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Diffstat (limited to 'clutter/clutter/clutter-constraint.c')
| -rw-r--r-- | clutter/clutter/clutter-constraint.c | 250 |
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diff --git a/clutter/clutter/clutter-constraint.c b/clutter/clutter/clutter-constraint.c deleted file mode 100644 index fc0590744..000000000 --- a/clutter/clutter/clutter-constraint.c +++ /dev/null @@ -1,250 +0,0 @@ -/* - * Clutter. - * - * An OpenGL based 'interactive canvas' library. - * - * Copyright (C) 2010 Intel Corporation. - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library. If not, see <http://www.gnu.org/licenses/>. - * - * Author: - * Emmanuele Bassi <ebassi@linux.intel.com> - */ - -/** - * SECTION:clutter-constraint - * @Title: ClutterConstraint - * @Short_Description: Abstract class for constraints on position or size - * @See_Also: #ClutterAction - * - * #ClutterConstraint is a base abstract class for modifiers of a #ClutterActor - * position or size. - * - * A #ClutterConstraint sub-class should contain the logic for modifying - * the position or size of the #ClutterActor to which it is applied, by - * updating the actor's allocation. Each #ClutterConstraint can change the - * allocation of the actor to which they are applied by overriding the - * #ClutterConstraintClass.update_allocation() virtual function. - * - * #ClutterConstraint is available since Clutter 1.4 - * - * ## Using Constraints - * - * Constraints can be used with fixed layout managers, like - * #ClutterFixedLayout, or with actors implicitly using a fixed layout - * manager, like #ClutterGroup and #ClutterStage. - * - * Constraints provide a way to build user interfaces by using - * relations between #ClutterActors, without explicit fixed - * positioning and sizing, similarly to how fluid layout managers like - * #ClutterBoxLayout lay out their children. - * - * Constraints are attached to a #ClutterActor, and are available - * for inspection using clutter_actor_get_constraints(). - * - * Clutter provides different implementation of the #ClutterConstraint - * abstract class, for instance: - * - * - #ClutterAlignConstraint, a constraint that can be used to align - * an actor to another one on either the horizontal or the vertical - * axis, using a normalized value between 0 and 1. - * - #ClutterBindConstraint, a constraint binds the X, Y, width or height - * of an actor to the corresponding position or size of a source actor, - * with or without an offset. - * - #ClutterSnapConstraint, a constraint that "snaps" together the edges - * of two #ClutterActors; if an actor uses two constraints on both its - * horizontal or vertical edges then it can also expand to fit the empty - * space. - * - * The [constraints example](https://git.gnome.org/browse/clutter/tree/examples/constraints.c?h=clutter-1.18) - * uses various types of #ClutterConstraints to lay out three actors on a - * resizable stage. Only the central actor has an explicit size, and no - * actor has an explicit position. - * - * - The #ClutterActor with #ClutterActor:name `layerA` is explicitly - * sized to 100 pixels by 25 pixels, and it's added to the #ClutterStage - * - two #ClutterAlignConstraints are used to anchor `layerA` to the - * center of the stage, by using 0.5 as the alignment #ClutterAlignConstraint:factor on - * both the X and Y axis - * - the #ClutterActor with #ClutterActor:name `layerB` is added to the - * #ClutterStage with no explicit size - * - the #ClutterActor:x and #ClutterActor:width of `layerB` are bound - * to the same properties of `layerA` using two #ClutterBindConstraint - * objects, thus keeping `layerB` aligned to `layerA` - * - the top edge of `layerB` is snapped together with the bottom edge - * of `layerA`; the bottom edge of `layerB` is also snapped together with - * the bottom edge of the #ClutterStage; an offset is given to the two - * #ClutterSnapConstraintss to allow for some padding; since `layerB` is - * snapped between two different #ClutterActors, its height is stretched - * to match the gap - * - the #ClutterActor with #ClutterActor:name `layerC` mirrors `layerB`, - * snapping the top edge of the #ClutterStage to the top edge of `layerC` - * and the top edge of `layerA` to the bottom edge of `layerC` - * - * You can try resizing interactively the #ClutterStage and verify - * that the three #ClutterActors maintain the same position and - * size relative to each other, and to the #ClutterStage. - * - * It is important to note that Clutter does not avoid loops or - * competing constraints; if two or more #ClutterConstraints - * are operating on the same positional or dimensional attributes of an - * actor, or if the constraints on two different actors depend on each - * other, then the behavior is undefined. - * - * ## Implementing a ClutterConstraint - * - * Creating a sub-class of #ClutterConstraint requires the - * implementation of the #ClutterConstraintClass.update_allocation() - * virtual function. - * - * The `update_allocation()` virtual function is called during the - * allocation sequence of a #ClutterActor, and allows any #ClutterConstraint - * attached to that actor to modify the allocation before it is passed to - * the actor's #ClutterActorClass.allocate() implementation. - * - * The #ClutterActorBox passed to the `update_allocation()` implementation - * contains the original allocation of the #ClutterActor, plus the eventual - * modifications applied by the other #ClutterConstraints, in the same order - * the constraints have been applied to the actor. - * - * It is not necessary for a #ClutterConstraint sub-class to chain - * up to the parent's implementation. - * - * If a #ClutterConstraint is parametrized - i.e. if it contains - * properties that affect the way the constraint is implemented - it should - * call clutter_actor_queue_relayout() on the actor to which it is attached - * to whenever any parameter is changed. The actor to which it is attached - * can be recovered at any point using clutter_actor_meta_get_actor(). - */ - -#include "clutter-build-config.h" - -#include <string.h> - -#include "clutter-constraint-private.h" - -#include "clutter-actor.h" -#include "clutter-actor-meta-private.h" -#include "clutter-private.h" - -G_DEFINE_ABSTRACT_TYPE (ClutterConstraint, - clutter_constraint, - CLUTTER_TYPE_ACTOR_META); - -static void -constraint_update_allocation (ClutterConstraint *constraint, - ClutterActor *actor, - ClutterActorBox *allocation) -{ -} - -static void -constraint_update_preferred_size (ClutterConstraint *constraint, - ClutterActor *actor, - ClutterOrientation direction, - float for_size, - float *minimum_size, - float *natural_size) -{ -} - -static void -clutter_constraint_set_enabled (ClutterActorMeta *meta, - gboolean is_enabled) -{ - ClutterActorMetaClass *parent_class = - CLUTTER_ACTOR_META_CLASS (clutter_constraint_parent_class); - ClutterActor *actor; - - actor = clutter_actor_meta_get_actor (meta); - if (actor) - clutter_actor_queue_relayout (actor); - - parent_class->set_enabled (meta, is_enabled); -} - -static void -clutter_constraint_class_init (ClutterConstraintClass *klass) -{ - ClutterActorMetaClass *actor_meta_class = CLUTTER_ACTOR_META_CLASS (klass); - - actor_meta_class->set_enabled = clutter_constraint_set_enabled; - - klass->update_allocation = constraint_update_allocation; - klass->update_preferred_size = constraint_update_preferred_size; -} - -static void -clutter_constraint_init (ClutterConstraint *self) -{ -} - -/*< private > - * clutter_constraint_update_allocation: - * @constraint: a #ClutterConstraint - * @actor: a #ClutterActor - * @allocation: (inout): the allocation to modify - * - * Asks the @constraint to update the @allocation of a #ClutterActor. - * - * Returns: %TRUE if the allocation was updated - */ -gboolean -clutter_constraint_update_allocation (ClutterConstraint *constraint, - ClutterActor *actor, - ClutterActorBox *allocation) -{ - ClutterActorBox old_alloc; - - g_return_val_if_fail (CLUTTER_IS_CONSTRAINT (constraint), FALSE); - g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), FALSE); - g_return_val_if_fail (allocation != NULL, FALSE); - - old_alloc = *allocation; - - CLUTTER_CONSTRAINT_GET_CLASS (constraint)->update_allocation (constraint, - actor, - allocation); - - return !clutter_actor_box_equal (allocation, &old_alloc); -} - -/** - * clutter_constraint_update_preferred_size: - * @constraint: a #ClutterConstraint - * @actor: a #ClutterActor - * @direction: a #ClutterOrientation - * @for_size: the size in the opposite direction - * @minimum_size: (inout): the minimum size to modify - * @natural_size: (inout): the natural size to modify - * - * Asks the @constraint to update the size request of a #ClutterActor. - */ -void -clutter_constraint_update_preferred_size (ClutterConstraint *constraint, - ClutterActor *actor, - ClutterOrientation direction, - float for_size, - float *minimum_size, - float *natural_size) -{ - g_return_if_fail (CLUTTER_IS_CONSTRAINT (constraint)); - g_return_if_fail (CLUTTER_IS_ACTOR (actor)); - - CLUTTER_CONSTRAINT_GET_CLASS (constraint)->update_preferred_size (constraint, actor, - direction, - for_size, - minimum_size, - natural_size); -} |