Enum ContentFit

pub enum ContentFit {
    Contain,
    Cover,
    Fill,
    None,
    ScaleDown,
}

The strategy used to fit the contents of a widget to its bounding box.

Each variant of this enum is a strategy that can be applied for resolving differences in aspect ratio and size between the image being displayed and the space its being displayed in.

For an interactive demonstration of these properties as they are implemented in CSS, see Mozilla’s docs, or run the tour example

Variants

Contain

Scale as big as it can be without needing to crop or hide parts.

The image will be scaled (preserving aspect ratio) so that it just fits within the window. This won’t distort the image or crop/hide any edges, but if the image doesn’t fit perfectly, there may be whitespace on the top/bottom or left/right.

This is a great fit for when you need to display an image without losing any part of it, particularly when the image itself is the focus of the screen.

Cover

Scale the image to cover all of the bounding box, cropping if needed.

This doesn’t distort the image, and it ensures that the widget’s area is completely covered, but it might crop off a bit of the edges of the widget, particularly when there is a big difference between the aspect ratio of the widget and the aspect ratio of the image.

This is best for when you’re using an image as a background, or to fill space, and any details of the image around the edge aren’t too important.

Fill

Distort the image so the widget is 100% covered without cropping.

This stretches the image to fit the widget, without any whitespace or cropping. However, because of the stretch, the image may look distorted or elongated, particularly when there’s a mismatch of aspect ratios.

None

Don’t resize or scale the image at all.

This will not apply any transformations to the provided image, but also means that unless you do the math yourself, the widget’s area will not be completely covered, or the image might be cropped.

This is best for when you’ve sized the image yourself.

ScaleDown

Scale the image down if it’s too big for the space, but never scale it up.

This works much like Contain, except that if the image would have been scaled up, it keeps its original resolution to avoid the bluring that accompanies upscaling images.

Implementations

impl ContentFit

pub fn fit(&self, content: Size, bounds: Size) -> Size

Attempt to apply the given fit for a content size within some bounds.

The returned value is the recommended scaled size of the content.

Trait Implementations

impl Clone for ContentFit

fn clone(&self) -> ContentFit

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ContentFit

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

Formats the value using the given formatter.

impl Default for ContentFit

fn default() -> ContentFit

Returns the “default value” for a type.

impl Display for ContentFit

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

Formats the value using the given formatter.

impl Hash for ContentFit

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ContentFit

fn eq(&self, other: &ContentFit) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ContentFit

impl Eq for ContentFit

impl StructuralPartialEq for ContentFit