Selections: GDK 3 Reference Manual

## Selections Selections — Functions for transferring data between programs |

## Functions

gboolean | gdk_selection_owner_set ()
gboolean | gdk_selection_owner_set_for_display ()
GdkWindow * | gdk_selection_owner_get ()
GdkWindow * | gdk_selection_owner_get_for_display ()
void | gdk_selection_convert ()
gint | gdk_selection_property_get ()
void | gdk_selection_send_notify ()
void | gdk_selection_send_notify_for_display ()

## Types and Values

#define | GDK_SELECTION_PRIMARY
#define | GDK_SELECTION_SECONDARY
#define | GDK_SELECTION_CLIPBOARD
#define | GDK_TARGET_BITMAP
#define | GDK_TARGET_COLORMAP
#define | GDK_TARGET_DRAWABLE
#define | GDK_TARGET_PIXMAP
#define | GDK_TARGET_STRING
#define | GDK_SELECTION_TYPE_ATOM
#define | GDK_SELECTION_TYPE_BITMAP
#define | GDK_SELECTION_TYPE_COLORMAP
#define | GDK_SELECTION_TYPE_DRAWABLE
#define | GDK_SELECTION_TYPE_INTEGER
#define | GDK_SELECTION_TYPE_PIXMAP
#define | GDK_SELECTION_TYPE_WINDOW
#define | GDK_SELECTION_TYPE_STRING

## Includes

    #include <gdk/gdk.h>

## Description

GDK’s selection functions, based on the X selection mechanism, provide a way to transfer arbitrary chunks of data between programs. A “selection” is a essentially a named clipboard, identified by a string interned as a GdkAtom. By claiming ownership of a selection, an application indicates that it will be responsible for supplying its contents. The most common selections are `PRIMARY` and `CLIPBOARD`.

The contents of a selection can be represented in a number of formats, called “targets”. Each target is identified by an atom. A list of all possible targets supported by the selection owner can be retrieved by requesting the special target `TARGETS`. When a selection is retrieved, the data is accompanied by a type (an atom), and a format (an integer, representing the number of bits per item). See Properties and Atoms for more information.

The functions in this section only contain the lowlevel parts of the selection protocol. A considerably more complicated implementation is needed on top of this. GTK+ contains such an implementation in the functions in `gtkselection.h` and programmers should use those functions instead of the ones presented here. If you plan to implement selection handling directly on top of the functions here, you should refer to the X Inter-Client Communication Conventions Manual (ICCCM).

Note that although much of the selection API design is based on that of X, it will work on other GDK backends too.

## Functions

### gdk_selection_owner_set ()

    gboolean
    gdk_selection_owner_set (GdkWindow *owner,
                             GdkAtom selection,
                             guint32 time_,
                             gboolean send_event);

Sets the owner of the given selection.

#### Parameters

owner | a GdkWindow or `NULL` to indicate that the the owner for the given should be unset. | [allow-none]
selection | an atom identifying a selection. |
time_ | timestamp to use when setting the selection. If this is older than the timestamp given last time the owner was set for the given selection, the request will be ignored. |
send_event | if `TRUE`, and the new owner is different from the current owner, the current owner will be sent a SelectionClear event. |

#### Returns

`TRUE` if the selection owner was successfully changed to `owner` , otherwise `FALSE`.

### gdk_selection_owner_set_for_display ()

    gboolean
    gdk_selection_owner_set_for_display (GdkDisplay *display,
                                         GdkWindow *owner,
                                         GdkAtom selection,
                                         guint32 time_,
                                         gboolean send_event);

Sets the GdkWindow `owner` as the current owner of the selection `selection` .

#### Parameters

display | the GdkDisplay |
owner | a GdkWindow or `NULL` to indicate that the owner for the given should be unset. | [nullable]
selection | an atom identifying a selection |
time_ | timestamp to use when setting the selection If this is older than the timestamp given last time the owner was set for the given selection, the request will be ignored |
send_event | if `TRUE`, and the new owner is different from the current owner, the current owner will be sent a SelectionClear event |

#### Returns

`TRUE` if the selection owner was successfully changed to owner, otherwise `FALSE`.

Since: 2.2

### gdk_selection_owner_get ()

    GdkWindow *
    gdk_selection_owner_get (GdkAtom selection);

Determines the owner of the given selection.

#### Parameters

selection | an atom indentifying a selection. |

#### Returns

if there is a selection owner for this window, and it is a window known to the current process, the GdkWindow that owns the selection, otherwise `NULL`. Note that the return value may be owned by a different process if a foreign window was previously created for that window, but a new foreign window will never be created by this call.

[nullable][transfer none]

### gdk_selection_owner_get_for_display ()

    GdkWindow *
    gdk_selection_owner_get_for_display (GdkDisplay *display,
                                         GdkAtom selection);

Determine the owner of the given selection.

Note that the return value may be owned by a different process if a foreign window was previously created for that window, but a new foreign window will never be created by this call.

#### Parameters

display | a GdkDisplay |
selection | an atom indentifying a selection |

#### Returns

if there is a selection owner for this window, and it is a window known to the current process, the GdkWindow that owns the selection, otherwise `NULL`.

[nullable][transfer none]

Since: 2.2

### gdk_selection_convert ()

    void
    gdk_selection_convert (GdkWindow *requestor,
                           GdkAtom selection,
                           GdkAtom target,
                           guint32 time_);

Retrieves the contents of a selection in a given form.

