makVre::DtChatQmlModel Class Reference

Detailed Description

This class demonstrates the REUSABLE pattern for creating custom Qt models that expose C++ data to QML user interfaces. Key concepts:

• Inheriting from QAbstractListModel for list-based data
• Defining custom roles for QML property access
• Implementing required virtual methods (rowCount, data, roleNames)
• Proper model change notifications (beginInsertRows, endInsertRows, etc.)

This pattern can be adapted for any list-based data that needs to be displayed in a QML ListView or Repeater.

#include <exampleQtQuick.h>

Inheritance diagram for makVre::DtChatQmlModel:

Public Types
enum	ChatRoles { SenderRole = Qt::UserRole + 1 , ReceiverRole , TimeRole , MessageRole }

Public Member Functions
	DtChatQmlModel (QObject *parent=nullptr)
virtual void	addChatEntry (const DtChatEntry &entry)
virtual void	clear ()
virtual int	getIndexOfName (const QString &messageName)
virtual QString	getMessage (const int idx)
virtual bool	removeRows (int row, int column=0, const QModelIndex &parent=QModelIndex()) override
virtual int	rowCount (const QModelIndex &parent=QModelIndex()) const override
virtual QVariant	data (const QModelIndex &index, int role=Qt::DisplayRole) const override
virtual bool	setData (const QModelIndex &index, const QVariant &value, int role) override

Protected Member Functions
virtual QHash< int, QByteArray >	roleNames () const override

Protected Attributes
QList< DtChatEntry >	myChatEntries

Member Enumeration Documentation

ChatRoles

enum makVre::DtChatQmlModel::ChatRoles

Custom roles for accessing chat entry fields from QML.

Qt roles allow QML to access C++ data using named properties. Start at Qt::UserRole + 1 to avoid conflicts with standard roles.

Enumerator
SenderRole	Access sender name via "sender" in QML.
ReceiverRole	Access receiver name via "receiver" in QML.
TimeRole	Access message time via "time" in QML.
MessageRole	Access message text via "msg" in QML.

Constructor & Destructor Documentation

DtChatQmlModel()

makVre::DtChatQmlModel::DtChatQmlModel

(

QObject *

parent = nullptr

)

Constructor initializing the model.

Parameters

parent

Optional parent QObject for Qt ownership hierarchy

Member Function Documentation

addChatEntry()

virtual void makVre::DtChatQmlModel::addChatEntry ( const DtChatEntry & entry )

virtual

Adds a new chat entry to the model.

This demonstrates proper model update notifications:

• beginInsertRows notifies views that data is being added
• Actual data modification
• endInsertRows triggers view updates

Parameters

entry

The chat entry to add to the model

clear()

virtual void makVre::DtChatQmlModel::clear ( )

virtual

Clears all chat entries from the model.

Uses beginResetModel/endResetModel for bulk changes.

getIndexOfName()

virtual int makVre::DtChatQmlModel::getIndexOfName ( const QString & messageName )

virtual

Finds the index of a message by its text content.

Parameters

messageName

The message text to search for

Returns

Index of the message, or -1 if not found

getMessage()

virtual QString makVre::DtChatQmlModel::getMessage ( const int idx )

virtual

Gets the message text at a specific index.

Parameters

idx	The index of the message

Returns

The message text

removeRows()

virtual bool makVre::DtChatQmlModel::removeRows ( int row, int column = 0, const QModelIndex & parent = QModelIndex() )

overridevirtual

Removes rows from the model.

Parameters

row	The row index to remove
column	Unused for list models (default 0)
parent	Unused for list models

Returns

true if removal succeeded

rowCount()

virtual int makVre::DtChatQmlModel::rowCount ( const QModelIndex & parent = QModelIndex() ) const

overridevirtual

Returns the number of entries in the model.

Parameters

parent

Unused for list models

Returns

Number of chat entries

data()

virtual QVariant makVre::DtChatQmlModel::data ( const QModelIndex & index, int role = Qt::DisplayRole ) const

overridevirtual

Returns data for a specific role at a given index.

This is the core method QML uses to access data.

Parameters

index	The model index of the item
role	The data role being requested (SenderRole, MessageRole, etc.)

Returns

The requested data as a QVariant

setData()

virtual bool makVre::DtChatQmlModel::setData ( const QModelIndex & index, const QVariant & value, int role )

overridevirtual

Sets data for a specific role at a given index.

Parameters

index	The model index of the item
value	The new value to set
role	The data role being modified

Returns

true if data was successfully set

roleNames()

virtual QHash< int, QByteArray > makVre::DtChatQmlModel::roleNames ( ) const

overrideprotectedvirtual

Maps role enum values to QML property names.

This method tells Qt how to expose roles as named properties in QML. For example, SenderRole becomes accessible as "sender" in QML.

Returns

Hash mapping role integers to QML property names

Member Data Documentation

myChatEntries

QList<DtChatEntry> makVre::DtChatQmlModel::myChatEntries

protected

Storage for all chat entries.

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The documentation for this class was generated from the following file:

• examples/state/exampleQtQuick.h