gi-gtk-3.0.24: Gtk bindings

Copyright Will Thompson Iñaki García Etxebarria and Jonas Platte LGPL-2.1 Iñaki García Etxebarria (garetxe@gmail.com) None Haskell2010

GI.Gtk.Objects.Clipboard

Description

The Clipboard 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 Atom. (Conversion to and from strings can be done with atomIntern and atomName.) 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 clipboardSetText), 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 clearFunc 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 Object (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 clearFunc 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, clipboardRequestContents 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 clipboardWaitForContents. 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, clipboardRequestText and clipboardWaitForText. 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+.)

Synopsis

# Exported types

newtype Clipboard Source #

Memory-managed wrapper type.

Constructors

 Clipboard (ManagedPtr Clipboard)
Instances
 Source # Instance detailsDefined in GI.Gtk.Objects.Clipboard Methods Source # Instance detailsDefined in GI.Gtk.Objects.Clipboard Source # Instance detailsDefined in GI.Gtk.Objects.Clipboard

class GObject o => IsClipboard o Source #

Type class for types which can be safely cast to Clipboard, for instance with toClipboard.

Instances
 (GObject a, (UnknownAncestorError Clipboard a :: Constraint)) => IsClipboard a Source # Instance detailsDefined in GI.Gtk.Objects.Clipboard Source # Instance detailsDefined in GI.Gtk.Objects.Clipboard

toClipboard :: (MonadIO m, IsClipboard o) => o -> m Clipboard Source #

Cast to Clipboard, for types for which this is known to be safe. For general casts, use castTo.

A convenience alias for Nothing :: Maybe Clipboard.

# Methods

## clear

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m ()

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 clearFunc you supplied is called. Otherwise, the clipboard may be owned by someone else.

## get

Arguments

 :: (HasCallStack, MonadIO m) => Atom selection: a Atom which identifies the clipboard to use -> m Clipboard 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 unreffed.

Returns the clipboard object for the given selection. See clipboardGetForDisplay for complete details.

## getDefault

Arguments

 :: (HasCallStack, MonadIO m, IsDisplay a) => a display: the Display for which the clipboard is to be retrieved. -> m Clipboard Returns: the default clipboard object.

Returns the default clipboard object for use with cut/copy/paste menu items and keyboard shortcuts.

Since: 3.16

## getDisplay

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m Display Returns: the Display associated with clipboard

Gets the Display associated with clipboard

Since: 2.2

## getForDisplay

Arguments

 :: (HasCallStack, MonadIO m, IsDisplay a) => a display: the Display for which the clipboard is to be retrieved or created. -> Atom selection: a Atom which identifies the clipboard to use. -> m Clipboard 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.

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 the FreeDesktop Clipboard Specification 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”.

Since: 2.2

## getOwner

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m (Maybe Object) Returns: the owner of the clipboard, if any; otherwise Nothing.

If the clipboard contents callbacks were set with gtk_clipboard_set_with_owner(), and the gtk_clipboard_set_with_data() or clipboardClear has not subsequently called, returns the owner set by gtk_clipboard_set_with_owner().

## requestContents

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> Atom target: an atom representing the form into which the clipboard owner should convert the selection. -> ClipboardReceivedFunc callback: A function to call when the results are received (or the retrieval fails). If the retrieval fails the length field of selectionData will be negative. -> m ()

Requests the contents of clipboard as the given target. When the results of the result are later received the supplied callback will be called.

## requestImage

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> ClipboardImageReceivedFunc callback: a function to call when the image is received, or the retrieval fails. (It will always be called one way or the other.) -> m ()

Requests the contents of the clipboard as image. When the image is later received, it will be converted to a Pixbuf, and callback will be called.

The pixbuf parameter to callback will contain the resulting Pixbuf if the request succeeded, or Nothing 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.

Since: 2.6

## requestRichText

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a, IsTextBuffer b) => a clipboard: a Clipboard -> b buffer: a TextBuffer -> ClipboardRichTextReceivedFunc callback: a function to call when the text is received, or the retrieval fails. (It will always be called one way or the other.) -> m ()

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 Nothing 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.

Since: 2.10

## requestTargets

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> ClipboardTargetsReceivedFunc callback: a function to call when the targets are received, or the retrieval fails. (It will always be called one way or the other.) -> m ()

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 Nothing if it failed.

