PagingModel QML Type

The PagingModel is a generic model to load its data using the "Paging" aproach. More...

• List of all members, including inherited members

Properties

• capabilities : enumeration
• chunkSize : int
• count : int
• fetchMoreThreshold : int
• loadingType : enumeration

Signals

• fetchMoreThresholdReached()

Methods

• object get(i)
• reload()

Detailed Description

The PagingModel should be used directly or as a base class whenever a lot of data needs to be presented in a ListView.

The model only fetches the data it really needs and can it can be configured how this can be done using the loadingType property.

All rows in the model need to be subclassed from StandardItem.

The following roles are available in this model:

Setting it up

The PagingModel is using QtIviCore's Dynamic Backend System and is derived from QIviAbstractFeatureListModel. Other than most "QtIvi Feature classes", the PagingModel doesn't automatically connect to available backends.

The easiest approach to set it up, is to connect to the same backend used by another feature. E.g. for connecting to the media backend, use the instance from the mediaplayer feature:

Item {
    MediaPlayer {
        id: player
    }

    PagingModel {
        serviceObject: player.serviceObject
    }
}

Loading Types

Multiple loading types are supported, as the PagingModel is made to work with asynchronous requests to fetch its data. The FetchMore loading type is the default and is using the canFetchMore()/fetchMore() functions of QAbstractItemModel to fetch new data once the view hits the end of the currently available data. As fetching can take some time, there is the fetchMoreThreshold property which controls how much in advance a new fetch should be started.

The other loading type is DataChanged. In contrast to FetchMore, the complete model is pre-populated with empty rows and the actual data for a specific row is fetched the first time the data() function is called. Once the data is available, the dataChanged() signal will be triggered for this row and the view will start to render the new data.

Please see the documentation of loadingType for more details on how the modes work and when they are suitable to use.

See the Models section for more information about all models in QtIvi.

Property Documentation

Signal Documentation

Method Documentation