MultiPointTouchArea QML Type

These properties hold the range of touch points to be handled by the touch area.

These are convenience that allow you to, for example, have nested MultiPointTouchAreas, one handling two finger touches, and another handling three finger touches.

By default, all touch points within the touch area are handled.

If mouseEnabled is true, the mouse acts as a touch point, so it is also subject to these constraints: for example if maximumTouchPoints is two, you can use the mouse as one touch point and a finger as another touch point for a total of two.

This property controls whether the MultiPointTouchArea will handle mouse events too. If it is true (the default), the touch area will treat the mouse the same as a single touch point; if it is false, the touch area will ignore mouse events and allow them to "pass through" so that they can be handled by other items underneath.

This property holds a set of user-defined touch point objects that can be bound to.

If mouseEnabled is true (the default) and the left mouse button is pressed while the mouse is over the touch area, the current mouse position will be one of these touch points.

In the following example, we have two small rectangles that follow our touch points.

import QtQuick

Rectangle {
    width: 400; height: 400
    MultiPointTouchArea {
        anchors.fill: parent
        touchPoints: [
            TouchPoint { id: point1 },
            TouchPoint { id: point2 }
        ]
    }

    Rectangle {
        width: 30; height: 30
        color: "green"
        x: point1.x
        y: point1.y
    }

    Rectangle {
        width: 30; height: 30
        color: "yellow"
        x: point2.x
        y: point2.y
    }
}

By default this property holds an empty list.

See also TouchPoint.

This signal is emitted when new touch events have been canceled because another item stole the touch event handling.

This signal is for advanced use: it is useful when there is more than one MultiPointTouchArea that is handling input, or when there is a MultiPointTouchArea inside a Flickable. In the latter case, if you execute some logic in the onPressed signal handler and then start dragging, the Flickable may steal the touch handling from the MultiPointTouchArea. In these cases, to reset the logic when the MultiPointTouchArea has lost the touch handling to the Flickable, canceled should be handled in addition to released.

touchPoints is the list of canceled points.

onCanceled: (points) => console.log("canceled", points.length)

This signal is emitted when the global drag threshold has been reached.

This signal is typically used when a MultiPointTouchArea has been nested in a Flickable or another MultiPointTouchArea. When the threshold has been reached and the signal is handled, you can determine whether or not the touch area should grab the current touch points. By default they will not be grabbed; to grab them call gesture.grab(). If the gesture is not grabbed, the nesting Flickable, for example, would also have an opportunity to grab.

The gesture object also includes information on the current set of touchPoints and the dragThreshold.

This signal is emitted when new touch points are added. touchPoints is a list of these new points.

If minimumTouchPoints is set to a value greater than one, this signal will not be emitted until the minimum number of required touch points has been reached.

onPressed: (points) => console.log("pressed", points.length)

This signal is emitted when existing touch points are removed. touchPoints is a list of these removed points.

onReleased: (points) => console.log("released", points.length)

This signal is emitted when the touch points handled by the MultiPointTouchArea change. This includes adding new touch points, removing or canceling previous touch points, as well as updating current touch point data. touchPoints is the list of all current touch points.

This signal is emitted when existing touch points are updated. touchPoints is a list of these updated points.

onUpdated: (points) => console.log("updated", points.length)