Struct gtk4::CellLayout [−][src]
pub struct CellLayout(_);Expand description
An interface for packing cells
CellLayout is an interface to be implemented by all objects which
want to provide a TreeViewColumn like API for packing cells,
setting attributes and data funcs.
One of the notable features provided by implementations of
CellLayout are attributes. Attributes let you set the properties
in flexible ways. They can just be set to constant values like regular
properties. But they can also be mapped to a column of the underlying
tree model with gtk_cell_layout_set_attributes(), which means that the value
of the attribute can change from cell to cell as they are rendered by
the cell renderer. Finally, it is possible to specify a function with
CellLayoutExt::set_cell_data_func() that is called to determine the
value of the attribute for each cell that is rendered.
GtkCellLayouts as GtkBuildable
Implementations of GtkCellLayout which also implement the GtkBuildable
interface (CellView, IconView, ComboBox,
EntryCompletion, TreeViewColumn) accept CellRenderer objects
as <child> elements in UI definitions. They support a custom <attributes>
element for their children, which can contain multiple <attribute>
elements. Each <attribute> element has a name attribute which specifies
a property of the cell renderer; the content of the element is the
attribute value.
This is an example of a UI definition fragment specifying attributes:
⚠️ The following code is in C ⚠️
combo = g_object_new (GTK_TYPE_COMBO_BOX, "cell-area", my_cell_area, NULL);to use a custom cell area with a combo box. But construct properties
are only initialized after instance init()
functions have run, which means that using functions which rely on
the existence of the cell area in your subclass’ init() function will
cause the default cell area to be instantiated. In this case, a provided
construct property value will be ignored (with a warning, to alert
you to the problem).
⚠️ The following code is in C ⚠️
static void
my_combo_box_init (MyComboBox *b)
{
GtkCellRenderer *cell;
cell = gtk_cell_renderer_pixbuf_new ();
// The following call causes the default cell area for combo boxes,
// a GtkCellAreaBox, to be instantiated
gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (b), cell, FALSE);
...
}
GtkWidget *
my_combo_box_new (GtkCellArea *area)
{
// This call is going to cause a warning about area being ignored
return g_object_new (MY_TYPE_COMBO_BOX, "cell-area", area, NULL);
}If supporting alternative cell areas with your derived widget is
not important, then this does not have to concern you. If you want
to support alternative cell areas, you can do so by moving the
problematic calls out of init() and into a constructor()
for your class.
Implements
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 CellLayout
impl !Send for CellLayout
impl !Sync for CellLayout
impl Unpin for CellLayout
impl UnwindSafe for CellLayout
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.