3f66f6a5b3
This keyword is not expanded by Git which means it's not replaced with the correct revision value in the releases made using git-based scripts and it's confusing to have lines with unexpanded "$Id$" in the released files. As expanding them with Git is not that simple (it could be done with git archive and export-subst attribute) and there are not many benefits in having them in the first place, just remove all these lines. If nothing else, this will make an eventual transition to Git simpler. Closes #14487. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74602 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
93 lines
3.7 KiB
C
93 lines
3.7 KiB
C
/////////////////////////////////////////////////////////////////////////////
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// Name: dnd.h
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// Purpose: topic overview
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// Author: wxWidgets team
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// Licence: wxWindows licence
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/////////////////////////////////////////////////////////////////////////////
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/**
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@page overview_dnd Drag and Drop Overview
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@tableofcontents
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It may be noted that data transfer to and from the clipboard is quite
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similar to data transfer with drag and drop and the code to implement
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these two types is almost the same. In particular, both data transfer
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mechanisms store data in some kind of wxDataObject and identify its format(s)
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using the wxDataFormat class.
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Note that @c wxUSE_DRAG_AND_DROP must be defined in @c setup.h in order
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to use drag and drop in wxWidgets.
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@see @ref overview_dataobject, @ref group_class_dnd, @ref page_samples_dnd
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@section overview_dnd_dropsource Drop Source Requirements
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To be a @e "drop source", i.e. to provide the data which may be dragged by
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the user elsewhere, you should implement the following steps:
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@li @b Preparation: First of all, a data object must be created and
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initialized with the data you wish to drag. For example:
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@code
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wxTextDataObject my_data("This text will be dragged.");
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@endcode
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@li <b>Drag start</b>: To start the dragging process (typically in response to a
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mouse click) you must call wxDropSource::DoDragDrop like this:
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@code
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wxDropSource dragSource( this );
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dragSource.SetData( my_data );
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wxDragResult result = dragSource.DoDragDrop( true );
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@endcode
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@li @b Dragging: The call to DoDragDrop() blocks the program until the user
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releases the mouse button (unless you override the
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wxDropSource::GiveFeedback function to do something special). When the
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mouse moves in a window of a program which understands the same
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drag-and-drop protocol (any program under Windows or any program supporting
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the XDnD protocol under X Windows), the corresponding wxDropTarget methods
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are called - see below.
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@li <b>Processing the result</b>: DoDragDrop() returns an @e effect code which
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is one of the values of @c wxDragResult enum (explained in wxDropTarget page):
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@code
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switch (result)
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{
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case wxDragCopy:
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// copy the data
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break;
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case wxDragMove:
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// move the data
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break;
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default:
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// do nothing
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break;
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}
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@endcode
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@section overview_dnd_droptarget Drop Target Requirements
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To be a @e "drop target", i.e. to receive the data dropped by the user you should
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follow the instructions below:
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@li @b Initialization: For a window to be a drop target, it needs to have
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an associated wxDropTarget object. Normally, you will call wxWindow::SetDropTarget
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during window creation associating your drop target with it. You must derive a class
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from wxDropTarget and override its pure virtual methods. Alternatively, you may
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derive from wxTextDropTarget or wxFileDropTarget and override their OnDropText()
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or OnDropFiles() method.
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@li @b Drop: When the user releases the mouse over a window, wxWidgets
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asks the associated wxDropTarget object if it accepts the data. For this,
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a wxDataObject must be associated with the drop target and this data object will
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be responsible for the format negotiation between the drag source and the drop target.
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If all goes well, then wxDropTarget::OnData will get called and the wxDataObject belonging
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to the drop target can get filled with data.
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@li <b>The end</b>: After processing the data, DoDragDrop() returns either
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wxDragCopy or wxDragMove depending on the state of the keys Ctrl, Shift
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and Alt at the moment of the drop. There is currently no way for the drop
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target to change this return code.
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*/
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