Struct gdk4::DisplayManager

#[repr(transparent)]
pub struct DisplayManager { /* private fields */ }

A singleton object that offers notification when displays appear or disappear.

You can use get() to obtain the DisplayManager singleton, but that should be rarely necessary. Typically, initializing GTK opens a display that you can work with without ever accessing the DisplayManager.

The GDK library can be built with support for multiple backends. The DisplayManager object determines which backend is used at runtime.

In the rare case that you need to influence which of the backends is being used, you can use set_allowed_backends(). Note that you need to call this function before initializing GTK.

Backend-specific code

When writing backend-specific code that is supposed to work with multiple GDK backends, you have to consider both compile time and runtime. At compile time, use the GDK_WINDOWING_X11, GDK_WINDOWING_WIN32 macros, etc. to find out which backends are present in the GDK library you are building your application against. At runtime, use type-check macros like GDK_IS_X11_DISPLAY() to find out which backend is in use:

⚠️ The following code is in c ⚠️

#ifdef GDK_WINDOWING_X11
  if (GDK_IS_X11_DISPLAY (display))
    {
      // make X11-specific calls here
    }
  else
#endif
#ifdef GDK_WINDOWING_MACOS
  if (GDK_IS_MACOS_DISPLAY (display))
    {
      // make Quartz-specific calls here
    }
  else
#endif
  g_error ("Unsupported GDK backend");

Properties

default-display

The default display.

Readable | Writeable

Signals

display-opened

Emitted when a display is opened.

Implementations

impl DisplayManager

pub fn default_display(&self) -> Option<Display>

Gets the default Display.

Returns

a Display

pub fn list_displays(&self) -> Vec<Display>

List all currently open displays.

Returns

a newly allocated GSList of Display objects

pub fn open_display(&self, name: &str) -> Option<Display>

Opens a display.

name

the name of the display to open

Returns

a Display, or None if the display could not be opened

pub fn set_default_display(&self, display: &impl IsA<Display>)

Sets @display as the default display.

display

a Display

pub fn get() -> DisplayManager

Gets the singleton DisplayManager object.

When called for the first time, this function consults the GDK_BACKEND environment variable to find out which of the supported GDK backends to use (in case GDK has been compiled with multiple backends).

Applications can use set_allowed_backends() to limit what backends will be used.

Returns

The global DisplayManager singleton

pub fn connect_display_opened<F: Fn(&Self, &Display) + 'static>( &self, f: F ) -> SignalHandlerId

Emitted when a display is opened.

display

the opened display

pub fn connect_default_display_notify<F: Fn(&Self) + 'static>( &self, f: F ) -> SignalHandlerId

Trait Implementations

impl Clone for DisplayManager

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DisplayManager

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

Formats the value using the given formatter.

impl Display for DisplayManager

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

Formats the value using the given formatter.

impl HasParamSpec for DisplayManager

type ParamSpec = ParamSpecObject

type SetValue = DisplayManager

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, DisplayManager>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for DisplayManager

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

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 Ord for DisplayManager

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl ParentClassIs for DisplayManager

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for DisplayManager

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl<OT: ObjectType> PartialOrd<OT> for DisplayManager

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

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for DisplayManager

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for DisplayManager