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Tried to make wxDataViewModel docs clearer

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git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65110 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Robert Roebling 2010-07-25 19:27:07 +00:00
parent 354a9ddf94
commit a36bceb633
1 changed files with 29 additions and 13 deletions
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42
interface/wx/dataview.h
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@ -20,17 +20,26 @@
wxDataViewModel::GetValue in order to define the data model which acts as an
interface between your actual data and the wxDataViewCtrl.
Since you will usually also allow the wxDataViewCtrl to change your data
Note that wxDataViewModel does not define the position or index of any item
in the control because different controls might display the same data differently.
wxDataViewModel does provide a wxDataViewModel::Compare method which the
wxDataViewCtrl may use to sort the data either in conjunction with a column
header or without (see wxDataViewModel::HasDefaultCompare).
wxDataViewModel (as indeed the entire wxDataViewCtrl code) is using wxVariant
to store data and its type in a generic way. wxVariant can be extended to contain
almost any data without changes to the original class. To a certain extent,
you can use (the somewhat more elegant) wxAny instead of wxVariant as there
is code to convert between the two, but it is unclear what impact this will
have on performance.
Since you will usually allow the wxDataViewCtrl to change your data
through its graphical interface, you will also have to override
wxDataViewModel::SetValue which the wxDataViewCtrl will call when a change
to some data has been committed.
wxDataViewModel (as indeed the entire wxDataViewCtrl code) is using wxVariant
to store data and its type in a generic way. wxVariant can be extended to contain
almost any data without changes to the original class.
The data that is presented through this data model is expected to change at
run-time. You need to inform the data model when a change happened.
If the data represented by the model is changed by something else than its
associated wxDataViewCtrl, the control has to be notified about the change.
Depending on what happened you need to call one of the following methods:
- wxDataViewModel::ValueChanged,
- wxDataViewModel::ItemAdded,
@ -44,12 +53,6 @@
- wxDataViewModel::ItemsDeleted,
- wxDataViewModel::ItemsChanged.
Note that wxDataViewModel does not define the position or index of any item
in the control because different controls might display the same data differently.
wxDataViewModel does provide a wxDataViewModel::Compare method which the
wxDataViewCtrl may use to sort the data either in conjunction with a column
header or without (see wxDataViewModel::HasDefaultCompare).
This class maintains a list of wxDataViewModelNotifier which link this class
to the specific implementations on the supported platforms so that e.g. calling
wxDataViewModel::ValueChanged on this model will just call
@ -75,6 +78,19 @@
// add columns now
@endcode
A potentially better way to avoid memory leaks is to use wxObjectDataPtr
@code
wxObjectDataPtr<MyMusicModel> musicModel;
wxDataViewCtrl *musicCtrl = new wxDataViewCtrl( this, wxID_ANY );
musicModel = new MyMusicModel;
m_musicCtrl->AssociateModel( musicModel.get() );
// add columns now
@endcode
@library{wxadv}
@category{dvc}
*/