Touch Input

Navigation applications have support for touch events, including both single and multitouch events. This includes interactions such as panning and pinch. A developer may use the included SDLTouchManager class, or yourself by listening to the SDLDidReceiveTouchEventNotification notification.

Note

You must have a valid and approved appId in order to recieve touch events.

Using SDLTouchManager

SDLTouchManager has multiple callbacks that will ease the implementation of touch events.

Note

The view passed from the following callbacks are dependent on using the built-in focusable item manager to send haptic rects. See supporting haptic input "Automatic Focusable Rects" for more information.

The following callbacks are provided:

Objective-C

- (void)touchManager:(SDLTouchManager *)manager didReceiveSingleTapForView:(nullable UIView *)view atPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager didReceiveDoubleTapForView:(nullable UIView *)view atPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager panningDidStartInView:(nullable UIView *)view atPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager didReceivePanningFromPoint:(CGPoint)fromPoint toPoint:(CGPoint)toPoint;
- (void)touchManager:(SDLTouchManager *)manager panningDidEndInView:(nullable UIView *)view atPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager panningCanceledAtPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager pinchDidStartInView:(nullable UIView *)view atCenterPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager didReceivePinchAtCenterPoint:(CGPoint)point withScale:(CGFloat)scale;
- (void)touchManager:(SDLTouchManager *)manager didReceivePinchInView:(nullable UIView *)view atCenterPoint:(CGPoint)point withScale:(CGFloat)scale;
- (void)touchManager:(SDLTouchManager *)manager pinchDidEndInView:(nullable UIView *)view atCenterPoint:(CGPoint)point;
- (void)touchManager:(SDLTouchManager *)manager pinchCanceledAtCenterPoint:(CGPoint)point;

Swift

    optional public func touchManager(_ manager: SDLTouchManager, didReceiveSingleTapFor view: UIView?, at point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, didReceiveDoubleTapFor view: UIView?, at point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, panningDidStartIn view: UIView?, at point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, didReceivePanningFrom fromPoint: CGPoint, to toPoint: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, panningDidEndIn view: UIView?, at point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, panningCanceledAt point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, pinchDidStartIn view: UIView?, atCenter point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, didReceivePinchAtCenter point: CGPoint, withScale scale: CGFloat)
    optional public func touchManager(_ manager: SDLTouchManager, didReceivePinchIn view: UIView?, atCenter point: CGPoint, withScale scale: CGFloat)
    optional public func touchManager(_ manager: SDLTouchManager, pinchDidEndIn view: UIView?, atCenter point: CGPoint)
    optional public func touchManager(_ manager: SDLTouchManager, pinchCanceledAtCenter point: CGPoint)

Note

Points that are provided via these callbacks are in the head unit's coordinate space. This is likely to correspond to your own streaming coordinate space. You can retrieve the head unit dimensions from SDLStreamingMediaManager.screenSize.

Implementing onTouchEvent Yourself

If apps want to have access to the raw touch data, the SDLDidReceiveTouchEventNotification notification can be evaluated. This callback will be fired for every touch of the user and contains the following data:

Type

Touch Type	What does this mean?
BEGIN	Sent for the first touch event of a touch.
MOVE	Sent if the touch moved.
END	Sent when the touch is lifted.
CANCEL	Sent when the touch is canceled (for example, if a dialog appeared over the touchable screen while the touch was in progress).

Event

Touch Event	What does this mean?
touchEventId	Unique ID of the touch. Increases for multiple touches (0, 1, 2, ...).
timeStamp	Timestamp of the head unit time. Can be used to compare time passed between touches.
coord	X and Y coordinates in the head unit coordinate system. (0, 0) is the top left.

Example

Objective-C

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(touchEventAvailable:) name:SDLDidReceiveTouchEventNotification object:nil];

- (void)touchEventAvailable:(SDLRPCNotificationNotification *)notification {
    if (![notification.notification isKindOfClass:SDLOnTouchEvent.class]) {
      return;
    }
    SDLOnTouchEvent *touchEvent = (SDLOnTouchEvent *)notification.notification;

    // Grab something like type
    SDLTouchType* type = touchEvent.type;
}

Swift

// To Register
NotificationCenter.default.addObserver(self, selector: #selector(touchEventAvailable(_:)), name: .SDLDidReceiveTouchEvent, object: nil)

// On Receive
@objc private func touchEventAvailable(_ notification: SDLRPCNotificationNotification) {
    guard let touchEvent = notification.notification as? SDLOnTouchEvent else {
        print("Error retrieving onTouchEvent object")
        return
    }

    // Grab something like type
    let type = touchEvent.type
}

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