ScrollView or NewText is not infinite - lua

I am making a changelog for my app and I inserted a bunch of text into display.newText. Is there a limit to the amount of characters display.newText can take or is it a problem in ScrollView? My code:
local widget = require( "widget" )
scrollView = widget.newScrollView
{
hideBackground = true,
hideScrollBar = true,
left = 0,
top = 170,
width = display.contentWidth,
height = contH - 300,
topPadding = 150,
bottomPadding = 20,
horizontalScrollDisabled = true,
verticalScrollDisabled = false,
}
ChangeLogText = [[ ...a bunch of text here... ]]
ChangeLog = display.newText(ChangeLogText, contW / 2, 4730, contW - 100, 0, "Fonts/visitor1.ttf", 40)
scrollView:insert(ChangeLog)
I can see ~164 lines of text, but it just stops there... Is there a way to make it infinite?

I had the same problem just recently - too bad that such limitations are detailed nowhere in the API.
I started with this github repository, witch contains the full widget library of Corona SDK (it's no longer developed AFAIK), but managed to find nothing.
The workaround I eventually settled with, is to start with only the first part of the text inserted into the text display object, and then use scrollView scrollListener to reload text whenever top/bottom limit is reached.
Part of scrollListener (event.direction == "up" is basically the mirror image of this):
elseif ( event.direction == "down" ) then
--check if limit is reached or close to it, y is from scrollView:getContentPosition(), -800 is arbitrary
if ( event.limitReached ) or y > - 800 then print( "Reached top limit" )
--firstS stores number of first visible sign of a string
if chat.firstS > 1 then
--copy string
local shownText = stringText
--update display object
chat.text = shownText
local firstS, lastS
--do while display object is too high - I found that scrollView stops scrolling ~25000 height
while (chat.height) > 24000 do
--basically cut the text in half
firstS = chat.firstS - #shownText/4
if firstS < 1 then firstS = 1 end
lastS = firstS + #shownText/2
shownText = string.sub( stringText, firstS, lastS)
chat.text = shownText
end
chat.firstS = firstS
chat.lastS = lastS
--scroll to halfway position in no time for seamless transition
mainView:scrollToPosition({y = -(chat.height)/2, time = 0})
end
end
end
This is an early version and needs some refinement, but I hope it helps. If you find anything better, let me know. Also, I display text from bottom, so you might need to adjust it accordingly.

Related

MapView to background - Corona SDK

I need some help with the MapView in Corona SDK. I want to put the map as background (but with all functions) and, in this case, a button to the front. Here is my code:
function scene:createScene( event )
local group = self.view
if ( system.getInfo( "environment" ) == "simulator" ) then
local simulatorMessage = "Maps not supported in Corona Simulator.\nYou must build for iOS or Android to test native.newMapView() support."
local label = display.newText( simulatorMessage, 36, 40, 270, 0, native.systemFont, 12 )
label.anchorX = 0
label.anchorY = 0
end
myMap = native.newMapView( 20, 20, display.contentWidth, display.contentHeight )
if ( myMap ) then
myMap.mapType = "normal"
myMap.x = display.contentCenterX
myMap.y = display.contentCenterY
myMap:setCenter( currentLatitude, currentLongitude )
myMap:addEventListener("mapLocation", mapLocationListener)
end
backBtn = widget.newButton
{
id="backButton",
label="Back",
fontSize="30",
labelColor={ default={1, 1, 1}, over={0, 0, 0, 0.5} },
defaultFile="images/button.png",
width = dispWidth * 0.25, height = dispHeight * 0.1,
onRelease = onBackBtnRelease
}
backBtn.anchorX = 0.5
backBtn.anchorY = 0.5
backBtn.x = display.contentWidth * 0.8
backBtn.y = dispHeight * 0.8
backBtn:toFront()
group:insert( backBtn )
group:toFront() --second try to put that button to front
end
Since the MapView is a native object I can't add it to any group and 'mapView:toBack()' doesn't work as well ('attempt to index upvalue 'myMap' (a nil value)'). In Corona SDK the button appears without the map, as expected. On device I get the map without my button, not as expected.
Is it any possible to put a native object to the back, or to force something to be in the front?
What you are trying to do with the map and the button is not currently possible with CoronaSDK.
Indeed the MapView is a native object. According to Corona's documentation, you cannot place other objects on top of a MapView.
The documentation says:
Map objects, like other native display objects, cannot be inserted into groups and are always displayed on top of regular Display Objects (groups, vector, images, and text).
See documentation here
Good luck coding.
First Check the Following :
If button doesn't appear on device most common problem will be , you might misspell the Image names(Check for Caps) or check the path of the file is proper or not.
To know in detail about the mapView : http://docs.coronalabs.com/api/library/native/newMapView.html
I know you might have visited already, its better you look again.
Thanks,

