Sets our main struct and passes it to the parent class
Activates area, usually by activating the currently focused cell, however some subclasses which embed widgets in the area can also activate a widget if it currently has the focus.
This is used by GtkCellArea subclasses when handling events to activate cells, the base GtkCellArea class activates cells for keyboard events for free in its own GtkCellArea->activate() implementation.
Adds renderer to area with the default child cell properties.
Adds sibling to renderer's focusable area, focus will be drawn around renderer and all of its siblings if renderer can focus for a given row. Events handled by focus siblings can also activate the given focusable renderer.
Indicates that editing has started on renderer and that editable should be added to the owning cell-layouting widget at cell_area. Since 3.0
This signal is emitted whenever applying attributes to area from model Since 3.0
Indicates that focus changed on this area. This signal is emitted either as a result of focus handling or event handling. It's possible that the signal is emitted even if the currently focused renderer did not change, this is because focus may change to the same renderer in the same cell area for a different row of data. Since 3.0
Indicates that editing finished on renderer and that editable should be removed from the owning cell-layouting widget. Since 3.0
Applies any connected attributes to the renderers in area by pulling the values from tree_model.
Connects an attribute to apply values from column for the GtkTreeModel in use.
Disconnects attribute for the renderer in area so that attribute will no longer be updated with values from the model.
Gets the value of a cell property for renderer in area.
Gets the values of one or more cell properties for renderer in area.
Sets a cell property for renderer in area.
Sets one or more cell properties for renderer in area.
This is sometimes needed for cases where rows need to share alignments in one orientation but may be separately grouped in the opposing orientation. For instance, GtkIconView creates all icons (rows) to have the same width and the cells theirin to have the same horizontal alignments. However each row of icons may have a separate collective height. GtkIconView uses this to request the heights of each row based on a context which was already used to request all the row widths that are to be displayed.
Creates a GtkCellAreaContext to be used with area for all purposes. GtkCellAreaContext stores geometry information for rows for which it was operated on, it is important to use the same context for the same row of data at all times (i.e. one should render and handle events with the same GtkCellAreaContext which was used to request the size of those rows of data).
Delegates event handling to a GtkCellArea.
This should be called by the area's owning layout widget when focus is to be passed to area, or moved within area for a given direction and row data. Implementing GtkCellArea classes should implement this method to receive and navigate focus in its own way particular to how it lays out cells.
Calls callback for every GtkCellRenderer in area.
Calls callback for every GtkCellRenderer in area with the allocated rectangle inside cell_area.
Derives the allocation of renderer inside area if area were to be renderered in cell_area.
Gets the GtkCellRenderer at x and y coordinates inside area and optionally returns the full cell allocation for it inside cell_area.
Gets the current GtkTreePath string for the currently applied GtkTreeIter, this is implicitly updated when gtk_cell_area_apply_attributes() is called and can be used to interact with renderers from GtkCellArea subclasses.
Gets the GtkCellEditable widget currently used to edit the currently edited cell.
Gets the GtkCellRenderer in area that is currently being edited.
Retrieves the currently focused cell for area
Gets the GtkCellRenderer which is expected to be focusable for which renderer is, or may be a sibling. This is handy for GtkCellArea subclasses when handling events, after determining the renderer at the event location it can then chose to activate the focus cell for which the event cell may have been a sibling.
Gets the focus sibling cell renderers for renderer.
Retrieves a cell area's initial minimum and natural height. area will store some geometrical information in context along the way; when requesting sizes over an arbitrary number of rows, it's not important to check the minimum_height and natural_height of this call but rather to consult gtk_cell_area_context_get_preferred_height() after a series of requests.
Retrieves a cell area's minimum and natural height if it would be given the specified width. area stores some geometrical information in context along the way while calling gtk_cell_area_get_preferred_width(). It's important to perform a series of gtk_cell_area_get_preferred_width() requests with context first and then call gtk_cell_area_get_preferred_height_for_width() on each cell area individually to get the height for width of each fully requested row. If at some point, the width of a single row changes, it should be requested with gtk_cell_area_get_preferred_width() again and then the full width of the requested rows checked again with gtk_cell_area_context_get_preferred_width().
