class Gtk::CellAreaContext
- Gtk::CellAreaContext
- GObject::Object
- Reference
- Object
Overview
Stores geometrical information for a series of rows in a Gtk::CellArea
The Gtk::CellAreaContext object is created by a given Gtk::CellArea
implementation via its Gtk::CellAreaClass.create_context() virtual
method and is used to store cell sizes and alignments for a series of
Gtk::TreeModel rows that are requested and rendered in the same context.
Gtk::CellLayout widgets can create any number of contexts in which to
request and render groups of data rows. However, it’s important that the
same context which was used to request sizes for a given Gtk::TreeModel
row also be used for the same row when calling other Gtk::CellArea APIs
such as gtk_cell_area_render() and gtk_cell_area_event().
Defined in:
lib/gi-crystal/src/auto/gtk-4.0/cell_area_context.crConstructors
-
.new
Initialize a new
CellAreaContext. - .new(*, area : Gtk::CellArea | Nil = nil, minimum_height : Int32 | Nil = nil, minimum_width : Int32 | Nil = nil, natural_height : Int32 | Nil = nil, natural_width : Int32 | Nil = nil)
Class Method Summary
-
.g_type : UInt64
Returns the type id (GType) registered in GLib type system.
Instance Method Summary
-
#==(other : self)
Returns
trueif this reference is the same as other. -
#allocate(width : Int32, height : Int32) : Nil
Allocates a width and/or a height for all rows which are to be rendered with context.
-
#allocation : Nil
Fetches the current allocation size for context.
-
#area : Gtk::CellArea
Fetches the
Gtk::CellAreathis context was created by. - #area=(value : Gtk::CellArea | Nil) : Gtk::CellArea | Nil
-
#hash(hasher)
See
Object#hash(hasher) - #minimum_height : Int32
- #minimum_width : Int32
- #natural_height : Int32
- #natural_width : Int32
-
#preferred_height : Nil
Gets the accumulative preferred height for all rows which have been requested with this context.
-
#preferred_height_for_width(width : Int32) : Nil
Gets the accumulative preferred height for width for all rows which have been requested for the same said width with this context.
-
#preferred_width : Nil
Gets the accumulative preferred width for all rows which have been requested with this context.
-
#preferred_width_for_height(height : Int32) : Nil
Gets the accumulative preferred width for height for all rows which have been requested for the same said height with this context.
-
#push_preferred_height(minimum_height : Int32, natural_height : Int32) : Nil
Causes the minimum and/or natural height to grow if the new proposed sizes exceed the current minimum and natural height.
-
#push_preferred_width(minimum_width : Int32, natural_width : Int32) : Nil
Causes the minimum and/or natural width to grow if the new proposed sizes exceed the current minimum and natural width.
-
#reset : Nil
Resets any previously cached request and allocation data.
