## Documentation

Table of Contents
Class Inheritance Tree
Widget Screenshots
Package groups

## Index

Package: Clipboard

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# Description

    package Gtk.Clipboard is

The Gtk_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 Gdk_Atom. (Conversion to and from strings can be done with gdk.properties.atom_intern and gdk.properties.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 Set_Text), or you can supply a callback to be called at a later time when the data is needed (via Set_With_Data or Set_With_Owner.) Providing a callback also avoids having to make copies of the data when it is not needed.

Set_With_Data and 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 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 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, 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 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, Request_Text and 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+.)

Binding from C File version 2.8.17

<testgtk>create_clipboard.adb</testgtk>

# Types

### Gtk_Clipboard

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    type Gtk_Clipboard is new Glib.C_Proxy;

### Gtk_Clipboard_Text_Received_Func

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    type Gtk_Clipboard_Text_Received_Func is access
         procedure (Clipboard : Gtk_Clipboard;
                    Text      : Interfaces.C.Strings.chars_ptr;
                    Data      : System.Address);

### Gtk_Clipboard_Image_Received_Func

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    type Gtk_Clipboard_Image_Received_Func is access
         procedure (Clipboard : Gtk_Clipboard;
                    Pixbuf    : System.Address;
                    Data      : System.Address);

### Gtk_Clipboard_Get_Func

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    type Gtk_Clipboard_Get_Func is access procedure
         (Clipboard          : Gtk_Clipboard;
          Selection_Data     : Gtk.Selection.Selection_Data;
          Info               : Guint;
          User_Data_Or_Owner : System.Address);

### Gtk_Clipboard_Clear_Func

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    type Gtk_Clipboard_Clear_Func is access procedure
         (Clipboard          : Gtk_Clipboard;
          User_Data_Or_Owner : System.Address);

### Gtk_Clipboard_Received_Func

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    type Gtk_Clipboard_Received_Func is access procedure
         (Clipboard      : Gtk_Clipboard;
          Selection_Data : Gtk.Selection.Selection_Data;
          User_Data      : System.Address);

### Gtk_Clipboard_Targets_Received_Func

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    type Gtk_Clipboard_Targets_Received_Func is access procedure
         (Clipboard      : Gtk_Clipboard;
          Atoms          : Gdk.Types.Gdk_Atom_Array;
          N_Atoms        : Gint;
          User_Data      : System.Address);

# Constants & Global variables

### Signal_Owner_Change

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(Glib.Signal_Name)

    Signal_Owner_Change : constant Glib.Signal_Name := "owner_change";

# Subprograms & Entries

### Get_Type

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    function Get_Type return Glib.GType;

Return the internal type used for clipboards

### Get_Clipboard

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    function Get_Clipboard (Widget: access Gtk.Widget.Gtk_Widget_Record'Class;Selection: Gdk.Types.Gdk_Atom) return Gtk.Clipboard.Gtk_Clipboard;

Returns the clipboard object for the given selection to be used with Widget. Widget must have a Gdk_Display associated with it, so must be attached to a toplevel window. Return value: 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 for all time.

### Get

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    function Get (Selection: Gdk.Types.Gdk_Atom := Gdk.Types.Gdk_None) return Gtk_Clipboard;

Return the clipboard object for the given selection. Cut/copy/paste menu items and keyboard shortcuts should use the default clipboard, returned by passing Gdk_None for Selection. The currently-selected object or text should be provided on the clipboard identified by Selection_Primary. Cut/copy/paste menu items conceptually copy the contents of the 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 Atom_Intern ("CLIPBOARD", False). See http://standards.freedesktop.org/clipboards-spec/ for a detailed discussion of the "CLIPBOARD" vs. "PRIMARY" selections under the X window system. On Win32 the 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". Selection is a Gdk_Atom which identifies the clipboard to use. If no clipboard already exists, a new one will be created. Once clipboard object has been created, it is persistent for all time and cannot be freed.

### Set_Can_Store

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    procedure Set_Can_Store (Clipboard: Gtk_Clipboard;Targets: Gtk.Selection.Target_Entry_Array);

Hints that the clipboard data should be stored somewhere when the application exits or when Store is called. This value is reset when the clipboard owner changes. Where the clipboard data is stored is platform dependent. Targets is an array containing information about which forms should be stored, or an empty array to indicate that all forms should be stored.

