GDK 3 Reference Manual: Drag And Drop

## Drag And Drop Drag And Drop — Functions for controlling drag and drop handling |

## Functions

GdkAtom | gdk_drag_get_selection ()
void | gdk_drag_abort ()
void | gdk_drop_reply ()
void | gdk_drag_drop ()
void | gdk_drag_find_window_for_screen ()
GdkDragContext * | gdk_drag_begin ()
GdkDragContext * | gdk_drag_begin_for_device ()
gboolean | gdk_drag_motion ()
void | gdk_drop_finish ()
void | gdk_drag_status ()
gboolean | gdk_drag_drop_succeeded ()
GdkDragProtocol | gdk_window_get_drag_protocol ()
GdkDragAction | gdk_drag_context_get_actions ()
GdkDragAction | gdk_drag_context_get_suggested_action ()
GdkDragAction | gdk_drag_context_get_selected_action ()
GList * | gdk_drag_context_list_targets ()
GdkDevice * | gdk_drag_context_get_device ()
void | gdk_drag_context_set_device ()
GdkWindow * | gdk_drag_context_get_source_window ()
GdkWindow * | gdk_drag_context_get_dest_window ()
GdkDragProtocol | gdk_drag_context_get_protocol ()

## Types and Values

| GdkDragContext
enum | GdkDragProtocol
enum | GdkDragAction

## Object Hierarchy

        GObject
        ╰── GdkDragContext

## Includes

    #include <gdk/gdk.h>

## Description

These functions provide a low level interface for drag and drop. The X backend of GDK supports both the Xdnd and Motif drag and drop protocols transparently, the Win32 backend supports the WM_DROPFILES protocol.

GTK+ provides a higher level abstraction based on top of these functions, and so they are not normally needed in GTK+ applications. See the Drag and Drop section of the GTK+ documentation for more information.

## Functions

### gdk_drag_get_selection ()

    GdkAtom
    gdk_drag_get_selection (GdkDragContext *context);

Returns the selection atom for the current source window.

#### Parameters

context | a GdkDragContext. |

#### Returns

the selection atom, or `GDK_NONE`.

[transfer none]

### gdk_drag_abort ()

    void
    gdk_drag_abort (GdkDragContext *context,
                    guint32 time_);

Aborts a drag without dropping.

This function is called by the drag source.

#### Parameters

context | a GdkDragContext |
time_ | the timestamp for this operation |

### gdk_drop_reply ()

    void
    gdk_drop_reply (GdkDragContext *context,
                    gboolean accepted,
                    guint32 time_);

Accepts or rejects a drop.

This function is called by the drag destination in response to a drop initiated by the drag source.

#### Parameters

context | a GdkDragContext |
accepted | `TRUE` if the drop is accepted |
time_ | the timestamp for this operation |

### gdk_drag_drop ()

    void
    gdk_drag_drop (GdkDragContext *context,
                   guint32 time_);

Drops on the current destination.

This function is called by the drag source.

#### Parameters

context | a GdkDragContext |
time_ | the timestamp for this operation |

### gdk_drag_find_window_for_screen ()

    void
    gdk_drag_find_window_for_screen (GdkDragContext *context,
                                     GdkWindow *drag_window,
                                     GdkScreen *screen,
                                     gint x_root,
                                     gint y_root,
                                     GdkWindow **dest_window,
                                     GdkDragProtocol *protocol);

Finds the destination window and DND protocol to use at the given pointer position.

This function is called by the drag source to obtain the `dest_window` and `protocol` parameters for `gdk_drag_motion()`.

#### Parameters

context | a GdkDragContext |
drag_window | a window which may be at the pointer position, but should be ignored, since it is put up by the drag source as an icon |
screen | the screen where the destination window is sought |
x_root | the x position of the pointer in root coordinates |
y_root | the y position of the pointer in root coordinates |
dest_window | location to store the destination window in. | [out]
protocol | location to store the DND protocol in. | [out]

Since 2.2

### gdk_drag_begin ()

    GdkDragContext *
    gdk_drag_begin (GdkWindow *window,
                    GList *targets);

Starts a drag and creates a new drag context for it. This function assumes that the drag is controlled by the client pointer device, use `gdk_drag_begin_for_device()` to begin a drag with a different device.

