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. Add the following to your Cargo.toml:
 10//!
 11//! ```
 12//! gpui = { git = "https://github.com/zed-industries/zed" }
 13//! ```
 14//!
 15//! Everything in GPUI starts with an [`App`]. You can create one with [`App::new`], and
 16//! kick off your application by passing a callback to [`App::run`]. Inside this callback,
 17//! you can create a new window with [`AppContext::open_window`], and register your first root
 18//! view. See [gpui.rs](https://www.gpui.rs/) for a complete example.
 19//!
 20//! ## The Big Picture
 21//!
 22//! GPUI offers three different [registers](https://en.wikipedia.org/wiki/Register_(sociolinguistics)) depending on your needs:
 23//!
 24//! - State management and communication with Models. Whenever you need to store application state
 25//!   that communicates between different parts of your application, you'll want to use GPUI's
 26//!   models. Models are owned by GPUI and are only accessible through an owned smart pointer
 27//!   similar to an [`Rc`]. See the [`app::model_context`] module for more information.
 28//!
 29//! - High level, declarative UI with Views. All UI in GPUI starts with a View. A view is simply
 30//!   a model that can be rendered, via the [`Render`] trait. At the start of each frame, GPUI
 31//!   will call this render method on the root view of a given window. Views build a tree of
 32//!   `elements`, lay them out and style them with a tailwind-style API, and then give them to
 33//!   GPUI to turn into pixels. See the [`elements::Div`] element for an all purpose swiss-army
 34//!   knife for UI.
 35//!
 36//! - Low level, imperative UI with Elements. Elements are the building blocks of UI in GPUI, and they
 37//!   provide a nice wrapper around an imperative API that provides as much flexibility and control as
 38//!   you need. Elements have total control over how they and their child elements are rendered and and
 39//!   can be used for making efficient views into large lists, implement custom layouting for a code editor,
 40//!   and anything else you can think of. See the [`element`] module for more information.
 41//!
 42//!  Each of these registers has one or more corresponding contexts that can be accessed from all GPUI services.
 43//!  This context is your main interface to GPUI, and is used extensively throughout the framework.
 44//!
 45//! ## Other Resources
 46//!
 47//! In addition to the systems above, GPUI provides a range of smaller services that are useful for building
 48//! complex applications:
 49//!
 50//! - Actions are user-defined structs that are used for converting keystrokes into logical operations in your UI.
 51//!   Use this for implementing keyboard shortcuts, such as cmd-q. See the [`action`] module for more information.
 52//! - Platform services, such as `quit the app` or `open a URL` are available as methods on the [`app::AppContext`].
 53//! - An async executor that is integrated with the platform's event loop. See the [`executor`] module for more information.,
 54//! - The [gpui::test] macro provides a convenient way to write tests for your GPUI applications. Tests also have their
 55//!   own kind of context, a [`TestAppContext`] which provides ways of simulating common platform input. See [`app::test_context`]
 56//!   and [`test`] modules for more details.
 57//!
 58//! 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
 59//! a question in the [Zed Discord](https://discord.gg/U4qhCEhMXP). We're working on improving the documentation, creating more examples,
 60//! and will be publishing more guides to GPUI on our [blog](https://zed.dev/blog).
 61
 62#![deny(missing_docs)]
 63#![allow(clippy::type_complexity)]
 64
 65#[macro_use]
 66mod action;
 67mod app;
 68
 69mod arena;
 70mod assets;
 71mod color;
 72mod element;
 73mod elements;
 74mod executor;
 75mod geometry;
 76mod image_cache;
 77mod input;
 78mod interactive;
 79mod key_dispatch;
 80mod keymap;
 81mod platform;
 82pub mod prelude;
 83mod scene;
 84mod shared_string;
 85mod shared_uri;
 86mod style;
 87mod styled;
 88mod subscription;
 89mod svg_renderer;
 90mod taffy;
 91#[cfg(any(test, feature = "test-support"))]
 92pub mod test;
 93mod text_system;
 94mod util;
 95mod view;
 96mod window;
 97
 98/// Do not touch, here be dragons for use by gpui_macros and such.
 99#[doc(hidden)]
100pub mod private {
101    pub use linkme;
102    pub use serde;
103    pub use serde_derive;
104    pub use serde_json;
105}
106
107mod seal {
108    /// A mechanism for restricting implementations of a trait to only those in GPUI.
