TAbstractObjectReader
[Properties (by Name)][Methods (by Name)][Events (by Name)]
Abstract driver class to read stored component data.
Declaration
Source position: classesh.inc line 1384
Type
TAbstractObjectReader = class
public
procedure FlushBuffer; Virtual;
function NextValue : TValueType; Virtual; Abstract;
function ReadValue : TValueType; Virtual; Abstract;
procedure BeginRootComponent; Virtual; Abstract;
procedure BeginComponent(var Flags: TFilerFlags;
var AChildPos: Integer;
var CompClassName: string; var CompName: string)
; Virtual; Abstract;
function BeginProperty : string; Virtual; Abstract;
procedure Read(var Buf; Count: LongInt); Virtual; Abstract;
procedure ReadBinary(const DestData: TMemoryStream); Virtual; Abstract;
function ReadFloat : Extended; Virtual; Abstract;
function ReadSingle : Single; Virtual; Abstract;
function ReadDate : TDateTime; Virtual; Abstract;
function ReadCurrency : Currency; Virtual; Abstract;
function ReadIdent(ValueType: TValueType) : string; Virtual; Abstract;
function ReadInt8 : ShortInt; Virtual; Abstract;
function ReadInt16 : SmallInt; Virtual; Abstract;
function ReadInt32 : LongInt; Virtual; Abstract;
function ReadInt64 : Int64; Virtual; Abstract;
function ReadSet(EnumType: Pointer) : Integer; Virtual; Abstract;
procedure ReadSignature; Virtual; Abstract;
function ReadStr : string; Virtual; Abstract;
function ReadString(StringType: TValueType) : string; Virtual
; Abstract;
function ReadWideString : WideString; Virtual; Abstract;
function ReadUnicodeString : UnicodeString; Virtual; Abstract;
procedure SkipComponent(SkipComponentInfos: Boolean); Virtual
; Abstract;
procedure SkipValue; Virtual; Abstract;
end
;
Description
The Free Pascal streaming mechanism, while compatible with Delphi's mechanism, differs from it in the sense that the streaming mechanism uses a driver class when streaming components. The TAbstractObjectReader class is the base driver class for reading property values from streams. It consists entirely of abstract methods, which must be implemented by descendant classes.
Different streaming mechanisms can be implemented by making a descendant from TAbstractObjectReader. The TBinaryObjectReader class is such a descendant class, which streams data in binary (Delphi compatible) format.
All methods described in this class, must be implemented by descendant classes.
Members
| Member | Type | Visibility | Description |
|---|---|---|---|
| BeginComponent | Method | public | Marks the reading of a new component. |
| BeginProperty | Method | public | Marks the reading of a property value. |
| BeginRootComponent | Method | public | Starts the reading of the root component. |
| FlushBuffer | Method | public | Flush the buffer |
| NextValue | Method | public | Returns the type of the next value in the stream. |
| Read | Method | public | Read raw data from stream |
| ReadBinary | Method | public | Read binary data from the stream. |
| ReadCurrency | Method | public | Read a currency value from the stream. |
| ReadDate | Method | public | Read a date value from the stream. |
| ReadFloat | Method | public | Read a float value from the stream. |
| ReadIdent | Method | public | Read an identifier from the stream. |
| ReadInt16 | Method | public | Read a 16-bit integer from the stream. |
| ReadInt32 | Method | public | Read a 32-bit integer from the stream. |
| ReadInt64 | Method | public | Read a 64-bit integer from the stream. |
| ReadInt8 | Method | public | Read an 8-bit integer from the stream. |
| ReadSet | Method | public | Reads a set from the stream. |
| ReadSignature | Method | public | Read resource signature |
| ReadSingle | Method | public | Read a single (real-type) value from the stream. |
| ReadStr | Method | public | Read a shortstring from the stream |
| ReadString | Method | public | Read a string of type StringType from the stream. |
| ReadUnicodeString | Method | public | Read a Unicode string value |
| ReadValue | Method | public | Reads the type of the next value. |
| ReadWideString | Method | public | Read a widestring value from the stream. |
| SkipComponent | Method | public | Skip till the end of the component. |
| SkipValue | Method | public | Skip the current value. |
Inheritance
| Class | Description |
|---|---|
| TAbstractObjectReader | Abstract driver class to read stored component data. |
See also
| Name | Description |
|---|---|
| TBinaryObjectReader | Driver class descendant which reads component data stored in binary format. |