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iced_program/
lib.rs

1//! The definition of an iced program.
2pub use iced_graphics as graphics;
3pub use iced_runtime as runtime;
4pub use iced_runtime::core;
5pub use iced_runtime::futures;
6
7pub mod message;
8
9mod preset;
10
11pub use preset::Preset;
12
13use crate::core::renderer;
14use crate::core::text;
15use crate::core::theme;
16use crate::core::window;
17use crate::core::{Element, Font, Settings};
18use crate::futures::{Executor, Subscription};
19use crate::graphics::compositor;
20use crate::runtime::Task;
21
22/// An interactive, native, cross-platform, multi-windowed application.
23///
24/// A [`Program`] can execute asynchronous actions by returning a
25/// [`Task`] in some of its methods.
26#[allow(missing_docs)]
27pub trait Program: Sized {
28    /// The state of the program.
29    type State;
30
31    /// The message of the program.
32    type Message: Send + 'static;
33
34    /// The theme of the program.
35    type Theme: theme::Base;
36
37    /// The renderer of the program.
38    type Renderer: Renderer;
39
40    /// The executor of the program.
41    type Executor: Executor;
42
43    /// Returns the unique name of the [`Program`].
44    fn name() -> &'static str;
45
46    fn settings(&self) -> Settings;
47
48    fn window(&self) -> Option<window::Settings>;
49
50    fn boot(&self) -> (Self::State, Task<Self::Message>);
51
52    fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message>;
53
54    fn view<'a>(
55        &self,
56        state: &'a Self::State,
57        window: window::Id,
58    ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer>;
59
60    fn title(&self, _state: &Self::State, _window: window::Id) -> String {
61        let mut title = String::new();
62
63        for (i, part) in Self::name().split("_").enumerate() {
64            use std::borrow::Cow;
65
66            let part = match part {
67                "a" | "an" | "of" | "in" | "and" => Cow::Borrowed(part),
68                _ => {
69                    let mut part = part.to_owned();
70
71                    if let Some(first_letter) = part.get_mut(0..1) {
72                        first_letter.make_ascii_uppercase();
73                    }
74
75                    Cow::Owned(part)
76                }
77            };
78
79            if i > 0 {
80                title.push(' ');
81            }
82
83            title.push_str(&part);
84        }
85
86        format!("{title} - Iced")
87    }
88
89    fn subscription(&self, _state: &Self::State) -> Subscription<Self::Message> {
90        Subscription::none()
91    }
92
93    fn theme(&self, _state: &Self::State, _window: window::Id) -> Option<Self::Theme> {
94        None
95    }
96
97    fn style(&self, _state: &Self::State, theme: &Self::Theme) -> theme::Style {
98        theme::Base::base(theme)
99    }
100
101    fn scale_factor(&self, _state: &Self::State, _window: window::Id) -> f32 {
102        1.0
103    }
104
105    fn presets(&self) -> &[Preset<Self::State, Self::Message>] {
106        &[]
107    }
108}
109
110/// Decorates a [`Program`] with the given title function.
111pub fn with_title<P: Program>(
112    program: P,
113    title: impl Fn(&P::State, window::Id) -> String,
114) -> impl Program<State = P::State, Message = P::Message, Theme = P::Theme> {
115    struct WithTitle<P, Title> {
116        program: P,
117        title: Title,
118    }
119
120    impl<P, Title> Program for WithTitle<P, Title>
121    where
122        P: Program,
123        Title: Fn(&P::State, window::Id) -> String,
124    {
125        type State = P::State;
126        type Message = P::Message;
127        type Theme = P::Theme;
128        type Renderer = P::Renderer;
129        type Executor = P::Executor;
130
131        fn title(&self, state: &Self::State, window: window::Id) -> String {
132            (self.title)(state, window)
133        }
134
135        fn name() -> &'static str {
136            P::name()
137        }
138
139        fn settings(&self) -> Settings {
140            self.program.settings()
141        }
142
143        fn window(&self) -> Option<window::Settings> {
144            self.program.window()
145        }
146
147        fn boot(&self) -> (Self::State, Task<Self::Message>) {
148            self.program.boot()
149        }
150
151        fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message> {
152            self.program.update(state, message)
153        }
154
155        fn view<'a>(
156            &self,
157            state: &'a Self::State,
158            window: window::Id,
159        ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer> {
160            self.program.view(state, window)
161        }
162
163        fn theme(&self, state: &Self::State, window: window::Id) -> Option<Self::Theme> {
164            self.program.theme(state, window)
165        }
166
167        fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
168            self.program.subscription(state)
169        }
170
171        fn style(&self, state: &Self::State, theme: &Self::Theme) -> theme::Style {
172            self.program.style(state, theme)
173        }
174
175        fn scale_factor(&self, state: &Self::State, window: window::Id) -> f32 {
176            self.program.scale_factor(state, window)
177        }
178    }
179
180    WithTitle { program, title }
181}
182
183/// Decorates a [`Program`] with the given subscription function.