Instance methods inherited from class GObject::Object
==(other : self)
==,
bind_property(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags) : GObject::Binding
bind_property,
bind_property_full(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags, transform_to : GObject::Closure, transform_from : GObject::Closure) : GObject::Binding
bind_property_full,
data(key : String) : Pointer(Void) | Nil
data,
finalize
finalize,
freeze_notify : Nil
freeze_notify,
getv(names : Enumerable(String), values : Enumerable(_)) : Nil
getv,
hash(hasher)
hash,
notify(property_name : String) : Nil
notify,
notify_by_pspec(pspec : GObject::ParamSpec) : Nil
notify_by_pspec,
notify_signal
notify_signal,
property(property_name : String, value : _) : Nil
property,
qdata(quark : UInt32) : Pointer(Void) | Nil
qdata,
ref_count : UInt32
ref_count,
run_dispose : Nil
run_dispose,
set_data(key : String, data : Pointer(Void) | Nil) : Nil
set_data,
set_property(property_name : String, value : _) : Nil
set_property,
steal_data(key : String) : Pointer(Void) | Nil
steal_data,
steal_qdata(quark : UInt32) : Pointer(Void) | Nil
steal_qdata,
thaw_notify : Nil
thaw_notify,
to_unsafe : Pointer(Void)
to_unsafe,
watch_closure(closure : GObject::Closure) : Nil
watch_closure
Constructor methods inherited from class GObject::Object
cast(obj : GObject::Object) : self
cast,
new(pointer : Pointer(Void), transfer : GICrystal::Transfer)new new, newv(object_type : UInt64, parameters : Enumerable(GObject::Parameter)) : self newv
Class methods inherited from class GObject::Object
cast?(obj : GObject::Object) : self | Nil
cast?,
compat_control(what : UInt64, data : Pointer(Void) | Nil) : UInt64
compat_control,
g_type : UInt64
g_type,
interface_find_property(g_iface : GObject::TypeInterface, property_name : String) : GObject::ParamSpec
interface_find_property,
interface_list_properties(g_iface : GObject::TypeInterface) : Enumerable(GObject::ParamSpec)
interface_list_properties
Macros inherited from class GObject::Object
previous_vfunc(*args)
previous_vfunc,
previous_vfunc!(*args)
previous_vfunc!,
signal(signature)
signal
Constructor Detail
Class Method Detail
Returns the type id (GType) registered in GLib type system.
Instance Method Detail
Returns true if this reference is the same as other. Invokes same?.
Allocates a width and/or a height for all rows which are to be rendered with context.
Usually allocation is performed only horizontally or sometimes
vertically since a group of rows are usually rendered side by
side vertically or horizontally and share either the same width
or the same height. Sometimes they are allocated in both horizontal
and vertical orientations producing a homogeneous effect of the
rows. This is generally the case for Gtk::TreeView when
Gtk::TreeView:fixed-height-mode is enabled.
Fetches the current allocation size for context.
If the context was not allocated in width or height, or if the context was recently reset with gtk_cell_area_context_reset(), the returned value will be -1.
Fetches the Gtk::CellArea this context was created by.
This is generally unneeded by layouting widgets; however, it is important for the context implementation itself to fetch information about the area it is being used for.
For instance at Gtk::CellAreaContextClass.allocate() time
it’s important to know details about any cell spacing
that the Gtk::CellArea is configured with in order to
compute a proper allocation.
Gets the accumulative preferred height for all rows which have been requested with this context.
After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a Gtk::CellArea, the returned values are 0.
Gets the accumulative preferred height for width for all rows which have been requested for the same said width with this context.
After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a Gtk::CellArea, the returned values are -1.
Gets the accumulative preferred width for all rows which have been requested with this context.
After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a Gtk::CellArea, the returned values are 0.
Gets the accumulative preferred width for height for all rows which have been requested for the same said height with this context.
After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a Gtk::CellArea, the returned values are -1.
Causes the minimum and/or natural height to grow if the new proposed sizes exceed the current minimum and natural height.
This is used by Gtk::CellAreaContext implementations during
the request process over a series of Gtk::TreeModel rows to
progressively push the requested height over a series of
gtk_cell_area_get_preferred_height() requests.
Causes the minimum and/or natural width to grow if the new proposed sizes exceed the current minimum and natural width.
This is used by Gtk::CellAreaContext implementations during
the request process over a series of Gtk::TreeModel rows to
progressively push the requested width over a series of
gtk_cell_area_get_preferred_width() requests.
Resets any previously cached request and allocation data.
When underlying Gtk::TreeModel data changes its
important to reset the context if the content
size is allowed to shrink. If the content size
is only allowed to grow (this is usually an option
for views rendering large data stores as a measure
of optimization), then only the row that changed
or was inserted needs to be (re)requested with
gtk_cell_area_get_preferred_width().
When the new overall size of the context requires that the allocated size changes (or whenever this allocation changes at all), the variable row sizes need to be re-requested for every row.
For instance, if the rows are displayed all with the same width from top to bottom then a change in the allocated width necessitates a recalculation of all the displayed row heights using gtk_cell_area_get_preferred_height_for_width().