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//! ```toml
12//! [dependencies]
13//! gpui = { git = "https://github.com/zed-industries/zed" }
14//! ```
15//!
16//! - [Ownership and data flow](_ownership_and_data_flow)
17//!
18//! Everything in GPUI starts with an [`Application`]. You can create one with [`Application::new`], and
19//! kick off your application by passing a callback to [`Application::run`]. Inside this callback,
20//! you can create a new window with [`App::open_window`], and register your first root
21//! view. See [gpui.rs](https://www.gpui.rs/) for a complete example.
22//!
23//! ## The Big Picture
24//!
25//! GPUI offers three different [registers](https://en.wikipedia.org/wiki/Register_(sociolinguistics)) depending on your needs:
26//!
27//! - State management and communication with [`Entity`]'s. Whenever you need to store application state
28//! that communicates between different parts of your application, you'll want to use GPUI's
29//! entities. Entities are owned by GPUI and are only accessible through an owned smart pointer
30//! similar to an [`std::rc::Rc`]. See [`app::Context`] for more information.
31//!
32//! - High level, declarative UI with views. All UI in GPUI starts with a view. A view is simply
33//! a [`Entity`] that can be rendered, by implementing the [`Render`] trait. At the start of each frame, GPUI
34//! will call this render method on the root view of a given window. Views build a tree of
35//! [`Element`]s, lay them out and style them with a tailwind-style API, and then give them to
36//! GPUI to turn into pixels. See the [`elements::Div`] element for an all purpose swiss-army
37//! knife for UI.
38//!
39//! - Low level, imperative UI with Elements. Elements are the building blocks of UI in GPUI, and they
40//! provide a nice wrapper around an imperative API that provides as much flexibility and control as
41//! you need. Elements have total control over how they and their child elements are rendered and
42//! can be used for making efficient views into large lists, implement custom layouting for a code editor,
43//! and anything else you can think of. See the [`elements`] module for more information.
44//!
45//! Each of these registers has one or more corresponding contexts that can be accessed from all GPUI services.
46//! This context is your main interface to GPUI, and is used extensively throughout the framework.
47//!
48//! ## Other Resources
49//!
50//! In addition to the systems above, GPUI provides a range of smaller services that are useful for building
51//! complex applications:
52//!
53//! - Actions are user-defined structs that are used for converting keystrokes into logical operations in your UI.
54//! Use this for implementing keyboard shortcuts, such as cmd-q (See `action` module for more information).
55//! - Platform services, such as `quit the app` or `open a URL` are available as methods on the [`app::App`].
56//! - An async executor that is integrated with the platform's event loop. See the [`executor`] module for more information.,
57//! - The [`gpui::test`](macro@test) macro provides a convenient way to write tests for your GPUI applications. Tests also have their
58//! own kind of context, a [`TestAppContext`] which provides ways of simulating common platform input. See [`TestAppContext`]
59//! and [`mod@test`] modules for more details.
60//!
61//! 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
62//! a question in the [Zed Discord](https://zed.dev/community-links). We're working on improving the documentation, creating more examples,
63//! and will be publishing more guides to GPUI on our [blog](https://zed.dev/blog).
64
65#![deny(missing_docs)]
66#![allow(clippy::type_complexity)] // Not useful, GPUI makes heavy use of callbacks
67#![allow(clippy::collapsible_else_if)] // False positives in platform specific code
68#![allow(unused_mut)] // False positives in platform specific code
69
70extern crate self as gpui;
71
72#[macro_use]
73mod action;
74mod app;
75
76mod arena;
77mod asset_cache;
78mod assets;
79mod bounds_tree;
80mod color;
81/// The default colors used by GPUI.
82pub mod colors;
83mod element;
84mod elements;
85mod executor;
86mod geometry;
87mod global;
88mod input;
89mod inspector;
90mod interactive;
91mod key_dispatch;
92mod keymap;
93mod path_builder;
94mod platform;
95pub mod prelude;
96mod scene;
97mod shared_string;
98mod shared_uri;
99mod style;
100mod styled;
101mod subscription;
102mod svg_renderer;
103mod tab_stop;
104mod taffy;
105#[cfg(any(test, feature = "test-support"))]
106pub mod test;
107mod text_system;
108mod util;
109mod view;
110mod window;
111
112#[cfg(doc)]
113pub mod _ownership_and_data_flow;
114
115/// Do not touch, here be dragons for use by gpui_macros and such.
