DropTargetAsyncProtocol

public protocol DropTargetAsyncProtocol : EventControllerProtocol

GtkDropTargetAsync is an event controller to receive Drag-and-Drop operations, asynchronously.

It is the more complete but also more complex method of handling drop operations compared to [classGtk.DropTarget], and you should only use it if GtkDropTarget doesn’t provide all the features you need.

To use a GtkDropTargetAsync to receive drops on a widget, you create a GtkDropTargetAsync object, configure which data formats and actions you support, connect to its signals, and then attach it to the widget with [methodGtk.Widget.add_controller].

During a drag operation, the first signal that a GtkDropTargetAsync emits is [signalGtk.DropTargetAsync::accept], which is meant to determine whether the target is a possible drop site for the ongoing drop. The default handler for the accept signal accepts the drop if it finds a compatible data format and an action that is supported on both sides.

If it is, and the widget becomes a target, you will receive a [signalGtk.DropTargetAsync::drag-enter] signal, followed by [signalGtk.DropTargetAsync::drag-motion] signals as the pointer moves, optionally a [signalGtk.DropTargetAsync::drop] signal when a drop happens, and finally a [signalGtk.DropTargetAsync::drag-leave] signal when the pointer moves off the widget.

The drag-enter and drag-motion handler return a GdkDragAction to update the status of the ongoing operation. The drop handler should decide if it ultimately accepts the drop and if it does, it should initiate the data transfer and finish the operation by calling [methodGdk.Drop.finish].

Between the drag-enter and drag-leave signals the widget is a current drop target, and will receive the GTK_STATE_FLAG_DROP_ACTIVE state, which can be used by themes to style the widget as a drop target.

The DropTargetAsyncProtocol protocol exposes the methods and properties of an underlying GtkDropTargetAsync instance. The default implementation of these can be found in the protocol extension below. For a concrete class that implements these methods and properties, see DropTargetAsync. Alternatively, use DropTargetAsyncRef as a lighweight, unowned reference if you already have an instance you just want to use.

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ptr
Untyped pointer to the underlying GtkDropTargetAsync instance.
Declaration
Swift

var ptr: UnsafeMutableRawPointer! { get }
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drop_target_async_ptr Default implementation
Typed pointer to the underlying GtkDropTargetAsync instance.

Default Implementation

Return the stored, untyped pointer as a typed pointer to the GtkDropTargetAsync instance.
Declaration
Swift

var drop_target_async_ptr: UnsafeMutablePointer<GtkDropTargetAsync>! { get }
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init(raw:)
Required Initialiser for types conforming to DropTargetAsyncProtocol
Declaration
Swift

init(raw: UnsafeMutableRawPointer)
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DropTargetAsync Class


                    
                    
                    bind(property:to:_:flags:transformFrom:transformTo:)

Extension method

Bind a DropTargetAsyncPropertyName source property to a given target object.

Declaration

Swift

@discardableResult
@inlinable
func bind<Q, T>(property source_property: DropTargetAsyncPropertyName, to target: T, _ target_property: Q, flags f: BindingFlags = .default, transformFrom transform_from: @escaping GLibObject.ValueTransformer = { $0.transform(destValue: $1) }, transformTo transform_to: @escaping GLibObject.ValueTransformer = { $0.transform(destValue: $1) }) -> BindingRef! where Q : PropertyNameProtocol, T : ObjectProtocol

Parameters

`source_property`	the source property to bind
`target`	the target object to bind to
`target_property`	the target property to bind to
`flags`	the flags to pass to the `Binding`
`transform_from`	`ValueTransformer` to use for forward transformation
`transform_to`	`ValueTransformer` to use for backwards transformation

Return Value

binding reference or nil in case of an error

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                    get(property:)

Extension method

Get the value of a DropTargetAsync property

Declaration

Swift

@inlinable
func get(property: DropTargetAsyncPropertyName) -> GLibObject.Value

Parameters


                                property

the property to get the value for

Return Value

the value of the named property

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                    set(property:value:)

Extension method

Set the value of a DropTargetAsync property. Note that this will only have an effect on properties that are writable and not construct-only!