184pub fn with_subscription<P: Program>(
185    program: P,
186    f: impl Fn(&P::State) -> Subscription<P::Message>,
187) -> impl Program<State = P::State, Message = P::Message, Theme = P::Theme> {
188    struct WithSubscription<P, F> {
189        program: P,
190        subscription: F,
191    }
192
193    impl<P: Program, F> Program for WithSubscription<P, F>
194    where
195        F: Fn(&P::State) -> Subscription<P::Message>,
196    {
197        type State = P::State;
198        type Message = P::Message;
199        type Theme = P::Theme;
200        type Renderer = P::Renderer;
201        type Executor = P::Executor;
202
203        fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
204            (self.subscription)(state)
205        }
206
207        fn name() -> &'static str {
208            P::name()
209        }
210
211        fn settings(&self) -> Settings {
212            self.program.settings()
213        }
214
215        fn window(&self) -> Option<window::Settings> {
216            self.program.window()
217        }
218
219        fn boot(&self) -> (Self::State, Task<Self::Message>) {
220            self.program.boot()
221        }
222
223        fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message> {
224            self.program.update(state, message)
225        }
226
227        fn view<'a>(
228            &self,
229            state: &'a Self::State,
230            window: window::Id,
231        ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer> {
232            self.program.view(state, window)
233        }
234
235        fn title(&self, state: &Self::State, window: window::Id) -> String {
236            self.program.title(state, window)
237        }
238
239        fn theme(&self, state: &Self::State, window: window::Id) -> Option<Self::Theme> {
240            self.program.theme(state, window)
241        }
242
243        fn style(&self, state: &Self::State, theme: &Self::Theme) -> theme::Style {
244            self.program.style(state, theme)
245        }
246
247        fn scale_factor(&self, state: &Self::State, window: window::Id) -> f32 {
248            self.program.scale_factor(state, window)
249        }
250    }
251
252    WithSubscription {
253        program,
254        subscription: f,
255    }
256}
257
258/// Decorates a [`Program`] with the given theme function.
259pub fn with_theme<P: Program>(
260    program: P,
261    f: impl Fn(&P::State, window::Id) -> Option<P::Theme>,
262) -> impl Program<State = P::State, Message = P::Message, Theme = P::Theme> {
263    struct WithTheme<P, F> {
264        program: P,
265        theme: F,
266    }
267
268    impl<P: Program, F> Program for WithTheme<P, F>
269    where
270        F: Fn(&P::State, window::Id) -> Option<P::Theme>,
271    {
272        type State = P::State;
273        type Message = P::Message;
274        type Theme = P::Theme;
275        type Renderer = P::Renderer;
276        type Executor = P::Executor;
277
278        fn theme(&self, state: &Self::State, window: window::Id) -> Option<Self::Theme> {
279            (self.theme)(state, window)
280        }
281
282        fn name() -> &'static str {
283            P::name()
284        }
285
286        fn settings(&self) -> Settings {
287            self.program.settings()
288        }
289
290        fn window(&self) -> Option<window::Settings> {
291            self.program.window()
292        }
293
294        fn boot(&self) -> (Self::State, Task<Self::Message>) {
295            self.program.boot()
296        }
297
298        fn title(&self, state: &Self::State, window: window::Id) -> String {
299            self.program.title(state, window)
300        }
301
302        fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message> {
303            self.program.update(state, message)
304        }
305
306        fn view<'a>(
307            &self,
308            state: &'a Self::State,
309            window: window::Id,
310        ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer> {
311            self.program.view(state, window)
312        }
313
314        fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
315            self.program.subscription(state)
316        }
317
318        fn style(&self, state: &Self::State, theme: &Self::Theme) -> theme::Style {
319            self.program.style(state, theme)
320        }
321
322        fn scale_factor(&self, state: &Self::State, window: window::Id) -> f32 {
323            self.program.scale_factor(state, window)
324        }
325    }
326
327    WithTheme { program, theme: f }
328}
329
330/// Decorates a [`Program`] with the given style function.