Retrieves a cell area's initial minimum and natural width. area will store some geometrical information in context along the way; when requesting sizes over an arbitrary number of rows, it's not important to check the minimum_width and natural_width of this call but rather to consult gtk_cell_area_context_get_preferred_width() after a series of requests.
Retrieves a cell area's minimum and natural width if it would be given the specified height. area stores some geometrical information in context along the way while calling gtk_cell_area_get_preferred_height(). It's important to perform a series of gtk_cell_area_get_preferred_height() requests with context first and then call gtk_cell_area_get_preferred_width_for_height() on each cell area individually to get the height for width of each fully requested row. If at some point, the height of a single row changes, it should be requested with gtk_cell_area_get_preferred_height() again and then the full height of the requested rows checked again with gtk_cell_area_context_get_preferred_height().
Gets whether the area prefers a height-for-width layout or a width-for-height layout.
the main Gtk struct as a void*
Checks if area contains renderer.
This is a convenience function for GtkCellArea implementations to get the inner area where a given GtkCellRenderer will be rendered. It removes any padding previously added by gtk_cell_area_request_renderer().
Returns whether the area can do anything when activated, after applying new attributes to area.
Returns whether sibling is one of renderer's focus siblings (see gtk_cell_area_add_focus_sibling()).
Removes renderer from area.
Removes sibling from renderer's focus sibling list (see gtk_cell_area_add_focus_sibling()).
Renders area's cells according to area's layout onto widget at the given coordinates.
This is a convenience function for GtkCellArea implementations to request size for cell renderers. It's important to use this function to request size and then use gtk_cell_area_inner_cell_area() at render and event time since this function will add padding around the cell for focus painting.
Explicitly sets the currently focused cell to renderer. This is generally called by implementations of GtkCellAreaClass.focus() or GtkCellAreaClass.event(), however it can also be used to implement functions such as gtk_tree_view_set_cursor_on_cell().
Explicitly stops the editing of the currently edited cell. If canceled is TRUE, the currently edited cell renderer will emit the ::editing-canceled signal, otherwise the the ::editing-done signal will be emitted on the current edit widget. See gtk_cell_area_get_edited_cell() and gtk_cell_area_get_edit_widget().
Finds a cell property of a cell area class by name.
Installs a cell property on a cell area class.
Returns all cell properties of a cell area class.
the main Gtk struct
the main Gtk struct
the main Gtk struct as a void*
Gets a D Object from the objects table of associations.
The notify signal is emitted on an object when one of its properties has been changed. Note that getting this signal doesn't guarantee that the value of the property has actually changed, it may also be emitted when the setter for the property is called to reinstate the previous value.
Installs a new property. This is usually done in the class initializer. Note that it is possible to redefine a property in a derived class, by installing a property with the same name. This can be useful at times, e.g. to change the range of allowed values or the default value.
Installs new properties from an array of GParamSpecs. This is usually done in the class initializer. The property id of each property is the index of each GParamSpec in the pspecs array. The property id of 0 is treated specially by GObject and it should not be used to store a GParamSpec. This function should be used if you plan to use a static array of GParamSpecs and g_object_notify_by_pspec(). For instance, this Since 2.26
Looks up the GParamSpec for a property of a class.
Get an array of GParamSpec* for all properties of a class.