Text alignment to left in Corona

My problem is that I can't align my text to left. I need to set a position where the text will start and it will go to the left and it wont be centered. Its like in html, you make position and it goes from that position to the right, eventually it makes another line. Maybe a picture example will make you understand better because its hard to describe it.
How it should look and where it should start all the time if I add more text it should just continue to the right.
How it looks if I add more text, and that's not how I want it
Here's a bit of the code
text = display.newText("Fair", 0, 0, "HelveticaNeue-Light", 22)
text.x = halfW - 300
text.y = halfH + 110
text.align = "left"
Are you using the Current Public Release (2014.2100) + ?
Try using text.anchorX = 0 instead of text.align = "left"
So anchorX = .5 is same as "middle" and anchorX = 1 is same as "right".

Corona SDK display.remove() in lua

this code (lua) gives you a random value from the table "local a" by pressing the text "new". Unfortunately the new random value just appears above the old one. I've tried to remove the old value e.g. with display.remove(mmDis), but it doesn't work.
The second problem is that sometimes I also get back the value "nil" and not only the four entries from the table.
Both things must be easy to solve, but as newbie to lua and working on these small things for almost 4 hours now I just don't get what to change to make it work.
-- references
local mmDis
-- functions
function randomText(event)
display.remove(mmDis)
local a = {"Banana!","Apple!","Potato","Pie"}
com = (a[math.random(0.5,#a)])
local mmDis = display.newText(tostring(com),
display.contentWidth*0.57, display.contentHeight*0.7,
display.contentWidth*0.9, display.contentHeight*0.8, "Calibri", 60)
end
-- menu button
local textnew = display.newText("New", 0, 0, "Calibri", 40)
textnew.x = display.contentWidth*0.2
textnew.y = display.contentHeight*0.9
textnew:addEventListener ("tap", randomText )
It's hard to understand what you are trying to do because when you create textnew you have it in one position and size, while in randomeText() you seem to want to replace that text object with a new one, but you put it at a different pos and size. It appears you want to change the object's text every time you press on tap; in this case, you don't need to replace the text object, you just replace its text.
Also:
you have two "local mmDis", the second one will hide the first, not sure what you're after there
read carefully the docs for math.random
com is already a string so you don't need tostring
Try this code and let me know if this is not what you are after:
local menuTextOptions = {
text = "New",
x = display.contentWidth*0.2,
y = display.contentHeight*0.9,
align = 'left',
font = "Calibri",
fontSize = 40,
}
local textnew = display.newText(menuTextOptions)
-- functions
function randomText(event)
local a = {"Banana!","Apple!","Potato","Pie"}
local com = a[math.random(1,#a)]
textnew.text = com
-- if you want to change position too:
-- textnew.x = display.contentWidth*0.2
-- textnew.y = display.contentHeight*0.9
-- if you want to change size too, but only used for multiline text:
-- textnew.width = display.contentWidth*0.9
-- textnew.height = display.contentHeight*0.8
end
textnew:addEventListener ("tap", randomText )
Sometimes it looks like the button doesn't do anything when you tap but that's because the random number happens to be same as previous, you could put a loop to guard against that. Ig you actually want to change the pos and/or width, then the above code makes it clear where you should do that.
So, that's the basic code (without any extras at the moment :)) how it should be. Big thanks to Scholli!:
local menuTextOptions = {
text = "New",
x = display.contentWidth*0.2,
y = display.contentHeight*0.9,
align = 'left',
font = "Calibri",
fontSize = 40,
}
local textnew = display.newText(menuTextOptions)
local replacement = display.newText(menuTextOptions)
replacement.y = display.contentHeight*0.5
-- functions
function randomText(event)
local a = {"Banana!","Apple!","Potato","Pie"}
local com = a[math.random(1,#a)]
replacement.text = com
end
textnew:addEventListener ("tap", randomText )

How to hide native.newTextField after clicking submit?

