class Gtk::DropTarget

• Gtk::DropTarget
• Gtk::EventController
• GObject::Object
• Reference
• Object

Overview

Gtk::DropTarget is an event controller to receive Drag-and-Drop operations.

The most basic way to use a Gtk::DropTarget to receive drops on a widget is to create it via Gtk::DropTarget.new, passing in the GType of the data you want to receive and connect to the Gtk::DropTarget::#drop signal to receive the data:

WARNING ⚠️ The following code is in c ⚠️

static gboolean
on_drop (Gtk::DropTarget *target,
         const GValue  *value,
         double         x,
         double         y,
         gpointer       data)
{
  MyWidget *self = data;

  // Call the appropriate setter depending on the type of data
  // that we received
  if (G_VALUE_HOLDS (value, G_TYPE_FILE))
    my_widget_set_file (self, g_value_get_object (value));
  else if (G_VALUE_HOLDS (value, GDK_TYPE_PIXBUF))
    my_widget_set_pixbuf (self, g_value_get_object (value));
  else
    return FALSE;

  return TRUE;
}

static void
my_widget_init (MyWidget *self)
{
  Gtk::DropTarget *target =
    gtk_drop_target_new (G_TYPE_INVALID, GDK_ACTION_COPY);

  // This widget accepts two types of drop types: GFile objects
  // and Gdk::Pixbuf objects
  gtk_drop_target_set_gtypes (target, (GTypes [2]) {
    G_TYPE_FILE,
    GDK_TYPE_PIXBUF,
  }, 2);

  g_signal_connect (target, "drop", G_CALLBACK (on_drop), self);
  gtk_widget_add_controller (GTK_WIDGET (self), GTK_EVENT_CONTROLLER (target));
}

Gtk::DropTarget supports more options, such as:

• rejecting potential drops via the Gtk::DropTarget::#accept signal and the Gtk::DropTarget#reject function to let other drop targets handle the drop
• tracking an ongoing drag operation before the drop via the Gtk::DropTarget::#enter, Gtk::DropTarget::#motion and Gtk::DropTarget::#leave signals
• configuring how to receive data by setting the Gtk::DropTarget#preload property and listening for its availability via the Gtk::DropTarget#value property

However, Gtk::DropTarget is ultimately modeled in a synchronous way and only supports data transferred via GType. If you want full control over an ongoing drop, the Gtk::DropTargetAsync object gives you this ability.

While a pointer is dragged over the drop target's widget and the drop has not been rejected, that widget will receive the %GTK_STATE_FLAG_DROP_ACTIVE state, which can be used to style the widget.

If you are not interested in receiving the drop, but just want to update UI state during a Drag-and-Drop operation (e.g. switching tabs), you can use Gtk::DropControllerMotion.

Defined in:

Constructors

• .new(type : UInt64, actions : Gdk::DragAction) : self

  Creates a new Gtk::DropTarget object.

• .new

  Initialize a new DropTarget.

• .new(*, actions : Gdk::DragAction | Nil = nil, current_drop : Gdk::Drop | Nil = nil, formats : Gdk::ContentFormats | Nil = nil, name : String | Nil = nil, preload : Bool | Nil = nil, propagation_limit : Gtk::PropagationLimit | Nil = nil, propagation_phase : Gtk::PropagationPhase | Nil = nil, value : GObject::Value | Nil = nil, widget : Gtk::Widget | Nil = nil)

Class Method Summary

• .g_type : UInt64

  Returns the type id (GType) registered in GLib type system.

Instance Method Summary

• #==(other : self)

  Returns true if this reference is the same as other.

• #accept_signal
• #actions : Gdk::DragAction

  Gets the actions that this drop target supports.

• #actions=(actions : Gdk::DragAction) : Nil

  Sets the actions that this drop target supports.

• #current_drop : Gdk::Drop | Nil

  Gets the currently handled drop operation.

• #drop : Gdk::Drop | Nil

  Gets the currently handled drop operation.

  DEPRECATED

• #drop_signal
• #enter_signal
• #formats : Gdk::ContentFormats | Nil

  Gets the data formats that this drop target accepts.

• #formats=(value : Gdk::ContentFormats | Nil) : Gdk::ContentFormats | Nil
• #gtypes : Enumerable(UInt64) | Nil

  Gets the list of supported GTypes that can be dropped on the target.

• #gtypes=(types : Enumerable(UInt64) | Nil) : Nil

  Sets the supported GTypes for this drop target.

• #hash(hasher)

  See Object#hash(hasher)

• #leave_signal
• #motion_signal
• #preload : Bool

  Gets whether data should be preloaded on hover.

• #preload=(preload : Bool) : Nil

  Sets whether data should be preloaded on hover.

• #preload? : Bool
• #reject : Nil

  Rejects the ongoing drop operation.

• #value : GObject::Value | Nil

  Gets the current drop data, as a GValue.

Constructor Detail

Class Method Detail

Instance Method Detail