Struct gtk4::DrawingArea[−][src]

pub struct DrawingArea(_);

Expand description

DrawingArea is a widget that allows drawing with cairo.

An example GtkDrawingArea

It’s essentially a blank widget; you can draw on it. After creating a drawing area, the application may want to connect to:

The signal::Widget::realize signal to take any necessary actions when the widget is instantiated on a particular display. (Create GDK resources in response to this signal.)
The signal::DrawingArea::resize signal to take any necessary actions when the widget changes size.
Call DrawingAreaExtManual::set_draw_func() to handle redrawing the contents of the widget.

The following code portion demonstrates using a drawing area to display a circle in the normal widget foreground color.

Simple GtkDrawingArea usage

⚠️ The following code is in c ⚠️

static void
draw_function (GtkDrawingArea *area,
               cairo_t        *cr,
               int             width,
               int             height,
               gpointer        data)
{
  GdkRGBA color;
  GtkStyleContext *context;

  context = gtk_widget_get_style_context (GTK_WIDGET (area));

  cairo_arc (cr,
             width / 2.0, height / 2.0,
             MIN (width, height) / 2.0,
             0, 2 * G_PI);

  gtk_style_context_get_color (context,
                               &color);
  gdk_cairo_set_source_rgba (cr, &color);

  cairo_fill (cr);
}

int
main (int argc, char **argv)
{
  gtk_init ();

  GtkWidget *area = gtk_drawing_area_new ();
  gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (area), 100);
  gtk_drawing_area_set_content_height (GTK_DRAWING_AREA (area), 100);
  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (area),
                                  draw_function,
                                  NULL, NULL);
  return 0;
}

The draw function is normally called when a drawing area first comes onscreen, or when it’s covered by another window and then uncovered. You can also force a redraw by adding to the “damage region” of the drawing area’s window using WidgetExt::queue_draw(). This will cause the drawing area to call the draw function again.

The available routines for drawing are documented on the [GDK Drawing Primitives][gdk4-Cairo-Interaction] page and the cairo documentation.

To receive mouse events on a drawing area, you will need to use event controllers. To receive keyboard events, you will need to set the “can-focus” property on the drawing area, and you should probably draw some user-visible indication that the drawing area is focused.

If you need more complex control over your widget, you should consider creating your own Widget subclass.

Implements

DrawingAreaExt, WidgetExt, glib::ObjectExt, AccessibleExt, BuildableExt, ConstraintTargetExt, DrawingAreaExtManual, WidgetExtManual, AccessibleExtManual

Struct gtk4::DrawingArea[−][src]

Simple GtkDrawingArea usage

Implements

Implementations

impl DrawingArea

pub fn new() -> DrawingArea

Returns

pub fn builder() -> DrawingAreaBuilder

Trait Implementations

impl Clone for DrawingArea

fn clone(&self) -> DrawingArea

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

impl Debug for DrawingArea

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

impl Default for DrawingArea

fn default() -> Self

impl Display for DrawingArea

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

impl Hash for DrawingArea

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

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

impl<T: DrawingAreaImpl> IsSubclassable<T> for DrawingArea

fn class_init(class: &mut Class<Self>)

fn instance_init(instance: &mut InitializingObject<T>)

impl Ord for DrawingArea

fn cmp(&self, other: &DrawingArea) -> Ordering

fn max(self, other: Self) -> Self

fn min(self, other: Self) -> Self

fn clamp(self, min: Self, max: Self) -> Self

impl ParentClassIs for DrawingArea

type Parent = Widget

impl<T: ObjectType> PartialEq<T> for DrawingArea

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

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

impl<T: ObjectType> PartialOrd<T> for DrawingArea

fn partial_cmp(&self, other: &T) -> Option<Ordering>

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

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

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

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

impl StaticType for DrawingArea

fn static_type() -> Type

impl Eq for DrawingArea

impl IsA<Accessible> for DrawingArea

impl IsA<Buildable> for DrawingArea

impl IsA<ConstraintTarget> for DrawingArea

impl IsA<Widget> for DrawingArea

impl StructuralEq for DrawingArea

Auto Trait Implementations

impl RefUnwindSafe for DrawingArea

impl !Send for DrawingArea

impl !Sync for DrawingArea

impl Unpin for DrawingArea

impl UnwindSafe for DrawingArea

Blanket Implementations

impl<T> Any for T where T: 'static + ?Sized,

pub fn type_id(&self) -> TypeId

impl<T> Borrow<T> for T where T: ?Sized,

pub fn borrow(&self) -> &T

impl<T> BorrowMut<T> for T where T: ?Sized,

pub fn borrow_mut(&mut self) -> &mut T

impl<T> Cast for T where T: ObjectType,

fn upcast<T>(self) -> T where T: ObjectType, Self: IsA<T>,

fn upcast_ref<T>(&self) -> &T where T: ObjectType, Self: IsA<T>,

fn downcast<T>(self) -> Result<T, Self> where T: ObjectType, Self: CanDowncast<T>,

fn downcast_ref<T>(&self) -> Option<&T> where T: ObjectType, Self: CanDowncast<T>,

