/////////////////////////////////////////////////////////////////////////////
// Name: dataobj.h
-// Purpose: documentation for wxCustomDataObject class
+// Purpose: interface of wx*DataObject
// Author: wxWidgets team
// RCS-ID: $Id$
// Licence: wxWindows license
@class wxCustomDataObject
@wxheader{dataobj.h}
- wxCustomDataObject is a specialization of
- wxDataObjectSimple for some
- application-specific data in arbitrary (either custom or one of the standard
- ones). The only restriction is that it is supposed that this data can be
- copied bitwise (i.e. with @c memcpy()), so it would be a bad idea to make
- it contain a C++ object (though C struct is fine).
+ wxCustomDataObject is a specialization of wxDataObjectSimple for some
+ application-specific data in arbitrary (either custom or one of the
+ standard ones). The only restriction is that it is supposed that this data
+ can be copied bitwise (i.e. with @c memcpy()), so it would be a bad idea to
+ make it contain a C++ object (though C struct is fine).
- By default, wxCustomDataObject stores the data inside in a buffer. To put the
- data into the buffer you may use either
- wxCustomDataObject::SetData or
- wxCustomDataObject::TakeData depending on whether you want
- the object to make a copy of data or not.
+ By default, wxCustomDataObject stores the data inside in a buffer. To put
+ the data into the buffer you may use either SetData() or TakeData()
+ depending on whether you want the object to make a copy of data or not.
- If you already store the data in another place, it may be more convenient and
- efficient to provide the data on-demand which is possible too if you override
- the virtual functions mentioned below.
+ This class may be used as is, but if you don't want store the data inside
+ the object but provide it on demand instead, you should override GetSize(),
+ GetData() and SetData() (or may be only the first two or only the last one
+ if you only allow reading/writing the data).
@library{wxcore}
@category{dnd}
- @seealso
- wxDataObject
+ @see wxDataObject
*/
class wxCustomDataObject : public wxDataObjectSimple
{
public:
/**
- The constructor accepts a @e format argument which specifies the (single)
- format supported by this object. If it isn't set here,
- wxDataObjectSimple::SetFormat should be used.
+ The constructor accepts a @a format argument which specifies the
+ (single) format supported by this object. If it isn't set here,
+ wxDataObjectSimple::SetFormat() should be used.
*/
wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
/**
- The destructor will free the data hold by the object. Notice that although it
- calls a virtual Free() function, the base
- class version will always be called (C++ doesn't allow calling virtual
- functions from constructors or destructors), so if you override @c Free(), you
- should override the destructor in your class as well (which would probably
- just call the derived class' version of @c Free()).
+ The destructor will free the data held by the object. Notice that
+ although it calls the virtual Free() function, the base class version
+ will always be called (C++ doesn't allow calling virtual functions from
+ constructors or destructors), so if you override Free(), you should
+ override the destructor in your class as well (which would probably
+ just call the derived class' version of Free()).
*/
- ~wxCustomDataObject();
+ virtual ~wxCustomDataObject();
/**
- This function is called to allocate @e size bytes of memory from SetData().
- The default version just uses the operator new.
+ This function is called to allocate @a size bytes of memory from
+ SetData(). The default version just uses the operator new.
*/
- virtual void * Alloc(size_t size);
+ virtual void* Alloc(size_t size);
/**
- This function is called when the data is freed, you may override it to anything
- you want (or may be nothing at all). The default version calls operator
- delete[] on the data.
+ This function is called when the data is freed, you may override it to
+ anything you want (or may be nothing at all). The default version calls
+ operator delete[] on the data.
*/
virtual void Free();
/**
Returns a pointer to the data.
*/
- virtual void * GetData();
+ virtual void* GetData() const;
/**
Returns the data size in bytes.
*/
- virtual size_t GetSize();
+ virtual size_t GetSize() const;
/**
Set the data. The data object will make an internal copy.
+
+ @beginWxPythonOnly
+ This method expects a string in wxPython. You can pass nearly any
+ object by pickling it first.
+ @endWxPythonOnly
*/
virtual void SetData(size_t size, const void data);
/**
- Like SetData(), but doesn't copy the data -
- instead the object takes ownership of the pointer.
-
- @b wxPython note: This method expects a string in wxPython. You can pass
- nearly any object by pickling it first.
+ Like SetData(), but doesn't copy the data - instead the object takes
+ ownership of the pointer.
+
+ @beginWxPythonOnly
+ This method expects a string in wxPython. You can pass nearly any
+ object by pickling it first.
