Internal$signalsCompile-time signal type information.
This instance property is generated only for TypeScript type checking. It is not defined at runtime and should not be accessed in JS code.
Creates a new Gtk.TreeModel, with child_model as the child_model
and root as the virtual root.
Optionalroot: Gtk.TreePathA Gtk.TreePath or null.
A new Gtk.TreeModel.
Calls func on each node in model in a depth-first fashion.
If func returns true, then the tree ceases to be walked,
and gtk_tree_model_foreach() returns.
a function to be called on each row
Returns the type of the column.
the column index
the type of the column
Returns a set of flags supported by this interface.
The flags are a bitwise combination of Gtk.TreeModelFlags.
The flags supported should not change during the lifetime
of the tree_model.
the flags supported by this interface
Sets iter to a valid iterator pointing to path. If path does
not exist, iter is set to an invalid iterator and false is returned.
the Gtk.TreePath-struct
true, if iter was set
Sets iter to a valid iterator pointing to path_string, if it
exists. Otherwise, iter is left invalid and false is returned.
a string representation of a Gtk.TreePath-struct
true, if iter was set
Returns the number of columns supported by tree_model.
the number of columns
Returns a newly-created Gtk.TreePath-struct referenced by iter.
This path should be freed with gtk_tree_path_free().
the Gtk.TreeIter-struct
a newly-created Gtk.TreePath-struct
Generates a string representation of the iter.
This string is a “:” separated list of numbers. For example, “4:10:0:3” would be an acceptable return value for this string.
a Gtk.TreeIter-struct
a newly-allocated string. Must be freed with g_free().
Initializes and sets value to that at column.
When done with value, g_value_unset() needs to be called
to free any allocated memory.
the Gtk.TreeIter-struct
the column to lookup the value at
Sets iter to point to the first child of parent.
If parent has no children, false is returned and iter is
set to be invalid. parent will remain a valid node after this
function has been called.
If parent is null returns the first node, equivalent to
gtk_tree_model_get_iter_first (tree_model, iter);
Optionalparent: Gtk.TreeIterthe Gtk.TreeIter-struct, or null
true, if iter has been set to the first child
Returns true if iter has children, false otherwise.
the Gtk.TreeIter-struct to test for children
true if iter has children
Returns the number of children that iter has.
As a special case, if iter is null, then the number
of toplevel nodes is returned.
Optionaliter: Gtk.TreeIterthe Gtk.TreeIter-struct, or null
the number of children of iter
Sets iter to point to the node following it at the current level.
If there is no next iter, false is returned and iter is set
to be invalid.
the Gtk.TreeIter-struct
true if iter has been changed to the next node
Sets iter to be the child of parent, using the given index.
The first index is 0. If n is too big, or parent has no children,
iter is set to an invalid iterator and false is returned. parent
will remain a valid node after this function has been called. As a
special case, if parent is null, then the n-th root node
is set.
the Gtk.TreeIter-struct to get the child from, or null.
the index of the desired child
true, if parent has an n-th child
Sets iter to be the parent of child.
If child is at the toplevel, and doesn’t have a parent, then
iter is set to an invalid iterator and false is returned.
child will remain a valid node after this function has been
called.
iter will be initialized before the lookup is performed, so child
and iter cannot point to the same memory location.
the Gtk.TreeIter-struct
true, if iter is set to the parent of child
Sets iter to point to the previous node at the current level.
If there is no previous iter, false is returned and iter is
set to be invalid.
the Gtk.TreeIter-struct
true if iter has been changed to the previous node
Lets the tree ref the node.
This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons.
This function is primarily meant as a way for views to let caching models know when nodes are being displayed (and hence, whether or not to cache that node). Being displayed means a node is in an expanded branch, regardless of whether the node is currently visible in the viewport. For example, a file-system based model would not want to keep the entire file-hierarchy in memory, just the sections that are currently being displayed by every current view.
