Documentation

Touch Input

Navigation applications support touch events like single taps, double-taps, panning, and pinch gestures. You can use the SDLTouchManager class to get touch events, or you can manage the touch events yourself by listening for the SDLDidReceiveTouchEventNotification notification.

Note

You must have a valid and approved appId from an OEM in order to receive touch events.

Using SDLTouchManager

SDLTouchManager has multiple callbacks that will ease the implementation of touch events. You can register for callbacks through the stream manager:

Objective-C

self.sdlManager.streamManager.touchManager.touchEventDelegate = self

Swift

sdlManager.streamManager.touchManager.touchEventDelegate = self

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

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

// sdl_ios v6.3+
[self.sdlManager subscribeToRPC:SDLDidReceiveTouchEventNotification withObserver:self selector:@selector(touchEventAvailable:)];

// Pre sdl_ios v6.3
[[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

// sdl_ios v6.3+
sdlManager.subscribe(to: .SDLDidReceiveTouchEvent, observer: self, selector: #selector(touchEventAvailable(_:)))

// Pre sdl_ios v6.3
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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