+ @endWxPythonOnly
*/
virtual void TakeData(size_t size, const void data);
};
+
/**
@class wxDataObjectComposite
@wxheader{dataobj.h}
- wxDataObjectComposite is the simplest
- wxDataObject derivation which may be used to support
- multiple formats. It contains several
- wxDataObjectSimple objects and supports any
- format supported by at least one of them. Only one of these data objects is
- @e preferred (the first one if not explicitly changed by using the second
- parameter of wxDataObjectComposite::Add) and its format determines
+ wxDataObjectComposite is the simplest wxDataObject derivation which may be
+ used to support multiple formats. It contains several wxDataObjectSimple
+ objects and supports any format supported by at least one of them. Only one
+ of these data objects is @e preferred (the first one if not explicitly
+ changed by using the second parameter of Add()) and its format determines
the preferred format of the composite data object as well.
- See wxDataObject documentation for the reasons why you
- might prefer to use wxDataObject directly instead of wxDataObjectComposite for
- efficiency reasons.
+ See wxDataObject documentation for the reasons why you might prefer to use
+ wxDataObject directly instead of wxDataObjectComposite for efficiency
+ reasons.
@library{wxcore}
- @category{FIXME}
+ @category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview",
- wxDataObject, wxDataObjectSimple, wxFileDataObject, wxTextDataObject, wxBitmapDataObject
+ @see @ref overview_dnd, wxDataObject, wxDataObjectSimple, wxFileDataObject,
+ wxTextDataObject, wxBitmapDataObject
*/
class wxDataObjectComposite : public wxDataObject
{
wxDataObjectComposite();
/**
- Adds the @e dataObject to the list of supported objects and it becomes the
- preferred object if @e preferred is @true.
+ Adds the @a dataObject to the list of supported objects and it becomes
+ the preferred object if @a preferred is @true.
*/
-#define void Add(wxDataObjectSimple dataObject, bool preferred = @false) /* implementation is private */
+ void Add(wxDataObjectSimple dataObject, bool preferred = false);
/**
- Report the format passed to the SetData method. This should be the
+ Report the format passed to the SetData() method. This should be the
format of the data object within the composite that recieved data from
the clipboard or the DnD operation. You can use this method to find
out what kind of data object was recieved.
*/
- wxDataFormat GetReceivedFormat();
+ wxDataFormat GetReceivedFormat() const;
};
+
/**
@class wxDataObjectSimple
@wxheader{dataobj.h}
- This is the simplest possible implementation of the
- wxDataObject class. The data object of (a class derived
- from) this class only supports one format, so the number of virtual functions
- to be implemented is reduced.
+ This is the simplest possible implementation of the wxDataObject class. The
+ data object of (a class derived from) this class only supports one format,
+ so the number of virtual functions to be implemented is reduced.
- Notice that this is still an abstract base class and cannot be used but should
- be derived from.
+ Notice that this is still an abstract base class and cannot be used
+ directly, it must be derived. The objects supporting rendering the data
+ must override GetDataSize() and GetDataHere() while the objects which may
+ be set must override SetData(). Of course, the objects supporting both
+ operations must override all three methods.
- @b wxPython note: If you wish to create a derived wxDataObjectSimple class in
- wxPython you should derive the class from wxPyDataObjectSimple
- in order to get Python-aware capabilities for the various virtual
- methods.
+ @beginWxPythonOnly
+ If you wish to create a derived wxDataObjectSimple class in wxPython you
+ should derive the class from wxPyDataObjectSimple in order to get
+ Python-aware capabilities for the various virtual methods.
+ @endWxPythonOnly
- @b wxPerl note: In wxPerl, you need to derive your data object class
- from Wx::PlDataObjectSimple.
+ @beginWxPerlOnly
+ In wxPerl, you need to derive your data object class from
+ Wx::PlDataObjectSimple.
+ @endWxPerlOnly
@library{wxcore}
- @category{FIXME}
+ @category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview", @ref
- overview_samplednd "DnD sample", wxFileDataObject, wxTextDataObject, wxBitmapDataObject
+ @see @ref overview_dnd, @ref page_samples_dnd, wxFileDataObject,
+ wxTextDataObject, wxBitmapDataObject
*/
class wxDataObjectSimple : public wxDataObject
{
public:
/**
- Constructor accepts the supported format (none by default) which may also be
- set later with SetFormat().
+ Constructor accepts the supported format (none by default) which may
+ also be set later with SetFormat().
*/
wxDataObjectSimple(const wxDataFormat& format = wxFormatInvalid);
/**
- Copy the data to the buffer, return @true on success. Must be implemented in the
- derived class if the object supports rendering its data.
+ Copy the data to the buffer, return @true on success. Must be
+ implemented in the derived class if the object supports rendering its
+ data.