331pub fn with_style<P: Program>(
332    program: P,
333    f: impl Fn(&P::State, &P::Theme) -> theme::Style,
334) -> impl Program<State = P::State, Message = P::Message, Theme = P::Theme> {
335    struct WithStyle<P, F> {
336        program: P,
337        style: F,
338    }
339
340    impl<P: Program, F> Program for WithStyle<P, F>
341    where
342        F: Fn(&P::State, &P::Theme) -> theme::Style,
343    {
344        type State = P::State;
345        type Message = P::Message;
346        type Theme = P::Theme;
347        type Renderer = P::Renderer;
348        type Executor = P::Executor;
349
350        fn style(&self, state: &Self::State, theme: &Self::Theme) -> theme::Style {
351            (self.style)(state, theme)
352        }
353
354        fn name() -> &'static str {
355            P::name()
356        }
357
358        fn settings(&self) -> Settings {
359            self.program.settings()
360        }
361
362        fn window(&self) -> Option<window::Settings> {
363            self.program.window()
364        }
365
366        fn boot(&self) -> (Self::State, Task<Self::Message>) {
367            self.program.boot()
368        }
369
370        fn title(&self, state: &Self::State, window: window::Id) -> String {
371            self.program.title(state, window)
372        }
373
374        fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message> {
375            self.program.update(state, message)
376        }
377
378        fn view<'a>(
379            &self,
380            state: &'a Self::State,
381            window: window::Id,
382        ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer> {
383            self.program.view(state, window)
384        }
385
386        fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
387            self.program.subscription(state)
388        }
389
390        fn theme(&self, state: &Self::State, window: window::Id) -> Option<Self::Theme> {
391            self.program.theme(state, window)
392        }
393
394        fn scale_factor(&self, state: &Self::State, window: window::Id) -> f32 {
395            self.program.scale_factor(state, window)
396        }
397    }
398
399    WithStyle { program, style: f }
400}
401
402/// Decorates a [`Program`] with the given scale factor function.
403pub fn with_scale_factor<P: Program>(
404    program: P,
405    f: impl Fn(&P::State, window::Id) -> f32,
406) -> impl Program<State = P::State, Message = P::Message, Theme = P::Theme> {
407    struct WithScaleFactor<P, F> {
408        program: P,
409        scale_factor: F,
410    }
411
412    impl<P: Program, F> Program for WithScaleFactor<P, F>
413    where
414        F: Fn(&P::State, window::Id) -> f32,
415    {
416        type State = P::State;
417        type Message = P::Message;
418        type Theme = P::Theme;
419        type Renderer = P::Renderer;
420        type Executor = P::Executor;
421
422        fn title(&self, state: &Self::State, window: window::Id) -> String {
423            self.program.title(state, window)
424        }
425
426        fn name() -> &'static str {
427            P::name()
428        }
429
430        fn settings(&self) -> Settings {
431            self.program.settings()
432        }
433
434        fn window(&self) -> Option<window::Settings> {
435            self.program.window()
436        }
437
438        fn boot(&self) -> (Self::State, Task<Self::Message>) {
439            self.program.boot()
440        }
441
442        fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message> {
443            self.program.update(state, message)
444        }
445
446        fn view<'a>(
447            &self,
448            state: &'a Self::State,
449            window: window::Id,
450        ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer> {
451            self.program.view(state, window)
452        }
453
454        fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
455            self.program.subscription(state)
456        }
457
458        fn theme(&self, state: &Self::State, window: window::Id) -> Option<Self::Theme> {
459            self.program.theme(state, window)
460        }
461
462        fn style(&self, state: &Self::State, theme: &Self::Theme) -> theme::Style {
463            self.program.style(state, theme)
464        }
465
466        fn scale_factor(&self, state: &Self::State, window: window::Id) -> f32 {
467            (self.scale_factor)(state, window)
468        }
469    }
470
471    WithScaleFactor {
472        program,
473        scale_factor: f,
474    }
475}
476
477/// Decorates a [`Program`] with the given executor function.