Registers property_id as referring to a property with the name name in a parent class or in an interface implemented by oclass. This allows this class to override a property implementation in a parent class or to provide the implementation of a property from an interface. Note Internally, overriding is implemented by creating a property of type GParamSpecOverride; generally operations that query the properties of the object class, such as g_object_class_find_property() or g_object_class_list_properties() will return the overridden property. However, in one case, the construct_properties argument of the constructor virtual function, the GParamSpecOverride is passed instead, so that the param_id field of the GParamSpec will be correct. For virtually all uses, this makes no difference. If you need to get the overridden property, you can call g_param_spec_get_redirect_target(). Since 2.4
Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property. This function is meant to be called from the interface's default vtable initialization function (the class_init member of GTypeInfo.) It must not be called after after class_init has been called for any object types implementing this interface. Since 2.4
Find the GParamSpec with the given name for an interface. Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek(). Since 2.4
Lists the properties of an interface.Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek(). Since 2.4
Increases the reference count of object.
Decreases the reference count of object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).
Increase the reference count of object, and possibly remove the floating reference, if object has a floating reference. In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one. Since 2.10
Clears a reference to a GObject. object_ptr must not be NULL. If the reference is NULL then this function does nothing. Otherwise, the reference count of the object is decreased and the pointer is set to NULL. This function is threadsafe and modifies the pointer atomically, using memory barriers where needed. A macro is also included that allows this function to be used without pointer casts. Since 2.28
Checks whether object has a floating reference. Since 2.10
This function is intended for GObject implementations to re-enforce a floating object reference. Doing this is seldom required: all GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink(). Since 2.10
Adds a weak reference callback to an object. Weak references are used for notification when an object is finalized. They are called "weak references" because they allow you to safely hold a pointer to an object without calling g_object_ref() (g_object_ref() adds a strong reference, that is, forces the object to stay alive). Note that the weak references created by this method are not thread-safe: they cannot safely be used in one thread if the object's last g_object_unref() might happen in another thread. Use GWeakRef if thread-safety is required.
Removes a weak reference callback to an object.
Adds a weak reference from weak_pointer to object to indicate that the pointer located at weak_pointer_location is only valid during the lifetime of object. When the object is finalized, weak_pointer will be set to NULL. Note that as with g_object_weak_ref(), the weak references created by this method are not thread-safe: they cannot safely be used in one thread if the object's last g_object_unref() might happen in another thread. Use GWeakRef if thread-safety is required.
Removes a weak reference from object that was previously added using g_object_add_weak_pointer(). The weak_pointer_location has to match the one used with g_object_add_weak_pointer().
Increases the reference count of the object by one and sets a callback to be called when all other references to the object are dropped, or when this is already the last reference to the object and another reference is established. This functionality is intended for binding object to a proxy object managed by another memory manager. This is done with two paired references: the strong reference added by g_object_add_toggle_ref() and a reverse reference to the proxy object which is either a strong reference or weak reference. The setup is that when there are no other references to object, only a weak reference is held in the reverse direction from object to the proxy object, but when there are other references held to object, a strong reference is held. The notify callback is called when the reference from object to the proxy object should be toggled from strong to weak (is_last_ref true) or weak to strong (is_last_ref false). Since a (normal) reference must be held to the object before calling g_object_add_toggle_ref(), the initial state of the reverse link is always strong. Multiple toggle references may be added to the same gobject, however if there are multiple toggle references to an object, none of them will ever be notified until all but one are removed. For this reason, you should only ever use a toggle reference if there is important state in the proxy object. Since 2.8
Removes a reference added with g_object_add_toggle_ref(). The reference count of the object is decreased by one. Since 2.8
Emits a "notify" signal for the property property_name on object. When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.
Emits a "notify" signal for the property specified by pspec on object. This function omits the property name lookup, hence it is faster than g_object_notify(). One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with Since 2.26
Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one "notify" signal is emitted for each property modified while the object is frozen. This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.
Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted. Duplicate notifications for each property are squashed so that at most one "notify" signal is emitted for each property. It is an error to call this function when the freeze count is zero.
Gets a named field from the objects table of associations (see g_object_set_data()).
Each object carries around a table of associations from strings to pointers. This function lets you set an association. If the object already had an association with that name, the old association will be destroyed.
