Turbo Vision 2.0 Programming Guide
==================================

This file contains information on material added to Turbo Vision
2.0 after the Programming Guide had gone to press and also
corrections to a few errors in the manual.  We strongly suggest
that you mark these corrections and changes in your manual for
future reference.


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Changes and additions to Chapter 19, "Turbo Vision Reference"
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CreateFindDialog function                             Editors
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       Declaration  function CreateFindDialog: PDialog;

          Function  Constructs and returns a pointer to the
                    standard text search dialog box used by
                    StdEditorDialog. If you want to customize
                    the simpler editor dialog boxes but still
                    use the standard text search interface,
                    your editor dialog box function should
                    execute the dialog box returned by
                    CreateFindDialog for a Dialog parameter
                    of edFind.

          See also  EditorDialog variable, edXXXX constants,
                    StdEditorDialog function



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CreateReplaceDialog function                          Editors
=============================================================

       Declaration  function CreateReplaceDialog: PDialog;

          Function  Constructs and returns a pointer to the
                    standard text search-and-replace dialog
                    box used by StdEditorDialog. If you want
                    to customize the simpler editor dialog
                    boxes but still use the standard text
                    search interface, your editor dialog box
                    function should execute the dialog box
                    returned by CreateReplaceDialog for a
                    Dialog parameter of edReplace.

          See also  EditorDialog variable, edXXXX constants,
                    StdEditorDialog function



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FailSysErrors variable                                Drivers
=============================================================

       Declaration  FailSysErrors: Boolean = False;

                    If True, causes the system error handler
                    to behave as if the user had responded to
                    a system error message by pressing Esc.
                    Normally, the system error handler
                    displays a message on the last line of
                    the screen and waits for user input.
                    Setting FailSysErrors to True causes the
                    system error handler to bypass the
                    message and user prompt, and just return
                    as if the DOS call that produced the
                    error failed.

          See also  SysErrorFunc variable



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GetCtrlChar function                                  Drivers
=============================================================

       Declaration  function GetCtrlChar(KeyCode: Word):
                    Char;

          Function  Returns the character, Ch, for which
                    Ctrl+Ch produces the 2-byte scan code
                    given by the argument KeyCode. Gives the
                    reverse mapping to GetCtrlCode.

          See also  GetCtrlCode



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GetCtrlCode function                                  Drivers
=============================================================

       Declaration  function GetCtrlCode(Ch: Char): Word;

          Function  Returns the 2-byte scan code (keycode)
                    corresponding to Ctrl+Ch. This function
                    gives the reverse mapping to GetCtrlChar.

          See also  GetCtrlChar



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GetShiftState function                                Drivers
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       Declaration  function GetShiftState: Byte;

          Function  Returns a byte containing the current
                    Shift key state, as reported by DOS. The
                    return value contains a combination of
                    the kbXXXX constants for shift states.

                    You should call GetShiftState instead of
                    checking the ShiftState variable
                    directly. ShiftState is not guaranteed to
                    be valid in protected mode, but
                    GetShiftState returns the correct value
                    in either real or protected mode.

          See also  kbXXXX constants



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RegisterMenus procedure                                 Menus
=============================================================

       Declaration  procedure RegisterMenus;

          Function  Calls RegisterType for each of the object
                    types defined in the Menus unit:
                    TMenuBar, TMenuBox, TMenuPopup, and
                    TStatusLine. After calling RegisterMenus,
                    your application can read or write any of
                    those types with streams.

          See also  RegisterType procedure



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RegisterViews procedure                                 Views
=============================================================

       Declaration  procedure RegisterViews;

          Function  Calls RegisterType for each of the object
                    types defined in the Views unit: TView,
                    TFrame, TScrollBar, TScroller,
                    TListViewer, TGroup, and TWindow. After
                    calling RegisterViews, your application
                    can read or write any of those types with
                    streams.

          See also  RegisterType procedure



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ShiftState variable                                   Drivers
=============================================================

                    Although this variable exists to maintain
                    compatibility with version 1.0, you
                    should not check ShiftState directly.
                    Rather, you should call GetShiftState,
                    which returns a valid set of shift state
                    flags in either real or protected mode.



