corona sdk - scene keep old items - coronasdk

Question

I'm using director , to move from one scene to another. I have a problem that the buttons and text fields from intor still in the top of screen when moving to any scene.
How to remove items (text fields, btns from intro.lua screen) before move to next scene?
enter code here
-- into.lua
module(..., package.seeall)
function new()
--
-- Project: NativeKeyboard2
--
local widget = require( "widget" )
require("hijacks")
local tHeight -- forward reference
-------------------------------------------
-- General event handler for fields
-------------------------------------------
-- You could also assign different handlers for each textfield
local function fieldHandler( textField )
return function( event )
if ( "began" == event.phase ) then
-- This is the "keyboard has appeared" event
-- In some cases you may want to adjust the interface when the keyboard appears.
elseif ( "ended" == event.phase ) then
-- This event is called when the user stops editing a field: for example, when they touch a different field
elseif ( "editing" == event.phase ) then
elseif ( "submitted" == event.phase ) then
-- This event occurs when the user presses the "return" key (if available) on the onscreen keyboard
print( textField().text )
-- Hide keyboard
native.setKeyboardFocus( nil )
end
end
end
-- Predefine local objects for use later
local nameField, phoneField
local fields = display.newGroup()
-------------------------------------------
-- *** Create native input textfields ***
-------------------------------------------
-- Note: currently this feature works in device builds or Xcode simulator builds only (also works on Corona Mac Simulator)
local isAndroid = "Android" == system.getInfo("platformName")
local inputFontSize = 18
local inputFontHeight = 30
tHeight = 30
if isAndroid then
-- Android text fields have more chrome. It's either make them bigger, or make the font smaller.
-- We'll do both
inputFontSize = 14
inputFontHeight = 42
tHeight = 40
end
nameField = native.newTextField( 40, 120, 200, tHeight )
nameField.font = native.newFont( native.systemFontBold, inputFontSize )
nameField:addEventListener( "userInput", fieldHandler( function() return nameField end ) )
phoneField = native.newTextField( 40, 160, 200, tHeight )
phoneField.font = native.newFont( native.systemFontBold, inputFontSize )
phoneField.inputType = "phone"
phoneField:addEventListener( "userInput", fieldHandler( function() return phoneField end ) )
-- Add fields to our new group
fields:insert(nameField)
fields:insert(phoneField)
-------------------------------------------
-- *** Add field labels ***
-------------------------------------------
local defaultLabel = display.newText( "الاسم", 250, 120, native.systemFont, 18 )
defaultLabel:setTextColor( 255, 0, 0 )
local defaultLabel = display.newText( "رقم الجوال", 250, 160, native.systemFont, 18 )
defaultLabel:setTextColor( 255, 0, 0 )
-- -------------------------------------------
-- -- Create a Background touch event
-- -------------------------------------------
local listener = function( event )
-- Hide keyboard
print("tap pressed")
native.setKeyboardFocus( nil )
return true
end
-- Determine if running on Corona Simulator
--
local isSimulator = "simulator" == system.getInfo("environment")
if system.getInfo( "platformName" ) == "Mac OS X" then isSimulator = false; end
-- Native Text Fields not supported on Simulator
--
if isSimulator then
msg = display.newText( "الرجاء ادخال اسمك ورقم جوالك", 0, 280, native.systemFontBold, 12 )
msg.x = display.contentWidth/2 -- center title
msg:setTextColor( 255,0,0 )
end
-- -- Add listener to background for user "tap"
-- bkgd:addEventListener( "tap", listener )
-- display.remove( obj )
-- obj = nil
local introGroup = display.newGroup();
local background = display.newImage("graphics/intro_background.png")
local begin = display.newImage("graphics/begin_button.png")
begin.x = 160;
begin.y = 400;
begin.scene = "menu";
introGroup:insert(background);
introGroup:insert(begin);
begin:addEventListener("touch", changeScene)
return introGroup;
end

Answer 1

Corona provides a very good feature that is "Storyboard".I am giving you a brief explanation, Try this -
Storyboard - It is a scene (e.g. "screens" or "views") management library that provides developers an easy way to create and transition between scene modules in a Corona SDK app.
Syntax -
local storyboard = require "storyboard"
Example -
local scene1 = storyboard.newScene( "name of the Scene" )
Here are the different events used in the Storyboard -
1- Create Scene -
-- Called when the scene's view does not exist:
function scene:createScene( event )
local group = self.view
end
2- Enter Scene -
-- Called immediately after scene has moved onscreen:
function scene:enterScene( event )
local group = self.view
end
3- Exit Scene -
-- Called when scene is about to move offscreen:
function scene:exitScene( event )
local group = self.view
end
4 - Destroy Scene -
-- Called prior to the removal of scene's "view" (display group)
function scene:destroyScene( event )
local group = self.view
end
It will help you.