Like g_object_set_data() except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed. Note that the destroy callback is not called if data is NULL.
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
This is a variant of g_object_get_data() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object. If the key is not set on the object then dup_func will be called with a NULL argument. Note that dup_func is called while user data of object is locked. This function can be useful to avoid races when multiple threads are using object data on the same key on the same object. Since 2.34
Compares the user data for the key key on object with oldval, and if they are the same, replaces oldval with newval. This is like a typical atomic compare-and-exchange operation, for user data on an object. If the previous value was replaced then ownership of the old value (oldval) is passed to the caller, including the registered destroy notify for it (passed out in old_destroy). Its up to the caller to free this as he wishes, which may or may not include using old_destroy as sometimes replacement should not destroy the object in the normal way. Return: TRUE if the existing value for key was replaced by newval, FALSE otherwise. Since 2.34
This function gets back user data pointers stored via g_object_set_qdata().
This sets an opaque, named pointer on an object. The name is specified through a GQuark (retrived e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the object with g_object_get_qdata() until the object is finalized. Setting a previously set user data pointer, overrides (frees) the old pointer set, using NULL as pointer essentially removes the data stored.
This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with data as argument when the object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same quark.
This function gets back user data pointers stored via g_object_set_qdata() and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update
This is a variant of g_object_get_qdata() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object. If the quark is not set on the object then dup_func will be called with a NULL argument. Note that dup_func is called while user data of object is locked. This function can be useful to avoid races when multiple threads are using object data on the same key on the same object. Since 2.34
Compares the user data for the key quark on object with oldval, and if they are the same, replaces oldval with newval. This is like a typical atomic compare-and-exchange operation, for user data on an object. If the previous value was replaced then ownership of the old value (oldval) is passed to the caller, including the registered destroy notify for it (passed out in old_destroy). Its up to the caller to free this as he wishes, which may or may not include using old_destroy as sometimes replacement should not destroy the object in the normal way. Return: TRUE if the existing value for quark was replaced by newval, FALSE otherwise. Since 2.34
Sets a property on an object.
Gets a property of an object. value must have been initialized to the expected type of the property (or a type to which the expected type can be transformed) using g_value_init(). In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset(). Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.
Sets properties on an object.
Gets properties of an object. In general, a copy is made of the property contents and the caller is responsible for freeing the memory in the appropriate manner for the type, for instance by calling g_free() or g_object_unref(). See g_object_get().
This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling g_closure_invalidate() on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.
Releases all references to other objects. This can be used to break reference cycles. This functions should only be called from object system implementations.
the main Gtk struct as a void*
Sets the name of the buildable object. Since 2.12
Gets the name of the buildable object. GtkBuilder sets the name based on the GtkBuilder UI definition used to construct the buildable. Since 2.12
Adds a child to buildable. type is an optional string describing how the child should be added. Since 2.12
Sets the property name name to value on the buildable object. Since 2.12
Constructs a child of buildable with the name name. GtkBuilder calls this function if a "constructor" has been specified in the UI definition. Since 2.12
This is called for each unknown element under <child>. Since 2.12
This is called at the end of each custom element handled by the buildable. Since 2.12
This is similar to gtk_buildable_parser_finished() but is called once for each custom tag handled by the buildable. Since 2.12
Called when the builder finishes the parsing of a GtkBuilder UI definition. Note that this will be called once for each time gtk_builder_add_from_file() or gtk_builder_add_from_string() is called on a builder. Since 2.12
Get the internal child called childname of the buildable object. Since 2.12
the main Gtk struct as a void*
Packs the cell into the beginning of cell_layout. If expand is FALSE, then the cell is allocated no more space than it needs. Any unused space is divided evenly between cells for which expand is TRUE. Note that reusing the same cell renderer is not supported. Since 2.4
Adds the cell to the end of cell_layout. If expand is FALSE, then the cell is allocated no more space than it needs. Any unused space is divided evenly between cells for which expand is TRUE. Note that reusing the same cell renderer is not supported. Since 2.4
Returns the underlying GtkCellArea which might be cell_layout if called on a GtkCellArea or might be NULL if no GtkCellArea is used by cell_layout.
