Enum Animate 

pub enum Animate {
    Never,
    Allowed,
}

Whether a thumbnail request will accept an animated result.

MSC2705 gives the animated parameter three states and two behaviors: only animated=true may be answered with animation, while animated=false and an absent parameter alike forbid it.

Variants

Never

The response must be a still picture.

Allowed

The response may animate.

Implementations

impl Animate

pub fn allowed(self) -> bool

Returns true when the request will accept animation.

Only animated=true reaches this state; animated=false and an absent parameter alike forbid animation.

impl Animate

pub fn accepts_type(self, content_type: Option<&str>) -> bool

Returns true when content of this type may answer the request at all.

This reads the declared type, which whoever uploaded the picture chose, so it is only for deciding between stored rows, where the pictures themselves are not in hand. Prefer Self::accepts_picture anywhere the bytes are.

impl Animate

pub fn prefers_type(self, content_type: Option<&str>) -> bool

Returns true when this type is the variant the request asked for.

A source that animates leaves both variants stored at a size, so which one a lookup answers with must be stated rather than left to the order their keys fall in, which a remote row’s own disposition decides. The other variant still answers when it is the only one there, so this orders the rows rather than refusing any of them.

impl Animate

pub fn accepts_picture(self, bytes: &[u8]) -> bool

Returns true when this picture may answer the request.

The bytes decide, so a file cannot pass a request that forbade animation by declaring a content type that does not animate, and an APNG is caught despite being an image/png like every thumbnail.

impl Animate

pub fn accepts_fetched(self, fetched: &Fetched) -> bool

Returns true when a fetched picture may answer, walking it if nobody has.

Filing a row settles this on the way, and a redirect files none, so the walk that was skipped there happens here for the one caller that asks.

impl Animate

pub fn accepts_fallback(self, bytes: &[u8]) -> bool

Returns true when this picture may answer in a thumbnail’s place.

Nothing can be derived from a picture that will not decode, so the choice is between the original and refusing media the server holds. Only a walk that settled on animation withholds it here, where Self::accepts_picture withholds anything it could not settle, since refusing every unreadable still would cost more than it buys.

impl Animate

pub(in media) fn accepts_walk( self, animates: Option<bool>, bytes: &[u8], ) -> bool

Returns true when this picture may answer, walking it if nobody has.

A caller already holding a walk of these bytes states what it settled rather than paying for a second one over them, and where none was taken this is Self::accepts_picture exactly.

impl Animate

pub(in media) fn accepts_fallback_walk( self, names: Option<bool>, bytes: &[u8], ) -> bool

Returns true when this picture may answer in a thumbnail’s place, walking it if nobody has.

The settled-only rule of Self::accepts_fallback holds here too, so what the caller states is whether its walk named an animation rather than whether it withheld one.

impl Animate

fn accepts_animation(self, animates: bool) -> bool

Returns true when a picture may answer, given what a walk settled about it.

The walk that settles this is the same one picking the type a fetched row is filed under, so a caller already holding its answer states it here rather than reading the same bytes again through Self::accepts_picture.

Trait Implementations

impl Clone for Animate

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Animate

impl Debug for Animate

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

Formats the value using the given formatter.

impl Default for Animate

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Animate

impl From<Animate> for Option<bool>

fn from(animate: Animate) -> Self

Converts to this type from the input type.

impl From<Option<bool>> for Animate

fn from(animated: Option<bool>) -> Self

Converts to this type from the input type.

impl PartialEq for Animate

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Animate