gpui.rs

  1//! # Welcome to GPUI!
  2//!
  3//! GPUI is a hybrid immediate and retained mode, GPU accelerated, UI framework
  4//! for Rust, designed to support a wide variety of applications.
  5//!
  6//! ## Getting Started
  7//!
  8//! GPUI is still in active development as we work on the Zed code editor and isn't yet on crates.io.
  9//! You'll also need to use the latest version of stable rust and be on macOS. Add the following to your
 10//! Cargo.toml:
 11//!
 12//! ```
 13//! gpui = { git = "https://github.com/zed-industries/zed" }
 14//! ```
 15//!
 16//! Everything in GPUI starts with an [`App`]. You can create one with [`App::new`], and
 17//! kick off your application by passing a callback to [`App::run`]. Inside this callback,
 18//! you can create a new window with [`AppContext::open_window`], and register your first root
 19//! view. See [gpui.rs](https://www.gpui.rs/) for a complete example.
 20//!
 21//! ## The Big Picture
 22//!
 23//! GPUI offers three different [registers](https://en.wikipedia.org/wiki/Register_(sociolinguistics)) depending on your needs:
 24//!
 25//! - State management and communication with Models. Whenever you need to store application state
 26//!   that communicates between different parts of your application, you'll want to use GPUI's
 27//!   models. Models are owned by GPUI and are only accessible through an owned smart pointer
 28//!   similar to an [`Rc`]. See the [`app::model_context`] module for more information.
 29//!
 30//! - High level, declarative UI with Views. All UI in GPUI starts with a View. A view is simply
 31//!   a model that can be rendered, via the [`Render`] trait. At the start of each frame, GPUI
 32//!   will call this render method on the root view of a given window. Views build a tree of
 33//!   `elements`, lay them out and style them with a tailwind-style API, and then give them to
 34//!   GPUI to turn into pixels. See the [`elements::Div`] element for an all purpose swiss-army
 35//!   knife for UI.
 36//!
 37//! - Low level, imperative UI with Elements. Elements are the building blocks of UI in GPUI, and they
 38//!   provide a nice wrapper around an imperative API that provides as much flexibility and control as
 39//!   you need. Elements have total control over how they and their child elements are rendered and and
 40//!   can be used for making efficient views into large lists, implement custom layouting for a code editor,
 41//!   and anything else you can think of. See the [`element`] module for more information.
 42//!
 43//!  Each of these registers has one or more corresponding contexts that can be accessed from all GPUI services.
 44//!  This context is your main interface to GPUI, and is used extensively throughout the framework.
 45//!
 46//! ## Other Resources
 47//!
 48//! In addition to the systems above, GPUI provides a range of smaller services that are useful for building
 49//! complex applications:
 50//!
 51//! - Actions are user-defined structs that are used for converting keystrokes into logical operations in your UI.
 52//!   Use this for implementing keyboard shortcuts, such as cmd-q. See the [`action`] module for more information.
 53//! - Platform services, such as `quit the app` or `open a URL` are available as methods on the [`app::AppContext`].
 54//! - An async executor that is integrated with the platform's event loop. See the [`executor`] module for more information.,
 55//! - The [gpui::test] macro provides a convenient way to write tests for your GPUI applications. Tests also have their
 56//!   own kind of context, a [`TestAppContext`] which provides ways of simulating common platform input. See [`app::test_context`]
 57//!   and [`test`] modules for more details.
 58//!
 59//! Currently, the best way to learn about these APIs is to read the Zed source code, ask us about it at a fireside hack, or drop
 60//! a question in the [Zed Discord](https://discord.gg/U4qhCEhMXP). We're working on improving the documentation, creating more examples,
 61//! and will be publishing more guides to GPUI on our [blog](https://zed.dev/blog).
 62
 63#![deny(missing_docs)]
 64#![allow(clippy::type_complexity)]
 65
 66#[macro_use]
 67mod action;
 68mod app;
 69
 70mod arena;
 71mod assets;
 72mod color;
 73mod element;
 74mod elements;
 75mod executor;
 76mod geometry;
 77mod image_cache;
 78mod input;
 79mod interactive;
 80mod key_dispatch;
 81mod keymap;
 82mod platform;
 83pub mod prelude;
 84mod scene;
 85mod shared_string;
 86mod shared_url;
 87mod style;
 88mod styled;
 89mod subscription;
 90mod svg_renderer;
 91mod taffy;
 92#[cfg(any(test, feature = "test-support"))]
 93pub mod test;
 94mod text_system;
 95mod util;
 96mod view;
 97mod window;
 98
 99/// Do not touch, here be dragons for use by gpui_macros and such.
100#[doc(hidden)]
101pub mod private {
102    pub use linkme;
103    pub use serde;
104    pub use serde_derive;
105    pub use serde_json;
106}
107
108mod seal {
109    /// A mechanism for restricting implementations of a trait to only those in GPUI.
