ScrollingLayoutElement

ScrollingLayoutElement

Description

Box layout that supports smooth scrolling If numFlows == 1 then keep adding elements to that one flow and scroll along the axis of that flow If numFlows > 1 or numFlows == 0 (which means infinite/as many as needed) we fill a flow until an element does not fit the current one, then start a new flow until we reach numFlows

Parent

BoxLayoutElement

Functions

• copyAttributes
• invalidateLayout
• loadFromXML
• new
• onGuiSetupFinished
• onSliderValueChanged
• onVerticalCursorInput
• raiseSliderUpdateEvent
• removeActionEvents
• removeElement
• scrollTo

copyAttributes

Description

Definition

copyAttributes()

Arguments

any	src

Code

function ScrollingLayoutElement:copyAttributes(src)
    ScrollingLayoutElement:superClass().copyAttributes( self , src)

    self.topClipperElementName = src.topClipperElementName
    self.bottomClipperElementName = src.bottomClipperElementName
    self.supportsTouchScrolling = src.supportsTouchScrolling
end

invalidateLayout

Description

Rebuild the layout. Adjusts start Y with our visible Y

Definition

invalidateLayout()

Arguments

any	ignoreVisibility
any	blockLayoutUpdate

Code

function ScrollingLayoutElement:invalidateLayout(ignoreVisibility, blockLayoutUpdate)
    local needsUpdate = not blockLayoutUpdate
    if needsUpdate then
        self:updateLayoutCells(ignoreVisibility)
    end

    self:applyCellPositions( self.contentOffsetX, self.contentOffsetY)

    if self.handleFocus and self.focusDirection ~ = BoxLayoutElement.FLOW_NONE and needsUpdate then
        self:focusLinkCells( self.cells)
    end

    if needsUpdate then
        self:updateContentSize()
    end

    self:updateScrollClippers()

    return self.maxFlowSize
end

loadFromXML

Description

Definition

loadFromXML()

Arguments

any	xmlFile
any	key

Code

function ScrollingLayoutElement:loadFromXML(xmlFile, key)
    ScrollingLayoutElement:superClass().loadFromXML( self , xmlFile, key)

    self.topClipperElementName = getXMLString(xmlFile, key .. "#topClipperElementName" )
    self.bottomClipperElementName = getXMLString(xmlFile, key .. "#bottomClipperElementName" )
    self.supportsTouchScrolling = Utils.getNoNil(getXMLBool(xmlFile, key .. "#supportsTouchScrolling" ), self.supportsTouchScrolling)
end

new

Description

Definition

new()

Arguments

any	target
any	custom_mt

Code

function ScrollingLayoutElement.new(target, custom_mt)
    local self = BoxLayoutElement.new(target, custom_mt or ScrollingLayoutElement _mt)

    self.clipping = true
    self.wrapAround = true -- needed for focus handling when scrolling
        --if numFlows = = 1 then scrollDirection = flowDirection, if numFlows > 1 or numFlows = = 0 then it is flipped in onGuiSetupFinished
            self.scrollDirection = self.flowDirection

            self.sliderElement = nil -- sliders register themselves with lists in this field if they point at them via configuration

                self.contentOffsetX = 0
                self.contentOffsetY = 0
                self.targetContentOffsetX = 0
                self.targetContentOffsetY = 0
                self.contentSize = 1 -- height only for now

                    self.lastTouchPos = nil
                    self.usedTouchId = nil
                    self.currentTouchDelta = 0
                    self.scrollSpeed = 0
                    self.initialScrollSpeed = 0
                    self.supportsTouchScrolling = Platform.hasTouchInput

                    self.totalTouchMoveDistance = 0
                    self.touchMoveDistanceThreshold = 30

                    return self
                end

onGuiSetupFinished

Description

Definition

onGuiSetupFinished()

