DataFormat

A DataFormat 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 ( CLIPFORMAT under Windows or Atom under X11, for example) and the standard formats are, indeed, just numbers which can be implicitly converted to DataFormat. The standard formats are:

DF_INVALID	An invalid format - used as default argument for functions taking a DataFormat argument sometimes.
DF_TEXT	Text format (String).
DF_BITMAP	A bitmap ( Bitmap).
DF_METAFILE	A metafile (Metafile, Windows only).
DF_FILENAME	A list of filenames.
DF_HTML	An HTML string. This is only valid when passed to SetClipboardData when compiled with Visual C++ in non-Unicode mode.

As mentioned above, these standard formats may be passed to any function taking DataFormat argument because DataFormat has an implicit conversion from them (or, to be precise from the type DataFormat::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 registered) first, you shouldn’t care about it because it is done automatically the first time the DataFormat object corresponding to a given format name is created. The only implication of this is that you should avoid having global DataFormat 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!

See also

Drag and Drop Overview, DataObject

Inheritance Diagram

Inheritance diagram for class DataFormat

Methods Summary

__init__	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).
GetId	Returns the name of a custom format (this function will fail for a standard format).
GetType	Returns the platform-specific number identifying the format.
SetId	Sets the format to be the custom format identified by the given name.
SetType	Sets the format to the given value, which should be one of DF_XXX constants.
__ne__	Returns True if the formats are different.
__eq__	Returns True if the formats are equal.

Properties Summary

Id	See GetId and SetId
Type	See GetType and SetType

Class API

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class DataFormat(object)

A DataFormat is an encapsulation of a platform-specific format handle which is used by the system for the clipboard and drag and drop operations.

Possible constructors:

DataFormat(format=DF_INVALID)

DataFormat(format)

Methods

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__init__(self, *args, **kw)

Overloaded Implementations:

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__init__ (self, format=DF_INVALID)

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).

Parameters:format (DataFormatId) –

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__init__ (self, format)

Constructs a data format object for a custom format identified by its name format.

Parameters:format (string) –

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GetId(self)

Returns the name of a custom format (this function will fail for a standard format).

Return type:string

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GetType(self)

Returns the platform-specific number identifying the format.

Return type: DataFormatId

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SetId(self, format)

Sets the format to be the custom format identified by the given name.

Parameters:format (string) –

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SetType(self, type)

Sets the format to the given value, which should be one of DF_XXX constants.

Parameters:type (DataFormatId) –

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__ne__(self, *args, **kw)

Returns True if the formats are different.

Overloaded Implementations:

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__ne__ (self)

Parameters:format (DataFormat) –

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__ne__ (self)

Parameters:format (DataFormatId) –

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__eq__(self, *args, **kw)

Returns True if the formats are equal.

Overloaded Implementations:

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__eq__ (self)

Parameters:format (DataFormat) –

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__eq__ (self)

Parameters:format (DataFormatId) –

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Properties

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Id

See GetId and SetId

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Type

See GetType and SetType