1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files.git)
// DO NOT EDIT

use crate::EventController;
use crate::PropagationLimit;
use crate::PropagationPhase;
use glib::object::Cast;
use glib::object::ObjectType as ObjectType_;
use glib::signal::connect_raw;
use glib::signal::SignalHandlerId;
use glib::translate::*;
use glib::StaticType;
use glib::ToValue;
use std::boxed::Box as Box_;
use std::fmt;
use std::mem::transmute;

glib::wrapper! {
    /// [`DropTarget`][crate::DropTarget] is an event controller to receive Drag-and-Drop operations.
    ///
    /// The most basic way to use a [`DropTarget`][crate::DropTarget] to receive drops on a
    /// widget is to create it via [`new()`][Self::new()], passing in the
    /// `GType` of the data you want to receive and connect to the
    /// `signal::DropTarget::drop` signal to receive the data:
    ///
    /// **⚠️ The following code is in c ⚠️**
    ///
    /// ```c
    /// static gboolean
    /// on_drop (GtkDropTarget *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)
    /// {
    ///   GtkDropTarget *target =
    ///     gtk_drop_target_new (G_TYPE_INVALID, GDK_ACTION_COPY);
    ///
    ///   // This widget accepts two types of drop types: GFile objects
    ///   // and GdkPixbuf 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));
    /// }
    /// ```
    ///
    /// [`DropTarget`][crate::DropTarget] supports more options, such as:
    ///
    ///  * rejecting potential drops via the `signal::DropTarget::accept` signal
    ///    and the [`reject()`][Self::reject()] function to let other drop
    ///    targets handle the drop
    ///  * tracking an ongoing drag operation before the drop via the
    ///    `signal::DropTarget::enter`, `signal::DropTarget::motion` and
    ///    `signal::DropTarget::leave` signals
    ///  * configuring how to receive data by setting the
    ///    `property::DropTarget::preload` property and listening for its
    ///    availability via the `property::DropTarget::value` property
    ///
    /// However, [`DropTarget`][crate::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 [`DropTargetAsync`][crate::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
    /// [`StateFlags::DROP_ACTIVE`][crate::StateFlags::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 [`DropControllerMotion`][crate::DropControllerMotion].
    ///
    /// # Implements
    ///
    /// [`EventControllerExt`][trait@crate::prelude::EventControllerExt], [`trait@glib::ObjectExt`]
    #[doc(alias = "GtkDropTarget")]
    pub struct DropTarget(Object<ffi::GtkDropTarget, ffi::GtkDropTargetClass>) @extends EventController;

    match fn {
        type_ => || ffi::gtk_drop_target_get_type(),
    }
}

impl DropTarget {
    /// Creates a new [`DropTarget`][crate::DropTarget] object.
    ///
    /// If the drop target should support more than 1 type, pass
    /// `G_TYPE_INVALID` for @type_ and then call
    /// [`set_types()`][Self::set_types()].
    /// ## `type_`
    /// The supported type or `G_TYPE_INVALID`
    /// ## `actions`
    /// the supported actions
    ///
    /// # Returns
    ///
    /// the new [`DropTarget`][crate::DropTarget]
    #[doc(alias = "gtk_drop_target_new")]
    pub fn new(type_: glib::types::Type, actions: gdk::DragAction) -> DropTarget {
        assert_initialized_main_thread!();
        unsafe {
            from_glib_full(ffi::gtk_drop_target_new(
                type_.into_glib(),
                actions.into_glib(),
            ))
        }
    }

    // rustdoc-stripper-ignore-next
    /// Creates a new builder-pattern struct instance to construct [`DropTarget`] objects.
    ///
    /// This method returns an instance of [`DropTargetBuilder`](crate::builders::DropTargetBuilder) which can be used to create [`DropTarget`] objects.
    pub fn builder() -> DropTargetBuilder {
        DropTargetBuilder::default()
    }

