QmlObjectTreeModel.h

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/****************************************************************************
 *
 * (c) 2009-2024 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 *
 * QGroundControl is licensed according to the terms in the file
 * COPYING.md in the root of the source code directory.
 *
 ****************************************************************************/
 
#pragma once
 
#include "ObjectItemModelBase.h"
 
#include <QtQmlIntegration/QtQmlIntegration>
 
class QmlObjectTreeModel : public ObjectItemModelBase
{
    Q_OBJECT
    QML_ELEMENT
    QML_UNCREATABLE("")
 
public:
    explicit QmlObjectTreeModel(QObject* parent = nullptr);
    ~QmlObjectTreeModel() override;
 
    // -- ObjectItemModelBase overrides --
    int count() const override;
    void setDirty(bool dirty) override;
    void clear() override;
 
    // -- QAbstractItemModel overrides --
    QModelIndex index(int row, int column, const QModelIndex& parent = QModelIndex()) const override;
    QModelIndex parent(const QModelIndex& child) const override;
    int rowCount(const QModelIndex& parent = QModelIndex()) const override;
    int columnCount(const QModelIndex& parent = QModelIndex()) const override;
    bool hasChildren(const QModelIndex& parent = QModelIndex()) const override;
    QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
    bool setData(const QModelIndex& index, const QVariant& value, int role = Qt::EditRole) override;
    bool insertRows(int row, int count, const QModelIndex& parent = QModelIndex()) override;
    bool removeRows(int row, int count, const QModelIndex& parent = QModelIndex()) override;
    QHash<int, QByteArray> roleNames() const override;
 
    // -- QML-accessible tree operations --
 
    Q_INVOKABLE QObject* getObject(const QModelIndex& index) const;
 
    Q_INVOKABLE QModelIndex appendItem(QObject* object, const QModelIndex& parentIndex = QModelIndex());
 
    Q_INVOKABLE QModelIndex appendItem(QObject* object, const QModelIndex& parentIndex, const QString& nodeType);
 
    Q_INVOKABLE QModelIndex insertItem(int row, QObject* object, const QModelIndex& parentIndex = QModelIndex());
 
    Q_INVOKABLE QModelIndex insertItem(int row, QObject* object, const QModelIndex& parentIndex, const QString& nodeType);
 
    Q_INVOKABLE QObject* removeItem(const QModelIndex& index);
 
    Q_INVOKABLE int childCount(const QModelIndex& parentIndex = QModelIndex()) const { return rowCount(parentIndex); }
 
    Q_INVOKABLE QModelIndex childIndex(int row, const QModelIndex& parentIndex = QModelIndex()) const { return index(row, 0, parentIndex); }
 
    Q_INVOKABLE QModelIndex indexForObject(QObject* object) const;
 
    Q_INVOKABLE QModelIndex parentIndex(const QModelIndex& index) const { return parent(index); }
 
    Q_INVOKABLE int depth(const QModelIndex& index) const;
 
    // -- C++ convenience API --
    void    appendRootItem(QObject* object);
    void    appendChild(const QModelIndex& parentIndex, QObject* object);
    QObject* removeAt(const QModelIndex& parentIndex, int row);
    void    removeChildren(const QModelIndex& parentIndex); 
    void    clearAndDeleteContents(); 
    bool    contains(QObject* object) const;
 
    static constexpr int NodeTypeRole  = Qt::UserRole + 2;
    static constexpr int SeparatorRole = Qt::UserRole + 3;
 
private:
    struct TreeNode {
        QObject* object = nullptr;
        TreeNode* parentNode = nullptr;
        QList<TreeNode*> children;
        QString nodeType;   
 
        int row() const;
    };
 
    TreeNode*   _nodeFromIndex(const QModelIndex& index) const;
    QModelIndex _indexForNode(const TreeNode* node) const;
    TreeNode*   _findNode(const TreeNode* root, const QObject* object) const;
    static int  _subtreeCount(const TreeNode* node);
    void        _disconnectSubtree(TreeNode* node);
    void        _deleteSubtree(TreeNode* node, bool deleteObjects);
    void        _connectDirtyChanged(QObject* object);
    void        _disconnectDirtyChanged(QObject* object);
    void        _emitSeparatorChanged(const QModelIndex& parentIdx, int fromRow);
 
    TreeNode _rootNode; 
    int      _totalCount = 0; 
};