fn dynamic_cast<T>(self) -> Result<T, Self> where T: ObjectType,

fn dynamic_cast_ref<T>(&self) -> Option<&T> where T: ObjectType,

unsafe fn unsafe_cast<T>(self) -> T where T: ObjectType,

unsafe fn unsafe_cast_ref<T>(&self) -> &T where T: ObjectType,

impl<T> From<T> for T

pub fn from(t: T) -> T

impl<T, U> Into<U> for T where U: From<T>,

pub fn into(self) -> U

impl<T> ObjectExt for T where T: ObjectType,

pub fn is<U>(&self) -> bool where U: StaticType,

pub fn type_(&self) -> Type

pub fn object_class(&self) -> &Class<Object>

pub fn class(&self) -> &Class<T> where T: IsClass,

pub fn class_of<U>(&self) -> Option<&Class<U>> where U: IsClass,

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

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

impl<T> Any for T where
T: 'static + ?Sized,

impl<T> Borrow<T> for T where
T: ?Sized,

impl<T> BorrowMut<T> for T where
T: ?Sized,

impl<T> Cast for T where
T: ObjectType,

fn upcast<T>(self) -> T where
T: ObjectType,
Self: IsA<T>,

fn upcast_ref<T>(&self) -> &T where
T: ObjectType,
Self: IsA<T>,

fn downcast<T>(self) -> Result<T, Self> where
T: ObjectType,
Self: CanDowncast<T>,

fn downcast_ref<T>(&self) -> Option<&T> where
T: ObjectType,
Self: CanDowncast<T>,

fn dynamic_cast<T>(self) -> Result<T, Self> where
T: ObjectType,

fn dynamic_cast_ref<T>(&self) -> Option<&T> where
T: ObjectType,

unsafe fn unsafe_cast<T>(self) -> T where
T: ObjectType,

unsafe fn unsafe_cast_ref<T>(&self) -> &T where
T: ObjectType,

impl<T, U> Into<U> for T where
U: From<T>,

impl<T> ObjectExt for T where
T: ObjectType,

pub fn is<U>(&self) -> bool where
U: StaticType,

pub fn class(&self) -> &Class<T> where
T: IsClass,

pub fn class_of<U>(&self) -> Option<&Class<U>> where
U: IsClass,

pub fn interface<U>(&self) -> Option<InterfaceRef<'_, U>> where
U: IsInterface,

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(
&self,
property_values: &[(&str, &dyn ToValue )]
) -> Result<(), BoolError>

pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value )]
) -> Result<(), BoolError>

pub fn property<'a, N>(&self, property_name: N) -> Result<Value, BoolError> where
N: Into<&'a str>,

pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>,

pub fn property_type<'a, N>(&self, property_name: N) -> Option<Type> where
N: Into<&'a str>,

pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>,

pub unsafe fn set_qdata<QD>(&self, key: Quark, value: QD) where
QD: 'static,

pub unsafe fn qdata<QD>(&self, key: Quark) -> Option<NonNull<QD>> where
QD: 'static,

pub unsafe fn steal_qdata<QD>(&self, key: Quark) -> Option<QD> where
QD: 'static,

pub unsafe fn set_data<QD>(&self, key: &str, value: QD) where
QD: 'static,

pub unsafe fn data<QD>(&self, key: &str) -> Option<NonNull<QD>> where
QD: 'static,

pub unsafe fn steal_data<QD>(&self, key: &str) -> Option<QD> where
QD: 'static,

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,

pub fn connect_id<F>(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: 'static + Fn(&[Value ]) -> Option<Value> + Send + Sync,

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>,

pub fn connect_local_id<F>(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: 'static + Fn(&[Value ]) -> Option<Value>,

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>,

pub unsafe fn connect_unsafe_id<F>(
&self,
signal_id: SignalId,
details: Option<Quark>,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value ]) -> Option<Value>,

pub fn emit(
&self,
signal_id: SignalId,
args: &[&dyn ToValue ]
) -> Result<Option<Value>, BoolError>

pub fn emit_with_values(
&self,
signal_id: SignalId,
args: &[Value ]
) -> Result<Option<Value>, BoolError>

pub fn emit_by_name<'a, N>(
&self,
signal_name: N,
args: &[&dyn ToValue ]
) -> Result<Option<Value>, BoolError> where
N: Into<&'a str>,

pub fn emit_by_name_with_values<'a, N>(
&self,
signal_name: N,
args: &[Value ]
) -> Result<Option<Value>, BoolError> where
N: Into<&'a str>,

pub fn emit_with_details(
&self,
signal_id: SignalId,
details: Quark,
args: &[&dyn ToValue ]
) -> Result<Option<Value>, BoolError>

pub fn emit_with_details_and_values(
&self,
signal_id: SignalId,
details: Quark,
args: &[Value ]
) -> Result<Option<Value>, BoolError>

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 notify<'a, N>(&self, property_name: N) where
N: Into<&'a str>,

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>,

impl<T> ToOwned for T where
T: Clone,

impl<T> ToSendValue for T where
T: Send + ToValue + ?Sized,

impl<T> ToString for T where
T: Display + ?Sized,

impl<T, U> TryFrom<U> for T where
U: Into<T>,

impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

impl<Super, Sub> CanDowncast<Sub> for Super where
Super: IsA<Super>,
Sub: IsA<Super>,

impl<'a, T, C> FromValueOptional<'a> for T where
T: FromValue<'a, Checker = C>,
C: ValueTypeChecker<Error = ValueTypeMismatchOrNoneError>,