    /// Gets the actions that this drop target supports.
    ///
    /// # Returns
    ///
    /// the actions that this drop target supports
    #[doc(alias = "gtk_drop_target_get_actions")]
    #[doc(alias = "get_actions")]
    pub fn actions(&self) -> gdk::DragAction {
        unsafe { from_glib(ffi::gtk_drop_target_get_actions(self.to_glib_none().0)) }
    }

    /// Gets the currently handled drop operation.
    ///
    /// If no drop operation is going on, [`None`] is returned.
    ///
    /// # Returns
    ///
    /// The current drop
    #[cfg(any(feature = "v4_4", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v4_4")))]
    #[doc(alias = "gtk_drop_target_get_current_drop")]
    #[doc(alias = "get_current_drop")]
    pub fn current_drop(&self) -> Option<gdk::Drop> {
        unsafe { from_glib_none(ffi::gtk_drop_target_get_current_drop(self.to_glib_none().0)) }
    }

    /// Gets the currently handled drop operation.
    ///
    /// If no drop operation is going on, [`None`] is returned.
    ///
    /// # Deprecated since 4.4
    ///
    /// Use [`current_drop()`][Self::current_drop()] instead
    ///
    /// # Returns
    ///
    /// The current drop
    #[cfg_attr(feature = "v4_4", deprecated = "Since 4.4")]
    #[doc(alias = "gtk_drop_target_get_drop")]
    #[doc(alias = "get_drop")]
    pub fn drop(&self) -> Option<gdk::Drop> {
        unsafe { from_glib_none(ffi::gtk_drop_target_get_drop(self.to_glib_none().0)) }
    }

    /// Gets the data formats that this drop target accepts.
    ///
    /// If the result is [`None`], all formats are expected to be supported.
    ///
    /// # Returns
    ///
    /// the supported data formats
    #[doc(alias = "gtk_drop_target_get_formats")]
    #[doc(alias = "get_formats")]
    pub fn formats(&self) -> Option<gdk::ContentFormats> {
        unsafe { from_glib_none(ffi::gtk_drop_target_get_formats(self.to_glib_none().0)) }
    }

    /// Gets whether data should be preloaded on hover.
    ///
    /// # Returns
    ///
    /// [`true`] if drop data should be preloaded
    #[doc(alias = "gtk_drop_target_get_preload")]
    #[doc(alias = "get_preload")]
    pub fn is_preload(&self) -> bool {
        unsafe { from_glib(ffi::gtk_drop_target_get_preload(self.to_glib_none().0)) }
    }

    /// Gets the current drop data, as a `GValue`.
    ///
    /// # Returns
    ///
    /// The current drop data
    #[doc(alias = "gtk_drop_target_get_value")]
    #[doc(alias = "get_value")]
    pub fn value(&self) -> Option<glib::Value> {
        unsafe { from_glib_none(ffi::gtk_drop_target_get_value(self.to_glib_none().0)) }
    }

    /// Rejects the ongoing drop operation.
    ///
    /// If no drop operation is ongoing, i.e when `property::DropTarget::current-drop`
    /// is [`None`], 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.
    #[doc(alias = "gtk_drop_target_reject")]
    pub fn reject(&self) {
        unsafe {
            ffi::gtk_drop_target_reject(self.to_glib_none().0);
        }
    }

    /// Sets the actions that this drop target supports.
    /// ## `actions`
    /// the supported actions
    #[doc(alias = "gtk_drop_target_set_actions")]
    pub fn set_actions(&self, actions: gdk::DragAction) {
        unsafe {
            ffi::gtk_drop_target_set_actions(self.to_glib_none().0, actions.into_glib());
        }
    }

    /// Sets whether data should be preloaded on hover.
    /// ## `preload`
    /// [`true`] to preload drop data
    #[doc(alias = "gtk_drop_target_set_preload")]
    pub fn set_preload(&self, preload: bool) {
        unsafe {
            ffi::gtk_drop_target_set_preload(self.to_glib_none().0, preload.into_glib());
        }
    }