Returns the cell renderers which have been added to cell_layout. Since 2.12
Re-inserts cell at position. Note that cell has already to be packed into cell_layout for this to function properly. Since 2.4
Unsets all the mappings on all renderers on cell_layout and removes all renderers from cell_layout. Since 2.4
Adds an attribute mapping to the list in cell_layout. The column is the column of the model to get a value from, and the attribute is the parameter on cell to be set from the value. So for example if column 2 of the model contains strings, you could have the "text" attribute of a GtkCellRendererText get its values from column 2. Since 2.4
Sets the GtkCellLayoutDataFunc to use for cell_layout. This function is used instead of the standard attributes mapping for setting the column value, and should set the value of cell_layout's cell renderer(s) as appropriate. func may be NULL to remove a previously set function. Since 2.4
Clears all existing attributes previously set with gtk_cell_layout_set_attributes(). Since 2.4
The GtkCellArea is an abstract class for GtkCellLayout widgets (also referred to as "layouting widgets") to interface with an arbitrary number of GtkCellRenderers and interact with the user for a given GtkTreeModel row.
The cell area handles events, focus navigation, drawing and size requests and allocations for a given row of data.
Usually users dont have to interact with the GtkCellArea directly unless they are implementing a cell-layouting widget themselves.
Requesting area sizes
As outlined in GtkWidget's geometry management section, GTK+ uses a height-for-width geometry management system to compute the sizes of widgets and user interfaces. GtkCellArea uses the same semantics to calculate the size of an area for an arbitrary number of GtkTreeModel rows.
When requesting the size of a cell area one needs to calculate the size for a handful of rows, and this will be done differently by different layouting widgets. For instance a GtkTreeViewColumn always lines up the areas from top to bottom while a GtkIconView on the other hand might enforce that all areas received the same width and wrap the areas around, requesting height for more cell areas when allocated less width.
It's also important for areas to maintain some cell alignments with areas rendered for adjacent rows (cells can appear "columnized" inside an area even when the size of cells are different in each row). For this reason the GtkCellArea uses a GtkCellAreaContext object to store the alignments and sizes along the way (as well as the overall largest minimum and natural size for all the rows which have been calculated with the said context).
The GtkCellAreaContext is an opaque object specific to the GtkCellArea which created it (see gtk_cell_area_create_context()). The owning cell-layouting widget can create as many contexts as it wishes to calculate sizes of rows which should receive the same size in at least one orientation (horizontally or vertically), However, it's important that the same GtkCellAreaContext which was used to request the sizes for a given GtkTreeModel row be used when rendering or processing events for that row.
In order to request the width of all the rows at the root level of a GtkTreeModel one would do the following:
Note that in this example it's not important to observe the returned minimum and natural width of the area for each row unless the cell-layouting object is actually interested in the widths of individual rows. The overall width is however stored in the accompanying GtkCellAreaContext object and can be consulted at any time.
This can be useful since GtkCellLayout widgets usually have to support requesting and rendering rows in treemodels with an exceedingly large amount of rows. The GtkCellLayout widget in that case would calculate the required width of the rows in an idle or timeout source (see g_timeout_add()) and when the widget is requested its actual width in GtkWidgetClass.get_preferred_width() it can simply consult the width accumulated so far in the GtkCellAreaContext object.
A simple example where rows are rendered from top to bottom and take up the full width of the layouting widget would look like:
In the above example the Foo widget has to make sure that some row sizes have been calculated (the amount of rows that Foo judged was appropriate to request space for in a single timeout iteration) before simply returning the amount of space required by the area via the GtkCellAreaContext.