478pub fn with_executor<P: Program, E: Executor>(
479    program: P,
480) -> impl Program<State = P::State, Message = P::Message, Theme = P::Theme> {
481    use std::marker::PhantomData;
482
483    struct WithExecutor<P, E> {
484        program: P,
485        executor: PhantomData<E>,
486    }
487
488    impl<P: Program, E> Program for WithExecutor<P, E>
489    where
490        E: Executor,
491    {
492        type State = P::State;
493        type Message = P::Message;
494        type Theme = P::Theme;
495        type Renderer = P::Renderer;
496        type Executor = E;
497
498        fn title(&self, state: &Self::State, window: window::Id) -> String {
499            self.program.title(state, window)
500        }
501
502        fn name() -> &'static str {
503            P::name()
504        }
505
506        fn settings(&self) -> Settings {
507            self.program.settings()
508        }
509
510        fn window(&self) -> Option<window::Settings> {
511            self.program.window()
512        }
513
514        fn boot(&self) -> (Self::State, Task<Self::Message>) {
515            self.program.boot()
516        }
517
518        fn update(&self, state: &mut Self::State, message: Self::Message) -> Task<Self::Message> {
519            self.program.update(state, message)
520        }
521
522        fn view<'a>(
523            &self,
524            state: &'a Self::State,
525            window: window::Id,
526        ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer> {
527            self.program.view(state, window)
528        }
529
530        fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
531            self.program.subscription(state)
532        }
533
534        fn theme(&self, state: &Self::State, window: window::Id) -> Option<Self::Theme> {
535            self.program.theme(state, window)
536        }
537
538        fn style(&self, state: &Self::State, theme: &Self::Theme) -> theme::Style {
539            self.program.style(state, theme)
540        }
541
542        fn scale_factor(&self, state: &Self::State, window: window::Id) -> f32 {
543            self.program.scale_factor(state, window)
544        }
545    }
546
547    WithExecutor {
548        program,
549        executor: PhantomData::<E>,
550    }
551}
552
553/// The renderer of some [`Program`].
554pub trait Renderer: text::Renderer<Font = Font> + compositor::Default + renderer::Headless {}
555
556impl<T> Renderer for T where
557    T: text::Renderer<Font = Font> + compositor::Default + renderer::Headless
558{
559}
560
561/// A particular instance of a running [`Program`].
562pub struct Instance<P: Program> {
563    program: P,
564    state: P::State,
565}
566
567impl<P: Program> Instance<P> {
568    /// Creates a new [`Instance`] of the given [`Program`].
569    pub fn new(program: P) -> (Self, Task<P::Message>) {
570        let (state, task) = program.boot();
571
572        (Self { program, state }, task)
573    }
574
575    /// Returns the current title of the [`Instance`].
576    pub fn title(&self, window: window::Id) -> String {
577        self.program.title(&self.state, window)
578    }
579
580    /// Processes the given message and updates the [`Instance`].
581    pub fn update(&mut self, message: P::Message) -> Task<P::Message> {
582        self.program.update(&mut self.state, message)
583    }
584
585    /// Produces the current widget tree of the [`Instance`].
586    pub fn view(&self, window: window::Id) -> Element<'_, P::Message, P::Theme, P::Renderer> {
587        self.program.view(&self.state, window)
588    }
589
590    /// Returns the current [`Subscription`] of the [`Instance`].
591    pub fn subscription(&self) -> Subscription<P::Message> {
592        self.program.subscription(&self.state)
593    }
594
595    /// Returns the current theme of the [`Instance`].
596    pub fn theme(&self, window: window::Id) -> Option<P::Theme> {
597        self.program.theme(&self.state, window)
598    }
599
600    /// Returns the current [`theme::Style`] of the [`Instance`].
601    pub fn style(&self, theme: &P::Theme) -> theme::Style {
602        self.program.style(&self.state, theme)
603    }
604
605    /// Returns the current scale factor of the [`Instance`].
606    pub fn scale_factor(&self, window: window::Id) -> f32 {
607        self.program.scale_factor(&self.state, window)
608    }
609}