+
+ @beginWxPythonOnly
+ When implementing this method in wxPython, no additional parameters are
+ required and the data should be returned from the method as a string.
+ @endWxPythonOnly
*/
- virtual bool GetDataHere(void buf);
+ virtual bool GetDataHere(void buf) const;
/**
- Gets the size of our data. Must be implemented in the derived class if the
- object supports rendering its data.
+ Gets the size of our data. Must be implemented in the derived class if
+ the object supports rendering its data.
*/
- virtual size_t GetDataSize();
+ virtual size_t GetDataSize() const;
/**
- Returns the (one and only one) format supported by this object. It is supposed
- that the format is supported in both directions.
+ Returns the (one and only one) format supported by this object. It is
+ assumed that the format is supported in both directions.
*/
- const wxDataFormat GetFormat();
+ const wxDataFormat GetFormat() const;
/**
- Copy the data from the buffer, return @true on success. Must be implemented in
- the derived class if the object supports setting its data.
-
- @b wxPython note: When implementing this method in wxPython, the data comes
- as a single string parameter rather than the two shown here.
+ Copy the data from the buffer, return @true on success. Must be
+ implemented in the derived class if the object supports setting its
+ data.
+
+ @beginWxPythonOnly
+ When implementing this method in wxPython, the data comes as a single
+ string parameter rather than the two shown here.
+ @endWxPythonOnly
*/
virtual bool SetData(size_t len, const void buf);
};
+
/**
@class wxBitmapDataObject
@wxheader{dataobj.h}
- wxBitmapDataObject is a specialization of wxDataObject for bitmap data. It can
- be used without change to paste data into the
- wxClipboard or a wxDropSource. A
- user may wish to derive a new class from this class for providing a bitmap
- on-demand in order to minimize memory consumption when offering data in several
- formats, such as a bitmap and GIF.
+ wxBitmapDataObject is a specialization of wxDataObject for bitmap data. It
+ can be used without change to paste data into the wxClipboard or a
+ wxDropSource. A user may wish to derive a new class from this class for
+ providing a bitmap on-demand in order to minimize memory consumption when
+ offering data in several formats, such as a bitmap and GIF.
- @b wxPython note: If you wish to create a derived wxBitmapDataObject class in
- wxPython you should derive the class from wxPyBitmapDataObject
- in order to get Python-aware capabilities for the various virtual
- methods.
+ This class may be used as is, but GetBitmap() may be overridden to increase
+ efficiency.
+
+ @beginWxPythonOnly
+ If you wish to create a derived wxBitmapDataObject class in wxPython you
+ should derive the class from wxPyBitmapDataObject in order to get
+ Python-aware capabilities for the various virtual methods.
+ @endWxPythonOnly
@library{wxcore}
@category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview",
- wxDataObject, wxDataObjectSimple, wxFileDataObject, wxTextDataObject, wxDataObject
+ @see @ref overview_dnd, wxDataObject, wxDataObjectSimple, wxFileDataObject,
+ wxTextDataObject, wxDataObject
*/
class wxBitmapDataObject : public wxDataObjectSimple
{
public:
/**
- Constructor, optionally passing a bitmap (otherwise use
- SetBitmap() later).
+ Constructor, optionally passing a bitmap (otherwise use SetBitmap()
+ later).
*/
wxBitmapDataObject(const wxBitmap& bitmap = wxNullBitmap);
/**
- Returns the bitmap associated with the data object. You may wish to override
- this method when offering data on-demand, but this is not required by
- wxWidgets' internals. Use this method to get data in bitmap form from
- the wxClipboard.
+ Returns the bitmap associated with the data object. You may wish to
+ override this method when offering data on-demand, but this is not
+ required by wxWidgets' internals. Use this method to get data in bitmap
+ form from the wxClipboard.
*/
- virtual wxBitmap GetBitmap();
+ virtual wxBitmap GetBitmap() const;
/**
- Sets the bitmap associated with the data object. This method is called when the
- data object receives data. Usually there will be no reason to override this
- function.
+ Sets the bitmap associated with the data object. This method is called
+ when the data object receives data. Usually there will be no reason to
+ override this function.
*/
virtual void SetBitmap(const wxBitmap& bitmap);
};
+
/**
@class wxDataFormat
@wxheader{dataobj.h}
- A wxDataFormat is an encapsulation of a platform-specific format handle which
- is used by the system for the clipboard and drag and drop operations. The
- applications are usually only interested in, for example, pasting data from the
- clipboard only if the data is in a format the program understands and a data
- format is something which uniquely identifies this format.
+ A wxDataFormat is an encapsulation of a platform-specific format handle
+ which is used by the system for the clipboard and drag and drop operations.
