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Diffstat (limited to 'src/application/program.rs')
-rw-r--r-- | src/application/program.rs | 810 |
1 files changed, 810 insertions, 0 deletions
diff --git a/src/application/program.rs b/src/application/program.rs new file mode 100644 index 00000000..24e00efe --- /dev/null +++ b/src/application/program.rs @@ -0,0 +1,810 @@ +//! +//! # Example +//! ```no_run +//! use iced::widget::{button, column, text, Column}; +//! use iced::Theme; +//! +//! pub fn main() -> iced::Result { +//! iced::program("A counter", update, view) +//! .theme(|_| Theme::Dark) +//! .centered() +//! .run() +//! } +//! +//! #[derive(Debug, Clone)] +//! enum Message { +//! Increment, +//! } +//! +//! fn update(value: &mut u64, message: Message) { +//! match message { +//! Message::Increment => *value += 1, +//! } +//! } +//! +//! fn view(value: &u64) -> Column<Message> { +//! column![ +//! text(value), +//! button("+").on_press(Message::Increment), +//! ] +//! } +//! ``` +use crate::application::{self, Application}; +use crate::executor::{self, Executor}; +use crate::window; +use crate::{Command, Element, Font, Result, Settings, Subscription}; + +use std::borrow::Cow; + +/// Creates an iced [`Program`] given its title, update, and view logic. +/// +/// # Example +/// ```no_run +/// use iced::widget::{button, column, text, Column}; +/// +/// pub fn main() -> iced::Result { +/// iced::program("A counter", update, view).run() +/// } +/// +/// #[derive(Debug, Clone)] +/// enum Message { +/// Increment, +/// } +/// +/// fn update(value: &mut u64, message: Message) { +/// match message { +/// Message::Increment => *value += 1, +/// } +/// } +/// +/// fn view(value: &u64) -> Column<Message> { +/// column![ +/// text(value), +/// button("+").on_press(Message::Increment), +/// ] +/// } +/// ``` +pub fn program<State, Message>( + title: impl Title<State>, + update: impl Update<State, Message>, + view: impl for<'a> self::View<'a, State, Message>, +) -> Program< + impl Definition<State = State, Message = Message, Theme = crate::Theme>, +> +where + State: Default + 'static, + Message: Send + std::fmt::Debug, +{ + use std::marker::PhantomData; + + struct Application<State, Message, Update, View> { + update: Update, + view: View, + _state: PhantomData<State>, + _message: PhantomData<Message>, + } + + impl<State, Message, Update, View> Definition + for Application<State, Message, Update, View> + where + State: Default, + Message: Send + std::fmt::Debug, + Update: self::Update<State, Message>, + View: for<'a> self::View<'a, State, Message>, + { + type State = State; + type Message = Message; + type Theme = crate::Theme; + type Executor = executor::Default; + + fn build(&self) -> (Self::State, Command<Self::Message>) { + (Self::State::default(), Command::none()) + } + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message> { + self.update.update(state, message).into() + } + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme> { + self.view.view(state).into() + } + } + + Program { + raw: Application { + update, + view, + _state: PhantomData, + _message: PhantomData, + }, + settings: Settings::default(), + } + .title(title) +} + +/// The underlying definition and configuration of an iced [`Application`]. +/// +/// You can use this API to create and run iced applications +/// step by step—without coupling your logic to a trait +/// or a specific type. +/// +/// This API is meant to be a more convenient—although less +/// powerful—alternative to the [`Application`] trait. +/// +/// You can create a [`Program`] with the [`program`] helper. +/// +/// [`run`]: Program::run +#[derive(Debug)] +pub struct Program<P: Definition> { + raw: P, + settings: Settings, +} + +impl<P: Definition> Program<P> { + /// Runs the underlying [`Application`] of the [`Program`]. + pub fn run(self) -> Result + where + Self: 'static, + { + struct Instance<P: Definition> { + program: P, + state: P::State, + } + + impl<P: Definition> Application for Instance<P> { + type Message = P::Message; + type Theme = P::Theme; + type Flags = P; + type Executor = P::Executor; + + fn new(program: Self::Flags) -> (Self, Command<Self::Message>) { + let (state, command) = P::build(&program); + + (Self { program, state }, command) + } + + fn title(&self) -> String { + self.program.title(&self.state) + } + + fn update( + &mut self, + message: Self::Message, + ) -> Command<Self::Message> { + self.program.update(&mut