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 \twocolitem{wxDF\_HTML}{An HTML string. This is only valid when passed to wxSetClipboardData
  33 when compiled with Visual C++ in non-Unicode mode}
  34 \end{twocollist}
  35
  36 As mentioned above, these standard formats may be passed to any function taking
  37 wxDataFormat argument because wxDataFormat has an implicit conversion from
  38 them (or, to be precise from the type {\tt wxDataFormat::NativeFormat} which is
  39 the type used by the underlying platform for data formats).
  40
  41 Aside the standard formats, the application may also use custom formats which
  42 are identified by their names (strings) and not numeric identifiers. Although
  43 internally custom format must be created (or {\it registered}) first, you
  44 shouldn't care about it because it is done automatically the first time the
  45 wxDataFormat object corresponding to a given format name is created. The only
  46 implication of this is that you should avoid having global wxDataFormat objects
  47 with non-default constructor because their constructors are executed before the
  48 program has time to perform all necessary initialisations and so an attempt to
  49 do clipboard format registration at this time will usually lead to a crash!
  50
  51 \wxheading{Virtual functions to override}
  52
  53 None
  54
  55 \wxheading{Derived from}
  56
  57 None
  58
  59 \wxheading{See also}
  60
  61 \helpref{Clipboard and drag and drop overview}{wxdndoverview},
  62 \helpref{DnD sample}{samplednd},
  63 \helpref{wxDataObject}{wxdataobject}
  64
  65 \latexignore{\rtfignore{\wxheading{Members}}}
  66
  67 \membersection{wxDataFormat::wxDataFormat}\label{wxdataformatwxdataformatdef}
  68
  69 \func{}{wxDataFormat}{\param{NativeFormat}{ format = wxDF\_INVALID}}
  70
  71 Constructs a data format object for one of the standard data formats or an
  72 empty data object (use \helpref{SetType}{wxdataformatsettype} or
  73 \helpref{SetId}{wxdataformatsetid} later in this case)
  74
  75 \perlnote{In wxPerl this function is named {\tt newNative}.}
  76
  77 \membersection{wxDataFormat::wxDataFormat}\label{wxdataformatwxdataformat}
  78
  79 \func{}{wxDataFormat}{\param{const wxChar }{*format}}
  80
  81 Constructs a data format object for a custom format identified by its name
  82 {\it format}.
  83
  84 \perlnote{In wxPerl this function is named {\tt newUser}.}
  85
  86 \membersection{wxDataFormat::operator $==$}\label{wxdataformatoperatoreq}
  87
  88 \constfunc{bool}{operator $==$}{\param{const wxDataFormat\&}{ format}}
  89
  90 Returns true if the formats are equal.
  91
  92 \membersection{wxDataFormat::operator $!=$}\label{wxdataformatoperatorneq}
  93
  94 \constfunc{bool}{operator $!=$}{\param{const wxDataFormat\&}{ format}}
  95
  96 Returns true if the formats are different.
  97
  98 \membersection{wxDataFormat::GetId}\label{wxdataformatgetid}
  99
 100 \constfunc{wxString}{GetId}{\void}
 101
 102 Returns the name of a custom format (this function will fail for a standard
 103 format).
 104
 105 \membersection{wxDataFormat::GetType}\label{wxdataformatgettype}
 106
 107 \constfunc{NativeFormat}{GetType}{\void}
 108
 109 Returns the platform-specific number identifying the format.
 110
 111 \membersection{wxDataFormat::SetId}\label{wxdataformatsetid}
 112
 113 \func{void}{SetId}{\param{const wxChar }{*format}}
 114
 115 Sets the format to be the custom format identified by the given name.
 116
 117 \membersection{wxDataFormat::SetType}\label{wxdataformatsettype}
 118
 119 \func{void}{SetType}{\param{NativeFormat}{ format}}
 120
 121 Sets the format to the given value, which should be one of wxDF\_XXX constants.
 122