docs/latex/wx/dataviewmodel.tex

   1
   2 \section{\class{wxDataViewModel}}\label{wxdataviewmodel}
   3
   4 wxDataViewModel is the base class for all data model to be
   5 displayed by a \helpref{wxDataViewCtrl}{wxdataviewctrl}.
   6 All other models derive from it and must implement its
   7 pure virtual functions in order to define a complete
   8 data model. In detail, you need to override
   9 \helpref{IsContainer}{wxdataviewmodeliscontainer},
  10 \helpref{GetParent}{wxdataviewmodelgetparent},
  11 \helpref{GetColumnCount}{wxdataviewmodelgetcolumncount},
  12 \helpref{GetColumnType}{wxdataviewmodelgetcolumntype} and
  13 \helpref{GetValue}{wxdataviewmodelgetvalue} in order to
  14 define the data model which acts as an interface between
  15 your actual data and the wxDataViewCtrl. Since you will
  16 usually also allow the wxDataViewCtrl to change your data
  17 through its graphical interface, you will also have to override
  18 \helpref{SetValue}{wxdataviewlistmodelsetvalue} which the
  19 wxDataViewCtrl will call when a change to some data has been
  20 commited.
  21
  22 wxDataViewModel (as indeed the entire wxDataViewCtrl
  23 code) is using \helpref{wxVariant}{wxvariant} to store data and
  24 its type in a generic way. wxVariant can be extended to contain
  25 almost any data without changes to the original class.
  26
  27 The data that is presented through this data model is expected
  28 to change at run-time. You need to inform the data model when
  29 a change happened. Depending on what happened you need to call
  30 one of the following methods:
  31 \helpref{ValueChanged}{wxdataviewmodelvaluechanged},
  32 \helpref{ItemAdded}{wxdataviewmodelitemadded},
  33 \helpref{ItemDeleted}{wxdataviewmodelitemdeleted},
  34 \helpref{ItemChanged}{wxdataviewmodelitemchanged},
  35 \helpref{Cleared}{wxdataviewmodelcleared}.
  36
  37 Note that wxDataViewModel does not define the position or
  38 index of any item in the control since several control might
  39 display the data differently, but wxDataViewModel does
  40 provide a \helpref{Compare}{wxdataviewmodelcompare} method
  41 which the wxDataViewCtrl may use to sort the data.
  42
  43 This class maintains a list of
  44 \helpref{wxDataViewModelNotifier}{wxdataviewmodelnotifier}
  45 which link this class to the specific implementations on the
  46 supported platforms so that e.g. calling
  47 \helpref{ValueChanged}{wxdataviewmodelvaluechanged}
  48 on this model will just call
  49 \helpref{wxDataViewModelNotifier::ValueChanged}{wxdataviewmodelnotifiervaluechanged}
  50 for each notifier that has been added. You can also add
  51 your own notifier in order to get informed about any changes
  52 to the data in the list model.
  53
  54 Currently wxWidgets provides the following models apart
  55 from the base model:
  56 \helpref{wxDataViewIndexListModel}{wxdataviewindexlistmodel}.
  57 It is planned to add helper classes for simple tree
  58 and list stores in the future.
  59
  60 \wxheading{Derived from}
  61
  62 \helpref{wxObjectRefData}{wxobjectrefdata}
  63
  64 \wxheading{Include files}
  65
  66 <wx/dataview.h>
  67
  68 \wxheading{Library}
  69
  70 \helpref{wxAdv}{librarieslist}
  71
  72 \membersection{wxDataViewModel::wxDataViewModel}\label{wxdataviewmodelwxdataviewmodel}
  73
  74 \func{}{wxDataViewModel}{\void}
  75
  76 Constructor.
  77
  78
  79 \membersection{wxDataViewModel::\destruct{wxDataViewModel}}\label{wxdataviewmodeldtor}
  80
  81 \func{}{\destruct{wxDataViewModel}}{\void}
  82
  83 Destructor. This should not be called directly. Use DecRef() instead.
  84
  85
  86 \membersection{wxDataViewModel::AddNotifier}\label{wxdataviewmodeladdnotifier}
  87
  88 \func{void}{AddNotifier}{\param{wxDataViewModelNotifier* }{notifier}}
  89
  90 Adds a \helpref{wxDataViewModelNotifier}{wxdataviewlistmodelnotifier}
  91 to the model.
  92
  93 \membersection{wxDataViewModel::Cleared}\label{wxdataviewmodelcleared}
  94
  95 \func{bool}{Cleared}{\void}
  96
  97 Called to inform the model that all data has been deleted.
  98
  99 \membersection{wxDataViewModel::Compare}\label{wxdataviewmodelcompare}
 100
 101 \func{int}{Compare}{\param{const wxDataViewItem\& }{item1}, \param{const wxDataViewItem\& }{item2}, \param{unsigned int }{column}, \param{bool }{ascending}}
 102
 103 The compare function to be used by control. The default compare function
 104 sorts by container and other items separately and in ascending order.
