require "ui/geometry" GestureRange = { ges = nil, -- spatial range limits the gesture emitting position range = nil, -- temproal range limits the gesture emitting rate rate = nil, -- span limits of this gesture scale = nil, } function GestureRange:new(o) local o = o or {} setmetatable(o, self) self.__index = self return o end function GestureRange:match(gs) if gs.ges ~= self.ges then return false end if self.range then if not self.range:contains(gs.pos) then return false end end if self.rate then local last_time = self.last_time or TimeVal:new{} if gs.time - last_time > TimeVal:new{usec = 1000000 / self.rate} then self.last_time = gs.time else return false end end if self.scale then if self.scale[1] > gs.span or self.scale[2] < gs.span then return false end end return true end --[[ Current detectable gestures: * tap * pan * hold * swipe * pinch * spread * rotate * double_tap * inward_pan * outward_pan * pan_release * two_finger_tap * two_finger_pan * two_finger_swipe * two_finger_pan_release You change the state machine by feeding it touch events, i.e. calling GestureDetector:feedEvent(tev). a touch event should have following format: tev = { slot = 1, id = 46, x = 0, y = 1, timev = TimeVal:new{...}, } Don't confuse tev with raw evs from kernel, tev is build according to ev. GestureDetector:feedEvent(tev) will return a detection result when you feed a touch release event to it. --]] GestureDetector = { -- all the time parameters are in us DOUBLE_TAP_INTERVAL = 300 * 1000, TWO_FINGER_TAP_DURATION = 300 * 1000, HOLD_INTERVAL = 1000 * 1000, SWIPE_INTERVAL = 900 * 1000, -- distance parameters DOUBLE_TAP_DISTANCE = 50, TWO_FINGER_TAP_REGION = 20, PAN_THRESHOLD = 50, -- pinch/spread direction table DIRECTION_TABLE = { east = "horizontal", west = "horizontal", north = "vertical", south = "vertical", northeast = "diagonal", northwest = "diagonal", southeast = "diagonal", southwest = "diagonal", }, -- states are stored in separated slots states = {}, track_ids = {}, tev_stacks = {}, -- latest feeded touch event in each slots last_tevs = {}, first_tevs = {}, -- detecting status on each slots detectings = {}, -- for single/double tap last_taps = {}, } function GestureDetector:feedEvent(tevs) repeat local tev = table.remove(tevs) if tev then local slot = tev.slot if not self.states[slot] then self:clearState(slot) -- initiate state end local ges = self.states[slot](self, tev) if tev.id ~= -1 then self.last_tevs[slot] = tev end -- return no more than one gesture if ges then return ges end end until tev == nil end function GestureDetector:deepCopyEv(tev) return { x = tev.x, y = tev.y, id = tev.id, slot = tev.slot, timev = TimeVal:new{ sec = tev.timev.sec, usec = tev.timev.usec, } } end --[[ tap2 is the later tap --]] function GestureDetector:isDoubleTap(tap1, tap2) local tv_diff = tap2.timev - tap1.timev return ( math.abs(tap1.x - tap2.x) < self.DOUBLE_TAP_DISTANCE and math.abs(tap1.y - tap2.y) < self.DOUBLE_TAP_DISTANCE and (tv_diff.sec == 0 and (tv_diff.usec) < self.DOUBLE_TAP_INTERVAL) ) end function GestureDetector:isTwoFingerTap() if self.last_tevs[0] == nil or self.last_tevs[1] == nil then return false end local x_diff0 = math.abs(self.last_tevs[0].x - self.first_tevs[0].x) local x_diff1 = math.abs(self.last_tevs[1].x - self.first_tevs[1].x) local y_diff0 = math.abs(self.last_tevs[0].y - self.first_tevs[0].y) local y_diff1 = math.abs(self.last_tevs[1].y - self.first_tevs[1].y) local tv_diff0 = self.last_tevs[0].timev - self.first_tevs[0].timev local tv_diff1 = self.last_tevs[1].timev - self.first_tevs[1].timev return ( x_diff0 < self.TWO_FINGER_TAP_REGION and x_diff1 < self.TWO_FINGER_TAP_REGION and y_diff0 < self.TWO_FINGER_TAP_REGION and y_diff1 < self.TWO_FINGER_TAP_REGION and tv_diff0.sec == 0 and tv_diff0.usec < self.TWO_FINGER_TAP_DURATION and tv_diff1.sec == 0 and tv_diff1.usec < self.TWO_FINGER_TAP_DURATION ) end --[[ compare last_pan with first_tev in this slot return pan direction and distance --]] function GestureDetector:getPath(slot) local x_diff = self.last_tevs[slot].x - self.first_tevs[slot].x local y_diff = self.last_tevs[slot].y - self.first_tevs[slot].y local direction = nil local distance = math.sqrt(x_diff*x_diff + y_diff*y_diff) if x_diff == 0 and y_diff == 0 then else local v_direction = y_diff < 0 and "north" or "south" local h_direction = x_diff < 0 and "west" or "east" if math.abs(y_diff) > 0.577*math.abs(x_diff) and math.abs(y_diff) < 1.732*math.abs(x_diff) then direction = v_direction..h_direction elseif (math.abs(x_diff) > math.abs(y_diff)) then direction = h_direction else direction = v_direction end end return direction, distance end function GestureDetector:isSwipe(slot) if not self.first_tevs[slot] or not self.last_tevs[slot] then return end local tv_diff = self.first_tevs[slot].timev - self.last_tevs[slot].timev if (tv_diff.sec == 0) and (tv_diff.usec < self.SWIPE_INTERVAL) then local x_diff = self.last_tevs[slot].x - self.first_tevs[slot].x local y_diff = self.last_tevs[slot].y - self.first_tevs[slot].y if x_diff ~= 0 or y_diff ~= 0 then return true end end end function GestureDetector:getRotate(orig_point, start_point, end_point) local a = orig_point:distance(start_point) local b = orig_point:distance(end_point) local c = start_point:distance(end_point) return math.acos((a*a + b*b - c*c)/(2*a*b))*180/math.pi end --[[ Warning! this method won't update self.state, you need to do it in each state method! --]] function GestureDetector:switchState(state_new, tev, param) --@TODO do we need to check whether state is valid? (houqp) return self[state_new](self, tev, param) end function GestureDetector:clearState(slot) self.states[slot] = self.initialState self.detectings[slot] = false self.first_tevs[slot] = nil self.last_tevs[slot] = nil end function GestureDetector:clearStates() self:clearState(0) self:clearState(1) end function GestureDetector:initialState(tev) local slot = tev.slot if tev.id then -- a event ends if tev.id == -1 then self.detectings[slot] = false else self.track_ids[slot] = tev.id end end if tev.x and tev.y then -- user starts a new touch motion if not self.detectings[slot] then self.detectings[slot] = true self.first_tevs[slot] = self:deepCopyEv(tev) -- default to tap state return self:switchState("tapState", tev) end end end --[[ this method handles both single and double tap --]] function GestureDetector:tapState(tev) DEBUG("in tap state...") local slot = tev.slot if tev.id == -1 then -- end of tap event if self.detectings[0] and self.detectings[1] then if self:isTwoFingerTap() then local pos0 = Geom:new{ x = self.last_tevs[0].x, y = self.last_tevs[0].y, w = 0, h = 0, } local pos1 = Geom:new{ x = self.last_tevs[1].x, y = self.last_tevs[1].y, w = 0, h = 0, } local tap_span = pos0:distance(pos1) DEBUG("two-finger tap detected with span", tap_span) self:clearStates() return { ges = "two_finger_tap", pos = pos0:midpoint(pos1), span = tap_span, time = tev.timev, } else self:clearState(slot) end elseif self.last_tevs[slot] ~= nil then return self:handleDoubleTap(tev) else -- last tev in this slot is cleared by last two finger tap self:clearState(slot) return { ges = "tap", pos = Geom:new{ x = tev.x, y = tev.y, w = 0, h = 0, }, time = tev.timev, } end else return self:handleNonTap(tev) end end function GestureDetector:handleDoubleTap(tev) local slot = tev.slot local ges_ev = { -- default to single tap ges = "tap", pos = Geom:new{ x = self.last_tevs[slot].x, y = self.last_tevs[slot].y, w = 0, h = 0, }, time = tev.timev, } -- cur_tap is used for double tap detection local cur_tap = { x = tev.x, y = tev.y, timev = tev.timev, } if self.last_taps[slot] ~= nil and self:isDoubleTap(self.last_taps[slot], cur_tap) then -- it is a double