+ The applications are usually only interested in, for example, pasting data
+ from the clipboard only if the data is in a format the program understands
+ and a data format is something which uniquely identifies this format.
On the system level, a data format is usually just a number (@c CLIPFORMAT
under Windows or @c Atom under X11, for example) and the standard formats
are, indeed, just numbers which can be implicitly converted to wxDataFormat.
The standard formats are:
-
-
- wxDF_INVALID
-
-
- An invalid format - used as default argument for
- functions taking a wxDataFormat argument sometimes
-
-
- wxDF_TEXT
-
-
- Text format (wxString)
-
-
- wxDF_BITMAP
-
-
- A bitmap (wxBitmap)
-
-
- wxDF_METAFILE
-
-
- A metafile (wxMetafile, Windows only)
-
-
- wxDF_FILENAME
-
-
- A list of filenames
-
-
- wxDF_HTML
-
-
- An HTML string. This is only valid when passed to wxSetClipboardData
- when compiled with Visual C++ in non-Unicode mode
-
-
-
- As mentioned above, these standard formats may be passed to any function taking
- wxDataFormat argument because wxDataFormat has an implicit conversion from
- them (or, to be precise from the type @c wxDataFormat::NativeFormat which is
- the type used by the underlying platform for data formats).
-
- Aside the standard formats, the application may also use custom formats which
- are identified by their names (strings) and not numeric identifiers. Although
- internally custom format must be created (or @e registered) first, you
- shouldn't care about it because it is done automatically the first time the
- wxDataFormat object corresponding to a given format name is created. The only
- implication of this is that you should avoid having global wxDataFormat objects
- with non-default constructor because their constructors are executed before the
- program has time to perform all necessary initialisations and so an attempt to
- do clipboard format registration at this time will usually lead to a crash!
+ @beginDefList
+ @itemdef{wxDF_INVALID,
+ An invalid format - used as default argument for functions taking
+ a wxDataFormat argument sometimes.}
+ @itemdef{wxDF_TEXT,
+ Text format (wxString).}
+ @itemdef{wxDF_BITMAP,
+ A bitmap (wxBitmap).}
+ @itemdef{wxDF_METAFILE,
+ A metafile (wxMetafile, Windows only).}
+ @itemdef{wxDF_FILENAME,
+ A list of filenames.}
+ @itemdef{wxDF_HTML,
+ An HTML string. This is only valid when passed to
+ wxSetClipboardData when compiled with Visual C++ in non-Unicode
+ mode.}
+ @endDefList
+
+ As mentioned above, these standard formats may be passed to any function
+ taking wxDataFormat argument because wxDataFormat has an implicit
+ conversion from them (or, to be precise from the type
+ @c wxDataFormat::NativeFormat which is the type used by the underlying
+ platform for data formats).
+
+ Aside the standard formats, the application may also use custom formats
+ which are identified by their names (strings) and not numeric identifiers.
+ Although internally custom format must be created (or @e registered) first,
+ you shouldn't care about it because it is done automatically the first time
+ the wxDataFormat object corresponding to a given format name is created.
+ The only implication of this is that you should avoid having global
+ wxDataFormat objects with non-default constructor because their
+ constructors are executed before the program has time to perform all
+ necessary initialisations and so an attempt to do clipboard format
+ registration at this time will usually lead to a crash!
@library{wxbase}
@category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview", @ref
- overview_samplednd "DnD sample", wxDataObject
+ @see @ref overview_dnd, @ref page_samples_dnd, wxDataObject
*/
class wxDataFormat
{
public:
/**
- Constructs a data format object for a custom format identified by its name
- @e format.
+ Constructs a data format object for one of the standard data formats or
+ an empty data object (use SetType() or SetId() later in this case).
+ */
+ wxDataFormat(NativeFormat format = wxDF_INVALID);
+ /**
+ Constructs a data format object for a custom format identified by its
+ name @a format.
*/
wxDataFormat(const wxChar format);
/**
- Returns the name of a custom format (this function will fail for a standard
- format).
+ Returns the name of a custom format (this function will fail for a
+ standard format).
*/
- wxString GetId();
+ wxString GetId() const;
/**
Returns the platform-specific number identifying the format.
*/
- NativeFormat GetType();
+ NativeFormat GetType() const;
/**
Sets the format to be the custom format identified by the given name.
void SetId(const wxChar format);
/**
- Sets the format to the given value, which should be one of wxDF_XXX constants.
+ Sets the format to the given value, which should be one of wxDF_XXX
+ constants.
*/
void SetType(NativeFormat format);
/**
Returns @true if the formats are different.
