Touch Events

Inputs

blockDefaultTouchesboolean

Set this to true when you intend to have swipe behavior in the lens, like dragging an object, swiping, or pinching to zoom, or for lenses with double taps so as to prevent these gestures from accidentally triggering the snapchat UI.

allowDoubleTapboolean

Set this to false by default to prevent unintended camera switching. Only set this to true if you have blockDefaultTouches enabled and you explicitly want to allow Snapchat’s default double-tap behavior (switching between device cameras). If your experience uses double tap as part of its own interaction design, keep this set to false to avoid accidentally triggering the Snapchat camera swap.

enableHintboolean

Shows a system hint (on screen instruction) for the relevant interaction for touch events, true by default unless the lens shows it's own hint through text or another means.

Events

onDoubleTap

Double Tap event (two consecutive taps on the screen). If this is used, don't allowDoubleTap.

onTouchDown

Triggered when the user touches the screen.

onTouchMove

Triggered when the user moves a finger on the screen.

onTouchUp

Triggered when the user lifts a touch from screen. Touch ends.

onTap

Triggers on tap

More in Camera, Audio & Sensors

• Device CameraGives your Lens the camera picture, live or frozen as a still. Your Lens can show that picture on a surface, or keep the still to use later.
• Face EventsMakes your Lens react when you open your mouth, smile, kiss, raise your eyebrows or tilt your head. It also tells the Lens where your eyes, nose and mouth are on screen.
• Face MLChanges your face with one ready-made effect, for example an anime look, a meme grin or a skull. Say the look you want, and your Lens keeps that one effect.
• FaceLandmarksFollows where your eyes, nose, mouth and forehead are, so a sticker or text can sit on them and move with you. Ask for hearts on your eyes.
• GyroscopeTurns tilting and shaking your phone into a control for your Lens. Ask for a tilt game, for example a maze where you roll a ball to the exit.
• Hand TrackingFollows your hands and reads gestures like a fist, a pinch, a thumbs up or a peace sign. Ask for something your hand controls, for example drawing with a pinch.
• HapticsMakes your phone vibrate at the moments you choose. Ask for a buzz when you tap the screen or score a point.
• Picture in PicturePuts a frame with the live camera on the screen, with or without a border. Tap the frame to swap in a photo from your device.
• Selfie WidgetShows a small live camera view on the screen, as a circle or a rectangle. Choose where it sits and how big it is, for example in the corner of a game.
• SoundPlays a sound in the Lens. Add the sound you want, and the Lens can start it, pause it and resume it.
• Voice ChangerChanges your voice while you speak. Ask for the effect you want, for example a deep voice, a robot, an alien or an echo.
• ZoomZooms the view in on any point of the screen, smoothly or held in place the whole time. Say where to zoom, how close, and whether it repeats back and forth.