Struct gtk4::CellRenderer

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

List views use widgets for displaying their contents An object for rendering a single cell

The CellRenderer is a base class of a set of objects used for rendering a cell to a cairo::Context. These objects are used primarily by the TreeView widget, though they aren’t tied to them in any specific way. It is worth noting that CellRenderer is not a Widget and cannot be treated as such.

The primary use of a CellRenderer is for drawing a certain graphical elements on a cairo::Context. Typically, one cell renderer is used to draw many cells on the screen. To this extent, it isn’t expected that a CellRenderer keep any permanent state around. Instead, any state is set just prior to use using GObjects property system. Then, the cell is measured using gtk_cell_renderer_get_preferred_size(). Finally, the cell is rendered in the correct location using gtk_cell_renderer_snapshot().

There are a number of rules that must be followed when writing a new CellRenderer. First and foremost, it’s important that a certain set of properties will always yield a cell renderer of the same size, barring a style change. The CellRenderer also has a number of generic properties that are expected to be honored by all children.

Beyond merely rendering a cell, cell renderers can optionally provide active user interface elements. A cell renderer can be “activatable” like CellRendererToggle, which toggles when it gets activated by a mouse click, or it can be “editable” like CellRendererText, which allows the user to edit the text using a widget implementing the CellEditable interface, e.g. Entry. To make a cell renderer activatable or editable, you have to implement the CellRendererClass.activate or CellRendererClass.start_editing virtual functions, respectively.

Many properties of CellRenderer and its subclasses have a corresponding “set” property, e.g. “cell-background-set” corresponds to “cell-background”. These “set” properties reflect whether a property has been set or not. You should not set them independently.

This is an Abstract Base Class, you cannot instantiate it.

Properties

cell-background

Writeable

cell-background-rgba

Cell background as a gdk::RGBA

Readable | Writeable

cell-background-set

Readable | Writeable

editing

Readable

height

Readable | Writeable

is-expanded

Readable | Writeable

is-expander

Readable | Writeable

mode

Readable | Writeable

sensitive

Readable | Writeable

visible

Readable | Writeable

width

Readable | Writeable

xalign

Readable | Writeable

xpad

Readable | Writeable

yalign

Readable | Writeable

ypad

Readable | Writeable

Signals

editing-canceled

This signal gets emitted when the user cancels the process of editing a cell. For example, an editable cell renderer could be written to cancel editing when the user presses Escape.

See also: gtk_cell_renderer_stop_editing().

editing-started

This signal gets emitted when a cell starts to be edited. The intended use of this signal is to do special setup on @editable, e.g. adding a EntryCompletion or setting up additional columns in a ComboBox.

See gtk_cell_editable_start_editing() for information on the lifecycle of the @editable and a way to do setup that doesn’t depend on the @renderer.

Note that GTK doesn’t guarantee that cell renderers will continue to use the same kind of widget for editing in future releases, therefore you should check the type of @editable before doing any specific setup, as in the following example:

⚠️ The following code is in C ⚠️

static void
text_editing_started (GtkCellRenderer *cell,
                      GtkCellEditable *editable,
                      const char      *path,
                      gpointer         data)
{
  if (GTK_IS_ENTRY (editable))
    {
      GtkEntry *entry = GTK_ENTRY (editable);

      // ... create a GtkEntryCompletion

      gtk_entry_set_completion (entry, completion);
    }
}

Implements

CellRendererExt, glib::ObjectExt, [CellRendererExtManual][trait@crate::prelude::CellRendererExtManual]

Implementations

impl CellRenderer

pub const NONE: Option<&'static CellRenderer> = None

Trait Implementations

impl Clone for CellRenderer

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 CellRenderer

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

Formats the value using the given formatter.

impl Display for CellRenderer

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

Formats the value using the given formatter.

impl HasParamSpec for CellRenderer

type ParamSpec = ParamSpecObject

type SetValue = CellRenderer

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

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

fn param_spec_builder() -> Self::BuilderFn

impl Hash for CellRenderer

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<T: CellRendererImpl> IsSubclassable<T> for CellRenderer

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

Override the virtual methods of this class for the given subclass and do other class initialization.

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

Instance specific initialization.

impl Ord for CellRenderer

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 CellRenderer

type Parent = Object

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

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 CellRenderer

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 CellRenderer

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for CellRenderer

impl IsA<CellRenderer> for CellRendererAccel

impl IsA<CellRenderer> for CellRendererCombo

impl IsA<CellRenderer> for CellRendererPixbuf

impl IsA<CellRenderer> for CellRendererProgress

impl IsA<CellRenderer> for CellRendererSpin

impl IsA<CellRenderer> for CellRendererSpinner

impl IsA<CellRenderer> for CellRendererText

impl IsA<CellRenderer> for CellRendererToggle