self.state, message) + } + + fn view( + &self, + ) -> crate::Element<'_, Self::Message, Self::Theme, crate::Renderer> + { + self.program.view(&self.state) + } + + fn subscription(&self) -> Subscription<Self::Message> { + self.program.subscription(&self.state) + } + + fn theme(&self) -> Self::Theme { + self.program.theme(&self.state) + } + + fn style(&self, theme: &Self::Theme) -> application::Appearance { + self.program.style(&self.state, theme) + } + } + + let Self { raw, settings } = self; + + Instance::run(Settings { + flags: raw, + id: settings.id, + window: settings.window, + fonts: settings.fonts, + default_font: settings.default_font, + default_text_size: settings.default_text_size, + antialiasing: settings.antialiasing, + }) + } + + /// Sets the [`Settings`] that will be used to run the [`Program`]. + pub fn settings(self, settings: Settings) -> Self { + Self { settings, ..self } + } + + /// Sets the [`Settings::antialiasing`] of the [`Program`]. + pub fn antialiasing(self, antialiasing: bool) -> Self { + Self { + settings: Settings { + antialiasing, + ..self.settings + }, + ..self + } + } + + /// Sets the default [`Font`] of the [`Program`]. + pub fn default_font(self, default_font: Font) -> Self { + Self { + settings: Settings { + default_font, + ..self.settings + }, + ..self + } + } + + /// Adds a font to the list of fonts that will be loaded at the start of the [`Program`]. + pub fn font(mut self, font: impl Into<Cow<'static, [u8]>>) -> Self { + self.settings.fonts.push(font.into()); + self + } + + /// Sets the [`window::Settings::position`] to [`window::Position::Centered`] in the [`Program`]. + pub fn centered(self) -> Self { + Self { + settings: Settings { + window: window::Settings { + position: window::Position::Centered, + ..self.settings.window + }, + ..self.settings + }, + ..self + } + } + + /// Sets the [`window::Settings::exit_on_close_request`] of the [`Program`]. + pub fn exit_on_close_request(self, exit_on_close_request: bool) -> Self { + Self { + settings: Settings { + window: window::Settings { + exit_on_close_request, + ..self.settings.window + }, + ..self.settings + }, + ..self + } + } + + /// Sets the [`window::Settings::transparent`] of the [`Program`]. + pub fn transparent(self, transparent: bool) -> Self { + Self { + settings: Settings { + window: window::Settings { + transparent, + ..self.settings.window + }, + ..self.settings + }, + ..self + } + } + + /// Sets the [`Title`] of the [`Program`]. + pub(crate) fn title( + self, + title: impl Title<P::State>, + ) -> Program< + impl Definition<State = P::State, Message = P::Message, Theme = P::Theme>, + > { + Program { + raw: with_title(self.raw, title), + settings: self.settings, + } + } + + /// Runs the [`Command`] produced by the closure at startup. + pub fn load( + self, + f: impl Fn() -> Command<P::Message>, + ) -> Program< + impl Definition<State = P::State, Message = P::Message, Theme = P::Theme>, + > { + Program { + raw: with_load(self.raw, f), + settings: self.settings, + } + } + + /// Sets the subscription logic of the [`Program`]. + pub fn subscription( + self, + f: impl Fn(&P::State) -> Subscription<P::Message>, + ) -> Program< + impl Definition<State = P::State, Message = P::Message, Theme = P::Theme>, + > { + Program { + raw: with_subscription(self.raw, f), + settings: self.settings, + } + } + + /// Sets the theme logic of the [`Program`]. + pub fn theme( + self, + f: impl Fn(&P::State) -> P::Theme, + ) -> Program< + impl Definition<State = P::State, Message = P::Message, Theme = P::Theme>, + > { + Program { + raw: with_theme(self.raw, f), + settings: self.settings, + } + } + + /// Sets the style logic of the [`Program`]. + pub fn style( + self, + f: impl Fn(&P::State, &P::Theme) -> application::Appearance, + ) -> Program< + impl Definition<State = P::State, Message = P::Message, Theme = P::Theme>, + > { + Program { + raw: with_style(self.raw, f), + settings: self.settings, + } + } +} + +/// The internal definition of a [`Program`]. +/// +/// You should not need to implement this trait directly. Instead, use the +/// methods available in the [`Program`] struct. +#[allow(missing_docs)] +pub trait Definition: Sized { + /// The state of the program. + type State; + + /// The message of the program. + type Message: Send + std::fmt::Debug; + + /// The theme of the program. + type Theme: Default + application::DefaultStyle; + + /// The executor