110    /// See: https://predr.ag/blog/definitive-guide-to-sealed-traits-in-rust/
111    pub trait Sealed {}
112}
113
114pub use action::*;
115pub use anyhow::Result;
116pub use app::*;
117pub(crate) use arena::*;
118pub use assets::*;
119pub use color::*;
120pub use ctor::ctor;
121pub use element::*;
122pub use elements::*;
123pub use executor::*;
124pub use geometry::*;
125pub use gpui_macros::{register_action, test, IntoElement, Render};
126use image_cache::*;
127pub use input::*;
128pub use interactive::*;
129use key_dispatch::*;
130pub use keymap::*;
131pub use platform::*;
132pub use refineable::*;
133pub use scene::*;
134use seal::Sealed;
135pub use shared_string::*;
136pub use shared_url::*;
137pub use smol::Timer;
138pub use style::*;
139pub use styled::*;
140pub use subscription::*;
141use svg_renderer::*;
142pub use taffy::{AvailableSpace, LayoutId};
143#[cfg(any(test, feature = "test-support"))]
144pub use test::*;
145pub use text_system::*;
146pub use util::arc_cow::ArcCow;
147pub use view::*;
148pub use window::*;
149
150use std::{any::Any, borrow::BorrowMut};
151use taffy::TaffyLayoutEngine;
152
153/// The context trait, allows the different contexts in GPUI to be used
154/// interchangeably for certain operations.
155pub trait Context {
156    /// The result type for this context, used for async contexts that
157    /// can't hold a direct reference to the application context.
158    type Result<T>;
159
160    /// Create a new model in the app context.
161    fn new_model<T: 'static>(
162        &mut self,
163        build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
164    ) -> Self::Result<Model<T>>;
165
166    /// Update a model in the app context.
167    fn update_model<T, R>(
168        &mut self,
169        handle: &Model<T>,
170        update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
171    ) -> Self::Result<R>
172    where
173        T: 'static;
174
175    /// Read a model from the app context.
176    fn read_model<T, R>(
177        &self,
178        handle: &Model<T>,
179        read: impl FnOnce(&T, &AppContext) -> R,
180    ) -> Self::Result<R>
181    where
182        T: 'static;
183
184    /// Update a window for the given handle.
185    fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
186    where
187        F: FnOnce(AnyView, &mut WindowContext<'_>) -> T;
188
189    /// Read a window off of the application context.
190    fn read_window<T, R>(
191        &self,
192        window: &WindowHandle<T>,
193        read: impl FnOnce(View<T>, &AppContext) -> R,
194    ) -> Result<R>
195    where
196        T: 'static;
197}
198
199/// This trait is used for the different visual contexts in GPUI that
200/// require a window to be present.
201pub trait VisualContext: Context {
202    /// Construct a new view in the window referenced by this context.
203    fn new_view<V>(
204        &mut self,
205        build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
206    ) -> Self::Result<View<V>>
207    where
208        V: 'static + Render;
209
210    /// Update a view with the given callback
211    fn update_view<V: 'static, R>(
212        &mut self,
213        view: &View<V>,
214        update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
215    ) -> Self::Result<R>;
216
217    /// Replace the root view of a window with a new view.
218    fn replace_root_view<V>(
219        &mut self,
220        build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
221    ) -> Self::Result<View<V>>
222    where
223        V: 'static + Render;
224
225    /// Focus a view in the window, if it implements the [`FocusableView`] trait.
226    fn focus_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
227    where
228        V: FocusableView;
229
230    /// Dismiss a view in the window, if it implements the [`ManagedView`] trait.
231    fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
232    where
233        V: ManagedView;
234}
235
236/// A trait that allows models and views to be interchangeable in certain operations
237pub trait Entity<T>: Sealed {
238    /// The weak reference type for this entity.
239    type Weak: 'static;
240
241    /// The ID for this entity
242    fn entity_id(&self) -> EntityId;
243
244    /// Downgrade this entity to a weak reference.
245    fn downgrade(&self) -> Self::Weak;
246
247    /// Upgrade this entity from a weak reference.
248    fn upgrade_from(weak: &Self::Weak) -> Option<Self>
249    where
250        Self: Sized;
251}
252
253/// A trait for tying together the types of a GPUI entity and the events it can
254/// emit.
255pub trait EventEmitter<E: Any>: 'static {}
256
257/// A helper trait for auto-implementing certain methods on contexts that
258/// can be used interchangeably.
259pub trait BorrowAppContext {
260    /// Set a global value on the context.
261    fn set_global<T: 'static>(&mut self, global: T);
262}
263
264impl<C> BorrowAppContext for C
265where
266    C: BorrowMut<AppContext>,
267{
268    fn set_global<G: 'static>(&mut self, global: G) {
269        self.borrow_mut().set_global(global)
270    }
271}
272
273/// A flatten equivalent for anyhow `Result`s.
274pub trait Flatten<T> {
275    /// Convert this type into a simple `Result<T>`.
276    fn flatten(self) -> Result<T>;
277}
278
279impl<T> Flatten<T> for Result<Result<T>> {
280    fn flatten(self) -> Result<T> {
281        self?
282    }
283}
284
285impl<T> Flatten<T> for Result<T> {
286    fn flatten(self) -> Result<T> {
287        self
288    }
289}