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Functions
Description
The GtkClipboard object represents a clipboard of data shared
between different processes or between different widgets in
the same process. Each clipboard is identified by a name encoded as a
GdkAtom. (Conversion to and from strings can be done with
gdk_atom_intern() and gdk_atom_name().) The default clipboard
corresponds to the "CLIPBOARD" atom; another commonly used clipboard
is the "PRIMARY" clipboard, which, in X, traditionally contains
the currently selected text.
To support having a number of different formats on the clipboard
at the same time, the clipboard mechanism allows providing
callbacks instead of the actual data. When you set the contents
of the clipboard, you can either supply the data directly (via
functions like gtk_clipboard_set_text()), or you can supply a
callback to be called at a later time when the data is needed (via
gtk_clipboard_set_with_data() or gtk_clipboard_set_with_owner().)
Providing a callback also avoids having to make copies of the data
when it is not needed.
gtk_clipboard_set_with_data() and gtk_clipboard_set_with_owner()
are quite similar; the choice between the two depends mostly on
which is more convenient in a particular situation.
The former is most useful when you want to have a blob of data
with callbacks to convert it into the various data types that you
advertise. When the clear_func you provided is called, you
simply free the data blob. The latter is more useful when the
contents of clipboard reflect the internal state of a GObject
(As an example, for the PRIMARY clipboard, when an entry widget
provides the clipboard's contents the contents are simply the
text within the selected region.) If the contents change, the
entry widget can call gtk_clipboard_set_with_owner() to update
the timestamp for clipboard ownership, without having to worry
about clear_func being called.
Requesting the data from the clipboard is essentially
asynchronous. If the contents of the clipboard are provided within
the same process, then a direct function call will be made to
retrieve the data, but if they are provided by another process,
then the data needs to be retrieved from the other process, which
may take some time. To avoid blocking the user interface, the call
to request the selection, gtk_clipboard_request_contents() takes a
callback that will be called when the contents are received (or
when the request fails.) If you don't want to deal with providing
a separate callback, you can also use gtk_clipboard_wait_for_contents().
What this does is run the GLib main loop recursively waiting for
the contents. This can simplify the code flow, but you still have
to be aware that other callbacks in your program can be called
while this recursive mainloop is running.
Along with the functions to get the clipboard contents as an
arbitrary data chunk, there are also functions to retrieve
it as text, gtk_clipboard_request_text() and
gtk_clipboard_wait_for_text(). These functions take care of
determining which formats are advertised by the clipboard
provider, asking for the clipboard in the best available format
and converting the results into the UTF-8 encoding. (The standard
form for representing strings in GTK+.)
Functions
GtkClipboardReceivedFunc ()
void (*GtkClipboardReceivedFunc) (GtkClipboard *clipboard,GtkSelectionData *selection_data,gpointer data);
A function to be called when the results of gtk_clipboard_request_contents()
are received, or when the request fails.
Parameters
clipboard |
the GtkClipboard |
|
selection_data |
a GtkSelectionData containing the data was received.
If retrieving the data failed, then then length field
of |
|
data |
the |
GtkClipboardTextReceivedFunc ()
void (*GtkClipboardTextReceivedFunc) (GtkClipboard *clipboard,const gchar *text,gpointer data);
A function to be called when the results of gtk_clipboard_request_text()
are received, or when the request fails.
Parameters
clipboard |
the GtkClipboard |
|
text |
the text received, as a UTF-8 encoded string, or |
|
data |
the |
GtkClipboardImageReceivedFunc ()
void (*GtkClipboardImageReceivedFunc) (GtkClipboard *clipboard,GdkPixbuf *pixbuf,gpointer data);
A function to be called when the results of gtk_clipboard_request_image()
are received, or when the request fails.
Parameters
clipboard |
the GtkClipboard |
|
pixbuf |
the received image |
|
data |
the |
Since 2.6
GtkClipboardTargetsReceivedFunc ()
void (*GtkClipboardTargetsReceivedFunc) (GtkClipboard *clipboard,GdkAtom *atoms,gint n_atoms,gpointer data);
A function to be called when the results of gtk_clipboard_request_targets()
are received, or when the request fails.