Since: 2.4

## requestText

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> ClipboardTextReceivedFunc callback: a function to call when the text is received, or the retrieval fails. (It will always be called one way or the other.) -> m ()

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 Nothing 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.

## requestUris

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> ClipboardURIReceivedFunc callback: a function to call when the URIs are received, or the retrieval fails. (It will always be called one way or the other.) -> m ()

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 Nothing 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.

Since: 2.14

## setCanStore

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> Maybe [TargetEntry] targets: array containing information about which forms should be stored or Nothing to indicate that all forms should be stored. -> m ()

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.

Since: 2.6

## setImage

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a, IsPixbuf b) => a clipboard: a Clipboard object -> b pixbuf: a Pixbuf -> m ()

Sets the contents of the clipboard to the given Pixbuf. GTK+ will take responsibility for responding for requests for the image, and for converting the image into the requested format.

Since: 2.6

## setText

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard object -> Text text: a UTF-8 string. -> Int32 len: length of text, in bytes, or -1, in which case the length will be determined with strlen(). -> m ()

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.

## store

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m ()

Stores the current clipboard data somewhere so that it will stay around after the application has quit.

Since: 2.6

## waitForContents

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> Atom target: an atom representing the form into which the clipboard owner should convert the selection. -> m (Maybe SelectionData) Returns: a newly-allocated SelectionData object or Nothing if retrieving the given target failed. If non-Nothing, this value must be freed with selectionDataFree when you are finished with it.

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.

## waitForImage

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m (Maybe Pixbuf) Returns: a newly-allocated Pixbuf object which must be disposed with objectUnref, or Nothing 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.)

Requests the contents of the clipboard as image and converts the result to a Pixbuf. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.

Since: 2.6

## waitForTargets

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m (Bool, [Atom]) Returns: True if any targets are present on the clipboard, otherwise False.

Returns a list of targets that are present on the clipboard, or Nothing if there aren’t any targets available. The returned list must be freed with free. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.

Since: 2.4

## waitForText

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m (Maybe Text) Returns: a newly-allocated UTF-8 string which must be freed with free, or Nothing 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.)

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.

## waitForUris

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m (Maybe [Text]) Returns: a newly-allocated Nothing-terminated array of strings which must be freed with strfreev, or Nothing 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.)

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.

Since: 2.14

## waitIsImageAvailable

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m Bool Returns: True is there is an image available, False otherwise.

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 clipboardWaitForImage since it doesn’t need to retrieve the actual image data.

Since: 2.6

## waitIsRichTextAvailable

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a, IsTextBuffer b) => a clipboard: a Clipboard -> b buffer: a TextBuffer -> m Bool Returns: True is there is rich text available, False otherwise.

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 clipboardWaitForRichText since it doesn’t need to retrieve the actual text.

Since: 2.10

## waitIsTargetAvailable

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> Atom target: A Atom indicating which target to look for. -> m Bool Returns: True if the target is available, False otherwise.

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

## waitIsTextAvailable

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m Bool Returns: True is there is text available, False otherwise.

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 clipboardWaitForText since it doesn’t need to retrieve the actual text.

## waitIsUrisAvailable

Arguments

 :: (HasCallStack, MonadIO m, IsClipboard a) => a clipboard: a Clipboard -> m Bool Returns: True is there is an URI list available, False otherwise.

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 clipboardWaitForUris since it doesn’t need to retrieve the actual URI data.

Since: 2.14

# Signals

## ownerChange

type C_ClipboardOwnerChangeCallback = Ptr () -> Ptr EventOwnerChange -> Ptr () -> IO () Source #

Type for the callback on the (unwrapped) C side.

Arguments

 = EventOwnerChange event: the gdkEventOwnerChange event -> IO ()

The ::owner-change signal is emitted when GTK+ receives an event that indicates that the ownership of the selection associated with clipboard has changed.

Since: 2.6

Connect a signal handler for the “owner-change” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after clipboard #ownerChange callback


Wrap the callback into a Closure.

Generate a function pointer callable from C code, from a C_ClipboardOwnerChangeCallback.

A convenience synonym for Nothing :: Maybe ClipboardOwnerChangeCallback.

Connect a signal handler for the “owner-change” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on clipboard #ownerChange callback


Wrap a ClipboardOwnerChangeCallback into a C_ClipboardOwnerChangeCallback.