*/
- bool operator !=(const wxDataFormat& format);
+ bool operator !=(const wxDataFormat& format) const;
/**
Returns @true if the formats are equal.
*/
- bool operator ==(const wxDataFormat& format);
+ bool operator ==(const wxDataFormat& format) const;
};
+
/**
@class wxURLDataObject
@wxheader{dataobj.h}
- wxURLDataObject is a wxDataObject containing an URL
- and can be used e.g. when you need to put an URL on or retrieve it from the
- clipboard:
+ wxURLDataObject is a wxDataObject containing an URL and can be used e.g.
+ when you need to put an URL on or retrieve it from the clipboard:
@code
- wxTheClipboard-SetData(new wxURLDataObject(url));
+ wxTheClipboard->SetData(new wxURLDataObject(url));
@endcode
+ @note This class is derived from wxDataObjectComposite on Windows rather
+ than wxTextDataObject on all other platforms.
+
@library{wxcore}
@category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview", wxDataObject
+ @see @ref overview_dnd, wxDataObject
*/
-class wxURLDataObject
+class wxURLDataObject: public wxTextDataObject
{
public:
/**
- Constructor, may be used to initialize the URL. If @e url is empty,
+ Constructor, may be used to initialize the URL. If @a url is empty,
SetURL() can be used later.
*/
wxURLDataObject(const wxString& url = wxEmptyString);
/**
Returns the URL stored by this object, as a string.
*/
-#define wxString GetURL() /* implementation is private */
+ wxString GetURL() const;
/**
Sets the URL stored by this object.
*/
-#define void SetURL(const wxString& url) /* implementation is private */
+ void SetURL(const wxString& url);
};
+
/**
@class wxDataObject
@wxheader{dataobj.h}
- A wxDataObject represents data that can be copied to or from the clipboard, or
- dragged and dropped. The important thing about wxDataObject is that this is a
- 'smart' piece of data unlike 'dumb' data containers such as memory
- buffers or files. Being 'smart' here means that the data object itself should
- know what data formats it supports and how to render itself in each of
- its supported formats.
+ A wxDataObject represents data that can be copied to or from the clipboard,
+ or dragged and dropped. The important thing about wxDataObject is that this
+ is a 'smart' piece of data unlike 'dumb' data containers such as memory
+ buffers or files. Being 'smart' here means that the data object itself
+ should know what data formats it supports and how to render itself in each
+ of its supported formats.
- A supported format, incidentally, is exactly the format in which the data can
- be requested from a data object or from which the data object may be set. In
- the general case, an object may support different formats on 'input' and
- 'output', i.e. it may be able to render itself in a given format but not be
- created from data on this format or vice versa. wxDataObject defines an
- enumeration type
+ A supported format, incidentally, is exactly the format in which the data
+ can be requested from a data object or from which the data object may be
+ set. In the general case, an object may support different formats on
+ 'input' and 'output', i.e. it may be able to render itself in a given
+ format but not be created from data on this format or vice versa.
+ wxDataObject defines an enumeration type which distinguishes between them:
@code
enum Direction
};
@endcode
- which distinguishes between them. See
- wxDataFormat documentation for more about formats.
+ See wxDataFormat documentation for more about formats.
- Not surprisingly, being 'smart' comes at a price of added complexity. This is
- reasonable for the situations when you really need to support multiple formats,
- but may be annoying if you only want to do something simple like cut and paste
- text.
+ Not surprisingly, being 'smart' comes at a price of added complexity. This
+ is reasonable for the situations when you really need to support multiple
+ formats, but may be annoying if you only want to do something simple like
+ cut and paste text.
To provide a solution for both cases, wxWidgets has two predefined classes
which derive from wxDataObject: wxDataObjectSimple and
- wxDataObjectComposite.
- wxDataObjectSimple is
- the simplest wxDataObject possible and only holds data in a single format (such
- as HTML or text) and wxDataObjectComposite is
- the simplest way to implement a wxDataObject that does support multiple formats
- because it achieves this by simply holding several wxDataObjectSimple objects.
-
- So, you have several solutions when you need a wxDataObject class (and you need
- one as soon as you want to transfer data via the clipboard or drag and drop):
-
-
-
- @b 1. Use one of the built-in classes
-
-
- You may use wxTextDataObject,
- wxBitmapDataObject or wxFileDataObject in the simplest cases when you only need
- to support one format and your data is either text, bitmap or list of files.
-
-
- @b 2. Use wxDataObjectSimple
-
-
- Deriving from wxDataObjectSimple is the simplest
- solution for custom data - you will only support one format and so probably
- won't be able to communicate with other programs, but data transfer will work
- in your program (or between different copies of it).
