zed/crates/gpui
张小白 fdddbfc179
Fix caret movement issue for some special characters (#10198)
Currently in Zed, certain characters require pressing the key twice to
move the caret through that character. For example: "❤️" and "y̆".

The reason for this is as follows:

Currently, Zed uses `chars` to distinguish different characters, and
calling `chars` on `y̆` will yield two `char` values: `y` and `\u{306}`,
and calling `chars` on `❤️` will yield two `char` values: `❤` and
`\u{fe0f}`.

Therefore, consider the following scenario (where ^ represents the
caret):

- what we see: ❤️ ^
- the actual buffer: ❤ \u{fe0f} ^

After pressing the left arrow key once:

- what we see: ❤️ ^
- the actual buffer: ❤ ^ \u{fe0f}

After pressing the left arrow key again:
- what we see: ^ ❤️
- the actual buffer: ^ ❤ \u{fe0f}

Thus, two left arrow key presses are needed to move the caret, and this
PR fixes this bug (or this is actually a feature?).

I have tried to keep the scope of code modifications as minimal as
possible. In this PR, Zed handles such characters as follows:

- what we see: ❤️ ^
- the actual buffer: ❤ \u{fe0f} ^

After pressing the left arrow key once:

- what we see: ^ ❤️
- the actual buffer: ^ ❤ \u{fe0f}

Or after pressing the delete key:

- what we see: ^
- the actual buffer: ^

Please note that currently, different platforms and software handle
these special characters differently, and even the same software may
handle these characters differently in different situations. For
example, in my testing on Chrome on macOS, GitHub treats `y̆` as a
single character, just like in this PR; however, in Rust Playground,
`y̆` is treated as two characters, and pressing the delete key does not
delete the entire `y̆` character, but instead deletes `\u{306}` to yield
the character `y`. And they both treat `❤️` as a single character,
pressing the delete key will delete the entire `❤️` character.

This PR is based on the principle of making changes with the smallest
impact on the code, and I think that deleting the entire character with
the delete key is more intuitive.

Release Notes:

- Fix caret movement issue for some special characters

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
Co-authored-by: Thorsten <thorsten@zed.dev>
Co-authored-by: Bennet <bennetbo@gmx.de>
2024-04-10 13:01:25 -06:00
..
docs Fix broken character (#9992) 2024-03-30 14:39:45 -04:00
examples gpui: Add support for window transparency & blur on macOS (#9610) 2024-03-29 11:10:47 -04:00
src Improve the ergonomics of creating local buffers (#10347) 2024-04-10 08:32:51 -06:00
tests Remove some todo!'s 2024-01-09 11:36:36 +02:00
build.rs gpui: Update dependencies (second attempt) (#9836) 2024-03-28 10:22:31 -07:00
Cargo.toml Fix caret movement issue for some special characters (#10198) 2024-04-10 13:01:25 -06:00
LICENSE-APACHE chore: Add crate licenses. (#4158) 2024-01-23 16:56:22 +01:00
README.md Fix some comments (#8760) 2024-03-03 07:55:42 -05:00

Welcome to GPUI!

GPUI is a hybrid immediate and retained mode, GPU accelerated, UI framework for Rust, designed to support a wide variety of applications.

Getting Started

GPUI is still in active development as we work on the Zed code editor and isn't yet on crates.io. You'll also need to use the latest version of stable rust and be on macOS. Add the following to your Cargo.toml:

gpui = { git = "https://github.com/zed-industries/zed" }

Everything in GPUI starts with an App. You can create one with App::new(), and kick off your application by passing a callback to App::run(). Inside this callback, you can create a new window with AppContext::open_window(), and register your first root view. See gpui.rs for a complete example.

The Big Picture

GPUI offers three different registers depending on your needs:

  • State management and communication with Models. Whenever you need to store application state that communicates between different parts of your application, you'll want to use GPUI's models. Models are owned by GPUI and are only accessible through an owned smart pointer similar to an Rc. See the app::model_context module for more information.

  • High level, declarative UI with Views. All UI in GPUI starts with a View. A view is simply a model that can be rendered, via the Render trait. At the start of each frame, GPUI will call this render method on the root view of a given window. Views build a tree of elements, lay them out and style them with a tailwind-style API, and then give them to GPUI to turn into pixels. See the div element for an all purpose swiss-army knife of rendering.

  • Low level, imperative UI with Elements. Elements are the building blocks of UI in GPUI, and they provide a nice wrapper around an imperative API that provides as much flexibility and control as you need. Elements have total control over how they and their child elements are rendered and can be used for making efficient views into large lists, implement custom layouting for a code editor, and anything else you can think of. See the element module for more information.

Each of these registers has one or more corresponding contexts that can be accessed from all GPUI services. This context is your main interface to GPUI, and is used extensively throughout the framework.

Other Resources

In addition to the systems above, GPUI provides a range of smaller services that are useful for building complex applications:

  • Actions are user-defined structs that are used for converting keystrokes into logical operations in your UI. Use this for implementing keyboard shortcuts, such as cmd-q. See the action module for more information.

  • Platform services, such as quit the app or open a URL are available as methods on the app::AppContext.

  • An async executor that is integrated with the platform's event loop. See the executor module for more information.,

  • The [gpui::test] macro provides a convenient way to write tests for your GPUI applications. Tests also have their own kind of context, a TestAppContext which provides ways of simulating common platform input. See app::test_context and test modules for more details.

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 a question in the Zed Discord. We're working on improving the documentation, creating more examples, and will be publishing more guides to GPUI on our blog.