This function is called by the drag source.

#### Parameters

window | the source window for this drag. |
targets | the offered targets, as list of GdkAtoms. | [transfer none][element-type GdkAtom]

#### Returns

a newly created GdkDragContext.

[transfer full]

### gdk_drag_begin_for_device ()

    GdkDragContext *
    gdk_drag_begin_for_device (GdkWindow *window,
                               GdkDevice *device,
                               GList *targets);

Starts a drag and creates a new drag context for it.

This function is called by the drag source.

#### Parameters

window | the source window for this drag |
device | the device that controls this drag |
targets | the offered targets, as list of GdkAtoms. | [transfer none][element-type GdkAtom]

#### Returns

a newly created GdkDragContext.

[transfer full]

### gdk_drag_motion ()

    gboolean
    gdk_drag_motion (GdkDragContext *context,
                     GdkWindow *dest_window,
                     GdkDragProtocol protocol,
                     gint x_root,
                     gint y_root,
                     GdkDragAction suggested_action,
                     GdkDragAction possible_actions,
                     guint32 time_);

Updates the drag context when the pointer moves or the set of actions changes.

This function is called by the drag source.

#### Parameters

context | a GdkDragContext |
dest_window | the new destination window, obtained by `gdk_drag_find_window()` |
protocol | the DND protocol in use, obtained by `gdk_drag_find_window()` |
x_root | the x position of the pointer in root coordinates |
y_root | the y position of the pointer in root coordinates |
suggested_action | the suggested action |
possible_actions | the possible actions |
time_ | the timestamp for this operation |

#### Returns

### gdk_drop_finish ()

    void
    gdk_drop_finish (GdkDragContext *context,
                     gboolean success,
                     guint32 time_);

Ends the drag operation after a drop.

This function is called by the drag destination.

#### Parameters

context | a GtkDragContext |
success | `TRUE` if the data was successfully received |
time_ | the timestamp for this operation |

### gdk_drag_status ()

    void
    gdk_drag_status (GdkDragContext *context,
                     GdkDragAction action,
                     guint32 time_);

Selects one of the actions offered by the drag source.

This function is called by the drag destination in response to `gdk_drag_motion()` called by the drag source.

#### Parameters

context | a GdkDragContext |
action | the selected action which will be taken when a drop happens, or 0 to indicate that a drop will not be accepted |
time_ | the timestamp for this operation |

### gdk_drag_drop_succeeded ()

    gboolean
    gdk_drag_drop_succeeded (GdkDragContext *context);

Returns whether the dropped data has been successfully transferred. This function is intended to be used while handling a `GDK_DROP_FINISHED` event, its return value is meaningless at other times.

#### Parameters

context | a GdkDragContext |

#### Returns

`TRUE` if the drop was successful.

Since 2.6

### gdk_window_get_drag_protocol ()

    GdkDragProtocol
    gdk_window_get_drag_protocol (GdkWindow *window,
                                  GdkWindow **target);

Finds out the DND protocol supported by a window.

#### Parameters

window | the destination window |
target | location of the window where the drop should happen. This may be `window` or a proxy window, or `NULL` if `window` does not support Drag and Drop. | [out][allow-none][transfer full]

#### Returns

the supported DND protocol.

Since 3.0

### gdk_drag_context_get_actions ()

    GdkDragAction
    gdk_drag_context_get_actions (GdkDragContext *context);

Determines the bitmask of actions proposed by the source if `gdk_drag_context_get_suggested_action()` returns GDK_ACTION_ASK.

