Utils: Add a base for tree like models

That kind of boiler plate comes up often enough to justify a wrapper.

Change-Id: I94aa5b1ccbe5a98f091a47087654e59e9e122c1d
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/src/libs/utils/treemodel.h b/src/libs/utils/treemodel.h
new file mode 100644
index 0000000000..078f74b4f1
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+++ b/src/libs/utils/treemodel.h
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+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#ifndef UTILS_TREEMODEL_H
+#define UTILS_TREEMODEL_H
+
+#include "utils_global.h"
+
+#include <QAbstractItemModel>
+
+namespace Utils {
+
+class QTCREATOR_UTILS_EXPORT TreeItem
+{
+public:
+    TreeItem();
+    virtual ~TreeItem();
+
+    virtual TreeItem *parent() const { return m_parent; }
+    virtual TreeItem *child(int pos) const;
+    virtual bool isLazy() const;
+    virtual int columnCount() const;
+    virtual int rowCount() const;
+    virtual void populate();
+
+    virtual QVariant data(int column, int role) const;
+    virtual Qt::ItemFlags flags(int column) const;
+
+    void prependChild(TreeItem *item);
+    void appendChild(TreeItem *item);
+
+    void setLazy(bool on);
+    void setPopulated(bool on);
+    void setFlags(Qt::ItemFlags flags);
+
+private:
+    TreeItem(const TreeItem &) Q_DECL_EQ_DELETE;
+    void operator=(const TreeItem &) Q_DECL_EQ_DELETE;
+
+    void clear();
+    void ensurePopulated() const;
+
+    TreeItem *m_parent; // Not owned.
+    QVector<TreeItem *> m_children; // Owned.
+    bool m_lazy;
+    mutable bool m_populated;
+    Qt::ItemFlags m_flags;
+};
+
+class QTCREATOR_UTILS_EXPORT TreeModel : public QAbstractItemModel
+{
+public:
+    explicit TreeModel(QObject *parent = 0);
+    virtual ~TreeModel();
+
+    int rowCount(const QModelIndex &idx = QModelIndex()) const;
+    int columnCount(const QModelIndex &idx) const;
+
+    QVariant data(const QModelIndex &idx, int role) const;
+    QModelIndex index(int, int, const QModelIndex &idx) const;
+    QModelIndex parent(const QModelIndex &idx) const;
+    Qt::ItemFlags flags(const QModelIndex &idx) const;
+
+    TreeItem *rootItem() const;
+    TreeItem *itemFromIndex(const QModelIndex &) const;
+    QModelIndex indexFromItem(const TreeItem *needle) const;
+
+private:
+    QModelIndex indexFromItemHelper(const TreeItem *needle,
+        TreeItem *parentItem, const QModelIndex &parentIndex) const;
+
+    void checkIndex(const QModelIndex &index) const;
+
+    TreeItem *m_root; // Owned.
+};
+
+} // namespace Utils
+
+#endif // UTILS_TREEMODEL_H