Struct Region

pub(crate) struct Region {
    pub min_rect: Rect,
    pub max_rect: Rect,
    pub(crate) cursor: Rect,
}

This describes the bounds and existing contents of an Ui. It is what is used and updated by Layout when adding new widgets.

Fields

min_rect: Rect

This is the minimal size of the Ui. When adding new widgets, this will generally expand.

Always finite.

The bounding box of all child widgets, but not necessarily a tight bounding box since Ui can start with a non-zero min_rect size.

max_rect: Rect

The maximum size of this Ui. This is a soft max meaning new widgets will try not to expand beyond it, but if they have to, they will.

Text will wrap at max_rect.right(). Some widgets (like separator lines) will try to fill the full max_rect width of the ui.

max_rect will always be at least the size of min_rect.

If the max_rect size is zero, it is a signal that child widgets should be as small as possible. If the max_rect size is infinite, it is a signal that child widgets should take up as much room as they want.

cursor: Rect

Where the next widget will be put.

One side of this will always be infinite: the direction in which new widgets will be added. The opposing side is what is incremented. The crossing sides are initialized to max_rect.

So one can think of cursor as a constraint on the available region.

If something has already been added, this will point to style.spacing.item_spacing beyond the latest child. The cursor can thus be style.spacing.item_spacing pixels outside of the min_rect.

Implementations

impl Region

pub fn expand_to_include_rect(&mut self, rect: Rect)

Expand the min_rect and max_rect of this ui to include a child at the given rect.

pub fn expand_to_include_x(&mut self, x: f32)

Ensure we are big enough to contain the given X-coordinate. This is sometimes useful to expand a ui to stretch to a certain place.

pub fn expand_to_include_y(&mut self, y: f32)

Ensure we are big enough to contain the given Y-coordinate. This is sometimes useful to expand a ui to stretch to a certain place.

pub fn sanity_check(&self)

Trait Implementations

impl Clone for Region

fn clone(&self) -> Region

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Region

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

Formats the value using the given formatter.

impl Copy for Region