1Gtk2::TreeModel(3) User Contributed Perl Documentation Gtk2::TreeModel(3)
2
6 Gtk2::TreeModel - wrapper for GtkTreeModel
7
9 # Three ways of getting the iter pointing to the location 3:2:5
10 # get the iterator from a string
12 $iter = $model->get_iter_from_string ("3:2:5");
13 # get the iterator from a path
15 $path = Gtk2::TreePath->new_from_string ("3:2:5");
16 $iter = $model->get_iter ($path);
17 # walk the tree to find the iterator
19 $iter = $model->iter_nth_child (undef, 3);
20 $iter = $model->iter_nth_child ($iter, 2);
21 $iter = $model->iter_nth_child ($iter, 5);
22 # getting and setting values
25 # assuming a model with these columns
27 use constant STRING_COLUMN => 0;
28 use constant INT_COLUMN => 1;
29 # set values
31 $model->set ($iter,
32 STRING_COLUMN, $new_string_value,
33 INT_COLUMN, $new_int_value);
34 # and get values
36 ($int, $str) = $model->get ($iter, INT_COLUMN, STRING_COLUMN);
37 # if you don't specify a list of column numbers,
39 # you get all of them.
40 @values = $model->get ($iter);
41
43 The Gtk2::TreeModel provides a generic tree interface for use by the
44 Gtk2::TreeView widget. It is an abstract interface, designed to be
45 usable with any appropriate data structure.
46 The model is represented as a hierarchical tree of strongly-typed,
48 columned data. In other words, the model can be seen as a tree where
49 every node has different values depending on which column is being
50 queried. The type of data found in a column is determined by using the
51 GType system (i.e. package names like Glib::Int, Gtk2::Button,
52 Glib::Scalar, etc). The types are homogeneous per column across all
53 nodes. It is important to note that this interface only provides a way
54 of examining a model and observing changes. The implementation of each
55 individual model decides how and if changes are made.
56 In order to make life simpler for programmers who do not need to write
58 their own specialized model, two generic models are provided - the
59 Gtk2::TreeStore and the Gtk2::ListStore. To use these, the developer
60 simply pushes data into these models as necessary. These models
61 provide the data structure as well as all appropriate tree interfaces.
62 As a result, implementing drag and drop, sorting, and storing data is
63 trivial. For the vast majority of trees and lists, these two models
64 are sufficient. For information on how to implement your own model in
65 Perl, see "CREATING A CUSTOM TREE MODEL".
66 Models are accessed on a node/column level of granularity. One can
68 query for the value of a model at a certain node and a certain column
69 on that node. There are two structures used to reference a particular
70 node in a model: the Gtk2::TreePath and the Gtk2::TreeIter (short for
71 "iterator"). Most of the interface consists of operations on a
72 Gtk2::TreeIter.
73 A path is essentially a potential node. It is a location on a model
75 that may or may not actually correspond to a node on a specific model.
76 The Gtk2::TreePath object can be converted into either an array of
77 unsigned integers or a string. The string form is a list of numbers
78 separated by a colon. Each number refers to the offset at that level.
79 Thus, the path '0' refers to the root node and the path '2:4' refers to
80 the fifth child of the third node.
81 By contrast, a Gtk2::TreeIter is a reference to a specific node on a
83 specific model. To the user of a model, the iter is merely an opaque
84 object. One can convert a path to an iterator by calling
85 "Gtk2::TreeModel::get_iter". These iterators are the primary way of
86 accessing a model and are similar to the iterators used by
87 Gtk2::TextBuffer. The model interface defines a set of operations using
88 them for navigating the model.
89 The iterators are generally used only for a short time, and their
91 behaviour is different to that suggested by the Gtk+ documentation.
92 They are not valid when the model is changed, even though get_flags
93 returns 'iters-persist'. Iterators obtained within a
94 GtkTreeModelForeachFunc are also invalid after the foreach terminates.
95 There may be other such cases. In the foreach case, and perhaps others,
96 a persistent iterator may be obtained by copying it (see
97 Glib::Boxed->copy).
98 (The preceding description and most of the method descriptions have
100 been adapted directly from the Gtk+ C API reference.)
101
103 Glib::Interface
104 +----Gtk2::TreeModel
105
107 string = $tree_model->get_column_type ($index_)
108 • $index_ (integer)
109 Returns the type of column $index_ as a package name.
111 treemodelflags = $tree_model->get_flags
113 $model->foreach ($func, $user_data=undef)
114 • $func (subroutine)
115 • $user_data (scalar)
117 Call $func on each row in $model as
119 bool = &$func ($model, $path, $iter, $user_data)
121 If $func returns true, the tree ceases to be walked, and
123 "$treemodel->foreach" returns.
124 $tree_model->get ($iter, ...)
126 • $iter (Gtk2::TreeIter)
127 • ... (list) of column indices
129 Fetch and return the model's values in the row pointed to by $iter. If
131 you specify no column indices, it returns the values for all of the
132 columns, otherwise, returns just those columns' values (in order).
