zed/crates/ui_macros/src/ui_macros.rs
Nate Butler 94d8ead270
Refactor Spacing into DynamicSpacing using proc macro (#20504)
Density tracking issue: #18078 

This PR refactors our spacing system to use a more flexible and
maintainable approach. We've replaced the static `Spacing` enum with a
dynamically generated `DynamicSpacing` enum using a proc macro.

Enum variants now use a `BaseXX` format, where XX = the pixel value @
default rem size and the default UI density.

For example:

`CustomSpacing::Base16` would return 16px at the default UI scale &
density.

I'd love to find another name other than `Base` that is clear (to avoid
base_10, etc confusion), let me know if you have any ideas!

Changes:

- Introduced a new `derive_dynamic_spacing` proc macro to generate the
`DynamicSpacing` enum
- Updated all usages of `Spacing` to use the new `DynamicSpacing`
- Removed the `custom_spacing` function, mapping previous usages to
appropriate `DynamicSpacing` variants
- Improved documentation and type safety for spacing values

New usage example:

```rust
.child(
    div()
        .flex()
        .flex_none()
        .m(DynamicSpacing::Base04.px(cx))
        .size(DynamicSpacing::Base16.rems(cx))
        .children(icon),
)
```

vs old usage example:

```
.child(
    div()
        .flex()
        .flex_none()
        .m(Spacing::Small.px(cx))
        .size(custom_spacing(px(16.)))
        .children(icon),
)
```

Release Notes:

- N/A
2024-11-11 11:08:55 -05:00

60 lines
2 KiB
Rust

mod derive_path_str;
mod dynamic_spacing;
use proc_macro::TokenStream;
/// Derives the `path` method for an enum.
///
/// This macro generates a `path` method for each variant of the enum, which returns a string
/// representation of the enum variant's path. The path is constructed using a prefix and
/// optionally a suffix, which are specified using attributes.
///
/// # Attributes
///
/// - `#[path_str(prefix = "...")]`: Required. Specifies the prefix for all paths.
/// - `#[path_str(suffix = "...")]`: Optional. Specifies a suffix for all paths.
/// - `#[strum(serialize_all = "...")]`: Optional. Specifies the case conversion for variant names.
///
/// # Example
///
/// ```
/// use strum::EnumString;
/// use ui_macros::{path_str, DerivePathStr};
///
/// #[derive(EnumString, DerivePathStr)]
/// #[path_str(prefix = "my_prefix", suffix = ".txt")]
/// #[strum(serialize_all = "snake_case")]
/// enum MyEnum {
/// VariantOne,
/// VariantTwo,
/// }
///
/// // These assertions would work if we could instantiate the enum
/// // assert_eq!(MyEnum::VariantOne.path(), "my_prefix/variant_one.txt");
/// // assert_eq!(MyEnum::VariantTwo.path(), "my_prefix/variant_two.txt");
/// ```
///
/// # Panics
///
/// This macro will panic if used on anything other than an enum.
#[proc_macro_derive(DerivePathStr, attributes(path_str))]
pub fn derive_path_str(input: TokenStream) -> TokenStream {
derive_path_str::derive_path_str(input)
}
/// A marker attribute for use with `DerivePathStr`.
///
/// This attribute is used to specify the prefix and suffix for the `path` method
/// generated by `DerivePathStr`. It doesn't modify the input and is only used as a
/// marker for the derive macro.
#[proc_macro_attribute]
pub fn path_str(_args: TokenStream, input: TokenStream) -> TokenStream {
// This attribute doesn't modify the input, it's just a marker
input
}
/// Generates the DynamicSpacing enum used for density-aware spacing in the UI.
#[proc_macro]
pub fn derive_dynamic_spacing(input: TokenStream) -> TokenStream {
dynamic_spacing::derive_spacing(input)
}