#### Parameters

context | a GdkDragContext |

#### Returns

the GdkDragAction flags

Since 2.22

### gdk_drag_context_get_suggested_action ()

    GdkDragAction
    gdk_drag_context_get_suggested_action (GdkDragContext *context);

Determines the suggested drag action of the context.

#### Parameters

context | a GdkDragContext |

#### Returns

a GdkDragAction value

Since 2.22

### gdk_drag_context_get_selected_action ()

    GdkDragAction
    gdk_drag_context_get_selected_action (GdkDragContext *context);

Determines the action chosen by the drag destination.

#### Parameters

context | a GdkDragContext |

#### Returns

a GdkDragAction value

Since 2.22

### gdk_drag_context_list_targets ()

    GList *
    gdk_drag_context_list_targets (GdkDragContext *context);

Retrieves the list of targets of the context.

#### Parameters

context | a GdkDragContext |

#### Returns

a GList of targets.

[transfer none][element-type GdkAtom]

Since 2.22

### gdk_drag_context_get_device ()

    GdkDevice *
    gdk_drag_context_get_device (GdkDragContext *context);

Returns the GdkDevice associated to the drag context.

#### Parameters

context | a GdkDragContext |

#### Returns

The GdkDevice associated to `context` .

[transfer none]

### gdk_drag_context_set_device ()

    void
    gdk_drag_context_set_device (GdkDragContext *context,
                                 GdkDevice *device);

Associates a GdkDevice to `context` , so all Drag and Drop events for `context` are emitted as if they came from this device.

#### Parameters

context | a GdkDragContext |
device | a GdkDevice |

### gdk_drag_context_get_source_window ()

    GdkWindow *
    gdk_drag_context_get_source_window (GdkDragContext *context);

Returns the GdkWindow where the DND operation started.

#### Parameters

context | a GdkDragContext |

#### Returns

a GdkWindow.

[transfer none]

Since 2.22

### gdk_drag_context_get_dest_window ()

    GdkWindow *
    gdk_drag_context_get_dest_window (GdkDragContext *context);

Returns the destination windw for the DND operation.

#### Parameters

context | a GdkDragContext |

#### Returns

a GdkWindow.

[transfer none]

Since 3.0

### gdk_drag_context_get_protocol ()

    GdkDragProtocol
    gdk_drag_context_get_protocol (GdkDragContext *context);

Returns the drag protocol thats used by this context.

#### Parameters

context | a GdkDragContext |

#### Returns

the drag protocol

Since 3.0

## Types and Values

### GdkDragContext

    typedef struct _GdkDragContext GdkDragContext;

### enum GdkDragProtocol

Used in GdkDragContext to indicate the protocol according to which DND is done.

#### Members

GDK_DRAG_PROTO_NONE | no protocol. |
GDK_DRAG_PROTO_MOTIF | The Motif DND protocol. No longer supported |
GDK_DRAG_PROTO_XDND | The Xdnd protocol. |
GDK_DRAG_PROTO_ROOTWIN | An extension to the Xdnd protocol for unclaimed root window drops. |
GDK_DRAG_PROTO_WIN32_DROPFILES | The simple WM_DROPFILES protocol. |
GDK_DRAG_PROTO_OLE2 | The complex OLE2 DND protocol (not implemented). |
GDK_DRAG_PROTO_LOCAL | Intra-application DND. |

### enum GdkDragAction

Used in GdkDragContext to indicate what the destination should do with the dropped data.

#### Members

GDK_ACTION_DEFAULT | Means nothing, and should not be used. |
GDK_ACTION_COPY | Copy the data. |
GDK_ACTION_MOVE | Move the data, i.e. first copy it, then delete it from the source using the DELETE target of the X selection protocol. |
GDK_ACTION_LINK | Add a link to the data. Note that this is only useful if source and destination agree on what it means. |
GDK_ACTION_PRIVATE | Special action which tells the source that the destination will do something that the source doesn't understand. |
GDK_ACTION_ASK | Ask the user what to do with the data. |