tap self:clearState(slot) ges_ev.ges = "double_tap" self.last_taps[slot] = nil DEBUG("double tap detected in slot", slot) return ges_ev end -- set current tap to last tap self.last_taps[slot] = cur_tap DEBUG("set up tap timer") -- deadline should be calculated by adding current tap time and the interval local deadline = cur_tap.timev + TimeVal:new{ sec = 0, usec = self.DOUBLE_TAP_INTERVAL, } Input:setTimeout(function() DEBUG("in tap timer", self.last_taps[slot] ~= nil) -- double tap will set last_tap to nil so if it is not, then -- user must only tapped once if self.last_taps[slot] ~= nil then self.last_taps[slot] = nil -- we are using closure here DEBUG("single tap detected in slot", slot) return ges_ev end end, deadline) -- we are already at the end of touch event -- so reset the state self:clearState(slot) end function GestureDetector:handleNonTap(tev) local slot = tev.slot if self.states[slot] ~= self.tapState then -- switched from other state, probably from initialState -- we return nil in this case self.states[slot] = self.tapState DEBUG("set up hold timer") local deadline = tev.timev + TimeVal:new{ sec = 0, usec = self.HOLD_INTERVAL } Input:setTimeout(function() if self.states[slot] == self.tapState then -- timer set in tapState, so we switch to hold DEBUG("hold gesture detected in slot", slot) return self:switchState("holdState", tev, true) end end, deadline) else -- it is not end of touch event, see if we need to switch to -- other states if (tev.x and math.abs(tev.x - self.first_tevs[slot].x) >= self.PAN_THRESHOLD) or (tev.y and math.abs(tev.y - self.first_tevs[slot].y) >= self.PAN_THRESHOLD) then -- if user's finger moved long enough in X or -- Y distance, we switch to pan state return self:switchState("panState", tev) end end end function GestureDetector:panState(tev) DEBUG("in pan state...") local slot = tev.slot if tev.id == -1 then -- end of pan, signal swipe gesture if necessary if self:isSwipe(slot) then if self.detectings[0] and self.detectings[1] then local ges_ev = self:handleTwoFingerPan(tev) self:clearStates() if ges_ev then if ges_ev.ges == "two_finger_pan" then ges_ev.ges = "two_finger_swipe" elseif ges_ev.ges == "inward_pan" then ges_ev.ges = "pinch" elseif ges_ev.ges == "outward_pan" then ges_ev.ges = "spread" end DEBUG(ges_ev.ges, ges_ev.direction, ges_ev.distance, "detected") end return ges_ev else return self:handleSwipe(tev) end else -- if end of pan is not swipe then it must be pan release. return self:handlePanRelease(tev) end else if self.states[slot] ~= self.panState then self.states[slot] = self.panState end return self:handlePan(tev) end end function GestureDetector:handleSwipe(tev) local slot = tev.slot local swipe_direction, swipe_distance = self:getPath(slot) local start_pos = Geom:new{ x = self.first_tevs[slot].x, y = self.first_tevs[slot].y, w = 0, h = 0, } DEBUG("swipe", swipe_direction, swipe_distance, "detected in slot", slot) self:clearState(slot) return { ges = "swipe", -- use first pan tev coordination as swipe start point pos = start_pos, direction = swipe_direction, distance = swipe_distance, time = tev.timev, } end function GestureDetector:handlePan(tev) local slot = tev.slot if self.detectings[0] and self.detectings[1] then return self:handleTwoFingerPan(tev) else local pan_direction, pan_distance = self:getPath(slot) local pan_ev = { ges = "pan", relative = { -- default to pan 0 x = 0, y = 0, }, pos = nil, direction = pan_direction, distance = pan_distance, time = tev.timev, } pan_ev.relative.x = tev.x - self.last_tevs[slot].x pan_ev.relative.y = tev.y - self.last_tevs[slot].y pan_ev.pos = Geom:new{ x = self.last_tevs[slot].x, y = self.last_tevs[slot].y, w = 0, h = 0, } return pan_ev end end function GestureDetector:handleTwoFingerPan(tev) -- triggering slot local tslot = tev.slot -- reference slot local rslot = tslot and 0 or 1 