docs/latex/wx/dataform.tex

   1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2 %% Name:        dataform.tex
   3 %% Purpose:     wxDataFormat documentation
   4 %% Author:      Vadim Zeitlin
   5 %% Modified by:
   6 %% Created:     03.11.99
   7 %% RCS-ID:      $Id$
   8 %% Copyright:   (c) Vadim Zeitlin
   9 %% License:     wxWindows license
  10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  11
  12 \section{\class{wxDataFormat}}\label{wxdataformat}
  13
  14 A wxDataFormat is an encapsulation of a platform-specific format handle which
  15 is used by the system for the clipboard and drag and drop operations. The
  16 applications are usually only interested in, for example, pasting data from the
  17 clipboard only if the data is in a format the program understands and a data
  18 format is something which uniquely identifies this format.
  19
  20 On the system level, a data format is usually just a number ({\tt CLIPFORMAT}
  21 under Windows or {\tt Atom} under X11, for example) and the standard formats
  22 are, indeed, just numbers which can be implicitly converted to wxDataFormat.
  23 The standard formats are:
  24
  25 \begin{twocollist}\itemsep=1cm
  26 \twocolitem{wxDF\_INVALID}{An invalid format - used as default argument for
  27 functions taking a wxDataFormat argument sometimes}
  28 \twocolitem{wxDF\_TEXT}{Text format (wxString)}
  29 \twocolitem{wxDF\_BITMAP}{A bitmap (wxBitmap)}
  30 \twocolitem{wxDF\_METAFILE}{A metafile (wxMetafile, Windows only)}
  31 \twocolitem{wxDF\_FILENAME}{A list of filenames}
  32 \end{twocollist}
  33
  34 As mentioned above, these standard formats may be passed to any function taking
  35 wxDataFormat argument because wxDataFormat has an implicit conversion from
  36 them (or, to be precise from the type {\tt wxDataFormat::NativeFormat} which is
  37 the type used by the underlying platform for data formats).
  38
  39 Aside the standard formats, the application may also use custom formats which
  40 are identified by their names (strings) and not numeric identifiers. Although
  41 internally custom format must be created (or {\it registered}) first, you
  42 shouldn't care about it because it is done automatically the first time the
  43 wxDataFormat object corresponding to a given format name is created. The only
  44 implication of this is that you should avoid having global wxDataFormat objects
  45 with non-default constructor because their constructors are executed before the
  46 program has time to perform all necessary initialisations and so an attempt to
  47 do clipboard format registration at this time will usually lead to a crash!
  48
  49 \wxheading{Virtual functions to override}
  50
  51 None
  52
  53 \wxheading{Derived from}
  54
  55 None
  56
  57 \wxheading{See also}
  58
  59 \helpref{Clipboard and drag and drop overview}{wxdndoverview},
  60 \helpref{DnD sample}{samplednd},
  61 \helpref{wxDataObject}{wxdataobject}
  62
  63 \latexignore{\rtfignore{\wxheading{Members}}}
  64
  65 \membersection{wxDataFormat::wxDataFormat}\label{wxdataformatwxdataformatdef}
  66
  67 \func{}{wxDataFormat}{\param{NativeFormat}{ format = wxDF\_INVALID}}
  68
  69 Constructs a data format object for one of the standard data formats or an
  70 empty data object (use \helpref{SetType}{wxdataformatsettype} or
  71 \helpref{SetId}{wxdataformatsetid} later in this case)
  72
  73 \membersection{wxDataFormat::wxDataFormat}\label{wxdataformatwxdataformat}
  74
  75 \func{}{wxDataFormat}{\param{const wxChar }{*format}}
  76
  77 Constructs a data format object for a custom format identified by its name
  78 {\it format}.
  79
  80 \membersection{wxDataFormat::operator $==$}\label{wxdataformatoperatoreq}
  81
  82 \constfunc{bool}{operator $==$}{\param{const wxDataFormat\&}{ format}}
  83
  84 Returns TRUE if the formats are equal.
  85
  86 \membersection{wxDataFormat::operator $!=$}\label{wxdataformatoperatorneq}
  87
  88 \constfunc{bool}{operator $!=$}{\param{const wxDataFormat\&}{ format}}
  89
  90 Returns TRUE if the formats are different.
  91
  92 \membersection{wxDataFormat::GetId}\label{wxdataformatgetid}
  93
  94 \constfunc{wxString}{GetId}{\void}
  95
  96 Returns the name of a custom format (this function will fail for a standard
  97 format).
  98
  99 \membersection{wxDataFormat::GetType}\label{wxdataformatgettype}
 100
 101 \constfunc{NativeFormat}{GetType}{\void}
 102
 103 Returns the platform-specific number identifying the format.
 104
 105 \membersection{wxDataFormat::SetId}\label{wxdataformatsetid}
 106
 107 \func{void}{SetId}{\param{const wxChar }{*format}}
 108
 109 Sets the format to be the custom format identified by the given name.
 110
 111 \membersection{wxDataFormat::SetType}\label{wxdataformatsettype}
 112
 113 \func{void}{SetType}{\param{NativeFormat}{ format}}
 114
 115 Sets the format to the given value, which should be one of wxDF\_XXX constants.
 116