 105 Override this for a different sorting behaviour.
 106
 107 \membersection{wxDataViewModel::GetColumnCount}\label{wxdataviewmodelgetcolumncount}
 108
 109 \constfunc{unsigned int}{GetColumnCount}{\void}
 110
 111 Override this to indicate the number of columns in the model.
 112
 113 \membersection{wxDataViewModel::GetColumnType}\label{wxdataviewmodelgetcolumntype}
 114
 115 \constfunc{wxString}{GetColumnType}{\param{unsigned int }{col}}
 116
 117 Override this to indicate what type of data is stored in the
 118 column specified by {\it col}. This should return a string
 119 indicating the type of data as reported by \helpref{wxVariant}{wxvariant}.
 120
 121 \membersection{wxDataViewModel::GetFirstChild}\label{wxdataviewmodelgetfirstchild}
 122
 123 \constfunc{wxDataViewItem}{GetFirstChild}{\param{const wxDataViewItem\& }{parent}}
 124
 125 To be removed.
 126
 127 \membersection{wxDataViewModel::GetNextSibling}\label{wxdataviewmodelgetnextsibling}
 128
 129 \constfunc{wxDataViewItem}{GetNextSibling}{\param{const wxDataViewItem\& }{item}}
 130
 131 To be removed.
 132
 133 \membersection{wxDataViewModel::GetParent}\label{wxdataviewmodelgetparent}
 134
 135 \constfunc{wxDataViewItem}{GetParent}{\param{const wxDataViewItem\& }{item}}
 136
 137 Override this to indicate which wxDataViewItem representing the parent
 138 of {\it item} or an invalid wxDataViewItem if {\it item} is the root item.
 139
 140 \membersection{wxDataViewModel::GetValue}\label{wxdataviewmodelgetvalue}
 141
 142 \constfunc{void}{GetValue}{\param{wxVariant\& }{variant}, \param{const wxDataViewItem\& }{item}, \param{unsigned int }{col}}
 143
 144 Override this to indicate the value of {\it item}
 145 A \helpref{wxVariant}{wxvariant} is used to store the data.
 146
 147 \membersection{wxDataViewModel::IsContainer}\label{wxdataviewmodeliscontainer}
 148
 149 \constfunc{bool}{IsContainer}{\param{const wxDataViewItem\& }{item}}
 150
 151 Override this to indicate of {\it item} is a container, i.e. if
 152 it can have child items.
 153
 154 \membersection{wxDataViewModel::ItemAdded}\label{wxdataviewmodelitemadded}
 155
 156 \func{bool}{ItemAdded}{\param{const wxDataViewItem\& }{parent}, \param{const wxDataViewItem\& }{item}}
 157
 158 Call this to inform the model that an item has been added
 159 to the data.
 160
 161 \membersection{wxDataViewModel::ItemChanged}\label{wxdataviewmodelitemchanged}
 162
 163 \func{bool}{ItemChanged}{\param{const wxDataViewItem\& }{item}}
 164
 165 Call this to inform the model that an item has changed.
 166
 167 \membersection{wxDataViewModel::ItemDeleted}\label{wxdataviewmodelitemdeleted}
 168
 169 \func{bool}{ItemDeleted}{\param{const wxDataViewItem\& }{parent}, \param{const wxDataViewItem\& }{item}}
 170
 171 Call this to inform the model that an item has been deleted.
 172
 173 \membersection{wxDataViewModel::RemoveNotifier}\label{wxdataviewmodelremovenotifier}
 174
 175 \func{void}{RemoveNotifier}{\param{wxDataViewModelNotifier* }{notifier}}
 176
 177 Remove the {\it notifier} from the list of notifiers.
 178
 179 \membersection{wxDataViewModel::Resort}\label{wxdataviewmodelresort}
 180
 181 \func{void}{Resort}{\void}
 182
 183 Call this to initiate a resort after the sort function has
 184 been changed.
 185
 186 \membersection{wxDataViewModel::SetValue}\label{wxdataviewmodelsetvalue}
 187
 188 \func{bool}{SetValue}{\param{const wxVariant\& }{variant}, \param{const wxDataViewItem\& }{item}, \param{unsigned int }{col}}
 189
 190 This gets called in order to set a value in the data model.
 191 The most common scenario is that the wxDataViewCtrl calls
 192 this method after the user changed some data in the view.
 193 Afterwards \helpref{ValueChanged}{wxdataviewmodelvaluechanged}
 194 has to be called!
 195
 196 \membersection{wxDataViewModel::ValueChanged}\label{wxdataviewmodelvaluechanged}
 197
 198 \func{bool}{ValueChanged}{\param{const wxDataViewItem\& }{item}, \param{unsigned int }{col}}
 199
 200 Call this to inform this model that a value in
 201 the model has been changed.
 202