Table of Contents

Class ListModel<T>

Namespace
Qt.Bridge.Models
Assembly
Qt.Bridge.CSharp.Api.dll

Provides a strongly typed base class for implementing a flat list model.

public abstract class ListModel<T> : ListModel

Type Parameters

T

The item type exposed by the model. This can be a simple value such as string or a custom type with multiple public properties.

Inheritance
ListModel<T>
Inherited Members

Remarks

Derive from ListModel<T> when each row in the list can be represented as a value of type T. Implement ItemCount() to report the number of items and Data(int) to return the item at a given row.

If T is a simple convertible type such as string or int, the model automatically exposes built-in display, edit, and item roles. If T is a custom type, the model can derive values from IDisplayable, IEditable, and IModelItem, and it also exposes each public instance property as an additional named role.

The generic list model follows the same item-type conventions as TableModel<T> while keeping a one-dimensional shape. If you need fully custom role names or custom role lookup logic, derive from ListModel instead and override RoleNames() and Data(ModelIndex, int) yourself. 

public class NameList : ListModel<string>
{
    private List<string> Names { get; } = ["Ada", "Linus", "Grace"];

    public override int ItemCount() => Names.Count;

    public override string Data(int index)
    {
        if (index < 0 || index >= Names.Count)
            return null;
        return Names[index];
    }
}

Properties

HasItemRole

Gets whether the whole item should be exposed through the item role.

protected virtual bool HasItemRole { get; }

Property Value

bool

Remarks

The default implementation returns true for backward compatibility with existing list-model usage patterns.

IsReadOnly

Gets whether the model should reject all edit operations.

protected virtual bool IsReadOnly { get; }

Property Value

bool

Remarks

When this property returns true, the model does not expose the built-in edit role and SetData(ModelIndex, object, int) always returns false.

RoleMap

Gets the role-to-property map inferred from T.

protected Dictionary<int, PropertyInfo> RoleMap { get; }

Property Value

Dictionary<int, PropertyInfo>

Remarks

For custom item types, each public instance property is assigned the next available role id after the optional item role and exposed under its QML-style property name.

Methods

BeginInsertItems(int, int)

Begins an item insertion notification for the specified inclusive item range.

protected void BeginInsertItems(int first, int last)

Parameters

first int
last int

Remarks

Call this immediately before inserting items into the backing collection. Pair it with EndInsertItems() in a try/finally block.

BeginRemoveItems(int, int)

Begins an item removal notification for the specified inclusive item range.

protected void BeginRemoveItems(int first, int last)

Parameters

first int
last int

Remarks

Call this immediately before removing items from the backing collection. Pair it with EndRemoveItems() in a try/finally block.

ClearItemData(ModelIndex)

Clears the value associated with the specified row.

public override sealed bool ClearItemData(ModelIndex index)

Parameters

index ModelIndex

Returns

bool

Remarks

This forwards a valid model index to ClearItemData(int) and rejects invalid indexes.

ClearItemData(int)

Clears the value associated with the specified row.

protected virtual bool ClearItemData(int index)

Parameters

index int

Returns

bool

Remarks

Override this when your list supports a dedicated clear operation distinct from setting a normal value. The default implementation returns false.

Data(ModelIndex, int)

Returns the value for the specified row and role.

public override sealed object Data(ModelIndex index, int role)

Parameters

index ModelIndex
role int

Returns

object

Remarks

For simple value types, the built-in display and edit roles return the item directly. For custom item types, the base class uses IDisplayable, IEditable, the optional item role, and public instance properties to resolve role values.

Data(int)

Returns the item at the specified row.

public abstract T Data(int index)

Parameters

index int

Returns

T

Remarks

Implement this as a simple row lookup against your backing collection. The generic base class validates the incoming Qt.DotNet.ModelIndex before calling this method. Return null for invalid rows when T is a reference type.

DataChanged(int)

Notifies that a single list item changed in place.

protected void DataChanged(int index)

Parameters

index int

EndInsertItems()

Ends the current item insertion notification sequence.

protected void EndInsertItems()

EndRemoveItems()

Ends the current item removal notification sequence.

protected void EndRemoveItems()

Flags(ModelIndex)

Returns the capability flags for the specified item.

public override sealed int Flags(ModelIndex index)

Parameters

index ModelIndex

Returns

int

Remarks

The base implementation derives enabled/selectable state from IModelItem when available and derives editability from IsReadOnly, T, and IEditable.

ItemCount()

Returns the number of items in the list.

public abstract int ItemCount()

Returns

int

RoleNames()

Returns the role names inferred from T.

public override sealed Dictionary<int, string> RoleNames()

Returns

Dictionary<int, string>

Remarks

Depending on the item type, this can include the built-in display and edit roles, the optional item role for the whole list item, and property-based roles generated from public instance properties.

RowCount(ModelIndex)

Returns the number of rows for the specified parent index.

public override sealed int RowCount(ModelIndex parent)

Parameters

parent ModelIndex

Returns

int

Remarks

For the root level, this returns ItemCount(). For valid parent indexes, it returns 0 because ListModel<T> is always a flat list.

SetData(ModelIndex, object, int)

Updates the value for the specified row and role.

public override sealed bool SetData(ModelIndex index, object value, int role)

Parameters

index ModelIndex
value object
role int

Returns

bool

Remarks

For editable simple value types, this updates the item through SetData(int, T). For custom item types, it updates either EditValue, the full item via the item role, or a writable public property. Successful updates automatically notify connected views.

SetData(int, T)

Updates the item at the specified row.

protected virtual bool SetData(int index, T value)

Parameters

index int
value T

Returns

bool

true if the item was updated; otherwise, false.

Remarks

Override this when the list should support replacing whole items, such as for editable simple value types or when exposing the item role for custom types.