#### Parameters

requestor | a GdkWindow. |
selection | an atom identifying the selection to get the contents of. |
target | the form in which to retrieve the selection. |
time_ | the timestamp to use when retrieving the selection. The selection owner may refuse the request if it did not own the selection at the time indicated by the timestamp. |

### gdk_selection_property_get ()

    gint
    gdk_selection_property_get (GdkWindow *requestor,
                                guchar **data,
                                GdkAtom *prop_type,
                                gint *prop_format);

Retrieves selection data that was stored by the selection data in response to a call to `gdk_selection_convert()`. This function will not be used by applications, who should use the GtkClipboard API instead.

[skip]

#### Parameters

requestor | the window on which the data is stored |
data | location to store a pointer to the retrieved data. If the retrieval failed, `NULL` we be stored here, otherwise, it will be non-`NULL` and the returned data should be freed with `g_free()` when you are finished using it. The length of the allocated memory is one more than the length of the returned data, and the final byte will always be zero, to ensure nul-termination of strings |
prop_type | location to store the type of the property |
prop_format | location to store the format of the property |

#### Returns

the length of the retrieved data.

### gdk_selection_send_notify ()

    void
    gdk_selection_send_notify (GdkWindow *requestor,
                               GdkAtom selection,
                               GdkAtom target,
                               GdkAtom property,
                               guint32 time_);

Sends a response to SelectionRequest event.

#### Parameters

requestor | window to which to deliver response. |
selection | selection that was requested. |
target | target that was selected. |
property | property in which the selection owner stored the data, or `GDK_NONE` to indicate that the request was rejected. |
time_ | timestamp. |

### gdk_selection_send_notify_for_display ()

    void
    gdk_selection_send_notify_for_display (GdkDisplay *display,
                                           GdkWindow *requestor,
                                           GdkAtom selection,
                                           GdkAtom target,
                                           GdkAtom property,
                                           guint32 time_);

Send a response to SelectionRequest event.

#### Parameters

display | the GdkDisplay where `requestor` is realized |
requestor | window to which to deliver response |
selection | selection that was requested |
target | target that was selected |
property | property in which the selection owner stored the data, or `GDK_NONE` to indicate that the request was rejected |
time_ | timestamp |

Since: 2.2

## Types and Values

### GDK_SELECTION_PRIMARY

    #define GDK_SELECTION_PRIMARY 		_GDK_MAKE_ATOM (1)

A GdkAtom representing the `PRIMARY` selection.

### GDK_SELECTION_SECONDARY

    #define GDK_SELECTION_SECONDARY 	_GDK_MAKE_ATOM (2)

A GdkAtom representing the `SECONDARY` selection.

### GDK_SELECTION_CLIPBOARD

    #define GDK_SELECTION_CLIPBOARD 	_GDK_MAKE_ATOM (69)

A GdkAtom representing the `CLIPBOARD` selection.

### GDK_TARGET_BITMAP

    #define GDK_TARGET_BITMAP 		_GDK_MAKE_ATOM (5)

A GdkAtom representing the `BITMAP` selection target.

### GDK_TARGET_COLORMAP

    #define GDK_TARGET_COLORMAP 		_GDK_MAKE_ATOM (7)

A GdkAtom representing the `COLORMAP` selection target.

### GDK_TARGET_DRAWABLE

    #define GDK_TARGET_DRAWABLE 		_GDK_MAKE_ATOM (17)

A GdkAtom representing the `DRAWABLE` selection target.

### GDK_TARGET_PIXMAP

    #define GDK_TARGET_PIXMAP 		_GDK_MAKE_ATOM (20)

A GdkAtom representing the `PIXMAP` selection target.

### GDK_TARGET_STRING

    #define GDK_TARGET_STRING 		_GDK_MAKE_ATOM (31)

A GdkAtom representing the `STRING` selection target.

### GDK_SELECTION_TYPE_ATOM

    #define GDK_SELECTION_TYPE_ATOM 	_GDK_MAKE_ATOM (4)

A GdkAtom representing the `ATOM` selection type.

### GDK_SELECTION_TYPE_BITMAP

    #define GDK_SELECTION_TYPE_BITMAP 	_GDK_MAKE_ATOM (5)

A GdkAtom representing the `BITMAP` selection type.

### GDK_SELECTION_TYPE_COLORMAP

    #define GDK_SELECTION_TYPE_COLORMAP 	_GDK_MAKE_ATOM (7)

A GdkAtom representing the `COLORMAP` selection type.

### GDK_SELECTION_TYPE_DRAWABLE

    #define GDK_SELECTION_TYPE_DRAWABLE 	_GDK_MAKE_ATOM (17)

A GdkAtom representing the `DRAWABLE` selection type.

### GDK_SELECTION_TYPE_INTEGER

    #define GDK_SELECTION_TYPE_INTEGER 	_GDK_MAKE_ATOM (19)

A GdkAtom representing the `INTEGER` selection type.

### GDK_SELECTION_TYPE_PIXMAP

    #define GDK_SELECTION_TYPE_PIXMAP 	_GDK_MAKE_ATOM (20)

A GdkAtom representing the `PIXMAP` selection type.

### GDK_SELECTION_TYPE_WINDOW

    #define GDK_SELECTION_TYPE_WINDOW 	_GDK_MAKE_ATOM (33)

A GdkAtom representing the `WINDOW` selection type.

### GDK_SELECTION_TYPE_STRING

    #define GDK_SELECTION_TYPE_STRING 	_GDK_MAKE_ATOM (31)

A GdkAtom representing the `STRING` selection type.