Struct gtk4::DragSource

source ·

#[repr(transparent)]
pub struct DragSource { /* private fields */ }

Expand description

DragSource is an event controller to initiate Drag-And-Drop operations.

DragSource can be set up with the necessary ingredients for a DND operation ahead of time. This includes the source for the data that is being transferred, in the form of a gdk::ContentProvider, the desired action, and the icon to use during the drag operation. After setting it up, the drag source must be added to a widget as an event controller, using WidgetExt::add_controller().

⚠️ The following code is in c ⚠️

static void
my_widget_init (MyWidget *self)
{
  GtkDragSource *drag_source = gtk_drag_source_new ();

  g_signal_connect (drag_source, "prepare", G_CALLBACK (on_drag_prepare), self);
  g_signal_connect (drag_source, "drag-begin", G_CALLBACK (on_drag_begin), self);

  gtk_widget_add_controller (GTK_WIDGET (self), GTK_EVENT_CONTROLLER (drag_source));
}

Setting up the content provider and icon ahead of time only makes sense when the data does not change. More commonly, you will want to set them up just in time. To do so, DragSource has signal::DragSource::prepare and signal::DragSource::drag-begin signals.

The ::prepare signal is emitted before a drag is started, and can be used to set the content provider and actions that the drag should be started with.

⚠️ The following code is in c ⚠️

static GdkContentProvider *
on_drag_prepare (GtkDragSource *source,
                 double         x,
                 double         y,
                 MyWidget      *self)
{
  // This widget supports two types of content: GFile objects
  // and GdkPixbuf objects; GTK will handle the serialization
  // of these types automatically
  GFile *file = my_widget_get_file (self);
  GdkPixbuf *pixbuf = my_widget_get_pixbuf (self);

  return gdk_content_provider_new_union ((GdkContentProvider *[2]) {
      gdk_content_provider_new_typed (G_TYPE_FILE, file),
      gdk_content_provider_new_typed (GDK_TYPE_PIXBUF, pixbuf),
    }, 2);
}

The ::drag-begin signal is emitted after the gdk::Drag object has been created, and can be used to set up the drag icon.

⚠️ The following code is in c ⚠️

static void
on_drag_begin (GtkDragSource *source,
               GdkDrag       *drag,
               MyWidget      *self)
{
  // Set the widget as the drag icon
  GdkPaintable *paintable = gtk_widget_paintable_new (GTK_WIDGET (self));
  gtk_drag_source_set_icon (source, paintable, 0, 0);
  g_object_unref (paintable);
}

During the DND operation, DragSource emits signals that can be used to obtain updates about the status of the operation, but it is not normally necessary to connect to any signals, except for one case: when the supported actions include gdk::DragAction::MOVE, you need to listen for the signal::DragSource::drag-end signal and delete the data after it has been transferred.

Implements

GestureSingleExt, GestureExt, EventControllerExt, glib::ObjectExt

Struct gtk4::DragSource

Implementations§

impl DragSource

pub fn new() -> DragSource

pub fn builder() -> DragSourceBuilder

pub fn drag_cancel(&self)

pub fn actions(&self) -> DragAction

pub fn content(&self) -> Option<ContentProvider>

pub fn drag(&self) -> Option<Drag>

pub fn set_actions(&self, actions: DragAction)

pub fn set_content(&self, content: Option<&impl IsA<ContentProvider>>)

pub fn set_icon( &self, paintable: Option<&impl IsA<Paintable>>, hot_x: i32, hot_y: i32 )

pub fn connect_drag_begin<F: Fn(&Self, &Drag) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_drag_cancel<F: Fn(&Self, &Drag, DragCancelReason) -> bool + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_drag_end<F: Fn(&Self, &Drag, bool) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_prepare<F: Fn(&Self, f64, f64) -> Option<ContentProvider> + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_actions_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

pub fn connect_content_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

Trait Implementations§

impl Clone for DragSource

fn clone(&self) -> Self

fn clone_from(&mut self, source: &Self)

impl Debug for DragSource

fn fmt(&self, f: &mut Formatter<'_>) -> Result

impl Default for DragSource

fn default() -> Self

impl Display for DragSource

fn fmt(&self, f: &mut Formatter<'_>) -> Result

impl Hash for DragSource

fn hash<H>(&self, state: &mut H)where H: Hasher,

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

impl Ord for DragSource

fn cmp(&self, other: &Self) -> Ordering

fn max(self, other: Self) -> Selfwhere Self: Sized,

fn min(self, other: Self) -> Selfwhere Self: Sized,

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

impl ParentClassIs for DragSource

type Parent = GestureSingle

impl<OT: ObjectType> PartialEq<OT> for DragSource

fn eq(&self, other: &OT) -> bool

fn ne(&self, other: &Rhs) -> bool

impl<OT: ObjectType> PartialOrd<OT> for DragSource

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

fn lt(&self, other: &Rhs) -> bool

fn le(&self, other: &Rhs) -> bool

fn gt(&self, other: &Rhs) -> bool

fn ge(&self, other: &Rhs) -> bool

impl StaticType for DragSource

fn static_type() -> Type

impl Eq for DragSource

impl IsA<EventController> for DragSource

impl IsA<Gesture> for DragSource

impl IsA<GestureSingle> for DragSource

Auto Trait Implementations§

impl RefUnwindSafe for DragSource

impl !Send for DragSource

impl !Sync for DragSource

impl Unpin for DragSource

impl UnwindSafe for DragSource

Blanket Implementations§

impl<T> Any for Twhere T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Twhere T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> Cast for Twhere T: ObjectType,

fn upcast<T>(self) -> Twhere T: ObjectType, Self: IsA<T>,

fn upcast_ref<T>(&self) -> &Twhere T: ObjectType, Self: IsA<T>,

fn downcast<T>(self) -> Result<T, Self>where T: ObjectType, Self: CanDowncast<T>,

fn downcast_ref<T>(&self) -> Option<&T>where T: ObjectType, Self: CanDowncast<T>,

fn dynamic_cast<T>(self) -> Result<T, Self>where T: ObjectType,

fn dynamic_cast_ref<T>(&self) -> Option<&T>where T: ObjectType,

unsafe fn unsafe_cast<T>(self) -> Twhere T: ObjectType,

unsafe fn unsafe_cast_ref<T>(&self) -> &Twhere T: ObjectType,

impl<T> From<T> for T

fn from(t: T) -> T

impl<T> FromGlibContainerAsVec<<T as GlibPtrDefault>::GlibType, *const GList> for Twhere T: GlibPtrDefault + FromGlibPtrNone<<T as GlibPtrDefault>::GlibType> + FromGlibPtrFull<<T as GlibPtrDefault>::GlibType>,

unsafe fn from_glib_none_num_as_vec( ptr: *const GList, num: usize ) -> Vec<T, Global>

unsafe fn from_glib_container_num_as_vec( _: *const GList, _: usize ) -> Vec<T, Global>