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
//! Build window-based GUI applications.
pub mod screenshot;

pub use screenshot::Screenshot;

use crate::core::time::Instant;
use crate::core::window::{
    Event, Icon, Id, Level, Mode, Settings, UserAttention,
};
use crate::core::{Point, Size};
use crate::futures::event;
use crate::futures::futures::channel::oneshot;
use crate::futures::Subscription;
use crate::task::{self, Task};

pub use raw_window_handle;

use raw_window_handle::WindowHandle;

/// An operation to be performed on some window.
#[allow(missing_debug_implementations)]
pub enum Action {
    /// Opens a new window with some [`Settings`].
    Open(Id, Settings, oneshot::Sender<Id>),

    /// Close the window and exits the application.
    Close(Id),

    /// Gets the [`Id`] of the oldest window.
    GetOldest(oneshot::Sender<Option<Id>>),

    /// Gets the [`Id`] of the latest window.
    GetLatest(oneshot::Sender<Option<Id>>),

    /// Move the window with the left mouse button until the button is
    /// released.
    ///
    /// There’s no guarantee that this will work unless the left mouse
    /// button was pressed immediately before this function is called.
    Drag(Id),

    /// Resize the window to the given logical dimensions.
    Resize(Id, Size),

    /// Get the current logical dimensions of the window.
    GetSize(Id, oneshot::Sender<Size>),

    /// Get if the current window is maximized or not.
    GetMaximized(Id, oneshot::Sender<bool>),

    /// Set the window to maximized or back
    Maximize(Id, bool),

    /// Get if the current window is minimized or not.
    ///
    /// ## Platform-specific
    /// - **Wayland:** Always `None`.
    GetMinimized(Id, oneshot::Sender<Option<bool>>),

    /// Set the window to minimized or back
    Minimize(Id, bool),

    /// Get the current logical coordinates of the window.
    GetPosition(Id, oneshot::Sender<Option<Point>>),

    /// Move the window to the given logical coordinates.
    ///
    /// Unsupported on Wayland.
    Move(Id, Point),

    /// Change the [`Mode`] of the window.
    ChangeMode(Id, Mode),

    /// Get the current [`Mode`] of the window.
    GetMode(Id, oneshot::Sender<Mode>),

    /// Toggle the window to maximized or back
    ToggleMaximize(Id),

    /// Toggle whether window has decorations.
    ///
    /// ## Platform-specific
    /// - **X11:** Not implemented.
    /// - **Web:** Unsupported.
    ToggleDecorations(Id),

    /// Request user attention to the window, this has no effect if the application
    /// is already focused. How requesting for user attention manifests is platform dependent,
    /// see [`UserAttention`] for details.
    ///
    /// Providing `None` will unset the request for user attention. Unsetting the request for
    /// user attention might not be done automatically by the WM when the window receives input.
    ///
    /// ## Platform-specific
    ///
    /// - **iOS / Android / Web:** Unsupported.
    /// - **macOS:** `None` has no effect.
    /// - **X11:** Requests for user attention must be manually cleared.
    /// - **Wayland:** Requires `xdg_activation_v1` protocol, `None` has no effect.
    RequestUserAttention(Id, Option<UserAttention>),

    /// Bring the window to the front and sets input focus. Has no effect if the window is
    /// already in focus, minimized, or not visible.
    ///
    /// This method steals input focus from other applications. Do not use this method unless
    /// you are certain that's what the user wants. Focus stealing can cause an extremely disruptive
    /// user experience.
    ///
    /// ## Platform-specific
    ///
    /// - **Web / Wayland:** Unsupported.
    GainFocus(Id),

    /// Change the window [`Level`].
    ChangeLevel(Id, Level),

    /// Show the system menu at cursor position.
    ///
    /// ## Platform-specific
    /// Android / iOS / macOS / Orbital / Web / X11: Unsupported.
    ShowSystemMenu(Id),

    /// Get the raw identifier unique to the window.
    GetRawId(Id, oneshot::Sender<u64>),

    /// Change the window [`Icon`].
    ///
    /// On Windows and X11, this is typically the small icon in the top-left
    /// corner of the titlebar.
    ///
    /// ## Platform-specific
    ///
    /// - **Web / Wayland / macOS:** Unsupported.
    ///
    /// - **Windows:** Sets `ICON_SMALL`. The base size for a window icon is 16x16, but it's
    ///   recommended to account for screen scaling and pick a multiple of that, i.e. 32x32.
    ///
    /// - **X11:** Has no universal guidelines for icon sizes, so you're at the whims of the WM. That
    ///   said, it's usually in the same ballpark as on Windows.
    ChangeIcon(Id, Icon),