A model should be expected to be able to get an iter independent of its reffed state.
the Gtk.TreeIter-struct
Emits the Gtk.TreeModel.SignalSignatures.row_changed | Gtk.TreeModel::row-changed signal on tree_model.
a Gtk.TreePath-struct pointing to the changed row
a valid Gtk.TreeIter-struct pointing to the changed row
Emits the Gtk.TreeModel.SignalSignatures.row_deleted | Gtk.TreeModel::row-deleted signal on tree_model.
This should be called by models after a row has been removed.
The location pointed to by path should be the location that
the row previously was at. It may not be a valid location anymore.
Nodes that are deleted are not unreffed, this means that any outstanding references on the deleted node should not be released.
a Gtk.TreePath-struct pointing to the previous location of the deleted row
Emits the Gtk.TreeModel.SignalSignatures.row_has_child_toggled | Gtk.TreeModel::row-has-child-toggled signal on
tree_model. This should be called by models after the child
state of a node changes.
a Gtk.TreePath-struct pointing to the changed row
a valid Gtk.TreeIter-struct pointing to the changed row
Emits the Gtk.TreeModel.SignalSignatures.row_inserted | Gtk.TreeModel::row-inserted signal on tree_model.
a Gtk.TreePath-struct pointing to the inserted row
a valid Gtk.TreeIter-struct pointing to the inserted row
Emits the Gtk.TreeModel.SignalSignatures.rows_reordered | Gtk.TreeModel::rows-reordered signal on tree_model.
This should be called by models when their rows have been reordered.
a Gtk.TreePath-struct pointing to the tree node whose children have been reordered
a valid Gtk.TreeIter-struct pointing to the node whose children have been reordered, or null if the depth of path is 0
an array of integers mapping the current position of each child to its old position before the re-ordering, i.e. new_order``[newpos] = oldpos
Lets the tree unref the node.
This is an optional method for models to implement.
To be more specific, models may ignore this call as it exists
primarily for performance reasons. For more information on what
this means, see gtk_tree_model_ref_node().
Please note that nodes that are deleted are not unreffed.
the Gtk.TreeIter-struct
Creates a binding between source_property on source and target_property
on target.
Whenever the source_property is changed the target_property is
updated using the same value. For instance:
g_object_bind_property (action, "active", widget, "sensitive", 0);
Will result in the "sensitive" property of the widget GObject.Object instance to be updated with the same value of the "active" property of the action GObject.Object instance.
If flags contains GObject.BindingFlags.BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well.
The binding will automatically be removed when either the source or the
target instances are finalized. To remove the binding without affecting the
source and the target you can just call g_object_unref() on the returned
GObject.Binding instance.
Removing the binding by calling g_object_unref() on it must only be done if
the binding, source and target are only used from a single thread and it
is clear that both source and target outlive the binding. Especially it
is not safe to rely on this if the binding, source or target can be
finalized from different threads. Keep another reference to the binding and
use g_binding_unbind() instead to be on the safe side.
A GObject.Object can have multiple bindings.
the property on source to bind
the target GObject.Object
the property on target to bind
flags to pass to GObject.Binding
the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.
Complete version of g_object_bind_property().
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
If flags contains GObject.BindingFlags.BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well. The transform_from function is only used in case
of bidirectional bindings, otherwise it will be ignored
The binding will automatically be removed when either the source or the
target instances are finalized. This will release the reference that is
being held on the GObject.Binding instance; if you want to hold on to the
GObject.Binding instance, you will need to hold a reference to it.
To remove the binding, call g_binding_unbind().
A GObject.Object can have multiple bindings.