133 This overrides overrides Glib::Object's "get", so you'll want to use
135 "$object->get_property" to get object properties.
136 treeiter = $tree_model->iter_children ($parent)
138 • $parent (Gtk2::TreeIter or undef)
139 Returns undef if $parent has no children, otherwise, returns a new iter
141 to the first child of $parent. $parent is unaltered. If $parent is
142 undef, this is equivalent to "Gtk2::TreeModel::get_iter_first".
143 treeiter = $tree_model->get_iter_first
145 Return a new iter pointing to the first node in the tree (the one at
146 path "0"), or undef if the tree is empty.
147 treeiter = $tree_model->get_iter_from_string ($path_string)
149 • $path_string (string)
150 Returns a new iter pointing to the node described by $path_string, or
152 undef if the path does not exist.
153 treeiter = $tree_model->get_iter ($path)
155 • $path (Gtk2::TreePath)
156 Returns a new Gtk2::TreeIter corresponding to $path.
158 boolean = $tree_model->iter_has_child ($iter)
160 • $iter (Gtk2::TreeIter)
161 Returns true if $iter has child nodes.
163 integer = $tree_model->iter_n_children ($iter=undef)
165 • $iter (Gtk2::TreeIter or undef)
166 Returns the number of children $iter has. If $iter is undef (or
168 omitted) then returns the number of toplevel nodes.
169 treeiter = $tree_model->iter_next ($iter)
171 • $iter (Gtk2::TreeIter)
172 Return a new iter pointing to node following $iter at the current
174 level, or undef if there is no next node. $iter is unaltered. (Note:
175 this is different from the C version, which modifies the iter.)
176 treeiter = $tree_model->iter_nth_child ($parent, $n)
178 • $parent (Gtk2::TreeIter or undef)
179 • $n (integer)
181 Returns an iter to the child of $parent at index $n, or undef if there
183 is no such child. $parent is unaltered.
184 treeiter = $tree_model->iter_parent ($child)
186 • $child (Gtk2::TreeIter)
187 Returns a new iter pointing to $child's parent node, or undef if $child
189 doesn't have a parent. $child is unaltered.
190 integer = $tree_model->get_n_columns
192 treepath = $tree_model->get_path ($iter)
193 • $iter (Gtk2::TreeIter)
194 Return a new Gtk2::TreePath corresponding to $iter.
196 $tree_model->ref_node ($iter)
198 • $iter (Gtk2::TreeIter)
199 Lets the tree ref the node. This is an optional method for models to
201 implement. To be more specific, models may ignore this call as it
202 exists primarily for performance reasons.
203 This function is primarily meant as a way for views to let caching
205 model know when nodes are being displayed (and hence, whether or not to
206 cache that node.) For example, a file-system based model would not
207 want to keep the entire file-hierarchy in memory, just the sections
208 that are currently being displayed by every current view.
209 A model should be expected to be able to get an iter independent of its
211 reffed state.
212 $tree_model->row_changed ($path, $iter)
214 • $path (Gtk2::TreePath)
215 • $iter (Gtk2::TreeIter)
217 Emits the "row_changed" signal on $tree_model.
219 $tree_model->row_deleted ($path)
221 • $path (Gtk2::TreePath)
222 Emits the "row_deleted" signal on $tree_model. This should be called
224 by models after a row has been removed. The location pointed to by
225 $path should be the removed row's old location. It may not be a valid
226 location anymore.
227 $tree_model->row_has_child_toggled ($path, $iter)
229 • $path (Gtk2::TreePath)
230 • $iter (Gtk2::TreeIter)
232 Emits the "row_has_child_toggled" signal on $tree_model. This should
234 be called by models after the child state of a node changes.
235 $tree_model->row_inserted ($path, $iter)
237 • $path (Gtk2::TreePath)
238 • $iter (Gtk2::TreeIter)
240 Emits the "row_inserted" signal on $tree_model.
242 $tree_model->rows_reordered ($path, $iter, ...)
244 • $path (Gtk2::TreePath) the tree node whose children have been
245 reordered
246 • $iter (Gtk2::TreeIter or undef) the tree node whose children have
248 been reordered
249 • ... (list) list of integers mapping the current position of each
251 child to its old position before the re-ordering, i.e.
252 $new_order[$newpos] = $oldpos. There should be as many elements in
253 this list as there are rows in $tree_model.
254 Emits the "rows-reordered" signal on $tree_model/ This should be
256 called by models with their rows have been reordered.
257 string = $tree_model->get_string_from_iter ($iter)
259 • $iter (Gtk2::TreeIter)
260 Generates a string representation of the iter. This string is a ':'
262 separated list of numbers. For example, "4:10:0:3" would be an
263 acceptable return value for this string.