Parameters
clipboard |
the GtkClipboard |
|
atoms |
the supported targets, as array of GdkAtom, or |
|
n_atoms |
the length of the |
|
data |
the |
Since 2.4
GtkClipboardRichTextReceivedFunc ()
void (*GtkClipboardRichTextReceivedFunc) (GtkClipboard *clipboard,GdkAtom format,const guint8 *text,gsize length,gpointer data);
GtkClipboardURIReceivedFunc ()
void (*GtkClipboardURIReceivedFunc) (GtkClipboard *clipboard,gchar **uris,gpointer data);
GtkClipboardGetFunc ()
void (*GtkClipboardGetFunc) (GtkClipboard *clipboard,GtkSelectionData *selection_data,guint info,gpointer user_data_or_owner);
A function that will be called to provide the contents of the selection.
If multiple types of data were advertised, the requested type can
be determined from the info parameter or by checking the target field
of selection_data. If the data could successfully be converted into
then it should be stored into the selection_data object by
calling gtk_selection_data_set() (or related functions such
as gtk_selection_data_set_text()). If no data is set, the requestor
will be informed that the attempt to get the data failed.
Parameters
clipboard |
the GtkClipboard |
|
selection_data |
a GtkSelectionData argument in which the requested data should be stored. |
|
info |
the info field corresponding to the requested
target from the GtkTargetEntry array passed to
|
|
user_data_or_owner |
the |
GtkClipboardClearFunc ()
void (*GtkClipboardClearFunc) (GtkClipboard *clipboard,gpointer user_data_or_owner);
A function that will be called when the contents of the clipboard are changed
or cleared. Once this has called, the user_data_or_owner argument
will not be used again.
Parameters
clipboard |
the GtkClipboard |
|
user_data_or_owner |
the |
gtk_clipboard_get ()
GtkClipboard *
gtk_clipboard_get (GdkAtom selection);
Returns the clipboard object for the given selection.
See gtk_clipboard_get_for_display() for complete details.
gtk_clipboard_get_for_display ()
GtkClipboard * gtk_clipboard_get_for_display (GdkDisplay *display,GdkAtom selection);
Returns the clipboard object for the given selection.
Cut/copy/paste menu items and keyboard shortcuts should use
the default clipboard, returned by passing GDK_SELECTION_CLIPBOARD for selection
.
(GDK_NONE is supported as a synonym for GDK_SELECTION_CLIPBOARD
for backwards compatibility reasons.)
The currently-selected object or text should be provided on the clipboard
identified by GDK_SELECTION_PRIMARY. Cut/copy/paste menu items
conceptually copy the contents of the GDK_SELECTION_PRIMARY clipboard
to the default clipboard, i.e. they copy the selection to what the
user sees as the clipboard.
(Passing GDK_NONE is the same as using gdk_atom_intern
("CLIPBOARD", FALSE). See
http://www.freedesktop.org/Standards/clipboards-spec
for a detailed discussion of the "CLIPBOARD" vs. "PRIMARY"
selections under the X window system. On Win32 the
GDK_SELECTION_PRIMARY clipboard is essentially ignored.)
It's possible to have arbitrary named clipboards; if you do invent new clipboards, you should prefix the selection name with an underscore (because the ICCCM requires that nonstandard atoms are underscore-prefixed), and namespace it as well. For example, if your application called "Foo" has a special-purpose clipboard, you might call it "_FOO_SPECIAL_CLIPBOARD".
Parameters
display |
the display for which the clipboard is to be retrieved or created |
|
selection |
a GdkAtom which identifies the clipboard to use. |
Returns
the appropriate clipboard object. If no clipboard already exists, a new one will be created. Once a clipboard object has been created, it is persistent and, since it is owned by GTK+, must not be freed or unrefd.
[transfer none]
Since 2.2
gtk_clipboard_get_display ()
GdkDisplay *
gtk_clipboard_get_display (GtkClipboard *clipboard);
Gets the GdkDisplay associated with clipboard
Since 2.2
gtk_clipboard_set_with_data ()
gboolean gtk_clipboard_set_with_data (GtkClipboard *clipboard,const GtkTargetEntry *targets,guint n_targets,GtkClipboardGetFunc get_func,GtkClipboardClearFunc clear_func,gpointer user_data);
Virtually sets the contents of the specified clipboard by providing a list of supported formats for the clipboard data and a function to call to get the actual data when it is requested.
Parameters
clipboard |
||
targets |
array containing information about the available forms for the clipboard data |
|
n_targets |
number of elements in |
|
get_func |
function to call to get the actual clipboard data |
|
clear_func |
when the clipboard contents are set again, this function will
be called, and |
|
user_data |
user data to pass to |
Returns
TRUE if setting the clipboard data succeeded. If setting
the clipboard data failed the provided callback functions
will be ignored.
gtk_clipboard_set_with_owner ()
gboolean gtk_clipboard_set_with_owner (GtkClipboard *clipboard,const GtkTargetEntry *targets,guint n_targets,GtkClipboardGetFunc get_func,GtkClipboardClearFunc clear_func,GObject *owner);
Virtually sets the contents of the specified clipboard by providing a list of supported formats for the clipboard data and a function to call to get the actual data when it is requested.
The difference between this function and gtk_clipboard_set_with_data()
is that instead of an generic user_data
pointer, a GObject is passed
in.
Parameters
clipboard |
||
targets |
array containing information about the available forms for the clipboard data |
|
n_targets |
number of elements in |
|
get_func |
function to call to get the actual clipboard data |
|
clear_func |
when the clipboard contents are set again, this function will
be called, and |
|
owner |
an object that "owns" the data. This object will be passed to the callbacks when called. |
Returns
TRUE if setting the clipboard data succeeded. If setting
the clipboard data failed the provided callback functions
will be ignored.
gtk_clipboard_get_owner ()
GObject *
gtk_clipboard_get_owner (GtkClipboard *clipboard);
If the clipboard contents callbacks were set with
gtk_clipboard_set_with_owner(), and the gtk_clipboard_set_with_data() or
gtk_clipboard_clear() has not subsequently called, returns the owner set
by gtk_clipboard_set_with_owner().
gtk_clipboard_clear ()
void
gtk_clipboard_clear (GtkClipboard *clipboard);
Clears the contents of the clipboard. Generally this should only
be called between the time you call gtk_clipboard_set_with_owner()
or gtk_clipboard_set_with_data(),
and when the clear_func
you supplied is called. Otherwise, the
clipboard may be owned by someone else.
gtk_clipboard_set_text ()
void gtk_clipboard_set_text (GtkClipboard *clipboard,const gchar *text,gint len);
Sets the contents of the clipboard to the given UTF-8 string. GTK+ will make a copy of the text and take responsibility for responding for requests for the text, and for converting the text into the requested format.
Parameters
clipboard |
a GtkClipboard object |
|
text |
a UTF-8 string. |
|
len |
length of |
gtk_clipboard_set_image ()
void gtk_clipboard_set_image (GtkClipboard *clipboard,GdkPixbuf *pixbuf);
Sets the contents of the clipboard to the given GdkPixbuf. GTK+ will take responsibility for responding for requests for the image, and for converting the image into the requested format.
Since 2.6
gtk_clipboard_request_contents ()
void gtk_clipboard_request_contents (GtkClipboard *clipboard,GdkAtom target,GtkClipboardReceivedFunc callback,gpointer user_data);
Requests the contents of clipboard as the given target. When the results of the result are later received the supplied callback will be called.
Parameters
clipboard |
||
target |
an atom representing the form into which the clipboard owner should convert the selection. |
|
callback |
A function to call when the results are received
(or the retrieval fails). If the retrieval fails
the length field of |
|
user_data |
user data to pass to |
gtk_clipboard_request_text ()
void gtk_clipboard_request_text (GtkClipboard *clipboard,GtkClipboardTextReceivedFunc callback,gpointer user_data);
Requests the contents of the clipboard as text. When the text is
later received, it will be converted to UTF-8 if necessary, and
callback
will be called.
The text
parameter to callback
will contain the resulting text if
the request succeeded, or NULL if it failed. This could happen for
various reasons, in particular if the clipboard was empty or if the
contents of the clipboard could not be converted into text form.
gtk_clipboard_request_image ()
void gtk_clipboard_request_image (GtkClipboard *clipboard,GtkClipboardImageReceivedFunc callback,gpointer user_data);
Requests the contents of the clipboard as image. When the image is
later received, it will be converted to a GdkPixbuf, and
callback
will be called.
The pixbuf
parameter to callback
will contain the resulting
GdkPixbuf if the request succeeded, or NULL if it failed. This
could happen for various reasons, in particular if the clipboard
was empty or if the contents of the clipboard could not be
converted into an image.