The same user_data parameter will be used for both transform_to
and transform_from transformation functions; the notify function will
be called once, when the binding is removed. If you need different data
for each transformation function, please use
g_object_bind_property_with_closures() instead.
the property on source to bind
the target GObject.Object
the property on target to bind
flags to pass to GObject.Binding
Optionaltransform_to: BindingTransformFuncthe transformation function from the source to the target, or null to use the default
Optionaltransform_from: BindingTransformFuncthe transformation function from the target to the source, or null to use the default
Optionalnotify: DestroyNotifya function to call when disposing the binding, to free resources used by the transformation functions, or null if not required
the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
This function is the language bindings friendly version of
g_object_bind_property_full(), using GClosures instead of
function pointers.
the property on source to bind
the target GObject.Object
the property on target to bind
flags to pass to GObject.Binding
a GObject.Closure wrapping the transformation function from the source to the target, or null to use the default
a GObject.Closure wrapping the transformation function from the target to the source, or null to use the default
the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.
Blocks a handler of an instance so it will not be called during any signal emissions
Handler ID of the handler to be blocked
SignalconnectSignalconnect_Disconnects a handler from an instance so it will not be called during any future or currently ongoing emissions of the signal it has been connected to.
Handler ID of the handler to be disconnected
SignalemitThis function is intended for GObject.Object implementations to re-enforce
a [floating][floating-ref] 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().
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
GObject.Object::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.
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
the data if found, or null if no such data exists.
Gets a property of an object.
The value can be:
In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling GObject.Value.unset.
Note that GObject.Object.get_property is really intended for language bindings, GObject.Object.get is much more convenient for C programming.
The name of the property to get
Return location for the property value. Can be an empty GObject.Value initialized by G_VALUE_INIT (auto-initialized with expected type since GLib 2.60), a GObject.Value initialized with the expected property type, or a GObject.Value initialized with a transformable type
This function gets back user data pointers stored via
g_object_set_qdata().
A GLib.Quark, naming the user data pointer
The user data pointer set, or null
Gets n_properties properties for an object.
Obtained properties will be set to values. All properties must be valid.
Warnings will be emitted and undefined behaviour may result if invalid
properties are passed in.
the names of each property to get
the values of each property to get
Checks whether object has a [floating][floating-ref] reference.
true if object has a floating reference
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.
Note that emission of the notify signal may be blocked with
g_object_freeze_notify(). In this case, the signal emissions are queued
and will be emitted (in reverse order) when g_object_thaw_notify() is
called.
the name of a property installed on the class of object.
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
g_object_class_install_property() inside a static array, e.g.:
typedef enum
{
PROP_FOO = 1,
PROP_LAST
} MyObjectProperty;
static GParamSpec *properties[PROP_LAST];
static void
my_object_class_init (MyObjectClass *klass)
{
properties[PROP_FOO] = g_param_spec_int ("foo", NULL, NULL,
0, 100,
50,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
g_object_class_install_property (gobject_class,
PROP_FOO,
properties[PROP_FOO]);
}
and then notify a change on the "foo" property with:
g_object_notify_by_pspec (self, properties[PROP_FOO]);
the GObject.ParamSpec of a property installed on the class of object.
Increases the reference count of object.
Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type
of object will be propagated to the return type (using the GCC typeof()
extension), so any casting the caller needs to do on the return type must be
explicit.
the same object
Increase the reference count of object, and possibly remove the
[floating][floating-ref] 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 GLib 2.56, the type of object will be propagated to the return type
under the same conditions as for g_object_ref().
object
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Sets multiple properties of an object at once. The properties argument should be a dictionary mapping property names to values.
Object containing the properties to set
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.
Internally, the key is converted to a GLib.Quark using g_quark_from_string().
This means a copy of key is kept permanently (even after object has been
finalized) — so it is recommended to only use a small, bounded set of values
for key in your program, to avoid the GLib.Quark storage growing unbounded.
name of the key
Optionaldata: anydata to associate with that key
Sets a property on an object.
The name of the property to set
The value to set the property to
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
name of the key
the data if found, or null if no such data exists.
