Description

An object for rendering a single cell

The Gnome::Gtk4::CellRenderer is a base class of a set of objects used for rendering a cell to a Gnome::Cairo::N-Context. These objects are used primarily by the Gnome::Gtk4::TreeView widget, though they aren’t tied to them in any specific way. It is worth noting that Gnome::Gtk4::CellRenderer is not a Gnome::Gtk4::Widget and cannot be treated as such.

The primary use of a Gnome::Gtk4::CellRenderer is for drawing a certain graphical elements on a Gnome::Cairo::N-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 Gnome::GObject::Objects property system. Then, the cell is measured using .get-preferred-size(). Finally, the cell is rendered in the correct location using .snapshot().

There are a number of rules that must be followed when writing a new Gnome::Gtk4::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 Gnome::Gtk4::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 Gnome::Gtk4::CellRendererToggle, which toggles when it gets activated by a mouse click, or it can be “editable” like Gnome::Gtk4::CellRendererText, which allows the user to edit the text using a widget implementing the Gnome::Gtk4::R-CellEditable interface, e.g. Gnome::Gtk4::Entry. To make a cell renderer activatable or editable, you have to implement the Gnome::Gtk4::CellRendererClass.activate or Gnome::Gtk4::CellRendererClass.start_editing virtual functions, respectively.

Many properties of Gnome::Gtk4::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.

Class initialization

Note: The native version of this class is deprecated in gtk4-lib() since version 4.10

new

:native-object

Create an object using a native object from elsewhere. See also Gnome::N::TopLevelSupportClass.

multi method new ( N-Object :$native-object! )

Methods

activate

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Passes an activate event to the cell renderer for possible processing. Some cell renderers may use events; for example, Gnome::Gtk4::CellRendererToggle toggles when it gets a mouse click.

method activate ( N-Object() $event, N-Object() $widget, Str $path, N-Object $background-area, N-Object $cell-area, UInt $flags --> Bool )

• $event; a Gnome::Gdk4::Event.

• $widget; widget that received the event.

• $path; widget-dependent string representation of the event location; e.g. for Gnome::Gtk4::TreeView, a string representation of Gnome::Gtk4::N-TreePath.

• $background-area; background area as passed to .render()

• $cell-area; cell area as passed to .render()

• $flags; render flags.

Return value; True if the event was consumed/handled.

get-aligned-area

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Gets the aligned area used by $cell inside $cell-area. Used for finding the appropriate edit and focus rectangle.

method get-aligned-area ( N-Object() $widget, UInt $flags, N-Object $cell-area, N-Object $aligned-area )

• $widget; the Gnome::Gtk4::Widget this cell will be rendering to.

• $flags; render flags.

• $cell-area; cell area which would be passed to .render()

• $aligned-area; the return location for the space inside $cell-area that would actually be used to render.

get-alignment

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Fills in $xalign and $yalign with the appropriate values of $cell.

method get-alignment ( Num() $xalign, Num() $yalign )

• $xalign; (transfer ownership: full) location to fill in with the x alignment of the cell.

• $yalign; (transfer ownership: full) location to fill in with the y alignment of the cell.

get-fixed-size

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Fills in $width and $height with the appropriate size of $cell.

method get-fixed-size ( Array[Int] $width, Array[Int] $height )

• $width; (transfer ownership: full) location to fill in with the fixed width of the cell.

• $height; (transfer ownership: full) location to fill in with the fixed height of the cell.

get-is-expanded

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Checks whether the given Gnome::Gtk4::CellRenderer is expanded.

method get-is-expanded (--> Bool )

Return value; True if the cell renderer is expanded.

get-is-expander

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Checks whether the given Gnome::Gtk4::CellRenderer is an expander.

method get-is-expander (--> Bool )

Return value; True if $cell is an expander, and False otherwise.

get-padding

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Fills in $xpad and $ypad with the appropriate values of $cell.

method get-padding ( Array[Int] $xpad, Array[Int] $ypad )

• $xpad; (transfer ownership: full) location to fill in with the x padding of the cell.