Parameters
clipboard |
||
callback |
a function to call when the image is received, or the retrieval fails. (It will always be called one way or the other.) |
|
user_data |
user data to pass to |
Since 2.6
gtk_clipboard_request_targets ()
void gtk_clipboard_request_targets (GtkClipboard *clipboard,GtkClipboardTargetsReceivedFunc callback,gpointer user_data);
Requests the contents of the clipboard as list of supported targets.
When the list is later received, callback
will be called.
The targets
parameter to callback
will contain the resulting targets if
the request succeeded, or NULL if it failed.
Parameters
clipboard |
||
callback |
a function to call when the targets are received, or the retrieval fails. (It will always be called one way or the other.) |
|
user_data |
user data to pass to |
Since 2.4
gtk_clipboard_request_rich_text ()
void gtk_clipboard_request_rich_text (GtkClipboard *clipboard,GtkTextBuffer *buffer,GtkClipboardRichTextReceivedFunc callback,gpointer user_data);
Requests the contents of the clipboard as rich text. When the rich
text is later received, callback
will be called.
The text
parameter to callback
will contain the resulting rich
text if the request succeeded, or NULL if it failed. The length
parameter will contain text
's length. This function can fail for
various reasons, in particular if the clipboard was empty or if the
contents of the clipboard could not be converted into rich text form.
Parameters
clipboard |
||
buffer |
||
callback |
a function to call when the text is received, or the retrieval fails. (It will always be called one way or the other.) |
|
user_data |
user data to pass to |
Since 2.10
gtk_clipboard_request_uris ()
void gtk_clipboard_request_uris (GtkClipboard *clipboard,GtkClipboardURIReceivedFunc callback,gpointer user_data);
Requests the contents of the clipboard as URIs. When the URIs are
later received callback
will be called.
The uris
parameter to callback
will contain the resulting array of
URIs if the request succeeded, or NULL if it failed. This could happen
for various reasons, in particular if the clipboard was empty or if the
contents of the clipboard could not be converted into URI form.
Parameters
clipboard |
||
callback |
a function to call when the URIs are received, or the retrieval fails. (It will always be called one way or the other.) |
|
user_data |
user data to pass to |
Since 2.14
gtk_clipboard_wait_for_contents ()
GtkSelectionData * gtk_clipboard_wait_for_contents (GtkClipboard *clipboard,GdkAtom target);
Requests the contents of the clipboard using the given target. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
Parameters
clipboard |
||
target |
an atom representing the form into which the clipboard owner should convert the selection. |
Returns
a newly-allocated GtkSelectionData object or NULL
if retrieving the given target failed. If non-NULL,
this value must be freed with gtk_selection_data_free()
when you are finished with it.
gtk_clipboard_wait_for_text ()
gchar *
gtk_clipboard_wait_for_text (GtkClipboard *clipboard);
Requests the contents of the clipboard as text and converts the result to UTF-8 if necessary. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
gtk_clipboard_wait_for_image ()
GdkPixbuf *
gtk_clipboard_wait_for_image (GtkClipboard *clipboard);
Requests the contents of the clipboard as image and converts the result to a GdkPixbuf. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
Returns
a newly-allocated GdkPixbuf object which must
be disposed with g_object_unref(), or NULL if
retrieving the selection data failed. (This
could happen for various reasons, in particular
if the clipboard was empty or if the contents of
the clipboard could not be converted into an image.).
[transfer full]
Since 2.6
gtk_clipboard_wait_for_rich_text ()
guint8 * gtk_clipboard_wait_for_rich_text (GtkClipboard *clipboard,GtkTextBuffer *buffer,GdkAtom *format,gsize *length);
Requests the contents of the clipboard as rich text. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
Parameters
clipboard |
||
buffer |
||
format |
return location for the format of the returned data |
|
length |
return location for the length of the returned data |
Returns
a
newly-allocated binary block of data which must
be freed with g_free(), or NULL if retrieving
the selection data failed. (This could happen
for various reasons, in particular if the
clipboard was empty or if the contents of the
clipboard could not be converted into text form.).
[array length=length][transfer full]
Since 2.10
gtk_clipboard_wait_for_uris ()
gchar **
gtk_clipboard_wait_for_uris (GtkClipboard *clipboard);
Requests the contents of the clipboard as URIs. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
Returns
a newly-allocated
NULL-terminated array of strings which must
be freed with g_strfreev(), or NULL if
retrieving the selection data failed. (This
could happen for various reasons, in particular
if the clipboard was empty or if the contents of
the clipboard could not be converted into URI form.).
