tableView.lua

-- tableView.lua, Table View Library
--
-- Version 1.3
--
-- Copyright (C) 2010 ANSCA Inc. All Rights Reserved.
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy of
-- this software and associated documentation files (the "Software"), to deal in the
-- Software without restriction, including without limitation the rights to use, copy,
-- modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
-- and to permit persons to whom the Software is furnished to do so, subject to the
-- following conditions:
--
-- The above copyright notice and this permission notice shall be included in all copies
-- or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-- INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-- PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-- FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-- OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-- DEALINGS IN THE SOFTWARE.

module(..., package.seeall)

--properties
 local screenW, screenH = display.contentWidth, display.contentHeight
local viewableScreenW, viewableScreenH = display.viewableContentWidth, display.viewableContentHeight
local screenOffsetW, screenOffsetH = display.contentWidth -  display.viewableContentWidth, display.contentHeight - display.viewableContentHeight

local currentTarget, detailScreen, velocity, currentDefault, currentOver, prevY
local startTime, lastTime, prevTime = 0, 0, 0

--methods

function showHighlight(event)
    local timePassed = system.getTimer() - startTime

    if timePassed > 100 then
        print("highlight")
        currentDefault.isVisible = false
        currentOver.isVisible = true
        Runtime:removeEventListener( "enterFrame", showHighlight )
    end
end

function newListItemHandler(self, event)
        local t = currentTarget --could use self.target.parent possibly
        local phase = event.phase
        print("touch: ".. phase)

        local default = self.default
        local over = self.over
        local top = self.top
        local bottom = self.bottom
        local upperLimit, bottomLimit = top, screenH - currentTarget.height - bottom

        local result = true

        if( phase == "began" ) then
            -- Subsequent touch events will target button even if they are outside the stageBounds of button
            display.getCurrentStage():setFocus( self )
            self.isFocus = true

            startPos = event.y
            prevPos = event.y
            delta, velocity = 0, 0
            if currentTarget.tween then transition.cancel(currentTarget.tween) end

            Runtime:removeEventListener("enterFrame", scrollList )
            Runtime:addEventListener("enterFrame", moveCat)

            -- Start tracking velocity
            Runtime:addEventListener("enterFrame", trackVelocity)

            if over then
                currentDefault = default
                currentOver = over
                startTime = system.getTimer()
                Runtime:addEventListener( "enterFrame", showHighlight )
            end

        elseif( self.isFocus ) then

            if( phase == "moved" ) then

                Runtime:removeEventListener( "enterFrame", showHighlight )
                if over then
                    default.isVisible = true
                    over.isVisible = false
                end

                delta = event.y - prevPos
                prevPos = event.y
                if ( t.y > upperLimit or t.y < bottomLimit ) then
                    t.y  = t.y + delta/2
                else
                    t.y = t.y + delta
                end

            elseif( phase == "ended" or phase == "cancelled" ) then

                lastTime = event.time

                local dragDistance = event.y - startPos
                --velocity = delta
                Runtime:removeEventListener("enterFrame", moveCat)
                Runtime:removeEventListener("enterFrame", trackVelocity)
                Runtime:addEventListener("enterFrame", scrollList )

                local bounds = self.stageBounds
                local x, y = event.x, event.y
                local isWithinBounds = bounds.xMin <= x and bounds.xMax >= x and bounds.yMin <= y and bounds.yMax >= y

                -- Only consider this a "click", if the user lifts their finger inside button's stageBounds
                if isWithinBounds and (dragDistance < 10 and dragDistance > -10 ) then
                    velocity = 0
                    result = self.onRelease(event)
                end

