Use a QDoubleEndedList for the children of animation group jobs

This way it's fundamentally impossible to add the same animation job to
two different group jobs. The pointers are not exposed anymore and no
one can re-order the jobs.

Task-number: QTBUG-90401
Change-Id: Iebff4b64960c853915dd32714acd144fc5cdc00d
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 292 insertions, 0 deletions

diff --git a/src/qml/qml/ftw/qdoubleendedlist_p.h b/src/qml/qml/ftw/qdoubleendedlist_p.h
new file mode 100644
index 0000000000..33fe97502d
--- /dev/null
+++ b/src/qml/qml/ftw/qdoubleendedlist_p.h
@@ -0,0 +1,292 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QDOUBLEENDEDLIST_P_H
+#define QDOUBLEENDEDLIST_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+
+QT_BEGIN_NAMESPACE
+
+class QInheritedListNode
+{
+public:
+    ~QInheritedListNode() { remove(); }
+    bool isInList() const
+    {
+        Q_ASSERT((m_prev && m_next) || (!m_prev && !m_next));
+        return m_prev != nullptr;
+    }
+
+private:
+    template<class N>
+    friend class QDoubleEndedList;
+
+    void remove()
+    {
+        Q_ASSERT((m_prev && m_next) || (!m_prev && !m_next));
+        if (!m_prev)
+            return;
+
+        m_prev->m_next = m_next;
+        m_next->m_prev = m_prev;
+        m_prev = nullptr;
+        m_next = nullptr;
+    }
+
+    QInheritedListNode *m_next = nullptr;
+    QInheritedListNode *m_prev = nullptr;
+};
+
+template<class N>
+class QDoubleEndedList
+{
+public:
+    QDoubleEndedList()
+    {
+        m_head.m_next = &m_head;
+        m_head.m_prev = &m_head;
+        assertHeadConsistent();
+    }
+
+    ~QDoubleEndedList()
+    {
+        assertHeadConsistent();
+        while (!isEmpty())
+            m_head.m_next->remove();
+        assertHeadConsistent();
+    }
+
+    bool isEmpty() const
+    {
+        assertHeadConsistent();
+        return m_head.m_next == &m_head;
+    }
+
+    void prepend(N *n)
+    {
+        assertHeadConsistent();
+        QInheritedListNode *nnode = n;
+        nnode->remove();
+
+        nnode->m_next = m_head.m_next ? m_head.m_next : &m_head;
+        nnode->m_next->m_prev = nnode;
+
+        m_head.m_next = nnode;
+        nnode->m_prev = &m_head;
+        assertHeadConsistent();
+    }
+
+    void append(N *n)
+    {
+        assertHeadConsistent();
+        QInheritedListNode *nnode = n;
+        nnode->remove();
+
+        nnode->m_prev = m_head.m_prev ? m_head.m_prev : &m_head;
+        nnode->m_prev->m_next = nnode;
+
+        m_head.m_prev = nnode;
+        nnode->m_next = &m_head;
+        assertHeadConsistent();
+    }
+
+    void remove(N *n) {
+        Q_ASSERT(contains(n));
+        QInheritedListNode *nnode = n;
+        nnode->remove();
+        assertHeadConsistent();
+    }
+
+    bool contains(const N *n) const
+    {
+        assertHeadConsistent();
+        for (const QInheritedListNode *nnode = m_head.m_next;
+             nnode != &m_head; nnode = nnode->m_next) {
+            if (nnode == n)
+                return true;
+        }
+
+        return false;
+    }
+
+    template<typename T, typename Node>
+    class base_iterator {
+    public:
+        T *operator*() const { return QDoubleEndedList<N>::nodeToN(m_node); }
+        T *operator->() const { return QDoubleEndedList<N>::nodeToN(m_node); }
+
+        bool operator==(const base_iterator &other) const { return other.m_node == m_node; }
+        bool operator!=(const base_iterator &other) const { return other.m_node != m_node; }
+
+        base_iterator &operator++()
+        {
+            m_node = m_node->m_next;
+            return *this;
+        }
+
+        base_iterator operator++(int)
+        {
+            const base_iterator self(m_node);
+            m_node = m_node->m_next;
+            return self;
+        }
+
+    private:
+        friend class QDoubleEndedList<N>;
+
+        base_iterator(Node *node) : m_node(node)
+        {
+            Q_ASSERT(m_node != nullptr);
+        }
+
+        Node *m_node = nullptr;
+    };
+
+    using iterator = base_iterator<N, QInheritedListNode>;
+    using const_iterator = base_iterator<const N, const QInheritedListNode>;
+
+    const N *first() const { return checkedNodeToN(m_head.m_next); }
+    N *first() { return checkedNodeToN(m_head.m_next); }
+
+    const N *last() const { return checkedNodeToN(m_head.m_prev); }
+    N *last() { return checkedNodeToN(m_head.m_prev); }
+
+    const N *next(const N *current) const
+    {
+        Q_ASSERT(contains(current));
+        const QInheritedListNode *nnode = current;
+        return checkedNodeToN(nnode->m_next);
+    }
+
+    N *next(N *current)
+    {
+        Q_ASSERT(contains(current));
+        const QInheritedListNode *nnode = current;
+        return checkedNodeToN(nnode->m_next);
+    }
+
+    const N *prev(const N *current) const
+    {
+        Q_ASSERT(contains(current));
+        const QInheritedListNode *nnode = current;
+        return checkedNodeToN(nnode->m_prev);
+    }
+
+    N *prev(N *current)
+    {
+        Q_ASSERT(contains(current));
+        const QInheritedListNode *nnode = current;
+        return checkedNodeToN(nnode->m_prev);
+    }
+
+    iterator begin()
+    {
+        assertHeadConsistent();
+        return iterator(m_head.m_next);
+    }
+
+    iterator end()
+    {
+        assertHeadConsistent();
+        return iterator(&m_head);
+    }
+
+    const_iterator begin() const
+    {
+        assertHeadConsistent();
+        return const_iterator(m_head.m_next);
+    }
+
+    const_iterator end() const
+    {
+        assertHeadConsistent();
+        return const_iterator(&m_head);
+    }
+
+    qsizetype count() const
+    {
+        assertHeadConsistent();
+        qsizetype result = 0;
+        for (const auto *node = m_head.m_next; node != &m_head; node = node->m_next)
+            ++result;
+        return result;
+    }
+
+private:
+    static N *nodeToN(QInheritedListNode *node)
+    {
+        return static_cast<N *>(node);
+    }
+
+    static const N *nodeToN(const QInheritedListNode *node)
+    {
+        return static_cast<const N *>(node);
+    }
+
+    N *checkedNodeToN(QInheritedListNode *node) const
+    {
+        assertHeadConsistent();
+        return (!node || node == &m_head) ? nullptr : nodeToN(node);
+    }
+
+    void assertHeadConsistent() const
+    {
+        Q_ASSERT(m_head.m_next != nullptr);
+        Q_ASSERT(m_head.m_prev != nullptr);
+        Q_ASSERT(m_head.m_next != &m_head || m_head.m_prev == &m_head);
+    }
+
+    QInheritedListNode m_head;
+};
+
+QT_END_NAMESPACE
+
+#endif // QDOUBLEENDEDLIST_P_H