Declaration

Swift

@inlinable
func set(property: DropTargetAsyncPropertyName, value v: GLibObject.Value)

Parameters


                                property

the property to get the value for

Return Value

the value of the named property

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DropTargetAsync signals


                    
                    
                    connect(signal:flags:handler:)

Extension method

Connect a Swift signal handler to the given, typed DropTargetAsyncSignalName signal

Declaration

Swift

@discardableResult
@inlinable
func connect(signal s: DropTargetAsyncSignalName, flags f: ConnectFlags = ConnectFlags(0), handler h: @escaping SignalHandler) -> Int

Parameters

`signal`	The signal to connect
`flags`	The connection flags to use
`data`	A pointer to user data to provide to the callback
`destroyData`	A `GClosureNotify` C function to destroy the data pointed to by `userData`
`handler`	The Swift signal handler (function or callback) to invoke on the given signal

Return Value

The signal handler ID (always greater than 0 for successful connections)

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                    connect(signal:flags:data:destroyData:signalHandler:)

Extension method

Connect a C signal handler to the given, typed DropTargetAsyncSignalName signal

Declaration

Swift

@discardableResult
@inlinable
func connect(signal s: DropTargetAsyncSignalName, flags f: ConnectFlags = ConnectFlags(0), data userData: gpointer!, destroyData destructor: GClosureNotify? = nil, signalHandler h: @escaping GCallback) -> Int

Parameters

`signal`	The signal to connect
`flags`	The connection flags to use
`data`	A pointer to user data to provide to the callback
`destroyData`	A `GClosureNotify` C function to destroy the data pointed to by `userData`
`signalHandler`	The C function to be called on the given signal

Return Value

The signal handler ID (always greater than 0 for successful connections)

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                    onAccept(flags:handler:)

Extension method

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 [methodGtk.DropTargetAsync.reject_drop] or ultimately by returning false from a [signalGtk.DropTargetAsync::drop] handler.

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 further processing, such as inspecting the data, this function should return true and proceed as is drop was accepted and if it decides to reject the drop later, it should call [methodGtk.DropTargetAsync.reject_drop].

Note

This represents the underlying accept signal

Declaration

Swift

@discardableResult
@inlinable
func onAccept(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ drop: Gdk.DropRef) -> Bool) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`drop`	the `GdkDrop`
`handler`	`true` if `drop` is accepted Run the given callback whenever the `accept` signal is emitted

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acceptSignal Extension method
Typed accept signal for using the connect(signal:) methods
Declaration
Swift

static var acceptSignal: DropTargetAsyncSignalName { get }
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                    onDragEnter(flags:handler:)

Extension method

Emitted on the drop site when the pointer enters the widget.

It can be used to set up custom highlighting.

Note

This represents the underlying drag-enter signal

Declaration

Swift

@discardableResult
@inlinable
func onDragEnter(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ drop: Gdk.DropRef, _ x: Double, _ y: Double) -> Gdk.DragAction) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`drop`	the `GdkDrop`
`x`	the x coordinate of the current pointer position
`y`	the y coordinate of the current pointer position
`handler`	Preferred action for this drag operation. Run the given callback whenever the `dragEnter` signal is emitted

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dragEnterSignal Extension method
Typed drag-enter signal for using the connect(signal:) methods
Declaration
Swift

static var dragEnterSignal: DropTargetAsyncSignalName { get }
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                    onDragLeave(flags:handler:)

Extension method

Emitted on the drop site when the pointer leaves the widget.

Its main purpose it to undo things done in GtkDropTargetAsyncdrag-enter.

Note

This represents the underlying drag-leave signal

Declaration

Swift

@discardableResult
@inlinable
func onDragLeave(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ drop: Gdk.DropRef) -> Void) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`drop`	the `GdkDrop`
`handler`	The signal handler to call Run the given callback whenever the `dragLeave` signal is emitted

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dragLeaveSignal Extension method
Typed drag-leave signal for using the connect(signal:) methods
Declaration
Swift

static var dragLeaveSignal: DropTargetAsyncSignalName { get }
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                    onDragMotion(flags:handler:)

Extension method

Emitted while the pointer is moving over the drop target.

Note

This represents the underlying drag-motion signal

Declaration

Swift

@discardableResult
@inlinable
func onDragMotion(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ drop: Gdk.DropRef, _ x: Double, _ y: Double) -> Gdk.DragAction) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`drop`	the `GdkDrop`
`x`	the x coordinate of the current pointer position
`y`	the y coordinate of the current pointer position
`handler`	Preferred action for this drag operation. Run the given callback whenever the `dragMotion` signal is emitted

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dragMotionSignal Extension method
Typed drag-motion signal for using the connect(signal:) methods
Declaration
Swift

static var dragMotionSignal: DropTargetAsyncSignalName { get }
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                    onDrop(flags:handler:)

Extension method

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 must ensure that [methodGdk.Drop.finish] is called to let the source know that the drop is done. The call to [methodGdk.Drop.finish] must only be done when all data has been received.

To receive the data, use one of the read functions provided by [classGdk.Drop] such as [methodGdk.Drop.read_async] or [methodGdk.Drop.read_value_async].