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
user data pointers with a destroy notifier, for example:
void
object_add_to_user_list (GObject *object,
const gchar *new_string)
{
// the quark, naming the object data
GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
// retrieve the old string list
GList *list = g_object_steal_qdata (object, quark_string_list);
// prepend new string
list = g_list_prepend (list, g_strdup (new_string));
// this changed 'list', so we need to set it again
g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
GList *node, *list = data;
for (node = list; node; node = node->next)
g_free (node->data);
g_list_free (list);
}
Using g_object_get_qdata() in the above example, instead of
g_object_steal_qdata() would have left the destroy function set,
and thus the partial string list would have been freed upon
g_object_set_qdata_full().
A GLib.Quark, naming the user data pointer
The user data pointer set, or null
Stops a signal's emission by the given signal name. This will prevent the default handler and any subsequent signal handlers from being invoked.
Name of the signal to stop emission of
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 GObject.Object::notify signal is emitted for each property, in the reverse order in which they have been queued.
It is an error to call this function when the freeze count is zero.
Unblocks a handler so it will be called again during any signal emissions
Handler ID of the handler to be unblocked
Decreases the reference count of object. When its reference count
drops to 0, the object is finalized (i.e. its memory is freed).
If the pointer to the GObject.Object may be reused in future (for example, if it is
an instance variable of another object), it is recommended to clear the
pointer to null rather than retain a dangling pointer to a potentially
invalid GObject.Object instance. Use g_clear_object() for this.
Virtualvfunc_the constructed function is called by g_object_new() as the
final step of the object creation process. At the point of the call, all
construction properties have been set on the object. The purpose of this
call is to allow for object initialisation steps that can only be performed
after construction properties have been set. constructed implementors
should chain up to the constructed call of their parent class to allow it
to complete its initialisation.
Virtualvfunc_Virtualvfunc_the dispose function is supposed to drop all references to other
objects, but keep the instance otherwise intact, so that client method
invocations still work. It may be run multiple times (due to reference
loops). Before returning, dispose should chain up to the dispose method
of the parent class.
Virtualvfunc_instance finalization function, should finish the finalization of
the instance begun in dispose and chain up to the finalize method of the
parent class.
Virtualvfunc_Virtualvfunc_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.
Note that emission of the notify signal may be blocked with
g_object_freeze_notify(). In this case, the signal emissions are queued
and will be emitted (in reverse order) when g_object_thaw_notify() is
called.
Virtualvfunc_the generic setter for all properties of this type. Should be
overridden for every type with properties. If implementations of
set_property don't emit property change notification explicitly, this will
be done implicitly by the type system. However, if the notify signal is
emitted explicitly, the type system will not emit it a second time.
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.
GObject.Closure to watch
Virtualvfunc_Virtualvfunc_Returns a set of flags supported by this interface.
The flags are a bitwise combination of Gtk.TreeModelFlags.
The flags supported should not change during the lifetime
of the tree_model.
Virtualvfunc_Sets iter to a valid iterator pointing to path. If path does
not exist, iter is set to an invalid iterator and false is returned.
the Gtk.TreePath-struct
Virtualvfunc_Returns the number of columns supported by tree_model.
Virtualvfunc_Returns a newly-created Gtk.TreePath-struct referenced by iter.
This path should be freed with gtk_tree_path_free().
the Gtk.TreeIter-struct
Virtualvfunc_Initializes and sets value to that at column.
When done with value, g_value_unset() needs to be called
to free any allocated memory.
the Gtk.TreeIter-struct
the column to lookup the value at
Virtualvfunc_Sets iter to point to the first child of parent.
If parent has no children, false is returned and iter is
set to be invalid. parent will remain a valid node after this
function has been called.
If parent is null returns the first node, equivalent to
gtk_tree_model_get_iter_first (tree_model, iter);
Optionalparent: Gtk.TreeIterthe Gtk.TreeIter-struct, or null
Virtualvfunc_Returns true if iter has children, false otherwise.
the Gtk.TreeIter-struct to test for children
Virtualvfunc_Returns the number of children that iter has.
As a special case, if iter is null, then the number
of toplevel nodes is returned.
Optionaliter: Gtk.TreeIterthe Gtk.TreeIter-struct, or null
Virtualvfunc_Sets iter to point to the node following it at the current level.