264 Since: gtk+ 2.2
266 $tree_model->unref_node ($iter)
268 • $iter (Gtk2::TreeIter)
269 Lets the tree unref the node. This is an optional method for models to
271 implement. To be more specific, models may ignore this call as it
272 exists primarily for performance reasons.
273 For more information on what this means, see
275 "Gtk2::TreeModel::ref_node". Please note that nodes that are deleted
276 are not unreffed.
277 $tree_model->get_value ($iter, ...)
279 • $iter (Gtk2::TreeIter)
280 • ... (list) of column indices
282 Alias for get.
284
286 GTK+ provides two model implementations, Gtk2::TreeStore and
287 Gtk2::ListStore, which should be sufficient in most cases. For some
288 cases, however, it is advantageous to provide a custom tree model
289 implementation. It is possible to create custom tree models in Perl,
290 because we're cool like that.
291 To do this, you create a Glib::Object derivative which implements the
293 Gtk2::TreeModel interface; this is gtk2-perl-speak for "you have to add
294 a special key when you register your object type." For example:
295 package MyModel;
297 use Gtk2;
298 use Glib::Object::Subclass
299 Glib::Object::,
300 interfaces => [ Gtk2::TreeModel:: ],
301 ;
302 This will cause perl to call several virtual methods with
304 ALL_CAPS_NAMES when Gtk+ attempts to perform certain actions on the
305 model. You simply provide (or override) those methods.
306 TREE ITERS
308 Gtk2::TreeIter is normally an opaque object, but on the implementation
309 side of a Gtk2::TreeModel, you have to define what's inside. The
310 virtual methods described below deal with iters as a reference to an
311 array containing four values:
312 o stamp (integer)
314 A number unique to this model.
315 o user_data (integer)
317 An arbitrary integer value.
318 o user_data2 (scalar)
320 An arbitrary reference. Will not persist. May be undef.
321 o user_data3 (scalar)
323 An arbitrary reference. Will not persist. May be undef.
324 The two references, if used, will generally be to data within the
326 model, like a row array, or a node object in a tree or linked list.
327 Keeping the things referred to alive is the model's responsibility. An
328 iter doesn't make them persist, and if the things are destroyed then
329 any iters still containing them will become invalid (and result in
330 memory corruption if used). An iter only has to remain valid until the
331 model contents change, so generally anything internal to the model is
332 fine.
333 VIRTUAL METHODS
335 An implementation of
336 treemodelflags = GET_FLAGS ($model)
338 integer = GET_N_COLUMNS ($model)
339 string = GET_COLUMN_TYPE ($model, $index)
340 ARRAYREF = GET_ITER ($model, $path)
341 See above for a description of what goes in the returned array
342 reference.
343 treepath = GET_PATH ($model, ARRAYREF)
345 scalar = GET_VALUE ($model, ARRAYREF, $column)
346 Implements $treemodel->get().
347 ARRAYREF = ITER_NEXT ($model, ARRAYREF)
349 ARRAYREF = ITER_CHILDREN ($model, ARRAYREF)
350 boolean = ITER_HAS_CHILD ($model, ARRAYREF)
351 integer = ITER_N_CHILDREN ($model, ARRAYREF)
352 ARRAYREF = ITER_NTH_CHILD ($model, ARRAYREF, $n)
353 ARRAYREF = ITER_PARENT ($model, ARRAYREF)
354 REF_NODE ($model, ARRAYREF)
355 Optional.
356 UNREF_NODE ($model, ARRAYREF)
358 Optional.
359
361 row-changed (Gtk2::TreeModel, Gtk2::TreePath, Gtk2::TreeIter)
362 row-deleted (Gtk2::TreeModel, Gtk2::TreePath)
363 row-has-child-toggled (Gtk2::TreeModel, Gtk2::TreePath, Gtk2::TreeIter)
364 row-inserted (Gtk2::TreeModel, Gtk2::TreePath, Gtk2::TreeIter)
365 rows-reordered (Gtk2::TreeModel, Gtk2::TreePath, Gtk2::TreeIter,
366 gpointer)
367 Note that currently in a Perl subclass of an object implementing
369 "Gtk2::TreeModel", the class closure, ie. class default signal handler,
370 for the "rows-reordered" signal is called only with an integer address
371 for the reorder array parameter, not a Perl arrayref like a handler
372 installed with "signal_connect" receives. It works to
373 "signal_chain_from_overridden" with the address, but it's otherwise
374 fairly useless and will likely change in the future.
375
377 flags Gtk2::TreeModelFlags
378 • 'iters-persist' / 'GTK_TREE_MODEL_ITERS_PERSIST'
379 • 'list-only' / 'GTK_TREE_MODEL_LIST_ONLY'
381
383 Gtk2, Glib::Interface
384
386 Copyright (C) 2003-2011 by the gtk2-perl team.
387 This software is licensed under the LGPL. See Gtk2 for a full notice.
389perl v5.34.0 2021-07-22 Gtk2::TreeModel(3)