Struct Breakpoints 

pub struct Breakpoints { /* private fields */ }

Fail the build if a hand-written breakpoint has drifted from SizeClass.

Every pixel width named by a media or container query must be a SizeClass boundary or one of the tuning widths. A container query is checked the same way: @container screen (width < 600px) states a width, and a container whose inline size tracks the shell is a breakpoint in disguise, so it must move with SizeClass or be declared a tuning width like any other.

makeover_webview::build::drift::Breakpoints::in_frontend("frontend")
    .tuning(&[1400])
    .run();

Without this, moving SizeClass::Medium::min_px regenerates the emitted stylesheets and leaves every hand-written query behind, and the result is a stylesheet that disagrees with itself at the old boundary rather than an error.

The generated stylesheets are scanned too, and pass by construction: they ask makeover-geometry for the number rather than stating it. Scanning them means a consumer never has to name which files are hand-written.

Implementations

impl Breakpoints

pub fn in_frontend(frontend: impl AsRef<Path>) -> Self

Every .css under frontend/css and every .js under frontend/js, recursively.

pub fn files<P: AsRef<Path>>(paths: &[P]) -> Self

A named list of files rather than a tree.

For a frontend whose generated and hand-written files share a directory, with nothing to point a directory scan at: the MNW server keeps both under static/ beside a bundler’s output. The list is hand-maintained, and a stylesheet nobody adds to it is unchecked rather than failing, so prefer in_frontend where the layout allows it.

A .js path is read as script and anything else as stylesheet.

pub fn tuning(self, widths: &[u16]) -> Self

Widths inside a shell where something reflows without the shell changing: a dashboard dropping from three columns to two, a pane’s width cap ending.

The one thing an app gets a say in. A shell boundary is a SizeClass edge and belongs to makeover-geometry; nothing switches shells at a tuning width, so it does not move when a size class does. Each entry owes a note beside it saying what it tunes: this list is where a genuine boundary goes to hide from the check.

pub fn run(&self)

Run the check. Emits cargo::rerun-if-changed for every file it read, and for the scanned directories.

Panics

If a listed file cannot be read (a listed path that no longer exists is a check covering less than it says), or if any width is neither a size-class boundary nor a tuning width. A build script has nowhere useful to return an error to.

Trait Implementations

impl Clone for Breakpoints

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Breakpoints

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.