// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
-// Licence: wxWindows license
+// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-/*!
+/**
- @page overview_dataobject wxDataObject overview
+@page overview_dataobject wxDataObject Overview
- Classes: #wxDataObject, #wxClipboard, #wxDataFormat, #wxDropSource, #wxDropTarget
+Classes: wxDataObject, wxClipboard, wxDataFormat, wxDropSource, wxDropTarget
- See also: @ref overview_dnd and @ref overview_samplednd
+See also: @ref overview_dnd and @ref page_samples_dnd
- This overview discusses data transfer through clipboard or drag and drop.
- In wxWidgets, these two ways to transfer data (either between different
- applications or inside one and the same) are very similar which allows to
- implement both of them using almost the same code - or, in other
- words, if you implement drag and drop support for your application, you get
- clipboard support for free and vice versa.
+This overview discusses data transfer through clipboard or drag and drop.
+In wxWidgets, these two ways to transfer data (either between different
+applications or inside one and the same) are very similar which allows to
+implement both of them using almost the same code - or, in other
+words, if you implement drag and drop support for your application, you get
+clipboard support for free and vice versa.
- At the heart of both clipboard and drag and drop operations lies the
- #wxDataObject class. The objects of this class (or, to
- be precise, classes derived from it) represent the data which is being carried
- by the mouse during drag and drop operation or copied to or pasted from the
- clipboard. wxDataObject is a "smart" piece of data because it knows which
- formats it supports (see GetFormatCount and GetAllFormats) and knows how to
- render itself in any of them (see GetDataHere). It can also receive its value
- from the outside in a format it supports if it implements the SetData method.
- Please see the documentation of this class for more details.
+At the heart of both clipboard and drag and drop operations lies the
+wxDataObject class. The objects of this class (or, to
+be precise, classes derived from it) represent the data which is being carried
+by the mouse during drag and drop operation or copied to or pasted from the
+clipboard. wxDataObject is a "smart" piece of data because it knows which
+formats it supports (see GetFormatCount and GetAllFormats) and knows how to
+render itself in any of them (see GetDataHere). It can also receive its value
+from the outside in a format it supports if it implements the SetData method.
+Please see the documentation of this class for more details.
- Both clipboard and drag and drop operations have two sides: the source and
- target, the data provider and the data receiver. These which may be in the same
- application and even the same window when, for example, you drag some text from
- one position to another in a word processor. Let us describe what each of them
- should do.
+Both clipboard and drag and drop operations have two sides: the source and
+target, the data provider and the data receiver. These which may be in the same
+application and even the same window when, for example, you drag some text from
+one position to another in a word processor. Let us describe what each of them
+should do.
- @li The data provider (source) duties
- @li The data receiver (target) duties
+@li @ref overview_dataobject_source
+@li @ref overview_dataobject_target
- @section overview_dataobject_source The data provider (source) duties
+<hr>
- The data provider is responsible for creating a #wxDataObject containing the
- data to be transferred. Then it should either pass it to the clipboard using
- #SetData function or to #wxDropSource and call #DoDragDrop function.
- The only (but important) difference is that the object for the clipboard
- transfer must always be created on the heap (i.e. using @c new) and it will
- be freed by the clipboard when it is no longer needed (indeed, it is not known
- in advance when, if ever, the data will be pasted from the clipboard). On the
- other hand, the object for drag and drop operation must only exist while
- #DoDragDrop executes and may be safely deleted afterwards and so can be
- created either on heap or on stack (i.e. as a local variable).
+@section overview_dataobject_source The data provider (source) duties
- Another small difference is that in the case of clipboard operation, the
- application usually knows in advance whether it copies or cuts (i.e. copies and
- deletes) data - in fact, this usually depends on which menu item the user
- chose. But for drag and drop it can only know it after
- #DoDragDrop returns (from its return value).
+The data provider is responsible for creating a wxDataObject containing the
+data to be transferred. Then it should either pass it to the clipboard using
+wxClipboard::SetData function or to wxDropSource and call wxDropSource::DoDragDrop
+function.
+The only (but important) difference is that the object for the clipboard
+transfer must always be created on the heap (i.e. using @c new) and it will
+be freed by the clipboard when it is no longer needed (indeed, it is not known
+in advance when, if ever, the data will be pasted from the clipboard). On the
+other hand, the object for drag and drop operation must only exist while
+wxDropSource::DoDragDrop executes and may be safely deleted afterwards and so
+can be created either on heap or on stack (i.e. as a local variable).
- @section overview_dataobject_target The data receiver (target) duties
+Another small difference is that in the case of clipboard operation, the
+application usually knows in advance whether it copies or cuts (i.e. copies and
+deletes) data - in fact, this usually depends on which menu item the user
+chose. But for drag and drop it can only know it after
+wxDropSource::DoDragDrop returns (from its return value).
- To receive (paste in usual terminology) data from the clipboard, you should
- create a #wxDataObject derived class which supports the data formats you need
- and pass it as argument to wxClipboard::GetData. If it returns @false,
- no data in (any of) the supported format(s) is available. If it returns @true,
- the data has been successfully transferred to wxDataObject.
+@section overview_dataobject_target The data receiver (target) duties
- For drag and drop case, the wxDropTarget::OnData virtual function will be called
- when a data object is dropped, from which the data itself may be requested by calling
- wxDropTarget::GetData method which fills the data object.
+To receive (paste in usual terminology) data from the clipboard, you should
+create a wxDataObject derived class which supports the data formats you need
+and pass it as argument to wxClipboard::GetData. If it returns @false,
+no data in (any of) the supported format(s) is available. If it returns @true,
+the data has been successfully transferred to wxDataObject.
+
+For drag and drop case, the wxDropTarget::OnData virtual function will be called
+when a data object is dropped, from which the data itself may be requested by calling
+wxDropTarget::GetData method which fills the data object.
*/
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