[array zero-terminated=1][element-type utf8][transfer full]
Since 2.14
gtk_clipboard_wait_is_text_available ()
gboolean
gtk_clipboard_wait_is_text_available (GtkClipboard *clipboard);
Test to see if there is text available to be pasted This is done by requesting the TARGETS atom and checking if it contains any of the supported text targets. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
This function is a little faster than calling
gtk_clipboard_wait_for_text() since it doesn't need to retrieve
the actual text.
gtk_clipboard_wait_is_image_available ()
gboolean
gtk_clipboard_wait_is_image_available (GtkClipboard *clipboard);
Test to see if there is an image available to be pasted This is done by requesting the TARGETS atom and checking if it contains any of the supported image targets. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
This function is a little faster than calling
gtk_clipboard_wait_for_image() since it doesn't need to retrieve
the actual image data.
Since 2.6
gtk_clipboard_wait_is_rich_text_available ()
gboolean gtk_clipboard_wait_is_rich_text_available (GtkClipboard *clipboard,GtkTextBuffer *buffer);
Test to see if there is rich text available to be pasted This is done by requesting the TARGETS atom and checking if it contains any of the supported rich text targets. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
This function is a little faster than calling
gtk_clipboard_wait_for_rich_text() since it doesn't need to retrieve
the actual text.
Since 2.10
gtk_clipboard_wait_is_uris_available ()
gboolean
gtk_clipboard_wait_is_uris_available (GtkClipboard *clipboard);
Test to see if there is a list of URIs available to be pasted This is done by requesting the TARGETS atom and checking if it contains the URI targets. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.
This function is a little faster than calling
gtk_clipboard_wait_for_uris() since it doesn't need to retrieve
the actual URI data.
Since 2.14
gtk_clipboard_wait_for_targets ()
gboolean gtk_clipboard_wait_for_targets (GtkClipboard *clipboard,GdkAtom **targets,gint *n_targets);
Returns a list of targets that are present on the clipboard, or NULL
if there aren't any targets available. The returned list must be
freed with g_free().
This function waits for the data to be received using the main
loop, so events, timeouts, etc, may be dispatched during the wait.
Parameters
clipboard |
||
targets |
location to store an array of targets. The result
stored here must be freed with |
[out][array length=n_targets][transfer container] |
n_targets |
location to store number of items in |
Since 2.4
gtk_clipboard_wait_is_target_available ()
gboolean gtk_clipboard_wait_is_target_available (GtkClipboard *clipboard,GdkAtom target);
Checks if a clipboard supports pasting data of a given type. This function can be used to determine if a "Paste" menu item should be insensitive or not.
If you want to see if there's text available on the clipboard, use
gtk_clipboard_wait_is_text_available() instead.
Since 2.6
gtk_clipboard_set_can_store ()
void gtk_clipboard_set_can_store (GtkClipboard *clipboard,const GtkTargetEntry *targets,gint n_targets);
Hints that the clipboard data should be stored somewhere when the
application exits or when gtk_clipboard_store() is called.
This value is reset when the clipboard owner changes.
Where the clipboard data is stored is platform dependent,
see gdk_display_store_clipboard() for more information.
Parameters
clipboard |
||
targets |
array containing
information about which forms should be stored or |
[allow-none][array length=n_targets] |
n_targets |
number of elements in |
Since 2.6
gtk_clipboard_store ()
void
gtk_clipboard_store (GtkClipboard *clipboard);
Stores the current clipboard data somewhere so that it will stay around after the application has quit.
Since 2.6
Signal Details
The “owner-change” signal
void user_function (GtkClipboard *clipboard, GdkEvent *event, gpointer user_data)
The ::owner-change signal is emitted when GTK+ receives an
event that indicates that the ownership of the selection
associated with clipboard
has changed.
Parameters
clipboard |
the GtkClipboard on which the signal is emitted |
|
event |
the |
|
user_data |
user data set when the signal handler was connected. |
Flags: Run First
Since 2.6
See Also
GtkSelection |
GtkClipboard provides a high-level wrapper around the lower level routines that deal with X selections. It is also possibly to directly manipulate the X selections, though it is seldom necessary to do so. |