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Functions
Signals
void | action-changed | Run Last |
void | cancel | Run Last |
void | dnd-finished | Run Last |
void | drop-performed | Run Last |
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.
gdk_drag_abort ()
void gdk_drag_abort (GdkDragContext *context
,guint32 time_
);
Aborts a drag without dropping.
This function is called by the drag source.
This function does not need to be called in managed drag and drop
operations. See gdk_drag_context_manage_dnd()
for more information.
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.
gdk_drag_drop ()
void gdk_drag_drop (GdkDragContext *context
,guint32 time_
);
Drops on the current destination.
This function is called by the drag source.
This function does not need to be called in managed drag and drop
operations. See gdk_drag_context_manage_dnd()
for more information.
gdk_drag_drop_done ()
void gdk_drag_drop_done (GdkDragContext *context
,gboolean success
);
Inform GDK if the drop ended successfully. Passing FALSE
for success
may trigger a drag cancellation animation.
This function is called by the drag source, and should
be the last call before dropping the reference to the
context
.
The GdkDragContext will only take the first gdk_drag_drop_done()
call as effective, if this function is called multiple times,
all subsequent calls will be ignored.
Since: 3.20
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 |
||
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] |
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] |
gdk_drag_begin_from_point ()
GdkDragContext * gdk_drag_begin_from_point (GdkWindow *window
,GdkDevice *device
,GList *targets
,gint x_root
,gint y_root
);
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] |
x_root |
the x coordinate where the drag nominally started |
|
y_root |
the y coordinate where the drag nominally started |
Since: 3.20
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.
This function does not need to be called in managed drag and drop
operations. See gdk_drag_context_manage_dnd()
for more information.
Parameters
context |
||
dest_window |
the new destination window, obtained by
|
|
protocol |
the DND protocol in use, obtained by |
|
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 |
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.
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.
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.
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 |
[out][allow-none][transfer full] |
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
.
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.
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.
Since: 2.22
gdk_drag_context_list_targets ()
GList *
gdk_drag_context_list_targets (GdkDragContext *context
);
Retrieves the list of targets of the context.
Since: 2.22
gdk_drag_context_get_device ()
GdkDevice *
gdk_drag_context_get_device (GdkDragContext *context
);
Returns the GdkDevice associated to the drag context.
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.
gdk_drag_context_get_source_window ()
GdkWindow *
gdk_drag_context_get_source_window (GdkDragContext *context
);
Returns the GdkWindow where the DND operation started.
Since: 2.22
gdk_drag_context_get_dest_window ()
GdkWindow *
gdk_drag_context_get_dest_window (GdkDragContext *context
);
Returns the destination window for the DND operation.
Since: 3.0
gdk_drag_context_get_protocol ()
GdkDragProtocol
gdk_drag_context_get_protocol (GdkDragContext *context
);
Returns the drag protocol that is used by this context.
Since: 3.0
gdk_drag_context_get_drag_window ()
GdkWindow *
gdk_drag_context_get_drag_window (GdkDragContext *context
);
Returns the window on which the drag icon should be rendered
during the drag operation. Note that the window may not be
available until the drag operation has begun. GDK will move
the window in accordance with the ongoing drag operation.
The window is owned by context
and will be destroyed when
the drag operation is over.
Since: 3.20
gdk_drag_context_set_hotspot ()
void gdk_drag_context_set_hotspot (GdkDragContext *context
,gint hot_x
,gint hot_y
);
Sets the position of the drag window that will be kept under the cursor hotspot. Initially, the hotspot is at the top left corner of the drag window.
Parameters
context |
||
hot_x |
x coordinate of the drag window hotspot |
|
hot_y |
y coordinate of the drag window hotspot |
Since: 3.20
gdk_drag_context_manage_dnd ()
gboolean gdk_drag_context_manage_dnd (GdkDragContext *context
,GdkWindow *ipc_window
,GdkDragAction actions
);
Requests the drag and drop operation to be managed by context
.
When a drag and drop operation becomes managed, the GdkDragContext
will internally handle all input and source-side GdkEventDND events
as required by the windowing system.
Once the drag and drop operation is managed, the drag context will emit the following signals:
The “action-changed” signal whenever the final action to be performed by the drag and drop operation changes.
The “drop-performed” signal after the user performs the drag and drop gesture (typically by releasing the mouse button).
The “dnd-finished” signal after the drag and drop operation concludes (after all GdkSelection transfers happen).
The “cancel” signal if the drag and drop operation is finished but doesn't happen over an accepting destination, or is cancelled through other means.
Parameters
context |
||
ipc_window |
Window to use for IPC messaging/events |
|
actions |
the actions supported by the drag source |
Since: 3.20
Types and Values
enum GdkDragCancelReason
Used in GdkDragContext to the reason of a cancelled DND operation.
Since: 3.20
enum GdkDragProtocol
Used in GdkDragContext to indicate the protocol according to which DND is done.
enum GdkDragAction
Used in GdkDragContext to indicate what the destination should do with the dropped data.
Members
Means nothing, and should not be used. |
||
Copy the data. |
||
Move the data, i.e. first copy it, then delete it from the source using the DELETE target of the X selection protocol. |
||
Add a link to the data. Note that this is only useful if source and destination agree on what it means. |
||
Special action which tells the source that the destination will do something that the source doesn’t understand. |
||
Ask the user what to do with the data. |
Signal Details
The “action-changed”
signal
void user_function (GdkDragContext *context, GdkDragAction action, gpointer user_data)
A new action is being chosen for the drag and drop operation.
This signal will only be emitted if the GdkDragContext manages
the drag and drop operation. See gdk_drag_context_manage_dnd()
for more information.
Parameters
context |
The object on which the signal is emitted |
|
action |
The action currently chosen |
|
user_data |
user data set when the signal handler was connected. |
Flags: Run Last
Since: 3.20
The “cancel”
signal
void user_function (GdkDragContext *context, GdkDragCancelReason reason, gpointer user_data)
The drag and drop operation was cancelled.
This signal will only be emitted if the GdkDragContext manages
the drag and drop operation. See gdk_drag_context_manage_dnd()
for more information.
Parameters
context |
The object on which the signal is emitted |
|
reason |
The reason the context was cancelled |
|
user_data |
user data set when the signal handler was connected. |
Flags: Run Last
Since: 3.20
The “dnd-finished”
signal
void user_function (GdkDragContext *context, gpointer user_data)
The drag and drop operation was finished, the drag destination finished reading all data. The drag source can now free all miscellaneous data.
This signal will only be emitted if the GdkDragContext manages
the drag and drop operation. See gdk_drag_context_manage_dnd()
for more information.
Parameters
context |
The object on which the signal is emitted |
|
user_data |
user data set when the signal handler was connected. |
Flags: Run Last
Since: 3.20
The “drop-performed”
signal
void user_function (GdkDragContext *context, int time, gpointer user_data)
The drag and drop operation was performed on an accepting client.
This signal will only be emitted if the GdkDragContext manages
the drag and drop operation. See gdk_drag_context_manage_dnd()
for more information.
Parameters
context |
The object on which the signal is emitted |
|
time |
the time at which the drop happened. |
|
user_data |
user data set when the signal handler was connected. |
Flags: Run Last
Since: 3.20