-
-
- @b 3. Use wxDataObjectComposite
-
-
- This is a simple but powerful
- solution which allows you to support any number of formats (either
- standard or custom if you combine it with the previous solution).
-
-
- @b 4. Use wxDataObject directly
-
-
- This is the solution for
- maximal flexibility and efficiency, but it is also the most difficult to
- implement.
-
-
-
- Please note that the easiest way to use drag and drop and the clipboard with
- multiple formats is by using wxDataObjectComposite, but it is not the most
- efficient one as each wxDataObjectSimple would contain the whole data in its
- respective formats. Now imagine that you want to paste 200 pages of text in
- your proprietary format, as well as Word, RTF, HTML, Unicode and plain text to
- the clipboard and even today's computers are in trouble. For this case, you
- will have to derive from wxDataObject directly and make it enumerate its
- formats and provide the data in the requested format on demand.
-
- Note that neither the GTK+ data transfer mechanisms for clipboard and
- drag and drop, nor OLE data transfer, copy any data until another application
- actually requests the data. This is in contrast to the 'feel' offered to the
- user of a program who would normally think that the data resides in the
- clipboard after having pressed 'Copy' - in reality it is only declared to be
- available.
+ wxDataObjectComposite. wxDataObjectSimple is the simplest wxDataObject
+ possible and only holds data in a single format (such as HTML or text) and
+ wxDataObjectComposite is the simplest way to implement a wxDataObject that
+ does support multiple formats because it achieves this by simply holding
+ several wxDataObjectSimple objects.
+
+ So, you have several solutions when you need a wxDataObject class (and you
+ need one as soon as you want to transfer data via the clipboard or drag and
+ drop):
+
+ -# Use one of the built-in classes.
+ - You may use wxTextDataObject, wxBitmapDataObject or wxFileDataObject
+ in the simplest cases when you only need to support one format and
+ your data is either text, bitmap or list of files.
+ -# Use wxDataObjectSimple
+ - Deriving from wxDataObjectSimple is the simplest solution for custom
+ data - you will only support one format and so probably won't be able
+ to communicate with other programs, but data transfer will work in
+ your program (or between different copies of it).
+ -# Use wxDataObjectComposite
+ - This is a simple but powerful solution which allows you to support
+ any number of formats (either standard or custom if you combine it
+ with the previous solution).
+ -# Use wxDataObject Directly
+ - This is the solution for maximal flexibility and efficiency, but it
+ is also the most difficult to implement.
+
+ Please note that the easiest way to use drag and drop and the clipboard
+ with multiple formats is by using wxDataObjectComposite, but it is not the
+ most efficient one as each wxDataObjectSimple would contain the whole data
+ in its respective formats. Now imagine that you want to paste 200 pages of
+ text in your proprietary format, as well as Word, RTF, HTML, Unicode and
+ plain text to the clipboard and even today's computers are in trouble. For
+ this case, you will have to derive from wxDataObject directly and make it
+ enumerate its formats and provide the data in the requested format on
+ demand.
+
+ Note that neither the GTK+ data transfer mechanisms for clipboard and drag
+ and drop, nor OLE data transfer, copy any data until another application
+ actually requests the data. This is in contrast to the 'feel' offered to
+ the user of a program who would normally think that the data resides in the
+ clipboard after having pressed 'Copy' - in reality it is only declared to
+ be available.
There are several predefined data object classes derived from
- wxDataObjectSimple: wxFileDataObject,
- wxTextDataObject,
- wxBitmapDataObject and
- wxURLDataObject
- which can be used without change.
-
- You may also derive your own data object classes from
- wxCustomDataObject for user-defined types. The
- format of user-defined data is given as a mime-type string literal, such as
- "application/word" or "image/png". These strings are used as they are under
- Unix (so far only GTK+) to identify a format and are translated into their
- Windows equivalent under Win32 (using the OLE IDataObject for data exchange to
- and from the clipboard and for drag and drop). Note that the format string
- translation under Windows is not yet finished.
-
- @b wxPython note: At this time this class is not directly usable from wxPython.
- Derive a class from wxPyDataObjectSimple
- instead.
-
- @b wxPerl note: This class is not currently usable from wxPerl; you may
- use Wx::PlDataObjectSimple instead.
+ wxDataObjectSimple: wxFileDataObject, wxTextDataObject, wxBitmapDataObject
+ and wxURLDataObject which can be used without change.
+
+ You may also derive your own data object classes from wxCustomDataObject
+ for user-defined types. The format of user-defined data is given as a
+ mime-type string literal, such as "application/word" or "image/png". These
+ strings are used as they are under Unix (so far only GTK+) to identify a
+ format and are translated into their Windows equivalent under Win32 (using
+ the OLE IDataObject for data exchange to and from the clipboard and for
+ drag and drop). Note that the format string translation under Windows is
+ not yet finished.
