diff options
Diffstat (limited to 'src/pure')
| -rw-r--r-- | src/pure/application.rs | 186 | ||||
| -rw-r--r-- | src/pure/sandbox.rs | 119 |
2 files changed, 305 insertions, 0 deletions
diff --git a/src/pure/application.rs b/src/pure/application.rs new file mode 100644 index 00000000..5f400bea --- /dev/null +++ b/src/pure/application.rs @@ -0,0 +1,186 @@ +use crate::pure::{self, Pure}; +use crate::window; +use crate::{Color, Command, Executor, Settings, Subscription}; + +/// A pure version of [`Application`]. +/// +/// Unlike the impure version, the `view` method of this trait takes an +/// immutable reference to `self` and returns a pure [`Element`]. +/// +/// [`Application`]: crate::Application +/// [`Element`]: pure::Element +pub trait Application: Sized { + /// The [`Executor`] that will run commands and subscriptions. + /// + /// The [default executor] can be a good starting point! + /// + /// [`Executor`]: Self::Executor + /// [default executor]: crate::executor::Default + type Executor: Executor; + + /// The type of __messages__ your [`Application`] will produce. + type Message: std::fmt::Debug + Send; + + /// The data needed to initialize your [`Application`]. + type Flags; + + /// Initializes the [`Application`] with the flags provided to + /// [`run`] as part of the [`Settings`]. + /// + /// Here is where you should return the initial state of your app. + /// + /// Additionally, you can return a [`Command`] if you need to perform some + /// async action in the background on startup. This is useful if you want to + /// load state from a file, perform an initial HTTP request, etc. + /// + /// [`run`]: Self::run + fn new(flags: Self::Flags) -> (Self, Command<Self::Message>); + + /// Returns the current title of the [`Application`]. + /// + /// This title can be dynamic! The runtime will automatically update the + /// title of your application when necessary. + fn title(&self) -> String; + + /// Handles a __message__ and updates the state of the [`Application`]. + /// + /// This is where you define your __update logic__. All the __messages__, + /// produced by either user interactions or commands, will be handled by + /// this method. + /// + /// Any [`Command`] returned will be executed immediately in the background. + fn update(&mut self, message: Self::Message) -> Command<Self::Message>; + + /// Returns the event [`Subscription`] for the current state of the + /// application. + /// + /// A [`Subscription`] will be kept alive as long as you keep returning it, + /// and the __messages__ produced will be handled by + /// [`update`](#tymethod.update). + /// + /// By default, this method returns an empty [`Subscription`]. + fn subscription(&self) -> Subscription<Self::Message> { + Subscription::none() + } + + /// Returns the widgets to display in the [`Application`]. + /// + /// These widgets can produce __messages__ based on user interaction. + fn view(&self) -> pure::Element<'_, Self::Message>; + + /// Returns the current [`Application`] mode. + /// + /// The runtime will automatically transition your application if a new mode + /// is returned. + /// + /// Currently, the mode only has an effect in native platforms. + /// + /// By default, an application will run in windowed mode. + fn mode(&self) -> window::Mode { + window::Mode::Windowed + } + + /// Returns the background color of the [`Application`]. + /// + /// By default, it returns [`Color::WHITE`]. + fn background_color(&self) -> Color { + Color::WHITE + } + + /// Returns the scale factor of the [`Application`]. + /// + /// It can be used to dynamically control the size of the UI at runtime + /// (i.e. zooming). + /// + /// For instance, a scale factor of `2.0` will make widgets twice as big, + /// while a scale factor of `0.5` will shrink them to half their size. + /// + /// By default, it returns `1.0`. + fn scale_factor(&self) -> f64 { + 1.0 + } + + /// Returns whether the [`Application`] should be terminated. + /// + /// By default, it returns `false`. + fn should_exit(&self) -> bool { + false + } + + /// Runs the [`Application`]. + /// + /// On native platforms, this method will take control of the current thread + /// until the [`Application`] exits. + /// + /// On the web platform, this method __will NOT return__ unless there is an + /// [`Error`] during startup. + /// + /// [`Error`]: crate::Error + fn run(settings: Settings<Self::Flags>) -> crate::Result + where + Self: 'static, + { + <Instance<Self> as crate::Application>::run(settings) + } +} + +struct