Code

function ScrollingLayoutElement:onGuiSetupFinished()
    ScrollingLayoutElement:superClass().onGuiSetupFinished( self )

    if self.topClipperElementName ~ = nil then
        self.topClipperElement = self.parent:getDescendantByName( self.topClipperElementName)
    end
    if self.bottomClipperElementName ~ = nil then
        self.bottomClipperElement = self.parent:getDescendantByName( self.bottomClipperElementName)
    end

    for _, e in pairs( self.elements) do
        self:addFocusListener(e)
    end

    if self.flowDirection = = "vertical" and self.numFlows = = 1 or self.flowDirection = = "horizontal" and self.numFlows ~ = 1 then
        self.scrollDirection = "vertical"
    else
            self.scrollDirection = "horizontal"
        end

        if self.scrollDirection = = "horizontal" then
            self.scrollSpeedInterval = GuiElement.SCROLL_SPEED_PIXEL_PER_MS * g_pixelSizeX
        else
                self.scrollSpeedInterval = GuiElement.SCROLL_SPEED_PIXEL_PER_MS * g_pixelSizeY
            end
        end

onSliderValueChanged

Description

Definition

onSliderValueChanged()

Arguments

any	slider
any	newValue

Code

function ScrollingLayoutElement:onSliderValueChanged(slider, newValue)
    if self.scrollDirection = = "vertical" then
        local newStartY = 0
        if slider.minValue ~ = slider.maxValue then
            newStartY = (( self.contentSize - self.absSize[ 2 ]) / (slider.maxValue - slider.minValue)) * (newValue - slider.minValue)
        end

        self:scrollTo(newStartY, false )
    else
            local newStartX = 0
            if slider.minValue ~ = slider.maxValue then
                newStartX = (( self.contentSize - self.absSize[ 1 ]) / (slider.maxValue - slider.minValue)) * ( - newValue + slider.minValue)
            end

            self:scrollTo(newStartX, false )
        end
    end

onVerticalCursorInput

Description

Event function for vertical cursor input bound to InputAction.MENU_AXIS_UP_DOWN_SECONDARY.

Definition

onVerticalCursorInput()

Arguments

any	_
any	inputValue

Code

function ScrollingLayoutElement:onVerticalCursorInput(_, inputValue)
    if not self.useMouse then
        self.sliderElement:setValue( self.sliderElement.currentValue + self.sliderElement.stepSize * inputValue)
    end
    self.useMouse = false
end

raiseSliderUpdateEvent

Description

Definition

raiseSliderUpdateEvent()

Code

function ScrollingLayoutElement:raiseSliderUpdateEvent()
    if self.sliderElement ~ = nil then
        self.sliderElement:onBindUpdate( self )
    end
end

removeActionEvents

Description

Remove non-GUI input action events.

Definition

removeActionEvents()

Code

function ScrollingLayoutElement:removeActionEvents()
    g_inputBinding:removeActionEventsByTarget( self )
end

removeElement

Description

Update content size when an element is removed

Definition

removeElement()

Arguments

any	element

Code

function ScrollingLayoutElement:removeElement(element)
    ScrollingLayoutElement:superClass().removeElement( self , element)

    if element.scrollingFocusEnter_orig = = nil then
        element.onFocusEnter = element.scrollingFocusEnter_orig
    end
end

scrollTo

Description

Scroll to an X or Y position within the content

Definition

scrollTo()

Arguments

any	startPos
any	updateSlider
any	noUpdateTarget

Code

function ScrollingLayoutElement:scrollTo(startPos, updateSlider, noUpdateTarget)
    if self.scrollDirection = = "vertical" then
        self.contentOffsetY = startPos

        if not noUpdateTarget then
            self.targetContentOffsetY = startPos
            self.isMovingToTarget = false
        end

        self:invalidateLayout( false , true )

        -- update scrolling
        if updateSlider = = nil or updateSlider then
            if self.sliderElement ~ = nil then
                local newValue = startPos / (( self.contentSize - self.absSize[ 2 ]) / self.sliderElement.maxValue)
                self.sliderElement:setValue(newValue, true )
            end
        end
    else
            self.contentOffsetX = startPos

            if not noUpdateTarget then
                self.targetContentOffsetX = startPos
                self.isMovingToTarget = false
            end

            self:invalidateLayout( false , true )

            -- update scrolling
            if updateSlider = = nil or updateSlider then
                if self.sliderElement ~ = nil then
                    local endPos = (( - self.contentSize + self.absSize[ 1 ]) / self.sliderElement.maxValue) --needed to avoid a divide by 0 if content size is exactly the elements size
                        local newValue = startPos / (endPos ~ = 0 and endPos or 1 )
                        self.sliderElement:setValue(newValue, true )
                    end
                end
            end

            self:raiseCallback( "onScrollCallback" )
        end