on error.

Return values

  asNOT_SUPPORTED | Calling convention must not be asCALL_GENERIC, or the routine's calling convention is not supported.
  asINVALID_ARG | obj must not be null for class methods.
  asWRONG_CALLING_CONV | callConv isn't compatible with the routines' calling convention.

This callback function will be called by the VM when a script exception is raised, which allow the application to examine the callstack and generate a detailed report before the callstack is cleaned up.

The callback function can be either a global function or a class method. For a global function the VM will pass two parameters, first the context pointer and then the object pointer specified by the application. For a class method, the VM will call the method using the object pointer as the owner.

void Callback(asIScriptContext *ctx, void *obj);
void Object::Callback(asIScriptContext *ctx);

The global function can use either asCALL_CDECL or asCALL_STDCALL, and the class method can use either asCALL_THISCALL, asCALL_CDECL_OBJLAST, or asCALL_CDECL_OBJFIRST.

See Also
  Exception handling

virtual int asIScriptContext::SetLineCallback | ( | asSFuncPtr | callback,
|  | void * | obj,
|  | int | callConv
| ) |  |
| pure virtual

Parameters

  [in] | callback | The callback function/method that should be called for each script line executed.
  [in] | obj | The object pointer on which the callback is called.
  [in] | callConv | The calling convention of the callback function/method.

Returns
  A negative value on error.

Return values

  asNOT_SUPPORTED | Calling convention must not be asCALL_GENERIC, or the routine's calling convention is not supported.
  asINVALID_ARG | obj must not be null for class methods.
  asWRONG_CALLING_CONV | callConv isn't compatible with the routines' calling convention.

This function sets a callback function that will be called by the VM each time the SUSPEND instruction is encounted. Generally this instruction is placed before each statement. Thus by setting this callback function it is possible to monitor the execution, and suspend the execution at application defined locations.

The callback function can be either a global function or a class method. For a global function the VM will pass two parameters, first the context pointer and then the object pointer specified by the application. For a class method, the VM will call the method using the object pointer as the owner.

void Callback(asIScriptContext *ctx, void *obj);
void Object::Callback(asIScriptContext *ctx);

The global function can use either asCALL_CDECL or asCALL_STDCALL, and the class method can use either asCALL_THISCALL, asCALL_CDECL_OBJLAST, or asCALL_CDECL_OBJFIRST.

See Also
  Debugging scripts

virtual int asIScriptContext::SetObject | ( | void * | obj | ) |
| pure virtual

Parameters

  [in] | obj | A pointer to the object.

Returns
  A negative value on error.

Return values

  asCONTEXT_NOT_PREPARED | The context is not in prepared state.
  asERROR | The prepared function is not a class method.

This method sets object pointer when calling class methods.

virtual void* asIScriptContext::SetUserData | ( | void * | data,
|  | asPWORD | type = `0`
| ) |  |
| pure virtual

Parameters

  [in] | data | A pointer to the user data.
  [in] | type | An identifier specifying the user data to set.

Returns
  The previous pointer stored in the context.

This method allows the application to associate a value, e.g. a pointer, with the context instance.

The type values 1000 through 1999 are reserved for use by the official add-ons.

Optionally, a callback function can be registered to clean up the user data when the context is destroyed. As the callback is registered with the engine, it is only necessary to do it once, even if more than one context is used.

virtual int asIScriptContext::Suspend | ( |  | ) |
| pure virtual

Returns
  A negative value on error.

Return values

  asERROR | Invalid context object.

Suspends the current execution of a script. The execution can then be resumed by calling Execute again.

If the call to Suspend is done from within a function called by the script, it will only take effect after that function returns.

See Also
  Calling a script function

virtual int asIScriptContext::Unprepare | ( |  | ) |
| pure virtual

Returns
  A negative value on error.

Return values

  asCONTEXT_ACTIVE | The context is still active or suspended.

This function frees resources held by the context. It's usually not necessary to call this function as the resources are automatically freed when the context is released, or reused when Prepare is called again.

virtual bool asIScriptContext::WillExceptionBeCaught | ( |  | ) |
| pure virtual

Returns
  True if the exception will be caught by the script.

This method is intended to be used from the exception callback, where the application can potentially make a different decision depending on whether the script will catch the exception or not.

The documentation for this class was generated from the following file:

- angelscript.h