diff options
| -rw-r--r-- | src/services/gesture_service/gesture_service.js | 15 | ||||
| -rw-r--r-- | test/unit/specs/services/gesture_service/gesture_service.spec.js | 120 |
2 files changed, 129 insertions, 6 deletions
diff --git a/src/services/gesture_service/gesture_service.js b/src/services/gesture_service/gesture_service.js index 2e39003c..efc0ca78 100644 --- a/src/services/gesture_service/gesture_service.js +++ b/src/services/gesture_service/gesture_service.js @@ -10,11 +10,14 @@ const touchEventCoord = e => ([e.touches[0].screenX, e.touches[0].screenY]) const vectorLength = v => Math.sqrt(v[0] * v[0] + v[1] * v[1]) -const perpendicular = v => [v[1], v[0]] +const perpendicular = v => [v[1], -v[0]] const dotProduct = (v1, v2) => v1[0] * v2[0] + v1[1] * v2[1] -const vectorFlatten = (v1, v2) => [v1[0] * v2[0], v1[1] * v2[1]] +const project = (v1, v2) => { + const scalar = (dotProduct(v1, v2) / dotProduct(v2, v2)) + return [scalar * v2[0], scalar * v2[1]] +} // direction: either use the constants above or an arbitrary 2d vector. // threshold: how many Px to move from touch origin before checking if the @@ -46,12 +49,12 @@ const updateSwipe = (event, gesture) => { // movement is opposite from direction if (dotProduct(delta, gesture.direction) < 0) return // movement perpendicular to direction is too much - const towardsDir = vectorFlatten(gesture.direction, delta) + const towardsDir = project(delta, gesture.direction) const perpendicularDir = perpendicular(gesture.direction) - const towardsPerpendicular = vectorFlatten(perpendicularDir, delta) + const towardsPerpendicular = project(delta, perpendicularDir) if ( - vectorLength(towardsDir) < - gesture.perpendicularTolerance * vectorLength(towardsPerpendicular) + vectorLength(towardsDir) * gesture.perpendicularTolerance < + vectorLength(towardsPerpendicular) ) return gesture.onSwipe() diff --git a/test/unit/specs/services/gesture_service/gesture_service.spec.js b/test/unit/specs/services/gesture_service/gesture_service.spec.js new file mode 100644 index 00000000..4a1b009a --- /dev/null +++ b/test/unit/specs/services/gesture_service/gesture_service.spec.js @@ -0,0 +1,120 @@ +import GestureService from 'src/services/gesture_service/gesture_service.js' + +const mockTouchEvent = (x, y) => ({ + touches: [ + { + screenX: x, + screenY: y + } + ] +}) + +describe.only('GestureService', () => { + describe('swipeGesture', () => { + it('calls the callback on a successful swipe', () => { + let swiped = false + const callback = () => { swiped = true } + const gesture = GestureService.swipeGesture( + GestureService.DIRECTION_RIGHT, + callback + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(200, 100), gesture) + + expect(swiped).to.eql(true) + }) + + it('calls the callback only once per begin', () => { + let hits = 0 + const callback = () => { hits += 1 } + const gesture = GestureService.swipeGesture( + GestureService.DIRECTION_RIGHT, + callback + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(150, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(200, 100), gesture) + + expect(hits).to.eql(1) + }) + + it('doesn\'t call the callback on an opposite swipe', () => { + let swiped = false + const callback = () => { swiped = true } + const gesture = GestureService.swipeGesture( + GestureService.DIRECTION_RIGHT, + callback + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(0, 100), gesture) + + expect(swiped).to.eql(false) + }) + + it('doesn\'t call the callback on a swipe below threshold', () => { + let swiped = false + const callback = () => { swiped = true } + const gesture = GestureService.swipeGesture( + GestureService.DIRECTION_RIGHT, + callback, + 100 + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(150, 100), gesture) + + expect(swiped).to.eql(false) + }) + + it('doesn\'t call the callback on a perpendicular swipe', () => { + let swiped = false + const callback = () => { swiped = true } + const gesture = GestureService.swipeGesture( + GestureService.DIRECTION_RIGHT, + callback, + 30, + 0.5 + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(150, 200), gesture) + + expect(swiped).to.eql(false) + }) + + it('calls the callback on perpendicular swipe if within tolerance', () => { + let swiped = false + const callback = () => { swiped = true } + const gesture = GestureService.swipeGesture( + GestureService.DIRECTION_RIGHT, + callback, + 30, + 2.0 + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(150, 150), gesture) + + expect(swiped).to.eql(true) + }) + + it('works with any arbitrary 2d directions', () => { + let swiped = false + const callback = () => { swiped = true } + const gesture = GestureService.swipeGesture( + [-1, -1], + callback, + 30, + 0.1 + ) + + GestureService.beginSwipe(mockTouchEvent(100, 100), gesture) + GestureService.updateSwipe(mockTouchEvent(60, 60), gesture) + + expect(swiped).to.eql(true) + }) + }) +}) |