109    /// See: https://predr.ag/blog/definitive-guide-to-sealed-traits-in-rust/
110    pub trait Sealed {}
111}
112
113pub use action::*;
114pub use anyhow::Result;
115pub use app::*;
116pub(crate) use arena::*;
117pub use assets::*;
118pub use color::*;
119pub use ctor::ctor;
120pub use element::*;
121pub use elements::*;
122pub use executor::*;
123pub use geometry::*;
124pub use gpui_macros::{register_action, test, IntoElement, Render};
125use image_cache::*;
126pub use input::*;
127pub use interactive::*;
128use key_dispatch::*;
129pub use keymap::*;
130pub use platform::*;
131pub use refineable::*;
132pub use scene::*;
133use seal::Sealed;
134pub use shared_string::*;
135pub use shared_uri::*;
136pub use smol::Timer;
137pub use style::*;
138pub use styled::*;
139pub use subscription::*;
140use svg_renderer::*;
141pub use taffy::{AvailableSpace, LayoutId};
142#[cfg(any(test, feature = "test-support"))]
143pub use test::*;
144pub use text_system::*;
145pub use util::arc_cow::ArcCow;
146pub use view::*;
147pub use window::*;
148
149use std::{any::Any, borrow::BorrowMut};
150use taffy::TaffyLayoutEngine;
151
152/// The context trait, allows the different contexts in GPUI to be used
153/// interchangeably for certain operations.
154pub trait Context {
155    /// The result type for this context, used for async contexts that
156    /// can't hold a direct reference to the application context.
157    type Result<T>;
158
159    /// Create a new model in the app context.
160    fn new_model<T: 'static>(
161        &mut self,
162        build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
163    ) -> Self::Result<Model<T>>;
164
165    /// Update a model in the app context.
166    fn update_model<T, R>(
167        &mut self,
168        handle: &Model<T>,
169        update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
170    ) -> Self::Result<R>
171    where
172        T: 'static;
173
174    /// Read a model from the app context.
175    fn read_model<T, R>(
176        &self,
177        handle: &Model<T>,
178        read: impl FnOnce(&T, &AppContext) -> R,
179    ) -> Self::Result<R>
180    where
181        T: 'static;
182
183    /// Update a window for the given handle.
184    fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
185    where
186        F: FnOnce(AnyView, &mut WindowContext<'_>) -> T;
187
188    /// Read a window off of the application context.
189    fn read_window<T, R>(
190        &self,
191        window: &WindowHandle<T>,
192        read: impl FnOnce(View<T>, &AppContext) -> R,
193    ) -> Result<R>
194    where
195        T: 'static;
196}
197
198/// This trait is used for the different visual contexts in GPUI that
199/// require a window to be present.
200pub trait VisualContext: Context {
201    /// Construct a new view in the window referenced by this context.
202    fn new_view<V>(
203        &mut self,
204        build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
205    ) -> Self::Result<View<V>>
206    where
207        V: 'static + Render;
208
209    /// Update a view with the given callback
210    fn update_view<V: 'static, R>(
211        &mut self,
212        view: &View<V>,
213        update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
214    ) -> Self::Result<R>;
215
216    /// Replace the root view of a window with a new view.
217    fn replace_root_view<V>(
218        &mut self,
219        build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
220    ) -> Self::Result<View<V>>
221    where
222        V: 'static + Render;
223
224    /// Focus a view in the window, if it implements the [`FocusableView`] trait.
225    fn focus_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
226    where
227        V: FocusableView;
228
229    /// Dismiss a view in the window, if it implements the [`ManagedView`] trait.
230    fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
231    where
232        V: ManagedView;
233}
234
235/// A trait that allows models and views to be interchangeable in certain operations
236pub trait Entity<T>: Sealed {
237    /// The weak reference type for this entity.
238    type Weak: 'static;
239
240    /// The ID for this entity
241    fn entity_id(&self) -> EntityId;
242
243    /// Downgrade this entity to a weak reference.
244    fn downgrade(&self) -> Self::Weak;
245
246    /// Upgrade this entity from a weak reference.
247    fn upgrade_from(weak: &Self::Weak) -> Option<Self>
248    where
249        Self: Sized;
250}
251
252/// A trait for tying together the types of a GPUI entity and the events it can
253/// emit.
254pub trait EventEmitter<E: Any>: 'static {}
255
256/// A helper trait for auto-implementing certain methods on contexts that
257/// can be used interchangeably.
258pub trait BorrowAppContext {
259    /// Set a global value on the context.
260    fn set_global<T: Global>(&mut self, global: T);
261}
262
263impl<C> BorrowAppContext for C
264where
265    C: BorrowMut<AppContext>,
266{
267    fn set_global<G: Global>(&mut self, global: G) {
268        self.borrow_mut().set_global(global)
269    }
270}
271
272/// A flatten equivalent for anyhow `Result`s.
273pub trait Flatten<T> {
274    /// Convert this type into a simple `Result<T>`.
275    fn flatten(self) -> Result<T>;
276}
277
278impl<T> Flatten<T> for Result<Result<T>> {
279    fn flatten(self) -> Result<T> {
280        self?
281    }
282}
283
284impl<T> Flatten<T> for Result<T> {
285    fn flatten(self) -> Result<T> {
286        self
287    }
288}
289
290/// A marker trait for types that can be stored in GPUI's global state.
291///
292/// Implement this on types you want to store in the context as a global.
293pub trait Global: 'static {}