Note

This represents the underlying drop signal

Declaration

Swift

@discardableResult
@inlinable
func onDrop(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ drop: Gdk.DropRef, _ x: Double, _ y: Double) -> Bool) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`drop`	the `GdkDrop`
`x`	the x coordinate of the current pointer position
`y`	the y coordinate of the current pointer position
`handler`	whether the drop is accepted at the given pointer position Run the given callback whenever the `drop` signal is emitted

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dropSignal Extension method
Typed drop signal for using the connect(signal:) methods
Declaration
Swift

static var dropSignal: DropTargetAsyncSignalName { get }
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                    onNotifyActions(flags:handler:)

Extension method

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

Note that getting this signal doesn’t itself guarantee that the value of the property has actually changed. When it is emitted is determined by the derived GObject class. If the implementor did not create the property with G_PARAM_EXPLICIT_NOTIFY, then any call to g_object_set_property() results in notify being emitted, even if the new value is the same as the old. If they did pass G_PARAM_EXPLICIT_NOTIFY, then this signal is emitted only when they explicitly call g_object_notify() or g_object_notify_by_pspec(), and common practice is to do that only when the value has actually changed.

This signal is typically used to obtain change notification for a single property, by specifying the property name as a detail in the g_signal_connect() call, like this:

(C Language Example):

g_signal_connect (text_view->buffer, "notify::paste-target-list",
                  G_CALLBACK (gtk_text_view_target_list_notify),
                  text_view)

It is important to note that you must use canonical parameter names as detail strings for the notify signal.

Note

This represents the underlying notify::actions signal

Declaration

Swift

@discardableResult
@inlinable
func onNotifyActions(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ pspec: ParamSpecRef) -> Void) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`pspec`	the `GParamSpec` of the property which changed.
`handler`	The signal handler to call Run the given callback whenever the `notifyActions` signal is emitted

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notifyActionsSignal Extension method
Typed notify::actions signal for using the connect(signal:) methods
Declaration
Swift

static var notifyActionsSignal: DropTargetAsyncSignalName { get }
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                    onNotifyFormats(flags:handler:)

Extension method

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

This signal is typically used to obtain change notification for a single property, by specifying the property name as a detail in the g_signal_connect() call, like this:

(C Language Example):

g_signal_connect (text_view->buffer, "notify::paste-target-list",
                  G_CALLBACK (gtk_text_view_target_list_notify),
                  text_view)

It is important to note that you must use canonical parameter names as detail strings for the notify signal.

Note

This represents the underlying notify::formats signal

Declaration

Swift

@discardableResult
@inlinable
func onNotifyFormats(flags: ConnectFlags = ConnectFlags(0), handler: @escaping (_ unownedSelf: DropTargetAsyncRef, _ pspec: ParamSpecRef) -> Void) -> Int

Parameters

`flags`	Flags
`unownedSelf`	Reference to instance of self
`pspec`	the `GParamSpec` of the property which changed.
`handler`	The signal handler to call Run the given callback whenever the `notifyFormats` signal is emitted

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notifyFormatsSignal Extension method
Typed notify::formats signal for using the connect(signal:) methods
Declaration
Swift

static var notifyFormatsSignal: DropTargetAsyncSignalName { get }
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DropTargetAsync Class: DropTargetAsyncProtocol extension (methods and fields)

getActions() Extension method
Gets the actions that this drop target supports.
Declaration
Swift

@inlinable func getActions() -> Gdk.DragAction
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getFormats() Extension method
Gets the data formats that this drop target accepts.

If the result is nil, all formats are expected to be supported.
Declaration
Swift

@inlinable func getFormats() -> Gdk.ContentFormatsRef!
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reject(drop:) Extension method
Sets the drop as not accepted on this drag site.

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

@inlinable func reject<DropT>(drop: DropT) where DropT : DropProtocol
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set(actions:) Extension method
Sets the actions that this drop target supports.
Declaration
Swift

@inlinable func set(actions: Gdk.DragAction)
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set(formats:) Extension method
Sets the data formats that this drop target will accept.
Declaration
Swift

@inlinable func set(formats: Gdk.ContentFormatsRef? = nil)
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                    set(formats:)

Extension method

Sets the data formats that this drop target will accept.

Declaration

Swift

@inlinable
func set<ContentFormatsT>(formats: ContentFormatsT?) where ContentFormatsT : ContentFormatsProtocol

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actions Extension method
The GdkDragActions that this drop target supports.
Declaration
Swift

@inlinable var actions: Gdk.DragAction { get nonmutating set }
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formats Extension method
The GdkContentFormats that determines the supported data formats.
Declaration
Swift

@inlinable var formats: Gdk.ContentFormatsRef! { get nonmutating set }
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DropTargetAsyncProtocol

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DropTargetAsync Class

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DropTargetAsync signals

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DropTargetAsync Class: DropTargetAsyncProtocol extension (methods and fields)

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