local tpan_dir, tpan_dis = self:getPath(tslot) local tstart_pos = Geom:new{ x = self.first_tevs[tslot].x, y = self.first_tevs[tslot].y, w = 0, h = 0, } local tend_pos = Geom:new{ x = self.last_tevs[tslot].x, y = self.last_tevs[tslot].y, w = 0, h = 0, } local rstart_pos = Geom:new{ x = self.first_tevs[rslot].x, y = self.first_tevs[rslot].y, w = 0, h = 0, } if self.states[rslot] == self.panState then local rpan_dir, rpan_dis = self:getPath(rslot) local rend_pos = Geom:new{ x = self.last_tevs[rslot].x, y = self.last_tevs[rslot].y, w = 0, h = 0, } local start_distance = tstart_pos:distance(rstart_pos) local end_distance = tend_pos:distance(rend_pos) local ges_ev = { ges = "two_finger_pan", -- use midpoint of tstart and rstart as swipe start point pos = tstart_pos:midpoint(rstart_pos), distance = tpan_dis + rpan_dis, direction = tpan_dir, time = tev.timev, } if tpan_dir ~= rpan_dir then if start_distance > end_distance then ges_ev.ges = "inward_pan" else ges_ev.ges = "outward_pan" end ges_ev.direction = self.DIRECTION_TABLE[tpan_dir] end DEBUG(ges_ev.ges, ges_ev.direction, ges_ev.distance, "detected") return ges_ev elseif self.states[rslot] == self.holdState then local angle = self:getRotate(rstart_pos, tstart_pos, tend_pos) DEBUG("rotate", angle, "detected") return { ges = "rotate", pos = rstart_pos, angle = angle, time = tev.timev, } end end function GestureDetector:handlePanRelease(tev) local slot = tev.slot local release_pos = Geom:new{ x = self.last_tevs[slot].x, y = self.last_tevs[slot].y, w = 0, h = 0, } local pan_ev = { ges = "pan_release", pos = release_pos, time = tev.timev, } if self.detectings[0] and self.detectings[1] then DEBUG("two finger pan release detected") pan_ev.ges = "two_finger_pan_release" self:clearStates() else DEBUG("pan release detected in slot", slot) self:clearState(slot) end return pan_ev end function GestureDetector:holdState(tev, hold) DEBUG("in hold state...") local slot = tev.slot -- when we switch to hold state, we pass additional param "hold" if tev.id ~= -1 and hold and self.last_tevs[slot].x and self.last_tevs[slot].y then self.states[slot] = self.holdState return { ges = "hold", pos = Geom:new{ x = self.last_tevs[slot].x, y = self.last_tevs[slot].y, w = 0, h = 0, }, time = tev.timev, } end if tev.id == -1 and self.last_tevs[slot] ~= nil then -- end of hold, signal hold release DEBUG("hold_release detected in slot", slot) local last_x = self.last_tevs[slot].x local last_y = self.last_tevs[slot].y self:clearState(slot) return { ges = "hold_release", pos = Geom:new{ x = last_x, y = last_y, w = 0, h = 0, }, time = tev.timev, } end end --[[ @brief change gesture's x and y coordinates according to screen view mode @param ges gesture that you want to adjust @return adjusted gesture. --]] function GestureDetector:adjustGesCoordinate(ges) if Screen.cur_rotation_mode == 1 then -- in landscape mode if ges.pos then ges.pos.x, ges.pos.y = (Screen.width - ges.pos.y), (ges.pos.x) end if ges.ges == "swipe" or ges.ges == "pan" or ges.ges == "two_finger_swipe" or ges.ges == "two_finger_pan" then if ges.direction == "north" then ges.direction = "east" elseif ges.direction == "south" then ges.direction = "west" elseif ges.direction == "east" then ges.direction = "south" elseif ges.direction == "west" then ges.direction = "north" elseif ges.direction == "northeast" then ges.direction = "southeast" elseif ges.direction == "northwest" then ges.direction = "northeast" elseif ges.direction == "southeast" then ges.direction = "southwest" elseif ges.direction == "southwest" then ges.direction = "northwest" end elseif ges.ges == "pinch" or ges.ges == "spread" or ges.ges == "inward_pan" or ges.ges == "outward_pan" then if ges.direction == "horizontal" then ges.direction = "vertical" elseif ges.direction == "vertical" then ges.direction = "horizontal" end end end return ges end