    /// 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 [`reject()`][Self::reject()]
    /// or ultimately by returning [`false`] from a `signal::DropTarget::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 depends
    /// on the data, this function should return [`true`], the
    /// `property::DropTarget::preload` property should be set and the value
    /// should be inspected via the ::notify:value signal, calling
    /// [`reject()`][Self::reject()] if required.
    /// ## `drop`
    /// the [`gdk::Drop`][crate::gdk::Drop]
    ///
    /// # Returns
    ///
    /// [`true`] if @drop is accepted
    #[doc(alias = "accept")]
    pub fn connect_accept<F: Fn(&Self, &gdk::Drop) -> bool + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn accept_trampoline<F: Fn(&DropTarget, &gdk::Drop) -> bool + 'static>(
            this: *mut ffi::GtkDropTarget,
            drop: *mut gdk::ffi::GdkDrop,
            f: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this), &from_glib_borrow(drop)).into_glib()
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"accept\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    accept_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// Emitted on the drop site when the pointer enters the widget.
    ///
    /// It can be used to set up custom highlighting.
    /// ## `x`
    /// the x coordinate of the current pointer position
    /// ## `y`
    /// the y coordinate of the current pointer position
    ///
    /// # Returns
    ///
    /// Preferred action for this drag operation or 0 if
    ///   dropping is not supported at the current @x,@y location.
    #[doc(alias = "enter")]
    pub fn connect_enter<F: Fn(&Self, f64, f64) -> gdk::DragAction + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn enter_trampoline<
            F: Fn(&DropTarget, f64, f64) -> gdk::DragAction + 'static,
        >(
            this: *mut ffi::GtkDropTarget,
            x: libc::c_double,
            y: libc::c_double,
            f: glib::ffi::gpointer,
        ) -> gdk::ffi::GdkDragAction {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this), x, y).into_glib()
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"enter\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    enter_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// Emitted on the drop site when the pointer leaves the widget.
    ///
    /// Its main purpose it to undo things done in
    /// `signal::DropTarget::enter`.
    #[doc(alias = "leave")]
    pub fn connect_leave<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn leave_trampoline<F: Fn(&DropTarget) + 'static>(
            this: *mut ffi::GtkDropTarget,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this))
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"leave\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    leave_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    /// Emitted while the pointer is moving over the drop target.
    /// ## `x`
    /// the x coordinate of the current pointer position
    /// ## `y`
    /// the y coordinate of the current pointer position
    ///
    /// # Returns
    ///
    /// Preferred action for this drag operation or 0 if
    ///   dropping is not supported at the current @x,@y location.
    #[doc(alias = "motion")]
    pub fn connect_motion<F: Fn(&Self, f64, f64) -> gdk::DragAction + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn motion_trampoline<
            F: Fn(&DropTarget, f64, f64) -> gdk::DragAction + 'static,
        >(
            this: *mut ffi::GtkDropTarget,
            x: libc::c_double,
            y: libc::c_double,
            f: glib::ffi::gpointer,
        ) -> gdk::ffi::GdkDragAction {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this), x, y).into_glib()
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"motion\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    motion_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "actions")]
    pub fn connect_actions_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_actions_trampoline<F: Fn(&DropTarget) + 'static>(
            this: *mut ffi::GtkDropTarget,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this))
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"notify::actions\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    notify_actions_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[cfg(any(feature = "v4_4", feature = "dox"))]
    #[cfg_attr(feature = "dox", doc(cfg(feature = "v4_4")))]
    #[doc(alias = "current-drop")]
    pub fn connect_current_drop_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_current_drop_trampoline<F: Fn(&DropTarget) + 'static>(
            this: *mut ffi::GtkDropTarget,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this))
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"notify::current-drop\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    notify_current_drop_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[cfg_attr(feature = "v4_4", deprecated = "Since 4.4")]
    #[doc(alias = "drop")]
    pub fn connect_drop_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_drop_trampoline<F: Fn(&DropTarget) + 'static>(
            this: *mut ffi::GtkDropTarget,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this))
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"notify::drop\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    notify_drop_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "preload")]
    pub fn connect_preload_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_preload_trampoline<F: Fn(&DropTarget) + 'static>(
            this: *mut ffi::GtkDropTarget,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this))
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"notify::preload\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    notify_preload_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "value")]
    pub fn connect_value_notify<F: Fn(&Self) + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_value_trampoline<F: Fn(&DropTarget) + 'static>(
            this: *mut ffi::GtkDropTarget,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(&from_glib_borrow(this))
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"notify::value\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    notify_value_trampoline::<F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }
}

