Struct zng::style::StyleFn

pub struct StyleFn(/* private fields */);

Boxed shared closure that generates a style instance for a given widget context.

You can also use the style_fn! macro to instantiate.

Implementations

impl StyleFn

pub fn nil() -> StyleFn

Default function, produces an empty style.

pub fn is_nil(&self) -> bool

If this function represents no style.

pub fn new( func: impl Fn(&StyleArgs) -> StyleBuilder + Send + Sync + 'static, ) -> StyleFn

New style function, the func closure is called for each styleable widget, before the widget is inited.

pub fn singleton(style: StyleBuilder) -> StyleFn

New style function that returns clones of style.

Note that if the style contains properties with node values the nodes will be moved to the last usage of the style, as nodes can’t be cloned.

Also note that the style will stay in memory for the lifetime of the StyleFn.

pub fn call(&self, args: &StyleArgs) -> Option<StyleBuilder>

Call the function to create a style for the styleable widget in the context.

Returns None if is_nil or empty, otherwise returns the style.

Note that you can call the style function directly:

fn foo(func: &StyleFn) {
    let a = func.call(&StyleArgs {});
    let b = func(&StyleArgs {});
}

In the example above a and b are both calls to the style function.

pub fn with_extend(self, other: StyleFn) -> StyleFn

New style function that instantiates self and other and then extend self with other.

Trait Implementations

impl Clone for StyleFn

fn clone(&self) -> StyleFn

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for StyleFn

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

Formats the value using the given formatter.

impl Default for StyleFn

fn default() -> StyleFn

Returns the “default value” for a type.

impl Deref for StyleFn

type Target = dyn Fn(&StyleArgs) -> Option<StyleBuilder>

The resulting type after dereferencing.

fn deref(&self) -> &<StyleFn as Deref>::Target

Dereferences the value.

impl From<StyleBuilder> for StyleFn

fn from(style: StyleBuilder) -> StyleFn

Singleton.

impl IntoVar<StyleFn> for StyleBuilder

fn into_var(self) -> <StyleBuilder as IntoVar<StyleFn>>::Var

Singleton.

type Var = LocalVar<StyleFn>

Variable type that will wrap the T value.

fn into_boxed_var(self) -> Box<dyn VarBoxed<T>>

where Self: Sized,

Converts into BoxedVar<T>.

impl PartialEq for StyleFn

fn eq(&self, other: &StyleFn) -> 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 IntoValue<StyleFn> for StyleBuilder