of the program. + type Executor: Executor; + + fn build(&self) -> (Self::State, Command<Self::Message>); + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message>; + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme>; + + fn title(&self, _state: &Self::State) -> String { + String::from("A cool iced application!") + } + + fn subscription( + &self, + _state: &Self::State, + ) -> Subscription<Self::Message> { + Subscription::none() + } + + fn theme(&self, _state: &Self::State) -> Self::Theme { + Self::Theme::default() + } + + fn style( + &self, + _state: &Self::State, + theme: &Self::Theme, + ) -> application::Appearance { + application::DefaultStyle::default_style(theme) + } +} + +fn with_title<P: Definition>( + program: P, + title: impl Title<P::State>, +) -> impl Definition<State = P::State, Message = P::Message, Theme = P::Theme> { + struct WithTitle<P, Title> { + program: P, + title: Title, + } + + impl<P, Title> Definition for WithTitle<P, Title> + where + P: Definition, + Title: self::Title<P::State>, + { + type State = P::State; + type Message = P::Message; + type Theme = P::Theme; + type Executor = P::Executor; + + fn build(&self) -> (Self::State, Command<Self::Message>) { + self.program.build() + } + + fn title(&self, state: &Self::State) -> String { + self.title.title(state) + } + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message> { + self.program.update(state, message) + } + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme> { + self.program.view(state) + } + + fn theme(&self, state: &Self::State) -> Self::Theme { + self.program.theme(state) + } + + fn subscription( + &self, + state: &Self::State, + ) -> Subscription<Self::Message> { + self.program.subscription(state) + } + + fn style( + &self, + state: &Self::State, + theme: &Self::Theme, + ) -> application::Appearance { + self.program.style(state, theme) + } + } + + WithTitle { program, title } +} + +fn with_load<P: Definition>( + program: P, + f: impl Fn() -> Command<P::Message>, +) -> impl Definition<State = P::State, Message = P::Message, Theme = P::Theme> { + struct WithLoad<P, F> { + program: P, + load: F, + } + + impl<P: Definition, F> Definition for WithLoad<P, F> + where + F: Fn() -> Command<P::Message>, + { + type State = P::State; + type Message = P::Message; + type Theme = P::Theme; + type Executor = executor::Default; + + fn build(&self) -> (Self::State, Command<Self::Message>) { + let (state, command) = self.program.build(); + + (state, Command::batch([command, (self.load)()])) + } + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message> { + self.program.update(state, message) + } + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme> { + self.program.view(state) + } + + fn title(&self, state: &Self::State) -> String { + self.program.title(state) + } + + fn subscription( + &self, + state: &Self::State, + ) -> Subscription<Self::Message> { + self.program.subscription(state) + } + + fn theme(&self, state: &Self::State) -> Self::Theme { + self.program.theme(state) + } + + fn style( + &self, + state: &Self::State, + theme: &Self::Theme, + ) -> application::Appearance { + self.program.style(state, theme) + } + } + + WithLoad { program, load: f } +} + +fn with_subscription<P: Definition>( + program: P, + f: impl Fn(&P::State) -> Subscription<P::Message>, +) -> impl Definition<State = P::State, Message = P::Message, Theme = P::Theme> { + struct WithSubscription<P, F> { + program: P, + subscription: F, + } + + impl<P: Definition, F> Definition for WithSubscription<P, F> + where + F: Fn(&P::State) -> Subscription<P::Message>, + { + type State = P::State; + type Message = P::Message; + type Theme = P::Theme; + type Executor = executor::Default; + + fn subscription( + &self, + state: &Self::State, + ) -> Subscription<Self::Message> { + (self.subscription)(state) + } + + fn build(&self) -> (Self::State, Command<Self::Message>) { + self.program.build() + } + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message> { + self.program.update(state, message) + } + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme> { + self.program.view(state) + } + + fn title(&self, state: &Self::State) -> String { + self.program.title(state) + } + + fn theme(&self, state: &Self::State) -> Self::Theme { + self.program.theme(state) + } + + fn style( + &self, + state: &Self::State, + theme: &Self::Theme, + ) -> application::Appearance { + self.program.style(state, theme) + } + } + + WithSubscription { + program, + subscription: f, + } +} + +fn with_theme<P: Definition>( + program: P, + f: impl Fn(&P::State) -> P::Theme, +) -> impl Definition<State = P::State, Message = P::Message, Theme = P::Theme> { + struct WithTheme<P, F> { + program: P, + theme: F, + } + + impl<P: Definition, F> Definition for WithTheme<P, F> + where + F: Fn(&P::State) -> P::Theme, + { + type State = P::State; + type Message = P::Message; + type Theme = P::Theme; + type Executor = P::Executor; + + fn theme(&self, state: &Self::State) -> Self::Theme { + (self.theme)(state) + } + + fn build(&self) -> (Self::State, Command<Self::Message>) { + self.program.build() + } + + fn title(&self, state: &Self::State) -> String { + self.program.title(state) + } + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message> { + self.program.update(state, message) + } + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme> { + self.program.view(state) + } + + fn subscription( + &self, + state: &Self::State, + ) -> Subscription<Self::Message> { + self.program.subscription(state) + } + + fn style( + &self, + state: &Self::State, + theme: &Self::Theme, + ) -> application::Appearance { + self.program.style(state, theme) + } + } + + WithTheme { program, theme: f } +} + +fn with_style<P: Definition>( + program: P, + f: impl Fn(&P::State, &P::Theme) -> application::Appearance, +) -> impl Definition<State = P::State, Message = P::Message, Theme = P::Theme> { + struct WithStyle<P, F> { + program: P, + style: F, + } + + impl<P: Definition, F> Definition for WithStyle<P, F> + where + F: Fn(&P::State, &P::Theme) -> application::Appearance, + { + type State = P::State; + type Message = P::Message; + type Theme = P::Theme; + type Executor = P::Executor; + + fn style( + &self, + state: &Self::State, + theme: &Self::Theme, + ) -> application::Appearance { + (self.style)(state, theme) + } + + fn build(&self) -> (Self::State, Command<Self::Message>) { + self.program.build() + } + + fn title(&self, state: &Self::State) -> String { + self.program.title(state) + } + + fn update( + &self, + state: &mut Self::State, + message: Self::Message, + ) -> Command<Self::Message> { + self.program.update(state, message) + } + + fn view<'a>( + &self, + state: &'a Self::State, + ) -> Element<'a, Self::Message, Self::Theme> { + self.program.view(state) + } + + fn subscription( + &self, + state: &Self::State, + ) -> Subscription<Self::Message> { + self.program.subscription(state) + } + + fn theme(&self, state: &Self::State) -> Self::Theme { + self.program.theme(state) + } + } + + WithStyle { program, style: f } +} + +/// The title logic of some [`Program`]. +/// +/// This trait is implemented both for `&static str` and +/// any closure `Fn(&State) -> String`. +/// +/// This trait allows the [`program`] builder to take any of them. +pub trait Title<State> { + /// Produces the title of the [`Program`]. + fn title(&self, state: &State) -> String; +} + +impl<State> Title<State> for &'static str { + fn title(&self, _state: &State) -> String { + self.to_string() + } +} + +impl<T, State> Title<State> for T +where + T: Fn(&State) -> String, +{ + fn title(&self, state: &State) -> String { + self(state) + } +} + +/// The update logic of some [`Program`]. +/// +/// This trait allows the [`program`] builder to take any closure that +/// returns any `Into<Command<Message>>`. +pub trait Update<State, Message> { + /// Processes the message and updates the state of the [`Program`]. + fn update( + &self, + state: &mut State, + message: Message, + ) -> impl Into<Command<Message>>; +} + +impl<T, State, Message, C> Update<State, Message> for T +where + T: Fn(&mut State, Message) -> C, + C: Into<Command<Message>>, +{ + fn update( + &self, + state: &mut State, + message: Message, + ) -> impl Into<Command<Message>> { + self(state, message) + } +} + +/// The view logic of some [`Program`]. +/// +/// This trait allows the [`program`] builder to take any closure that +/// returns any `Into<Element<'_, Message>>`. +pub trait View<'a, State, Message> { + /// Produces the widget of the [`Program`]. + fn view(&self, state: &'a State) -> impl Into<Element<'a, Message>>; +} + +impl<'a, T, State, Message, Widget> View<'a, State, Message> for T +where + T: Fn(&'a State) -> Widget, + State: 'static, + Widget: Into<Element<'a, Message>>, +{ + fn view(&self, state: &'a State) -> impl Into<Element<'a, Message>> { + self(state) + } +} |