impl Default for DropTarget {
    fn default() -> Self {
        glib::object::Object::new::<Self>(&[])
            .expect("Can't construct DropTarget object with default parameters")
    }
}

#[derive(Clone, Default)]
// rustdoc-stripper-ignore-next
/// A [builder-pattern] type to construct [`DropTarget`] objects.
///
/// [builder-pattern]: https://doc.rust-lang.org/1.0.0/style/ownership/builders.html
#[must_use = "The builder must be built to be used"]
pub struct DropTargetBuilder {
    actions: Option<gdk::DragAction>,
    formats: Option<gdk::ContentFormats>,
    preload: Option<bool>,
    name: Option<String>,
    propagation_limit: Option<PropagationLimit>,
    propagation_phase: Option<PropagationPhase>,
}

impl DropTargetBuilder {
    // rustdoc-stripper-ignore-next
    /// Create a new [`DropTargetBuilder`].
    pub fn new() -> Self {
        Self::default()
    }

    // rustdoc-stripper-ignore-next
    /// Build the [`DropTarget`].
    #[must_use = "Building the object from the builder is usually expensive and is not expected to have side effects"]
    pub fn build(self) -> DropTarget {
        let mut properties: Vec<(&str, &dyn ToValue)> = vec![];
        if let Some(ref actions) = self.actions {
            properties.push(("actions", actions));
        }
        if let Some(ref formats) = self.formats {
            properties.push(("formats", formats));
        }
        if let Some(ref preload) = self.preload {
            properties.push(("preload", preload));
        }
        if let Some(ref name) = self.name {
            properties.push(("name", name));
        }
        if let Some(ref propagation_limit) = self.propagation_limit {
            properties.push(("propagation-limit", propagation_limit));
        }
        if let Some(ref propagation_phase) = self.propagation_phase {
            properties.push(("propagation-phase", propagation_phase));
        }
        glib::Object::new::<DropTarget>(&properties)
            .expect("Failed to create an instance of DropTarget")
    }

    /// The `GdkDragActions` that this drop target supports.
    pub fn actions(mut self, actions: gdk::DragAction) -> Self {
        self.actions = Some(actions);
        self
    }

    /// The [`gdk::ContentFormats`][crate::gdk::ContentFormats] that determine the supported data formats.
    pub fn formats(mut self, formats: &gdk::ContentFormats) -> Self {
        self.formats = Some(formats.clone());
        self
    }

    /// 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-and-Drop operations, no data transfer is done,
    /// so enabling it there is free.
    pub fn preload(mut self, preload: bool) -> Self {
        self.preload = Some(preload);
        self
    }

    /// The name for this controller, typically used for debugging purposes.
    pub fn name(mut self, name: &str) -> Self {
        self.name = Some(name.to_string());
        self
    }

    /// The limit for which events this controller will handle.
    pub fn propagation_limit(mut self, propagation_limit: PropagationLimit) -> Self {
        self.propagation_limit = Some(propagation_limit);
        self
    }

    /// The propagation phase at which this controller will handle events.
    pub fn propagation_phase(mut self, propagation_phase: PropagationPhase) -> Self {
        self.propagation_phase = Some(propagation_phase);
        self
    }
}

impl fmt::Display for DropTarget {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("DropTarget")
    }
}