TObject

From Lazarus wiki
Jump to navigationJump to search

English (en) suomi (fi)

TObject is the base class for any other class, whether you declare it or not. It provides only some very generic methods, mostly virtual. The rationale for TObject is that in Object Pascal every class must be derived from another, TObject being the exception that ends the derivation chain.

The constructor TObject.Create(), inherited by every other class by default, can be hidden declaring another constructor with the same name in the derived class, with or without parameters. This come handy implementing the Singleton pattern.

 { Defined in objpash.inc }


constructor Create; 
destructor  Destroy; virtual;
class function newinstance : tobject; virtual;
procedure CleanupInstance;
procedure FreeInstance; virtual;

function  SafeCallException(exceptobject : tobject; exceptaddr : codepointer) : HResult; virtual;
procedure DefaultHandler(var message);virtual;
procedure Free;

class function InitInstance(instance : pointer) : tobject; 
class function ClassType : tclass; 
class function ClassInfo : pointer;
class function ClassName : shortstring;
class function ClassNameIs(const name : string) : boolean;
class function ClassParent : tclass;
class function InstanceSize : SizeInt;
class function InheritsFrom(aclass : tclass) : boolean;
class function StringMessageTable : pstringmessagetable;
class function MethodAddress(const name : shortstring) : codepointer;
class function MethodName(address : codepointer) : shortstring;
function FieldAddress(const name : shortstring) : pointer;

procedure AfterConstruction;virtual;
procedure BeforeDestruction;virtual;

procedure DefaultHandlerStr(var message);virtual;

procedure Dispatch(var message);virtual;
procedure DispatchStr(var message);virtual;

function GetInterface(const iid : tguid; out obj) : boolean;
function GetInterface(const iidstr : shortstring;out obj) : boolean;
function GetInterfaceByStr(const iidstr : shortstring; out obj) : boolean;
function GetInterfaceWeak(const iid : tguid; out obj) : boolean;

class function GetInterfaceEntry(const iid : tguid) : pinterfaceentry;
class function GetInterfaceEntryByStr(const iidstr : shortstring) : pinterfaceentry;
class function GetInterfaceTable : pinterfacetable;

class function UnitName : ansistring;
function Equals(Obj: TObject) : boolean; virtual;
function GetHashCode: PtrInt; virtual;
function ToString: ansistring; virtual;