Requesting the height for width (or width for height) of an area is a similar task except in this case the GtkCellAreaContext does not store the data (actually, it does not know how much space the layouting widget plans to allocate it for every row. It's up to the layouting widget to render each row of data with the appropriate height and width which was requested by the GtkCellArea).
In order to request the height for width of all the rows at the root level of a GtkTreeModel one would do the following:
Note that in the above example we would need to cache the heights returned for each row so that we would know what sizes to render the areas for each row. However we would only want to really cache the heights if the request is intended for the layouting widgets real allocation.
In some cases the layouting widget is requested the height for an arbitrary for_width, this is a special case for layouting widgets who need to request size for tens of thousands of rows. For this case it's only important that the layouting widget calculate one reasonably sized chunk of rows and return that height synchronously. The reasoning here is that any layouting widget is at least capable of synchronously calculating enough height to fill the screen height (or scrolled window height) in response to a single call to GtkWidgetClass.get_preferred_height_for_width(). Returning a perfect height for width that is larger than the screen area is inconsequential since after the layouting receives an allocation from a scrolled window it simply continues to drive the scrollbar values while more and more height is required for the row heights that are calculated in the background.
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Rendering Areas
Once area sizes have been aquired at least for the rows in the visible area of the layouting widget they can be rendered at GtkWidgetClass.draw() time.
A crude example of how to render all the rows at the root level runs as follows:
Note that the cached height in this example really depends on how the layouting widget works. The layouting widget might decide to give every row its minimum or natural height or, if the model content is expected to fit inside the layouting widget without scrolling, it would make sense to calculate the allocation for each row at "size-allocate" time using gtk_distribute_natural_allocation().
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Handling Events and Driving Keyboard Focus
Passing events to the area is as simple as handling events on any normal widget and then passing them to the gtk_cell_area_event() API as they come in. Usually GtkCellArea is only interested in button events, however some customized derived areas can be implemented who are interested in handling other events. Handling an event can trigger the "focus-changed" signal to fire; as well as "add-editable" in the case that an editable cell was clicked and needs to start editing. You can call gtk_cell_area_stop_editing() at any time to cancel any cell editing that is currently in progress.
The GtkCellArea drives keyboard focus from cell to cell in a way similar to GtkWidget. For layouting widgets that support giving focus to cells it's important to remember to pass GTK_CELL_RENDERER_FOCUSED to the area functions for the row that has focus and to tell the area to paint the focus at render time.
Layouting widgets that accept focus on cells should implement the GtkWidgetClass.focus() virtual method. The layouting widget is always responsible for knowing where GtkTreeModel rows are rendered inside the widget, so at GtkWidgetClass.focus() time the layouting widget should use the GtkCellArea methods to navigate focus inside the area and then observe the GtkDirectionType to pass the focus to adjacent rows and areas.
A basic example of how the GtkWidgetClass.focus() virtual method should be implemented:
Note that the layouting widget is responsible for matching the GtkDirectionType values to the way it lays out its cells.
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Cell Properties
The GtkCellArea introduces cell properties for GtkCellRenderers in very much the same way that GtkContainer introduces child properties for GtkWidgets. This provides some general interfaces for defining the relationship cell areas have with their cells. For instance in a GtkCellAreaBox a cell might "expand" and receive extra space when the area is allocated more than its full natural request, or a cell might be configured to "align" with adjacent rows which were requested and rendered with the same GtkCellAreaContext.
Use gtk_cell_area_class_install_cell_property() to install cell properties for a cell area class and gtk_cell_area_class_find_cell_property() or gtk_cell_area_class_list_cell_properties() to get information about existing cell properties.
To set the value of a cell property, use gtk_cell_area_cell_set_property(), gtk_cell_area_cell_set() or gtk_cell_area_cell_set_valist(). To obtain the value of a cell property, use gtk_cell_area_cell_get_property(), gtk_cell_area_cell_get() or gtk_cell_area_cell_get_valist().