If there is no next iter, false is returned and iter is set
to be invalid.
the Gtk.TreeIter-struct
Virtualvfunc_Sets iter to be the child of parent, using the given index.
The first index is 0. If n is too big, or parent has no children,
iter is set to an invalid iterator and false is returned. parent
will remain a valid node after this function has been called. As a
special case, if parent is null, then the n-th root node
is set.
the Gtk.TreeIter-struct to get the child from, or null.
the index of the desired child
Virtualvfunc_Sets iter to be the parent of child.
If child is at the toplevel, and doesn’t have a parent, then
iter is set to an invalid iterator and false is returned.
child will remain a valid node after this function has been
called.
iter will be initialized before the lookup is performed, so child
and iter cannot point to the same memory location.
the Gtk.TreeIter-struct
Virtualvfunc_Sets iter to point to the previous node at the current level.
If there is no previous iter, false is returned and iter is
set to be invalid.
the Gtk.TreeIter-struct
Virtualvfunc_Lets the tree ref the node.
This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons.
This function is primarily meant as a way for views to let caching models know when nodes are being displayed (and hence, whether or not to cache that node). Being displayed means a node is in an expanded branch, regardless of whether the node is currently visible in the viewport. For example, a file-system based model would not want to keep the entire file-hierarchy in memory, just the sections that are currently being displayed by every current view.
A model should be expected to be able to get an iter independent of its reffed state.
the Gtk.TreeIter-struct
Virtualvfunc_Emits the Gtk.TreeModel.SignalSignatures.row_changed | Gtk.TreeModel::row-changed signal on tree_model.
a Gtk.TreePath-struct pointing to the changed row
a valid Gtk.TreeIter-struct pointing to the changed row
Virtualvfunc_Emits the Gtk.TreeModel.SignalSignatures.row_deleted | Gtk.TreeModel::row-deleted signal on tree_model.
This should be called by models after a row has been removed.
The location pointed to by path should be the location that
the row previously was at. It may not be a valid location anymore.
Nodes that are deleted are not unreffed, this means that any outstanding references on the deleted node should not be released.
a Gtk.TreePath-struct pointing to the previous location of the deleted row
Virtualvfunc_Emits the Gtk.TreeModel.SignalSignatures.row_has_child_toggled | Gtk.TreeModel::row-has-child-toggled signal on
tree_model. This should be called by models after the child
state of a node changes.
a Gtk.TreePath-struct pointing to the changed row
a valid Gtk.TreeIter-struct pointing to the changed row
Virtualvfunc_Emits the Gtk.TreeModel.SignalSignatures.row_inserted | Gtk.TreeModel::row-inserted signal on tree_model.
a Gtk.TreePath-struct pointing to the inserted row
a valid Gtk.TreeIter-struct pointing to the inserted row
Virtualvfunc_Lets the tree unref the node.
This is an optional method for models to implement.
To be more specific, models may ignore this call as it exists
primarily for performance reasons. For more information on what
this means, see gtk_tree_model_ref_node().
Please note that nodes that are deleted are not unreffed.
the Gtk.TreeIter-struct
The Gtk.TreeModel interface defines a generic tree interface for use by the Gtk.TreeView widget. It is an abstract interface, and is designed to be usable with any appropriate data structure. The programmer just has to implement this interface on their own data type for it to be viewable by a Gtk.TreeView widget.
The model is represented as a hierarchical tree of strongly-typed, columned data. In other words, the model can be seen as a tree where every node has different values depending on which column is being queried. The type of data found in a column is determined by using the GType system (ie. #G_TYPE_INT, #GTK_TYPE_BUTTON, #G_TYPE_POINTER, etc). The types are homogeneous per column across all nodes. It is important to note that this interface only provides a way of examining a model and observing changes. The implementation of each individual model decides how and if changes are made.
