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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/object-hierarchy.h | |
parent | Initial commit. (diff) | |
download | inkscape-cca66b9ec4e494c1d919bff0f71a820d8afab1fa.tar.xz inkscape-cca66b9ec4e494c1d919bff0f71a820d8afab1fa.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/object-hierarchy.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/object-hierarchy.h b/src/object-hierarchy.h new file mode 100644 index 0000000..e515a3d --- /dev/null +++ b/src/object-hierarchy.h @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Authors: + * MenTaLguY <mental@rydia.net> + * + * Copyright (C) 2004 MenTaLguY + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#ifndef SEEN_INKSCAPE_OBJECT_HIERARCHY_H +#define SEEN_INKSCAPE_OBJECT_HIERARCHY_H + +#include <cstddef> +#include <exception> +#include <list> +#include <sigc++/connection.h> +#include <sigc++/signal.h> + +class SPObject; + +namespace Inkscape { + +/** + * An Inkscape::ObjectHierarchy is useful for situations where one wishes + * to keep a reference to an SPObject, but fall back on one of its ancestors + * when that object is removed. + * + * That cannot be accomplished simply by hooking the "release" signal of the + * SPObject, as by the time that signal is emitted, the object's parent + * field has already been cleared. + * + * There are also some subtle refcounting issues to take into account. + * + * @see SPObject + */ +class ObjectHierarchy { +public: + + /** + * Create new object hierarchy. + * @param top The first entry if non-NULL. + */ + ObjectHierarchy(SPObject *top=nullptr); + + ~ObjectHierarchy(); + + bool contains(SPObject *object); + + sigc::connection connectAdded(const sigc::slot<void, SPObject *> &slot) { + return _added_signal.connect(slot); + } + sigc::connection connectRemoved(const sigc::slot<void, SPObject *> &slot) { + return _removed_signal.connect(slot); + } + sigc::connection connectChanged(const sigc::slot<void, SPObject *, SPObject *> &slot) + { + return _changed_signal.connect(slot); + } + + /** + * Remove all entries. + */ + void clear(); + + SPObject *top() { + return !_hierarchy.empty() ? _hierarchy.back().object : nullptr; + } + + /** + * Trim or expand hierarchy on top such that object becomes top entry. + */ + void setTop(SPObject *object); + + SPObject *bottom() { + return !_hierarchy.empty() ? _hierarchy.front().object : nullptr; + } + + /** + * Trim or expand hierarchy at bottom such that object becomes bottom entry. + */ + void setBottom(SPObject *object); + +private: + struct Record { + Record(SPObject *o, sigc::connection c) + : object(o), connection(c) {} + + SPObject *object; + sigc::connection connection; + }; + + ObjectHierarchy(ObjectHierarchy const &); // no copy + + void operator=(ObjectHierarchy const &); // no assign + + /** + * Add hierarchy from junior's parent to senior to this + * hierarchy's top. + */ + void _addTop(SPObject *senior, SPObject *junior); + + /** + * Add object to top of hierarchy. + * \pre object!=NULL. + */ + void _addTop(SPObject *object); + + /** + * Remove all objects above limit from hierarchy. + */ + void _trimAbove(SPObject *limit); + + /** + * Add hierarchy from senior to junior, in range (senior, junior], to this hierarchy's bottom. + */ + void _addBottom(SPObject *senior, SPObject *junior); + + /** + * Add object at bottom of hierarchy. + * \pre object!=NULL + */ + void _addBottom(SPObject *object); + + /** + * Remove all objects under given object. + * @param limit If NULL, remove all. + */ + void _trimBelow(SPObject *limit); + + Record _attach(SPObject *object); + + void _detach(Record &record); + + void _clear() { _trimBelow(nullptr); } + + void _trim_for_release(SPObject *released); + + std::list<Record> _hierarchy; + sigc::signal<void, SPObject *> _added_signal; + sigc::signal<void, SPObject *> _removed_signal; + sigc::signal<void, SPObject *, SPObject *> _changed_signal; +}; + +} + +#endif +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : |