Struct masonry::BoxConstraints

pub struct BoxConstraints { /* private fields */ }

Constraints for layout.

The layout strategy for Masonry is strongly inspired by Flutter, and this struct is similar to the Flutter BoxConstraints class.

At the moment, it represents simply a minimum and maximum size. A widget’s layout method should choose an appropriate size that meets these constraints.

Further, a container widget should compute appropriate constraints for each of its child widgets, and pass those down when recursing.

The constraints are always rounded away from zero to integers to enable pixel perfect layout.

Implementations

impl BoxConstraints

pub const UNBOUNDED: BoxConstraints = _

An unbounded box constraints object.

Can be satisfied by any nonnegative size.

pub fn new(min: Size, max: Size) -> BoxConstraints

Create a new box constraints object.

Create constraints based on minimum and maximum size.

The given sizes are also rounded away from zero, so that the layout is aligned to integers.

pub fn tight(size: Size) -> BoxConstraints

Create a “tight” box constraints object.

A “tight” constraint can only be satisfied by a single size.

The given size is also rounded away from zero, so that the layout is aligned to integers.

pub fn loosen(&self) -> BoxConstraints

Create a “loose” version of the constraints.

Make a version with zero minimum size, but the same maximum size.

pub fn constrain(&self, size: impl Into<Size>) -> Size

Clamp a given size so that it fits within the constraints.

The given size is also rounded away from zero, so that the layout is aligned to integers.

pub fn max(&self) -> Size

Returns the max size of these constraints.

pub fn min(&self) -> Size

Returns the min size of these constraints.

pub fn is_width_bounded(&self) -> bool

Whether there is an upper bound on the width.

pub fn is_height_bounded(&self) -> bool

Whether there is an upper bound on the height.

pub fn debug_check(&self, name: &str)

Check to see if these constraints are legit.

In Debug mode, logs a warning if BoxConstraints are invalid.

pub fn shrink(&self, diff: impl Into<Size>) -> BoxConstraints

Shrink min and max constraints by size

The given size is also rounded away from zero, so that the layout is aligned to integers.

pub fn contains(&self, size: impl Into<Size>) -> bool

Test whether these constraints contain the given Size.

pub fn constrain_aspect_ratio(&self, aspect_ratio: f64, width: f64) -> Size

Find the Size within these BoxConstraints that minimises the difference between the returned Size’s aspect ratio and aspect_ratio, where aspect ratio is defined as height / width.

If multiple Sizes give the optimal aspect_ratio, then the one with the width nearest the supplied width will be used. Specifically, if width == 0.0 then the smallest possible Size will be chosen, and likewise if width == f64::INFINITY, then the largest Size will be chosen.

Use this function when maintaining an aspect ratio is more important than minimizing the distance between input and output size width and height.

Trait Implementations

impl Clone for BoxConstraints

fn clone(&self) -> BoxConstraints

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for BoxConstraints

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

Formats the value using the given formatter.

impl Copy for BoxConstraints