• $ypad; (transfer ownership: full) location to fill in with the y padding of the cell.

get-preferred-height

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Retrieves a renderer’s natural size when rendered to $widget.

method get-preferred-height ( N-Object() $widget, Array[Int] $minimum-size, Array[Int] $natural-size )

• $widget; the Gnome::Gtk4::Widget this cell will be rendering to.

• $minimum-size; (transfer ownership: full) location to store the minimum size.

• $natural-size; (transfer ownership: full) location to store the natural size.

get-preferred-height-for-width

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Retrieves a cell renderers’s minimum and natural height if it were rendered to $widget with the specified $width.

method get-preferred-height-for-width ( N-Object() $widget, Int() $width, Array[Int] $minimum-height, Array[Int] $natural-height )

• $widget; the Gnome::Gtk4::Widget this cell will be rendering to.

• $width; the size which is available for allocation.

• $minimum-height; (transfer ownership: full) location for storing the minimum size.

• $natural-height; (transfer ownership: full) location for storing the preferred size.

get-preferred-size

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Retrieves the minimum and natural size of a cell taking into account the widget’s preference for height-for-width management.

method get-preferred-size ( N-Object() $widget, N-Object $minimum-size, N-Object $natural-size )

• $widget; the Gnome::Gtk4::Widget this cell will be rendering to.

• $minimum-size; location for storing the minimum size

• $natural-size; location for storing the natural size

get-preferred-width

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Retrieves a renderer’s natural size when rendered to $widget.

method get-preferred-width ( N-Object() $widget, Array[Int] $minimum-size, Array[Int] $natural-size )

• $widget; the Gnome::Gtk4::Widget this cell will be rendering to.

• $minimum-size; (transfer ownership: full) location to store the minimum size.

• $natural-size; (transfer ownership: full) location to store the natural size.

get-preferred-width-for-height

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Retrieves a cell renderers’s minimum and natural width if it were rendered to $widget with the specified $height.

method get-preferred-width-for-height ( N-Object() $widget, Int() $height, Array[Int] $minimum-width, Array[Int] $natural-width )

• $widget; the Gnome::Gtk4::Widget this cell will be rendering to.

• $height; the size which is available for allocation.

• $minimum-width; (transfer ownership: full) location for storing the minimum size.

• $natural-width; (transfer ownership: full) location for storing the preferred size.

get-request-mode

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Gets whether the cell renderer prefers a height-for-width layout or a width-for-height layout.

method get-request-mode (--> GtkSizeRequestMode )

Return value; The enumeration GtkSizeRequestMode defined in Gnome::Gtk4::T-enums preferred by this renderer..

get-sensitive

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Returns the cell renderer’s sensitivity.

method get-sensitive (--> Bool )

Return value; True if the cell renderer is sensitive.

get-state

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Translates the cell renderer state to bit field GtkStateFlags defined in Gnome::Gtk4::T-enums, based on the cell renderer and widget sensitivity, and the given Gnome::Gtk4::CellRendererState.

method get-state ( N-Object() $widget, UInt $cell-state --> UInt )

• $widget; a Gnome::Gtk4::Widget.

• $cell-state; cell renderer state.

Return value; the widget state flags applying to $cell.

get-visible

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Returns the cell renderer’s visibility.

method get-visible (--> Bool )

Return value; True if the cell renderer is visible.

is-activatable

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Checks whether the cell renderer can do something when activated.

method is-activatable (--> Bool )

Return value; True if the cell renderer can do anything when activated.

set-alignment

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets the renderer’s alignment within its available space.

method set-alignment ( Num() $xalign, Num() $yalign )

• $xalign; the x alignment of the cell renderer.

• $yalign; the y alignment of the cell renderer.

set-fixed-size

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets the renderer size to be explicit, independent of the properties set.

method set-fixed-size ( Int() $width, Int() $height )

• $width; the width of the cell renderer, or -1.