                -- Allow touch events to be sent normally to the objects they "hit"
                display.getCurrentStage():setFocus( nil )
                self.isFocus = false

                if over then
                    default.isVisible = true
                    over.isVisible = false
                    Runtime:removeEventListener( "enterFrame", showHighlight )
                end
            end
        end

        return result
end

function newListItem(params)
        local data = params.data
        local default = params.default
        local over = params.over
        local onRelease = params.onRelease
        local top = params.top
        local bottom = params.bottom
        local callback = params.callback
        local id = params.id

        local thisItem = display.newGroup()

        if params.default then
                default = display.newImage( params.default )
                thisItem:insert( default )
                default.x = default.width*.5 - screenOffsetW
                thisItem.default  = default
        end

        if params.over then
                over = display.newImage( params.over )
                over.isVisible = false
                thisItem:insert( over )
                over.x = over.width*.5 - screenOffsetW
                thisItem.over = over
        end

        thisItem.id = id
        thisItem.data = data
        thisItem.onRelease = onRelease
        thisItem.top = top
        thisItem.bottom = bottom

        local t = callback(data)
        thisItem:insert( t )

        thisItem.touch = newListItemHandler
        thisItem:addEventListener( "touch", thisItem )

        return thisItem
end

function newList(params)
        local textSize = 16
        local data = params.data
        local default = params.default
        local over = params.over
        local onRelease = params.onRelease
        local top = params.top or 20
        local bottom = params.bottom or 48
        local cat = params.cat
        local order = params.order or {}
        local categoryBackground = params.categoryBackground
        local backgroundColor = params.backgroundColor
        local callback = params.callback or function(item)
                                                local t = display.newText(item, 0, 0, native.systemFontBold, textSize)
                                                t:setTextColor(255, 255, 255)
                                                t.x = math.floor(t.width/2) + 20
                                                t.y = 24
                                                return t
                                            end

        --setup the list view
        local listView = display.newGroup()
        local prevY, prevH = 0, 0


        if cat then
            local catTable = {}

            --get the implicit categories
            local prevCat = 0
            for i=1, #data do
                if data[i][cat] ~= prevCat then
                    table.insert(catTable, data[i][cat])
                    prevCat = data[i][cat]
                end
            end

            if order then
                --clean up the user provided order table by removing any empty categories
                local n = 1
                while n < #order do
                    if not in_table(order[n], catTable) then
                        table.remove(order, n)
                    else
                        n = n + 1
                    end
                end

                --add any categories not specified to the user order of categories
                for i=1, #catTable do
                    if not in_table(catTable[i], order) then
                        table.insert(order, catTable[i])
                    end
                end
            else
                order = catTable
            end

        end

        local j = 1
        local c = {}
        local offset = 12
        while true do
            local h = order[j]

            if h then
                local g = display.newGroup()
                local b
                if categoryBackground then
                    b = display.newImage(categoryBackground, true)
                else
                    b = display.newRect(0, 0, screenW, textSize*1.5)
                    b:setFillColor(0, 0, 0, 100)
                end
                g:insert( b )

                local labelShadow = display.newText( h, 0, 0, native.systemFontBold, textSize )
                labelShadow:setTextColor( 0, 0, 0, 128 )
                g:insert( labelShadow, true )
                labelShadow.x = labelShadow.width*.5 + 1 + offset + screenOffsetW*.5
                labelShadow.y = textSize*.8 + 1

                local t = display.newText(h, 0, 0, native.systemFontBold, textSize)
                t:setTextColor(255, 255, 255)
                g:insert( t )
                t.x = t.width*.5 + offset + screenOffsetW*.5
                t.y = textSize*.8

                listView:insert( g )
                g.x = 0
                g.y = prevY + prevH
                prevY = g.y
                prevH = g.height
                table.insert(c, g)
                c[#c].yInit = g.y
            end

