DeviceDiscoveryAgent QML Type

Discover external accessories from your app. More...

• List of all members, including inherited members

Properties

• deviceFilter : var
• devices : DeviceListModel
• error : string
• properties : object
• refreshInterval : int
• running : bool
• sortCompare : var

Signals

• deviceDiscovered(Device device)
• discoverDevicesCompleted()

Methods

• object propertyValue(string key)
• setPropertyValue(string key, object value)
• start()
• stop()

Detailed Description

The DeviceDiscoveryAgent component searches for connected devices and makes them available to interact with in your app. By default Bluetooth devices are automatically scanned, but USB and serial port connected devices can additionally be scanned for. When new devices are discovered they are added to a list model, which can be used to populate other components such as drop down boxes or scrollviews. The list model can be optionally filtered or ordered.

This code sample shows usage of DeviceDiscoveryAgent, displaying Bluetooth devices found through device discovery in a combo box. Data read from the currently selected device is then printed into a list view, informed by DeviceListModel.

Item {
        property DeviceListModel deviceListModel: discoveryAgent.devices
        property Device currentDevice

        ColumnLayout {
                anchors.fill: parent
                anchors.margins: 10

                ComboBox {
                        id: comboBox
                        Layout.fillWidth: true
                        model: deviceListModel
                        textRole: "name"
                        onCurrentTextChanged: selectDevice(deviceListModel.get(currentIndex))
                }

                ListView {
                        Layout.fillWidth: true
                        Layout.fillHeight: true
                        model: messagesListModel
                        delegate: Text { text: msg }
                }
        }

        DeviceDiscoveryAgent {
                id: discoveryAgent
        }

        DataSource {
                id: dataSource
                onReceivedDataChanged: log(receivedData.trim())
        }

        ListModel {
                id: messagesListModel
        }

        Connections {
                target: deviceListModel
                onCountChanged: if (comboBox.currentIndex == -1 && deviceListModel.count > 0) { comboBox.currentIndex = 0; }
        }

        Component.onCompleted: discoveryAgent.start()

        function selectDevice(device) {
                if (currentDevice) currentDevice.connected = false;
                currentDevice = device;
                messagesListModel.clear();
                JSON.stringify(device, undefined, 2).split("\n").forEach(log);
                dataSource.source = currentDevice;
                currentDevice.connected = true;
        }

        function log(txt) {
                console.log(txt);
                messagesListModel.append( { msg: txt } );
                if (messagesListModel.count > 20) { messagesListModel.remove(0); }
        }
}

Enumerations

DeviceFilter enumeration

Property Documentation

deviceFilter: function(device) {
    return !device.name.match(/^(COM|tty|cu)/i)
}

DeviceDiscoveryAgent {
    id: discoveryAgent

    properties: {
        "isScanBluetoothDevices" : false
    }
}

sortCompare: function (device1, device2) {
    return device1.name.toLowerCase() < device2.name.toLowerCase();
}

Signal Documentation

Method Documentation