In order to make life simpler for programmers who do not need to write their own specialized model, two generic models are provided — the Gtk.TreeStore and the Gtk.ListStore. To use these, the developer simply pushes data into these models as necessary. These models provide the data structure as well as all appropriate tree interfaces. As a result, implementing drag and drop, sorting, and storing data is trivial. For the vast majority of trees and lists, these two models are sufficient.
Models are accessed on a node/column level of granularity. One can query for the value of a model at a certain node and a certain column on that node. There are two structures used to reference a particular node in a model. They are the Gtk.TreePath-struct and the Gtk.TreeIter-struct (“iter” is short for iterator). Most of the interface consists of operations on a Gtk.TreeIter-struct.
A path is essentially a potential node. It is a location on a model that may or may not actually correspond to a node on a specific model. The Gtk.TreePath-struct can be converted into either an array of unsigned integers or a string. The string form is a list of numbers separated by a colon. Each number refers to the offset at that level. Thus, the path
0refers to the root node and the path2:4refers to the fifth child of the third node.By contrast, a Gtk.TreeIter-struct is a reference to a specific node on a specific model. It is a generic struct with an integer and three generic pointers. These are filled in by the model in a model-specific way. One can convert a path to an iterator by calling
gtk_tree_model_get_iter(). These iterators are the primary way of accessing a model and are similar to the iterators used by Gtk.TextBuffer. They are generally statically allocated on the stack and only used for a short time. The model interface defines a set of operations using them for navigating the model.It is expected that models fill in the iterator with private data. For example, the Gtk.ListStore model, which is internally a simple linked list, stores a list node in one of the pointers. The Gtk.TreeModelSort stores an array and an offset in two of the pointers. Additionally, there is an integer field. This field is generally filled with a unique stamp per model. This stamp is for catching errors resulting from using invalid iterators with a model.
The lifecycle of an iterator can be a little confusing at first. Iterators are expected to always be valid for as long as the model is unchanged (and doesn’t emit a signal). The model is considered to own all outstanding iterators and nothing needs to be done to free them from the user’s point of view. Additionally, some models guarantee that an iterator is valid for as long as the node it refers to is valid (most notably the Gtk.TreeStore and Gtk.ListStore). Although generally uninteresting, as one always has to allow for the case where iterators do not persist beyond a signal, some very important performance enhancements were made in the sort model. As a result, the #GTK_TREE_MODEL_ITERS_PERSIST flag was added to indicate this behavior.
To help show some common operation of a model, some examples are provided. The first example shows three ways of getting the iter at the location
3:2:5. While the first method shown is easier, the second is much more common, as you often get paths from callbacks.Acquiring a Gtk.TreeIter-struct
This second example shows a quick way of iterating through a list and getting a string and an integer from each row. The
populate_model()function used below is not shown, as it is specific to the Gtk.ListStore. For information on how to write such a function, see the Gtk.ListStore documentation.Reading data from a Gtk.TreeModel
The Gtk.TreeModel interface contains two methods for reference counting:
gtk_tree_model_ref_node()andgtk_tree_model_unref_node(). These two methods are optional to implement. The reference counting is meant as a way for views to let models know when nodes are being displayed. Gtk.TreeView will take a reference on a node when it is visible, which means the node is either in the toplevel or expanded. Being displayed does not mean that the node is currently directly visible to the user in the viewport. Based on this reference counting scheme a caching model, for example, can decide whether or not to cache a node based on the reference count. A file-system based model would not want to keep the entire file hierarchy in memory, but just the folders that are currently expanded in every current view.When working with reference counting, the following rules must be taken into account:
Never take a reference on a node without owning a reference on its parent. This means that all parent nodes of a referenced node must be referenced as well.
Outstanding references on a deleted node are not released. This is not possible because the node has already been deleted by the time the row-deleted signal is received.
Models are not obligated to emit a signal on rows of which none of its siblings are referenced. To phrase this differently, signals are only required for levels in which nodes are referenced. For the root level however, signals must be emitted at all times (however the root level is always referenced when any view is attached).