object:takeFocus()

Type Function
Library widget.*
Return value Number
Revision Current Public Release (2014.2511)
Keywords widget, scrollview, scrollbox, scrolling content
See also widget.newScrollView()

Overview

If you have an object with a touch listener inside a scroll view, such as a Button widget, you should call this method within the "moved" phase of that object's touch listener and pass the touch event's event table as the sole parameter of this method. This will give focus back to the scroll view, enabling it to continue to scroll.

Syntax

object:takeFocus( event )
event (required)

Table. The event table from the object's touch listener function.

Example

local widget = require( "widget" )

local scrollView = widget.newScrollView
{
    top = 100,
    left = 10,
    width = 300,
    height = 400,
    scrollWidth = 600,
    scrollHeight = 800,
    horizontalScrollDisabled = true
}

-- The touch listener function for the button (created below)
local function handleButtonEvent( event )

    local phase = event.phase

    if ( phase == "moved" ) then
        local dy = math.abs( ( event.y - event.yStart ) )
        -- If the touch on the button has moved more than 10 pixels,
        -- pass focus back to the scroll view so it can continue scrolling
        if ( dy > 10 ) then
            scrollView:takeFocus( event )
        end
    end
    return true
end

local button1 = widget.newButton
{
    left = 100,
    top = 200,
    id = "button1",
    label = "Default",
    onEvent = handleButtonEvent
}
scrollView:insert( button1 )