gtk_drop_target_new ()

GtkDropTarget *
gtk_drop_target_new (GType type,
                     GdkDragAction actions);

Creates a new GtkDropTarget object.

If the drop target should support more than 1 type, pass G_TYPE_INVALID for type and then call gtk_drop_target_set_gtypes().

gtk_drop_target_set_gtypes ()

void
gtk_drop_target_set_gtypes (GtkDropTarget *self,
                            GType *types,
                            gsize n_types);

Sets the supported GTypes for this drop target.

The GtkDropTarget::drop signal will

gtk_drop_target_get_gtypes ()

const GType *
gtk_drop_target_get_gtypes (GtkDropTarget *self,
                            gsize *n_types);

Gets the list of supported GTypes for self . If no type have been set, NULL will be returned.

gtk_drop_target_get_formats ()

GdkContentFormats *
gtk_drop_target_get_formats (GtkDropTarget *self);

Gets the data formats that this drop target accepts.

If the result is NULL, all formats are expected to be supported.

gtk_drop_target_set_actions ()

void
gtk_drop_target_set_actions (GtkDropTarget *self,
                             GdkDragAction actions);

Sets the actions that this drop target supports.

gtk_drop_target_get_actions ()

GdkDragAction
gtk_drop_target_get_actions (GtkDropTarget *self);

Gets the actions that this drop target supports.

gtk_drop_target_set_preload ()

void
gtk_drop_target_set_preload (GtkDropTarget *self,
                             gboolean preload);

Sets the GtkDropTarget:preload property.

gtk_drop_target_get_preload ()

gboolean
gtk_drop_target_get_preload (GtkDropTarget *self);

Gets the value of the GtkDropTarget:preload property.

gtk_drop_target_get_drop ()

GdkDrop *
gtk_drop_target_get_drop (GtkDropTarget *self);

Gets the currently handled drop operation.

If no drop operation is going on, NULL is returned.

gtk_drop_target_get_value ()

const GValue *
gtk_drop_target_get_value (GtkDropTarget *self);

Gets the value of the GtkDropTarget:value property.

gtk_drop_target_reject ()

void
gtk_drop_target_reject (GtkDropTarget *self);

Rejects the ongoing drop operation.

If no drop operation is ongoing - when GdkDropTarget:drop returns NULL - this function does nothing.

This function should be used when delaying the decision on whether to accept a drag or not until after reading the data.

GtkDropTarget

typedef struct _GtkDropTarget GtkDropTarget;

The “actions” property

  “actions”                  GdkDragAction

The GdkDragActions that this drop target supports

Owner: GtkDropTarget

Flags: Read / Write

The “drop” property

  “drop”                     GdkDrop *

The GdkDrop that is currently being performed

Owner: GtkDropTarget

Flags: Read

The “formats” property

  “formats”                  GdkContentFormats *

The GdkContentFormats that determine the supported data formats

Owner: GtkDropTarget

Flags: Read

The “preload” property

  “preload”                  gboolean

Whether the drop data should be preloaded when the pointer is only hovering over the widget but has not been released.

Setting this property allows finer grained reaction to an ongoing drop at the cost of loading more data.

The default value for this property is FALSE to avoid downloading huge amounts of data by accident. For example, if somebody drags a full document of gigabytes of text from a text editor across a widget with a preloading drop target, this data will be downloaded, even if the data is ultimately dropped elsewhere.

For a lot of data formats, the amount of data is very small (like GDK_TYPE_RGBA), so enabling this property does not hurt at all. And for local-only drag'n'drop operations, no data transfer is done, so enabling it there is free.

Owner: GtkDropTarget

Flags: Read / Write

Default value: FALSE

The “value” property

  “value”                    GValue *

The value for this drop operation or NULL if the data has not been loaded yet or no drop operation is going on.

Data may be available before the GtkDropTarget::drop signal gets emitted - for example when the GtkDropTarget:preload property is set. You can use the GObject::notify signal to be notified of available data.

Owner: GtkDropTarget

Flags: Read

The “accept” signal

gboolean
user_function (GtkDropTarget *self,
               GdkDrop       *drop,
               gpointer       user_data)

The ::accept signal is emitted on the drop site when a drop operation is about to begin. If the drop is not accepted, FALSE will be returned and the drop target will ignore the drop. If TRUE is returned, the drop is accepted for now but may be rejected later via a call to gtk_drop_target_reject() or ultimately by returning FALSE from GtkDropTarget::drop

The default handler for this signal decides whether to accept the drop based on the formats provided by the drop .

If the decision whether the drop will be accepted or rejected needs inspecting the data, this function should return TRUE, the GtkDropTarget:preload property should be set and the value should be inspected via the GObject::notify:value signal and then call gtk_drop_target_reject().

Flags: Run Last

The “drop” signal

gboolean
user_function (GtkDropTarget *self,
               GValue        *value,
               double         x,
               double         y,
               gpointer       user_data)

The ::drop signal is emitted on the drop site when the user drops the data onto the widget. The signal handler must determine whether the pointer position is in a drop zone or not. If it is not in a drop zone, it returns FALSE and no further processing is necessary.

Otherwise, the handler returns TRUE. In this case, this handler will accept the drop. The handler is responsible for rading the given value and performing the drop operation.

Flags: Run Last

The “enter” signal

GdkDragAction
user_function (GtkDropTarget *self,
               double         x,
               double         y,
               gpointer       user_data)

The ::enter signal is emitted on the drop site when the pointer enters the widget. It can be used to set up custom highlighting.

Flags: Run Last

The “leave” signal

void
user_function (GtkDropTarget *self,
               gpointer       user_data)

The ::leave signal is emitted on the drop site when the pointer leaves the widget. Its main purpose it to undo things done in “enter”.

Flags: Run Last

The “motion” signal

GdkDragAction
user_function (GtkDropTarget *self,
               double         x,
               double         y,
               gpointer       user_data)

The ::motion signal is emitted while the pointer is moving over the drop target.

Flags: Run Last