Merge branch 'feat/gesture-service' into 'develop'

Add a gesture service for easier touch gestures

See merge request pleroma/pleroma-fe!714

src/components/side_drawer/side_drawer.js

@@ -1,17 +1,16 @@
 import UserCard from '../user_card/user_card.vue'
 import { unseenNotificationsFromStore } from '../../services/notification_utils/notification_utils'
-
-// TODO: separate touch gesture stuff into their own utils if more components want them
-const deltaCoord = (oldCoord, newCoord) => [newCoord[0] - oldCoord[0], newCoord[1] - oldCoord[1]]
-
-const touchEventCoord = e => ([e.touches[0].screenX, e.touches[0].screenY])
+import GestureService from '../../services/gesture_service/gesture_service'
 
 const SideDrawer = {
   props: [ 'logout' ],
   data: () => ({
     closed: true,
-    touchCoord: [0, 0]
+    closeGesture: undefined
   }),
+  created () {
+    this.closeGesture = GestureService.swipeGesture(GestureService.DIRECTION_LEFT, this.toggleDrawer)
+  },
   components: { UserCard },
   computed: {
     currentUser () {
@@ -46,13 +45,10 @@ const SideDrawer = {
       this.toggleDrawer()
     },
     touchStart (e) {
-      this.touchCoord = touchEventCoord(e)
+      GestureService.beginSwipe(e, this.closeGesture)
     },
     touchMove (e) {
-      const delta = deltaCoord(this.touchCoord, touchEventCoord(e))
-      if (delta[0] < -30 && Math.abs(delta[1]) < Math.abs(delta[0]) && !this.closed) {
-        this.toggleDrawer()
-      }
+      GestureService.updateSwipe(e, this.closeGesture)
     }
   }
 }

src/components/side_drawer/side_drawer.vue

@@ -2,6 +2,7 @@
   <div class="side-drawer-container"
     :class="{ 'side-drawer-container-closed': closed, 'side-drawer-container-open': !closed }"
   >
+    <div class="side-drawer-darken" :class="{ 'side-drawer-darken-closed': closed}" />
     <div class="side-drawer"
       :class="{'side-drawer-closed': closed}"
       @touchstart="touchStart"
@@ -111,16 +112,32 @@
   height: 100%;
   display: flex;
   align-items: stretch;
+  transition-duration: 0s;
+  transition-property: transform;
 }
 
 .side-drawer-container-open {
+  transform: translate(0%);
+}
+
+.side-drawer-container-closed {
+  transition-delay: 0.35s;
+  transform: translate(-100%);
+}
+
+.side-drawer-darken {
+  top: 0;
+  left: 0;
+  width: 100vw;
+  height: 100vh;
+  position: fixed;
+  z-index: -1;
   transition: 0.35s;
   transition-property: background-color;
   background-color: rgba(0, 0, 0, 0.5);
 }
 
-.side-drawer-container-closed {
-  left: -100%;
+.side-drawer-darken-closed {
   background-color: rgba(0, 0, 0, 0);
 }
 
@@ -130,8 +147,9 @@
 
 .side-drawer {
   overflow-x: hidden;
-  transition: 0.35s;
   transition-timing-function: cubic-bezier(0, 1, 0.5, 1);
+  transition: 0.35s;
+  transition-property: transform;
   margin: 0 0 0 -100px;
   padding: 0 0 1em 100px;
   width: 80%;

src/services/gesture_service/gesture_service.js

@@ -0,0 +1,74 @@
+
+const DIRECTION_LEFT = [-1, 0]
+const DIRECTION_RIGHT = [1, 0]
+const DIRECTION_UP = [0, -1]
+const DIRECTION_DOWN = [0, 1]
+
+const deltaCoord = (oldCoord, newCoord) => [newCoord[0] - oldCoord[0], newCoord[1] - oldCoord[1]]
+
+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 dotProduct = (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
+//    callback should be called.
+// divergentTolerance: a scalar for much of divergent direction we tolerate when
+//    above threshold. for example, with 1.0 we only call the callback if
+//    divergent component of delta is < 1.0 * direction component of delta.
+const swipeGesture = (direction, onSwipe, threshold = 30, perpendicularTolerance = 1.0) => {
+  return {
+    direction,
+    onSwipe,
+    threshold,
+    perpendicularTolerance,
+    _startPos: [0, 0],
+    _swiping: false
+  }
+}
+
+const beginSwipe = (event, gesture) => {
+  gesture._startPos = touchEventCoord(event)
+  gesture._swiping = true
+}
+
+const updateSwipe = (event, gesture) => {
+  if (!gesture._swiping) return
+  // movement too small
+  const delta = deltaCoord(gesture._startPos, touchEventCoord(event))
+  if (vectorLength(delta) < gesture.threshold) return
+  // movement is opposite from direction
+  if (dotProduct(delta, gesture.direction) < 0) return
+  // movement perpendicular to direction is too much
+  const towardsDir = project(delta, gesture.direction)
+  const perpendicularDir = perpendicular(gesture.direction)
+  const towardsPerpendicular = project(delta, perpendicularDir)
+  if (
+    vectorLength(towardsDir) * gesture.perpendicularTolerance <
+    vectorLength(towardsPerpendicular)
+  ) return
+
+  gesture.onSwipe()
+  gesture._swiping = false
+}
+
+const GestureService = {
+  DIRECTION_LEFT,
+  DIRECTION_RIGHT,
+  DIRECTION_UP,
+  DIRECTION_DOWN,
+  swipeGesture,
+  beginSwipe,
+  updateSwipe
+}
+
+export default GestureService

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)
+    })
+  })
+})