    /// Runs the closure with the native window handle of the window with the given [`Id`].
    RunWithHandle(Id, Box<dyn FnOnce(WindowHandle<'_>) + Send>),

    /// Screenshot the viewport of the window.
    Screenshot(Id, oneshot::Sender<Screenshot>),
}

/// Subscribes to the frames of the window of the running application.
///
/// The resulting [`Subscription`] will produce items at a rate equal to the
/// refresh rate of the first application window. Note that this rate may be variable, as it is
/// normally managed by the graphics driver and/or the OS.
///
/// In any case, this [`Subscription`] is useful to smoothly draw application-driven
/// animations without missing any frames.
pub fn frames() -> Subscription<Instant> {
    event::listen_raw(|event, _status, _window| match event {
        crate::core::Event::Window(Event::RedrawRequested(at)) => Some(at),
        _ => None,
    })
}

/// Subscribes to all window events of the running application.
pub fn events() -> Subscription<(Id, Event)> {
    event::listen_with(|event, _status, id| {
        if let crate::core::Event::Window(event) = event {
            Some((id, event))
        } else {
            None
        }
    })
}

/// Subscribes to all [`Event::Closed`] occurrences in the running application.
pub fn open_events() -> Subscription<Id> {
    event::listen_with(|event, _status, id| {
        if let crate::core::Event::Window(Event::Opened { .. }) = event {
            Some(id)
        } else {
            None
        }
    })
}

/// Subscribes to all [`Event::Closed`] occurrences in the running application.
pub fn close_events() -> Subscription<Id> {
    event::listen_with(|event, _status, id| {
        if let crate::core::Event::Window(Event::Closed) = event {
            Some(id)
        } else {
            None
        }
    })
}

/// Subscribes to all [`Event::Resized`] occurrences in the running application.
pub fn resize_events() -> Subscription<(Id, Size)> {
    event::listen_with(|event, _status, id| {
        if let crate::core::Event::Window(Event::Resized(size)) = event {
            Some((id, size))
        } else {
            None
        }
    })
}

/// Subscribes to all [`Event::CloseRequested`] occurences in the running application.
pub fn close_requests() -> Subscription<Id> {
    event::listen_with(|event, _status, id| {
        if let crate::core::Event::Window(Event::CloseRequested) = event {
            Some(id)
        } else {
            None
        }
    })
}

/// Opens a new window with the given [`Settings`]; producing the [`Id`]
/// of the new window on completion.
pub fn open(settings: Settings) -> Task<Id> {
    let id = Id::unique();

    task::oneshot(|channel| {
        crate::Action::Window(Action::Open(id, settings, channel))
    })
}

/// Closes the window with `id`.
pub fn close<T>(id: Id) -> Task<T> {
    task::effect(crate::Action::Window(Action::Close(id)))
}

/// Gets the window [`Id`] of the oldest window.
pub fn get_oldest() -> Task<Option<Id>> {
    task::oneshot(|channel| crate::Action::Window(Action::GetOldest(channel)))
}

/// Gets the window [`Id`] of the latest window.
pub fn get_latest() -> Task<Option<Id>> {
    task::oneshot(|channel| crate::Action::Window(Action::GetLatest(channel)))
}

/// Begins dragging the window while the left mouse button is held.
pub fn drag<T>(id: Id) -> Task<T> {
    task::effect(crate::Action::Window(Action::Drag(id)))
}

/// Resizes the window to the given logical dimensions.
pub fn resize<T>(id: Id, new_size: Size) -> Task<T> {
    task::effect(crate::Action::Window(Action::Resize(id, new_size)))
}

/// Get the window's size in logical dimensions.
pub fn get_size(id: Id) -> Task<Size> {
    task::oneshot(move |channel| {
        crate::Action::Window(Action::GetSize(id, channel))
    })
}

/// Gets the maximized state of the window with the given [`Id`].
pub fn get_maximized(id: Id) -> Task<bool> {
    task::oneshot(move |channel| {
        crate::Action::Window(Action::GetMaximized(id, channel))
    })
}

/// Maximizes the window.
pub fn maximize<T>(id: Id, maximized: bool) -> Task<T> {
    task::effect(crate::Action::Window(Action::Maximize(id, maximized)))
}