Instance<A: Application> { + application: A, + state: pure::State, +} + +impl<A> crate::Application for Instance<A> +where + A: Application, + A::Message: 'static, +{ + type Executor = A::Executor; + type Message = A::Message; + type Flags = A::Flags; + + fn new(flags: Self::Flags) -> (Self, Command<Self::Message>) { + let (application, command) = A::new(flags); + + ( + Instance { + application, + state: pure::State::new(), + }, + command, + ) + } + + fn title(&self) -> String { + A::title(&self.application) + } + + fn update(&mut self, message: Self::Message) -> Command<Self::Message> { + A::update(&mut self.application, message) + } + + fn subscription(&self) -> Subscription<Self::Message> { + A::subscription(&self.application) + } + + fn view(&mut self) -> crate::Element<'_, Self::Message> { + let content = A::view(&self.application); + + Pure::new(&mut self.state, content).into() + } + + fn mode(&self) -> window::Mode { + A::mode(&self.application) + } + + fn background_color(&self) -> Color { + A::background_color(&self.application) + } + + fn scale_factor(&self) -> f64 { + A::scale_factor(&self.application) + } + + fn should_exit(&self) -> bool { + A::should_exit(&self.application) + } +} diff --git a/src/pure/sandbox.rs b/src/pure/sandbox.rs new file mode 100644 index 00000000..fbd1d7a8 --- /dev/null +++ b/src/pure/sandbox.rs @@ -0,0 +1,119 @@ +use crate::pure; +use crate::{Color, Command, Error, Settings, Subscription}; + +/// A pure version of [`Sandbox`]. +/// +/// Unlike the impure version, the `view` method of this trait takes an +/// immutable reference to `self` and returns a pure [`Element`]. +/// +/// [`Sandbox`]: crate::Sandbox +/// [`Element`]: pure::Element +pub trait Sandbox { + /// The type of __messages__ your [`Sandbox`] will produce. + type Message: std::fmt::Debug + Send; + + /// Initializes the [`Sandbox`]. + /// + /// Here is where you should return the initial state of your app. + fn new() -> Self; + + /// Returns the current title of the [`Sandbox`]. + /// + /// This title can be dynamic! The runtime will automatically update the + /// title of your application when necessary. + fn title(&self) -> String; + + /// Handles a __message__ and updates the state of the [`Sandbox`]. + /// + /// This is where you define your __update logic__. All the __messages__, + /// produced by user interactions, will be handled by this method. + fn update(&mut self, message: Self::Message); + + /// Returns the widgets to display in the [`Sandbox`]. + /// + /// These widgets can produce __messages__ based on user interaction. + fn view(&self) -> pure::Element<'_, Self::Message>; + + /// Returns the background color of the [`Sandbox`]. + /// + /// By default, it returns [`Color::WHITE`]. + fn background_color(&self) -> Color { + Color::WHITE + } + + /// Returns the scale factor of the [`Sandbox`]. + /// + /// It can be used to dynamically control the size of the UI at runtime + /// (i.e. zooming). + /// + /// For instance, a scale factor of `2.0` will make widgets twice as big, + /// while a scale factor of `0.5` will shrink them to half their size. + /// + /// By default, it returns `1.0`. + fn scale_factor(&self) -> f64 { + 1.0 + } + + /// Returns whether the [`Sandbox`] should be terminated. + /// + /// By default, it returns `false`. + fn should_exit(&self) -> bool { + false + } + + /// Runs the [`Sandbox`]. + /// + /// On native platforms, this method will take control of the current thread + /// and __will NOT return__. + /// + /// It should probably be that last thing you call in your `main` function. + fn run(settings: Settings<()>) -> Result<(), Error> + where + Self: 'static + Sized, + { + <Self as pure::Application>::run(settings) + } +} + +impl<T> pure::Application for T +where + T: Sandbox, +{ + type Executor = iced_futures::backend::null::Executor; + type Flags = (); + type Message = T::Message; + + fn new(_flags: ()) -> (Self, Command<T::Message>) { + (T::new(), Command::none()) + } + + fn title(&self) -> String { + T::title(self) + } + + fn update(&mut self, message: T::Message) -> Command<T::Message> { + T::update(self, message); + + Command::none() + } + + fn subscription(&self) -> Subscription<T::Message> { + Subscription::none() + } + + fn view(&self) -> pure::Element<'_, T::Message> { + T::view(self) + } + + fn background_color(&self) -> Color { + T::background_color(self) + } + + fn scale_factor(&self) -> f64 { + T::scale_factor(self) + } + + fn should_exit(&self) -> bool { + T::should_exit(self) + } +} |