### Store

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    procedure Store (Clipboard: Gtk_Clipboard);

Stores the current clipboard data somewhere so that it will stay around after the application has quit. See also Gdk.Display.Supports_Clipboard_Persistence and Gdk.Display.Store_Clipboard.

### Get_Owner

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    function Get_Owner (Clipboard: Gtk_Clipboard) return Glib.Object.GObject;

If the clipboard contents callbacks were set with Set_With_Owner, and the Set_With_Data or Clear has not subsequently called, returns the owner set by Set_With_Owner.

### Clear

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    procedure Clear (Clipboard: Gtk_Clipboard);

Clear the contents of the clipboard. Generally this should only be called between the time you call Set_With_Owner or Set_With_Data, and when the Clear_Func you supplied is called. Otherwise, the clipboard may be owned by someone else.

### Set_Text

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    procedure Set_Text (Clipboard: Gtk_Clipboard;Text: UTF8_String);

Set the contents of the clipboard.

### Wait_For_Text

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    function Wait_For_Text (Clipboard: Gtk_Clipboard) return UTF8_String;

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. Return "" 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)

### Wait_Is_Text_Available

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    function Wait_Is_Text_Available (Clipboard: Gtk_Clipboard) return Boolean;

Test to see if there is text available to be pasted. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.

### Request_Text

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    procedure Request_Text (Clipboard: Gtk_Clipboard;Callback: Gtk_Clipboard_Text_Received_Func;User_Data: System.Address);

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.

### Set_Image

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    procedure Set_Image (Clipboard: Gtk_Clipboard;Pixbuf: Gdk.Pixbuf.Gdk_Pixbuf);

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.

### Wait_For_Image

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    function Wait_For_Image (Clipboard: Gtk_Clipboard) return Gdk.Pixbuf.Gdk_Pixbuf;

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. The returned value must be freed with a call to Unref.

### Wait_Is_Image_Available

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    function Wait_Is_Image_Available (Clipboard: Gtk_Clipboard) return Boolean;

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 Wait_For_Image since it doesn't need to retrieve the actual image data.

### Request_Image

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    procedure Request_Image (Clipboard: Gtk_Clipboard;Callback: Gtk_Clipboard_Image_Received_Func;User_Data: System.Address);

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.

### Set_With_Data

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    function Set_With_Data (Clipboard: Gtk_Clipboard;Targets: Gtk.Selection.Target_Entry_Array;Get_Func: Gtk_Clipboard_Get_Func;Clear_Func: Gtk_Clipboard_Clear_Func;User_Data: System.Address) return Boolean;

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. No actual copy of the data is made until someones actually requests it. Targets contains information about the available forms for the clipboard data. This function returns True if setting the clipboard data succeeded.

### Set_With_Owner

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    function Set_With_Owner (Clipboard: Gtk_Clipboard;Targets: Gtk.Selection.Target_Entry_Array;Get_Func: Gtk_Clipboard_Get_Func;Clear_Func: Gtk_Clipboard_Clear_Func;Owner: access Glib.Object.GObject_Record'Class) return Boolean;

Same as Set_With_Data, but an actual object is passed instead of a generic user_data. This takes care of referencing the object as appropriate.

### Wait_For_Targets

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    function Wait_For_Targets (Clipboard: Gtk_Clipboard) return Gdk.Types.Gdk_Atom_Array;

Returns a list of targets that are present on the clipboard, or an empty array if there aren't any targets available. This function waits for the data to be received using the main loop, so events, timeouts, etc, may be dispatched during the wait.

### Wait_For_Contents

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    function Wait_For_Contents (Clipboard: Gtk_Clipboard;Target: Gdk.Types.Gdk_Atom) return Gtk.Selection.Selection_Data;

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. The result must be freed.

### Wait_Is_Target_Available

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    function Wait_Is_Target_Available (Clipboard: Gtk_Clipboard;Target: Gdk.Types.Gdk_Atom) return Boolean;

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 Wait_Is_Text_Available instead. The value for Target is similar to the one in Gtk.Selection.Target_Entry

### Request_Contents

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    procedure Request_Contents (Clipboard: Gtk_Clipboard;Target: Gdk.Types.Gdk_Atom;Callback: Gtk_Clipboard_Received_Func;User_Data: System.Address);

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

### Request_Targets

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    procedure Request_Targets (Clipboard: Gtk_Clipboard;Callback: Gtk_Clipboard_Targets_Received_Func;User_Data: System.Address);

Requests the contents of the clipboard as list of supported targets. When the list is later received, Callback will be called.