/// Gets the minimized state of the window with the given [`Id`].
pub fn get_minimized(id: Id) -> Task<Option<bool>> {
    task::oneshot(move |channel| {
        crate::Action::Window(Action::GetMinimized(id, channel))
    })
}

/// Minimizes the window.
pub fn minimize<T>(id: Id, minimized: bool) -> Task<T> {
    task::effect(crate::Action::Window(Action::Minimize(id, minimized)))
}

/// Gets the position in logical coordinates of the window with the given [`Id`].
pub fn get_position(id: Id) -> Task<Option<Point>> {
    task::oneshot(move |channel| {
        crate::Action::Window(Action::GetPosition(id, channel))
    })
}

/// Moves the window to the given logical coordinates.
pub fn move_to<T>(id: Id, position: Point) -> Task<T> {
    task::effect(crate::Action::Window(Action::Move(id, position)))
}

/// Changes the [`Mode`] of the window.
pub fn change_mode<T>(id: Id, mode: Mode) -> Task<T> {
    task::effect(crate::Action::Window(Action::ChangeMode(id, mode)))
}

/// Gets the current [`Mode`] of the window.
pub fn get_mode(id: Id) -> Task<Mode> {
    task::oneshot(move |channel| {
        crate::Action::Window(Action::GetMode(id, channel))
    })
}

/// Toggles the window to maximized or back.
pub fn toggle_maximize<T>(id: Id) -> Task<T> {
    task::effect(crate::Action::Window(Action::ToggleMaximize(id)))
}

/// Toggles the window decorations.
pub fn toggle_decorations<T>(id: Id) -> Task<T> {
    task::effect(crate::Action::Window(Action::ToggleDecorations(id)))
}

/// Request user attention to the window. This has no effect if the application
/// is already focused. How requesting for user attention manifests is platform dependent,
/// see [`UserAttention`] for details.
///
/// Providing `None` will unset the request for user attention. Unsetting the request for
/// user attention might not be done automatically by the WM when the window receives input.
pub fn request_user_attention<T>(
    id: Id,
    user_attention: Option<UserAttention>,
) -> Task<T> {
    task::effect(crate::Action::Window(Action::RequestUserAttention(
        id,
        user_attention,
    )))
}

/// Brings the window to the front and sets input focus. Has no effect if the window is
/// already in focus, minimized, or not visible.
///
/// This [`Task`] steals input focus from other applications. Do not use this method unless
/// you are certain that's what the user wants. Focus stealing can cause an extremely disruptive
/// user experience.
pub fn gain_focus<T>(id: Id) -> Task<T> {
    task::effect(crate::Action::Window(Action::GainFocus(id)))
}

/// Changes the window [`Level`].
pub fn change_level<T>(id: Id, level: Level) -> Task<T> {
    task::effect(crate::Action::Window(Action::ChangeLevel(id, level)))
}

/// Show the [system menu] at cursor position.
///
/// [system menu]: https://en.wikipedia.org/wiki/Common_menus_in_Microsoft_Windows#System_menu
pub fn show_system_menu<T>(id: Id) -> Task<T> {
    task::effect(crate::Action::Window(Action::ShowSystemMenu(id)))
}

/// Gets an identifier unique to the window, provided by the underlying windowing system. This is
/// not to be confused with [`Id`].
pub fn get_raw_id<Message>(id: Id) -> Task<u64> {
    task::oneshot(|channel| {
        crate::Action::Window(Action::GetRawId(id, channel))
    })
}

/// Changes the [`Icon`] of the window.
pub fn change_icon<T>(id: Id, icon: Icon) -> Task<T> {
    task::effect(crate::Action::Window(Action::ChangeIcon(id, icon)))
}

/// Runs the given callback with the native window handle for the window with the given id.
///
/// Note that if the window closes before this call is processed the callback will not be run.
pub fn run_with_handle<T>(
    id: Id,
    f: impl FnOnce(WindowHandle<'_>) -> T + Send + 'static,
) -> Task<T>
where
    T: Send + 'static,
{
    task::oneshot(move |channel| {
        crate::Action::Window(Action::RunWithHandle(
            id,
            Box::new(move |handle| {
                let _ = channel.send(f(handle));
            }),
        ))
    })
}

/// Captures a [`Screenshot`] from the window.
pub fn screenshot(id: Id) -> Task<Screenshot> {
    task::oneshot(move |channel| {
        crate::Action::Window(Action::Screenshot(id, channel))
    })
}