• $height; the height of the cell renderer, or -1.

set-is-expanded

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets whether the given Gnome::Gtk4::CellRenderer is expanded.

method set-is-expanded ( Bool() $is-expanded )

• $is-expanded; whether $cell should be expanded.

set-is-expander

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets whether the given Gnome::Gtk4::CellRenderer is an expander.

method set-is-expander ( Bool() $is-expander )

• $is-expander; whether $cell is an expander.

set-padding

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets the renderer’s padding.

method set-padding ( Int() $xpad, Int() $ypad )

• $xpad; the x padding of the cell renderer.

• $ypad; the y padding of the cell renderer.

set-sensitive

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets the cell renderer’s sensitivity.

method set-sensitive ( Bool() $sensitive )

• $sensitive; the sensitivity of the cell.

set-visible

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Sets the cell renderer’s visibility.

method set-visible ( Bool() $visible )

• $visible; the visibility of the cell.

snapshot

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Invokes the virtual render function of the Gnome::Gtk4::CellRenderer. The three passed-in rectangles are areas in $cr. Most renderers will draw within $cell-area; the xalign, yalign, xpad, and ypad fields of the Gnome::Gtk4::CellRenderer should be honored with respect to $cell-area. $background-area includes the blank space around the cell, and also the area containing the tree expander; so the $background-area rectangles for all cells tile to cover the entire $window.

method snapshot ( N-Object() $snapshot, N-Object() $widget, N-Object $background-area, N-Object $cell-area, UInt $flags )

• $snapshot; a Gnome::Gtk4::Snapshot to draw to.

• $widget; the widget owning $window.

• $background-area; entire cell area (including tree expanders and maybe padding on the sides)

• $cell-area; area normally rendered by a cell renderer

• $flags; flags that affect rendering.

start-editing

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Starts editing the contents of this $cell, through a new Gnome::Gtk4::R-CellEditable widget created by the Gnome::Gtk4::CellRendererClass.start_editing virtual function.

method start-editing ( N-Object() $event, N-Object() $widget, Str $path, N-Object $background-area, N-Object $cell-area, UInt $flags --> N-Object )

• $event; a Gnome::Gdk4::Event.

• $widget; widget that received the event.

• $path; widget-dependent string representation of the event location; e.g. for Gnome::Gtk4::TreeView, a string representation of Gnome::Gtk4::N-TreePath.

• $background-area; background area as passed to .render()

• $cell-area; cell area as passed to .render()

• $flags; render flags.

Return value; A new Gnome::Gtk4::R-CellEditable for editing this $cell, or undefined if editing is not possible.

stop-editing

Note: The native version of this routine is deprecated in gtk4-lib() since version 4.10

Informs the cell renderer that the editing is stopped. If $canceled is True, the cell renderer will emit the Gnome::Gtk4::CellRenderer::editing-canceled signal.

This function should be called by cell renderer implementations in response to the Gnome::Gtk4::R-CellEditable::editing-done` signal of Gnome::Gtk4::R-CellEditable.

method stop-editing ( Bool() $canceled )

• $canceled; True if the editing has been canceled.

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: .stop-editing().

method handler (
  Int :$_handle_id,
  N-GObject :$_native-object,
  Gnome::Gtk4::CellRenderer :$_widget,
  *C<user>-options
)

• $_handle_id; The registered event handler id.

• $_native-object; The native object provided by the Raku object which registered this event. This a native Gnome::Gtk4::CellRenderer object.

• $_widget; The object which registered the signal. User code may have left the object going out of scope.

• user-options; A list of named arguments provided at the .register-signal() method from Gnome::GObject::Object.

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 Gnome::Gtk4::EntryCompletion or setting up additional columns in a Gnome::Gtk4::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:

method handler (
  N-Object $editable,
  Str $path,
  Int :$_handle_id,
  N-GObject :$_native-object,
  Gnome::Gtk4::CellRenderer :$_widget,
  *C<user>-options
)

• $editable; the Gnome::Gtk4::R-CellEditable.

• $path; the path identifying the edited cell.

• $_handle_id; The registered event handler id.

• $_native-object; The native object provided by the Raku object which registered this event. This a native Gnome::Gtk4::CellRenderer object.

• $_widget; The object which registered the signal. User code may have left the object going out of scope.

• user-options; A list of named arguments provided at the .register-signal() method from Gnome::GObject::Object.