+
+ Each class derived directly from wxDataObject must override and implement
+ all of its functions which are pure virtual in the base class. The data
+ objects which only render their data or only set it (i.e. work in only one
+ direction), should return 0 from GetFormatCount().
+
+ @beginWxPythonOnly
+ At this time this class is not directly usable from wxPython. Derive a
+ class from wxPyDataObjectSimple() instead.
+ @endWxPythonOnly
+
+ @beginWxPerlOnly
+ This class is not currently usable from wxPerl; you may use
+ Wx::PlDataObjectSimple instead.
+ @endWxPerlOnly
@library{wxcore}
@category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview", @ref
- overview_samplednd "DnD sample", wxFileDataObject, wxTextDataObject, wxBitmapDataObject, wxCustomDataObject, wxDropTarget, wxDropSource, wxTextDropTarget, wxFileDropTarget
+ @see @ref overview_dnd, @ref page_samples_dnd, wxFileDataObject,
+ wxTextDataObject, wxBitmapDataObject, wxCustomDataObject,
+ wxDropTarget, wxDropSource, wxTextDropTarget, wxFileDropTarget
*/
class wxDataObject
{
~wxDataObject();
/**
- Copy all supported formats in the given direction to the array pointed to by
- @e formats. There is enough space for GetFormatCount(dir) formats in it.
+ Copy all supported formats in the given direction to the array pointed
+ to by @a formats. There is enough space for GetFormatCount(dir) formats
+ in it.
*/
- virtual void GetAllFormats(wxDataFormat * formats,
- Direction dir = Get);
+ virtual void GetAllFormats(wxDataFormat* formats,
+ Direction dir = Get) const;
/**
- The method will write the data of the format @e format in the buffer @e buf and
- return @true on success, @false on failure.
+ The method will write the data of the format @a format in the buffer
+ @a buf and return @true on success, @false on failure.
*/
- virtual bool GetDataHere(const wxDataFormat& format, void buf);
+ virtual bool GetDataHere(const wxDataFormat& format, void buf) const;
/**
- Returns the data size of the given format @e format.
+ Returns the data size of the given format @a format.
*/
- virtual size_t GetDataSize(const wxDataFormat& format);
+ virtual size_t GetDataSize(const wxDataFormat& format) const;
/**
- Returns the number of available formats for rendering or setting the data.
+ Returns the number of available formats for rendering or setting the
+ data.
*/
- virtual size_t GetFormatCount(Direction dir = Get);
+ virtual size_t GetFormatCount(Direction dir = Get) const;
/**
- Returns the preferred format for either rendering the data (if @e dir is @c Get,
- its default value) or for setting it. Usually this will be the
- native format of the wxDataObject.
+ Returns the preferred format for either rendering the data (if @a dir
+ is @c Get, its default value) or for setting it. Usually this will be
+ the native format of the wxDataObject.
*/
- virtual wxDataFormat GetPreferredFormat(Direction dir = Get);
+ virtual wxDataFormat GetPreferredFormat(Direction dir = Get) const;
/**
- Set the data in the format @e format of the length @e len provided in the
- buffer @e buf.
-
- Returns @true on success, @false on failure.
+ Set the data in the format @a format of the length @a len provided in
+ the buffer @a buf.
+
+ @return @true on success, @false on failure.
*/
virtual bool SetData(const wxDataFormat& format, size_t len,
- const void buf);
+ const void buf);
};
+
/**
@class wxTextDataObject
@wxheader{dataobj.h}
- wxTextDataObject is a specialization of wxDataObject for text data. It can be
- used without change to paste data into the wxClipboard
- or a wxDropSource. A user may wish to derive a new
- class from this class for providing text on-demand in order to minimize memory
- consumption when offering data in several formats, such as plain text and RTF
- because by default the text is stored in a string in this class, but it might
- as well be generated when requested. For this,
- wxTextDataObject::GetTextLength and
- wxTextDataObject::GetText will have to be overridden.
-
- Note that if you already have the text inside a string, you will not achieve
- any efficiency gain by overriding these functions because copying wxStrings is
- already a very efficient operation (data is not actually copied because
- wxStrings are reference counted).
-
- @b wxPython note: If you wish to create a derived wxTextDataObject class in
- wxPython you should derive the class from wxPyTextDataObject
- in order to get Python-aware capabilities for the various virtual
- methods.