116#[doc(hidden)]
117pub mod private {
118 pub use anyhow;
119 pub use inventory;
120 pub use schemars;
121 pub use serde;
122 pub use serde_json;
123}
124
125mod seal {
126 /// A mechanism for restricting implementations of a trait to only those in GPUI.
127 /// See: <https://predr.ag/blog/definitive-guide-to-sealed-traits-in-rust/>
128 pub trait Sealed {}
129}
130
131pub use action::*;
132pub use anyhow::Result;
133pub use app::*;
134pub(crate) use arena::*;
135pub use asset_cache::*;
136pub use assets::*;
137pub use color::*;
138pub use ctor::ctor;
139pub use element::*;
140pub use elements::*;
141pub use executor::*;
142pub use geometry::*;
143pub use global::*;
144pub use gpui_macros::{AppContext, IntoElement, Render, VisualContext, register_action, test};
145pub use http_client;
146pub use input::*;
147pub use inspector::*;
148pub use interactive::*;
149use key_dispatch::*;
150pub use keymap::*;
151pub use path_builder::*;
152pub use platform::*;
153pub use refineable::*;
154pub use scene::*;
155pub use shared_string::*;
156pub use shared_uri::*;
157pub use smol::Timer;
158pub use style::*;
159pub use styled::*;
160pub use subscription::*;
161use svg_renderer::*;
162pub(crate) use tab_stop::*;
163pub use taffy::{AvailableSpace, LayoutId};
164#[cfg(any(test, feature = "test-support"))]
165pub use test::*;
166pub use text_system::*;
167#[cfg(any(test, feature = "test-support"))]
168pub use util::smol_timeout;
169pub use util::{FutureExt, Timeout, arc_cow::ArcCow};
170pub use view::*;
171pub use window::*;
172
173use std::{any::Any, borrow::BorrowMut, future::Future};
174use taffy::TaffyLayoutEngine;
175
176/// The context trait, allows the different contexts in GPUI to be used
177/// interchangeably for certain operations.
178pub trait AppContext {
179 /// The result type for this context, used for async contexts that
180 /// can't hold a direct reference to the application context.
181 type Result<T>;
182
183 /// Create a new entity in the app context.
184 #[expect(
185 clippy::wrong_self_convention,
186 reason = "`App::new` is an ubiquitous function for creating entities"
187 )]
188 fn new<T: 'static>(
189 &mut self,
190 build_entity: impl FnOnce(&mut Context<T>) -> T,
191 ) -> Self::Result<Entity<T>>;
192
193 /// Reserve a slot for a entity to be inserted later.
194 /// The returned [Reservation] allows you to obtain the [EntityId] for the future entity.
195 fn reserve_entity<T: 'static>(&mut self) -> Self::Result<Reservation<T>>;
196
197 /// Insert a new entity in the app context based on a [Reservation] previously obtained from [`reserve_entity`].
198 ///
199 /// [`reserve_entity`]: Self::reserve_entity
200 fn insert_entity<T: 'static>(
201 &mut self,
202 reservation: Reservation<T>,
203 build_entity: impl FnOnce(&mut Context<T>) -> T,
204 ) -> Self::Result<Entity<T>>;
205
206 /// Update a entity in the app context.
207 fn update_entity<T, R>(
208 &mut self,
209 handle: &Entity<T>,
210 update: impl FnOnce(&mut T, &mut Context<T>) -> R,
211 ) -> Self::Result<R>
212 where
213 T: 'static;
214
215 /// Update a entity in the app context.
216 fn as_mut<'a, T>(&'a mut self, handle: &Entity<T>) -> Self::Result<GpuiBorrow<'a, T>>
217 where
218 T: 'static;
219
220 /// Read a entity from the app context.
221 fn read_entity<T, R>(
222 &self,
223 handle: &Entity<T>,
224 read: impl FnOnce(&T, &App) -> R,
225 ) -> Self::Result<R>
226 where
227 T: 'static;
228
229 /// Update a window for the given handle.
230 fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
231 where
232 F: FnOnce(AnyView, &mut Window, &mut App) -> T;
233
234 /// Read a window off of the application context.
