Struct gdk4::Paintable [−][src]
pub struct Paintable(_);Expand description
Paintable is a simple interface used by GTK to represent content that
can be painted.
The content of a Paintable can be painted anywhere at any size
without requiring any sort of layout. The interface is inspired by
similar concepts elsewhere, such as
ClutterContent,
HTML/CSS Paint Sources,
or SVG Paint Servers.
A Paintable can be snapshot at any time and size using
PaintableExt::snapshot(). How the paintable interprets that size and
if it scales or centers itself into the given rectangle is implementation
defined, though if you are implementing a Paintable and don’t know what
to do, it is suggested that you scale your paintable ignoring any potential
aspect ratio.
The contents that a Paintable produces may depend on the Snapshot
passed to it. For example, paintables may decide to use more detailed images
on higher resolution screens or when OpenGL is available. A Paintable
will however always produce the same output for the same snapshot.
A Paintable may change its contents, meaning that it will now produce
a different output with the same snapshot. Once that happens, it will call
PaintableExt::invalidate_contents() which will emit the
signal::GdkPaintable::invalidate-contents signal. If a paintable is known
to never change its contents, it will set the PaintableFlags::CONTENTS
flag. If a consumer cannot deal with changing contents, it may call
PaintableExt::current_image() which will return a static
paintable and use that.
A paintable can report an intrinsic (or preferred) size or aspect ratio it
wishes to be rendered at, though it doesn’t have to. Consumers of the interface
can use this information to layout thepaintable appropriately. Just like the
contents, the size of a paintable can change. A paintable will indicate this
by calling PaintableExt::invalidate_size() which will emit the
signal::GdkPaintable::invalidate-size signal. And just like for contents,
if a paintable is known to never change its size, it will set the
PaintableFlags::SIZE flag.
Besides API for applications, there are some functions that are only
useful for implementing subclasses and should not be used by applications:
PaintableExt::invalidate_contents(),
PaintableExt::invalidate_size(),
new_empty().
Implements
Implementations
Returns a paintable that has the given intrinsic size and draws nothing.
This is often useful for implementing the
vfunc::Gdk::Paintable::get_current_image virtual function
when the paintable is in an incomplete state (like a
Gtk::MediaStream before receiving the first frame).
intrinsic_width
The intrinsic width to report. Can be 0 for no width.
intrinsic_height
The intrinsic height to report. Can be 0 for no height.
Returns
Trait Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Returns the type identifier of Self.
Auto Trait Implementations
impl RefUnwindSafe for Paintable
impl UnwindSafe for Paintable
Blanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T. Read more
Upcasts an object to a reference of its superclass or interface T. Read more
Tries to downcast to a subclass or interface implementor T. Read more
Tries to downcast to a reference of its subclass or interface implementor T. Read more
Tries to cast to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast and upcast will do many checks at compile-time already. Read more
Casts to T unconditionally. Read more
Casts to &T unconditionally. Read more
Returns true if the object is an instance of (can be cast to) T.
pub fn set_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
N: Into<&'a str>,
V: ToValue,
pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>,
pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>
pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>,
pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>,
Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value> + Send + Sync,
Same as connect but takes a SignalId instead of a signal name.
pub fn connect_local<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: 'static + Fn(&[Value]) -> Option<Value>,
Same as connect_local but takes a SignalId instead of a signal name.
pub unsafe fn connect_unsafe<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
N: Into<&'a str>,
F: Fn(&[Value]) -> Option<Value>,
Same as connect_unsafe but takes a SignalId instead of a signal name.
Emit signal by signal id.
Same as emit but takes Value for the arguments.
Emit signal by its name.
Same as emit_by_name but takes Value for the arguments.
Emit signal with details by signal id.
Same as emit_with_details but takes Value for the arguments.
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync,
pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec),
pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec),
pub fn bind_property<'a, O, N, M>(
&'a self,
source_property: N,
target: &'a O,
target_property: M
) -> BindingBuilder<'a> where
O: ObjectType,
N: Into<&'a str>,
M: Into<&'a str>,
Returns a SendValue clone of self.