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TDesktop                                                  App
=============================================================

                    TDesktop has two additional methods not
                    documented.


           Methods  =========================================


              Load  constructor Load(var S: TStream);

                    Constructs and loads a desktop object
                    from the stream S by first calling the
                    Load constructor inherited from TGroup,
                    then calling GetSubViewPtr to set up the
                    Background field, then reading the
                    TileColumnsFirst field.

                    See also: TGroup.Load,
                    TGroup.GetSubViewPtr


             Store  procedure Store(var S: TStream);

                    Writes the desktop object to the stream S
                    by first calling the Store method
                    inherited from TGroup, then calling
                    PutSubViewPtr to store the Background
                    field, then writing the value of
                    TileColumnsFirst.

                    See also: TGroup.Store,
                    TGroup.PutSubViewPtr



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TMemoryStream                                         Objects
=============================================================

                    TMemoryStream implements a stream in heap
                    memory.
                    The mechanics of using memory streams are
                    simple. You construct a memory stream,
                    specifying its initial size and a block
                    size. The memory stream allocates as many
                    blocks on the heap as needed to meet the
                    initial size. Bytes stored on the stream
                    are not guaranteed to be in contiguous
                    memory locations unless the stream
                    consists of a single block.

                    Once you construct the stream, you use it
                    like any other. Writing beyond the end of
                    the stream causes the stream to grow in
                    increments of the initial block size, up
                    to a maximum of 16,384 blocks.

                    Changing the size of a memory stream by
                    enlarging or truncating could seriously
                    fragment your heap. Try to set the
                    initial size and block size of the stream
                    to reasonable values to minimize
                    individual allocations.


            Fields  =========================================

         BlockSize  BlockSize: Integer;

                    The size of each block allocated to the
                    memory stream.

            CurSeg  CurSeg: Integer;

                    Holds the segment part of the address of
                    the block that contains the current
                    stream position.

          Position  Position: Longint;

                    The position of the stream in bytes. The
                    first position is 0.

          SegCount  SegCount: Integer;

                    The number of blocks currently allocated
                    to the memory stream.

           SegList  SegList: PWordArray;

                    Contains the list of segment parts used
                    by each allocated block. The entries
                    0..SegCount-1 contain valid segments.

              Size  Size: Longint;

                    The size of the stream in bytes.


           Methods  =========================================

              Init  constructor Init(ALimit: Longint;
                    ABlockSize: Word);

                    Constructs a memory stream object by
                    first calling the Init constructor
                    inherited from TStream, then allocates
                    enough blocks of size ABlockSize to
                    collectively contain ALimit bytes. Sets
                    BlockSize to ABlockSize.

                    See also: TStream.Init

              Done  destructor Done; virtual;

                    Disposes of the memory stream object by
                    disposing of the memory allocated to the
                    stream, then calling the Done destructor
                    inherited from TStream.

                    See also: TStream.Done

            GetPos  function GetPos: Longint; virtual;

                    Returns the stream's current position.
                    The first position is 0.

           GetSize  function GetSize: Longint; virtual;

                    Returns the size of the stream in bytes.

              Read  procedure Read(var Buf; Count: Word);
                    virtual;

                    Reads Count bytes from the stream,
                    starting at the current position, into
                    the buffer Buf.

              Seek  procedure Seek(Pos: Longint); virtual;

                    Sets the current position to Pos bytes
                    from the start of the stream. The first
                    position is 0.

          Truncate  procedure Truncate; virtual;

                    Deletes all data on the stream from the
                    current position to the end. Sets the
                    current position to the new end of the
                    stream.

             Write  procedure Write(var Buf; Count: Word);
                    virtual;

                    Writes Count bytes from the buffer Buf to
                    the stream, starting at the current
                    position.



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TStringList                                           Objects
=============================================================

                    In the example code in the Load
                    constructor description, TBufStream
                    should be PBufStream.



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TStrListMaker                                         Objects
=============================================================

                    In the example code in the description of
                    how to use the string list maker,
                    TBufStream should be PBufStream.