235 fn read_window<T, R>(
236 &self,
237 window: &WindowHandle<T>,
238 read: impl FnOnce(Entity<T>, &App) -> R,
239 ) -> Result<R>
240 where
241 T: 'static;
242
243 /// Spawn a future on a background thread
244 fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
245 where
246 R: Send + 'static;
247
248 /// Read a global from this app context
249 fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> Self::Result<R>
250 where
251 G: Global;
252}
253
254/// Returned by [Context::reserve_entity] to later be passed to [Context::insert_entity].
255/// Allows you to obtain the [EntityId] for a entity before it is created.
256pub struct Reservation<T>(pub(crate) Slot<T>);
257
258impl<T: 'static> Reservation<T> {
259 /// Returns the [EntityId] that will be associated with the entity once it is inserted.
260 pub fn entity_id(&self) -> EntityId {
261 self.0.entity_id()
262 }
263}
264
265/// This trait is used for the different visual contexts in GPUI that
266/// require a window to be present.
267pub trait VisualContext: AppContext {
268 /// Returns the handle of the window associated with this context.
269 fn window_handle(&self) -> AnyWindowHandle;
270
271 /// Update a view with the given callback
272 fn update_window_entity<T: 'static, R>(
273 &mut self,
274 entity: &Entity<T>,
275 update: impl FnOnce(&mut T, &mut Window, &mut Context<T>) -> R,
276 ) -> Self::Result<R>;
277
278 /// Create a new entity, with access to `Window`.
279 fn new_window_entity<T: 'static>(
280 &mut self,
281 build_entity: impl FnOnce(&mut Window, &mut Context<T>) -> T,
282 ) -> Self::Result<Entity<T>>;
283
284 /// Replace the root view of a window with a new view.
285 fn replace_root_view<V>(
286 &mut self,
287 build_view: impl FnOnce(&mut Window, &mut Context<V>) -> V,
288 ) -> Self::Result<Entity<V>>
289 where
290 V: 'static + Render;
291
292 /// Focus a entity in the window, if it implements the [`Focusable`] trait.
293 fn focus<V>(&mut self, entity: &Entity<V>) -> Self::Result<()>
294 where
295 V: Focusable;
296}
297
298/// A trait for tying together the types of a GPUI entity and the events it can
299/// emit.
300pub trait EventEmitter<E: Any>: 'static {}
301
302/// A helper trait for auto-implementing certain methods on contexts that
303/// can be used interchangeably.
304pub trait BorrowAppContext {
305 /// Set a global value on the context.
306 fn set_global<T: Global>(&mut self, global: T);
307 /// Updates the global state of the given type.
308 fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
309 where
310 G: Global;
311 /// Updates the global state of the given type, creating a default if it didn't exist before.
312 fn update_default_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
313 where
314 G: Global + Default;
315}
316
317impl<C> BorrowAppContext for C
318where
319 C: BorrowMut<App>,
320{
321 fn set_global<G: Global>(&mut self, global: G) {
322 self.borrow_mut().set_global(global)
323 }
324
325 #[track_caller]
326 fn update_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
327 where
328 G: Global,
329 {
330 let mut global = self.borrow_mut().lease_global::<G>();
331 let result = f(&mut global, self);
332 self.borrow_mut().end_global_lease(global);
333 result
334 }
335
336 fn update_default_global<G, R>(&mut self, f: impl FnOnce(&mut G, &mut Self) -> R) -> R
337 where
338 G: Global + Default,
339 {
340 self.borrow_mut().default_global::<G>();
341 self.update_global(f)
342 }
343}
344
345/// A flatten equivalent for anyhow `Result`s.
346pub trait Flatten<T> {
347 /// Convert this type into a simple `Result<T>`.
348 fn flatten(self) -> Result<T>;
349}
350
351impl<T> Flatten<T> for Result<Result<T>> {
352 fn flatten(self) -> Result<T> {
353 self?
354 }
355}
356
357impl<T> Flatten<T> for Result<T> {
358 fn flatten(self) -> Result<T> {
359 self
360 }
361}
362
363/// Information about the GPU GPUI is running on.
364#[derive(Default, Debug, serde::Serialize, serde::Deserialize, Clone)]
365pub struct GpuSpecs {
366 /// Whether the GPU is really a fake (like `llvmpipe`) running on the CPU.
367 pub is_software_emulated: bool,
368 /// The name of the device, as reported by Vulkan.
369 pub device_name: String,
370 /// The name of the driver, as reported by Vulkan.
371 pub driver_name: String,
372 /// Further information about the driver, as reported by Vulkan.
373 pub driver_info: String,
374}