            --iterate over the data and add items to the list view
            for i=1, #data do
                if data[i][cat] == h then
                    local thisItem = newListItem{
                        data = data[i],
                        default = default,
                        over = over,
                        onRelease = onRelease,
                        top = top,
                        bottom = bottom,
                        callback = callback,
                        id = i
                    }

                    listView:insert( 1, thisItem )

                    thisItem.x = 0 + screenOffsetW*.5
                    thisItem.y = prevY + prevH

                    --save the Y and height
                    prevY = thisItem.y
                    prevH = thisItem.height
                end --if
            end --for

            j = j + 1

            if not order[j] then break end
        end --while

        if backgroundColor then
            local bgColor = display.newRect(0, 0, screenW, screenH)
            bgColor:setFillColor(backgroundColor[1], backgroundColor[2], backgroundColor[3])
            bgColor.width = listView.width
            bgColor.height = listView.height
            bgColor.y = bgColor.height*.5
            listView:insert(1, bgColor)
        end

        listView.y = top
        listView.top = top
        listView.bottom = bottom
        listView.c = c

        currentTarget = listView

        function listView:cleanUp()
            print("tableView cleanUp")
            Runtime:removeEventListener("enterFrame", moveCat )
            Runtime:removeEventListener("enterFrame", scrollList )
            Runtime:removeEventListener( "enterFrame", showHighlight )
            Runtime:removeEventListener("enterFrame", trackVelocity)
            local i
            for i = listView.numChildren, 1, -1 do
                --test
                listView[i]:removeEventListener("touch", newListItemHandler)
                listView:remove(i)
                listView[i] = nil
            end
        end

        return listView
end

function scrollList(event)
        local friction = 0.9
        local timePassed = event.time - lastTime
        lastTime = lastTime + timePassed

        --turn off scrolling if velocity is near zero
        if math.abs(velocity) < .01 then
                velocity = 0
                Runtime:removeEventListener("enterFrame", scrollList )
        end

        velocity = velocity*friction

        currentTarget.y = math.floor(currentTarget.y + velocity*timePassed)

        moveCat()

        local upperLimit = currentTarget.top
        local bottomLimit = screenH - currentTarget.height - currentTarget.bottom

        if ( currentTarget.y > upperLimit ) then
                velocity = 0
                Runtime:removeEventListener("enterFrame", scrollList )
                Runtime:addEventListener("enterFrame", moveCat )
                currentTarget.tween = transition.to(currentTarget, { time=400, y=upperLimit, transition=easing.outQuad})
        elseif ( currentTarget.y < bottomLimit and bottomLimit < 0 ) then
                velocity = 0
                Runtime:removeEventListener("enterFrame", scrollList )
                Runtime:addEventListener("enterFrame", moveCat )
                currentTarget.tween = transition.to(currentTarget, { time=400, y=bottomLimit, transition=easing.outQuad})
        elseif ( currentTarget.y < bottomLimit ) then
                velocity = 0
                Runtime:removeEventListener("enterFrame", scrollList )
                Runtime:addEventListener("enterFrame", moveCat )
                currentTarget.tween = transition.to(currentTarget, { time=400, y=upperLimit, transition=easing.outQuad})
        end

        return true
end

function moveCat()
        local upperLimit = currentTarget.top

        for i=1, #currentTarget.c do
            if( currentTarget.y > upperLimit - currentTarget.c[i].yInit ) then
                currentTarget.c[i].y = currentTarget.c[i].yInit
            end

            if ( currentTarget.y < upperLimit - currentTarget.c[i].yInit ) then
                currentTarget.c[i].y = upperLimit - currentTarget.y
            end

            if( i > 1 ) then
                if ( currentTarget.c[i].y < currentTarget.c[i-1].y + currentTarget.c[i].height ) then
                    currentTarget.c[i-1].y = currentTarget.c[i].y - currentTarget.c[i].height
                end
            end
        end

        return true
end

function trackVelocity(event)
    local timePassed = event.time - prevTime
    prevTime = prevTime + timePassed

    if prevY then
        velocity = (currentTarget.y - prevY)/timePassed
    end
    prevY = currentTarget.y
end

--look for an item in a table
function in_table ( e, t )
    for _,v in pairs(t) do
        if (v==e) then return true end
    end
    return false
end