+ wxTextDataObject is a specialization of wxDataObject for text data. It can
+ be used without change to paste data into the wxClipboard or a
+ wxDropSource. A user may wish to derive a new class from this class for
+ providing text on-demand in order to minimize memory consumption when
+ offering data in several formats, such as plain text and RTF because by
+ default the text is stored in a string in this class, but it might as well
+ be generated when requested. For this, GetTextLength() and GetText() will
+ have to be overridden.
+
+ Note that if you already have the text inside a string, you will not
+ achieve any efficiency gain by overriding these functions because copying
+ wxStrings is already a very efficient operation (data is not actually
+ copied because wxStrings are reference counted).
+
+ @beginWxPythonOnly
+ If you wish to create a derived wxTextDataObject class in wxPython you
+ should derive the class from wxPyTextDataObject in order to get
+ Python-aware capabilities for the various virtual methods.
+ @endWxPythonOnly
@library{wxcore}
@category{dnd}
- @seealso
- @ref overview_wxdndoverview "Clipboard and drag and drop overview",
- wxDataObject, wxDataObjectSimple, wxFileDataObject, wxBitmapDataObject
+ @see @ref overview_dnd, wxDataObject, wxDataObjectSimple, wxFileDataObject,
+ wxBitmapDataObject
*/
class wxTextDataObject : public wxDataObjectSimple
{
public:
/**
- Constructor, may be used to initialise the text (otherwise
- SetText() should be used later).
+ Constructor, may be used to initialise the text (otherwise SetText()
+ should be used later).
*/
wxTextDataObject(const wxString& text = wxEmptyString);
/**
- Returns the text associated with the data object. You may wish to override
- this method when offering data on-demand, but this is not required by
- wxWidgets' internals. Use this method to get data in text form from
- the wxClipboard.
+ Returns the text associated with the data object. You may wish to
+ override this method when offering data on-demand, but this is not
+ required by wxWidgets' internals. Use this method to get data in text
+ form from the wxClipboard.
*/
- virtual wxString GetText();
+ virtual wxString GetText() const;
/**
Returns the data size. By default, returns the size of the text data
- set in the constructor or using SetText().
- This can be overridden to provide text size data on-demand. It is recommended
- to return the text length plus 1 for a trailing zero, but this is not
- strictly required.
+ set in the constructor or using SetText(). This can be overridden to
+ provide text size data on-demand. It is recommended to return the text
+ length plus 1 for a trailing zero, but this is not strictly required.
*/
- virtual size_t GetTextLength();
+ virtual size_t GetTextLength() const;
/**
Sets the text associated with the data object. This method is called
- when the data object receives the data and, by default, copies the text into
- the member variable. If you want to process the text on the fly you may wish to
- override this function.
+ when the data object receives the data and, by default, copies the text
+ into the member variable. If you want to process the text on the fly
+ you may wish to override this function.
*/
virtual void SetText(const wxString& strText);
};
+
/**
@class wxFileDataObject
@wxheader{dataobj.h}
- wxFileDataObject is a specialization of wxDataObject
- for file names. The program works with it just as if it were a list of absolute
- file
- names, but internally it uses the same format as
- Explorer and other compatible programs under Windows or GNOME/KDE filemanager
- under Unix which makes it possible to receive files from them using this
- class.
+ wxFileDataObject is a specialization of wxDataObject for file names. The
+ program works with it just as if it were a list of absolute file names, but
+ internally it uses the same format as Explorer and other compatible
+ programs under Windows or GNOME/KDE filemanager under Unix which makes it
+ possible to receive files from them using this class.
- @b Warning: Under all non-Windows platforms this class is currently
- "input-only", i.e. you can receive the files from another application, but
- copying (or dragging) file(s) from a wxWidgets application is not currently
- supported. PS: GTK2 should work as well.
+ @warning Under all non-Windows platforms this class is currently
+ "input-only", i.e. you can receive the files from another
+ application, but copying (or dragging) file(s) from a wxWidgets
+ application is not currently supported. PS: GTK2 should work as
+ well.
@library{wxcore}
@category{dnd}
- @seealso
- wxDataObject, wxDataObjectSimple, wxTextDataObject, wxBitmapDataObject,
- wxDataObject
+ @see wxDataObject, wxDataObjectSimple, wxTextDataObject,
+ wxBitmapDataObject, wxDataObject
*/
class wxFileDataObject : public wxDataObjectSimple
{
wxFileDataObject();
/**
- @b MSW only: adds a file to the file list represented by this data object.
+ Adds a file to the file list represented by this data object (Windows
+ only).
*/
virtual void AddFile(const wxString& file);
/**
Returns the array of file names.
*/
- const wxArrayString GetFilenames();
+ const wxArrayString GetFilenames() const;
};
+
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