I'm trying trying to have users name fade in one letter at a time vertically. Example: Adam "A" would appear after 1 second , "d" would appear after 3 seconds under the displayed A, "a" would appear after 5 seconds under the displayed d, "m" would appear after 7 seconds under the displayed a. The visuals would have a sort of domino effect.When they appear they would stay displayed on screen.
When if I comment out userNameField:removeSelf () then the code works fine. I get the effect I want, but the problem is that I still have the userNamefield showing.
Please let me know if you need to see more code.
local greeting = display.newText( "Greetings, enter your name",0,0,native.systemFont, 20 )
greeting.x = display.contentWidth/2
greeting.y = 100
local submitButton = display.newImage( "submit.png" ,display.contentWidth/2, display.contentHeight - 50 )
local userNameField = native.newTextField( display.contentWidth * 0.5 , 150, 250, 45)
userNameField.inputtype = "defualt"
local incrementor = 0
function showNameLetters()
userNameField:removeSelf( )
if incrementor <= string.len ("userNameField.text") then
incrementor = incrementor + 1
personLetters = string.sub (userNameField.text, incrementor,incrementor)
display_personLetters = display.newText (personLetters, 290,30*incrementor, native.systemFont, 30)
display_personLetters.alpha = 0
transition.to(display_personLetters,{time = 3000, alpha = 1, onComplete = showNameLetters})
end
end
Update:
I've found a solution to my problem, by adding userNameField.isVisible = false in my function.
I've also found something very weird, and wish to have someone explain why this happens. If I add greeting:removeSelf() and submitButton:removeSelf() (I've commented them out in my code below to show you where I put them for testing). I get weird result of only the first letter fading in. If i set greeting.isVisible = false and submitButton.isVisible = false. The code works fine.
I'm so confused why object:removeSelf() wouldn't work. Can someone please clear this up for me.
That is, if I replace the following line:
userNameField:removeSelf( )
with:
userNameField.isVisible = false
then the app works fine. Please suggest me why/ any solution for the question. THanks in advance...
It seems like you're calling the showNameLetters multiple times, this means that you're removing the native text field more than once. Nil it and check for nil before removing it like this:
if userNameField ~= nil then
userNameField:removeSelf()
userNameField = nil
end
It shows that you are using data from userNameField after removing it (in the line below):
personLetters = string.sub (userNameField.text, incrementor,incrementor)
As well as you are calling object:removeSelf() again and again without checking its existance (as mentioned by hades2510). So before removing userNameField, check for it's existance:
if userNameField ~= nil then
userNameField:removeSelf()
userNameField = nil
end
And you won't get userNameField.text while userNameField is nil. So use a temporary variable to hold the previous userNameField.text and get the saved data from that variable when needed.
Extra note: Are you sure, you have to check the length of the text "userNameField.text" in the following line, or the variable userNameField.text? If you have to use the data from the text field, then this will also matter.
if incrementor <= string.len ("userNameField.text") then
........
end
Keep coding....................... :)

Lua - Corona SDK - Text not appearing inside a display Object

I am trying to move a display object that is hiding over the right side of the screen, into the scene. It works wonderfully with images (i.e. the background), but not with texts (the coords seem correct from debugging them with print(), but they never display, I already tried the obj:toFront).
I thought that they may work inside display objects, so I put everything in a display Object: Nothing. Just the text? Neither. Anyone knows why/how to override this?
function tscreen:init()
local textGroup = display.newGroup()
local menuBackground = self:getBtn("src/bgMenu.png")
menuBackground.isVisible = false
menuBackground.anchorX = 0.5
menuBackground.anchorY = 0.5
self.menuBackground = menuBackground
local optionsText = {
parent = textGroup,
text = "Hello World",
x = centerX,
y = centerY,
width = 128,
font = native.systemFontBold,
fontSize = 14,
align = "center"
}
local workText = display.newText( optionsText )
workText:setFillColor( 1, 0, 0 )
setPos(textGroup, W, 0)
--setPos() is a custom function that assigns x and y coords
textGroup.isVisible = false
self.textGroup = textGroup
end
function tscreen:show()
local menuBackground = self.menuBackground
local textGroup = self.textGroup
local inTime = 1200
setPos(menuBackground, 2*W + centerX, centerY)
menuBackground.isVisible = true
setPos(textGroup, W, 0)
textGroup.isVisible = true
self:cancelTween(menuBackground)
self:cancelTween(textGroup)
menuBackground.tween = transition.to(menuBackground, {time = inTime, transition = easing.outExpo, x = centerX,
onComplete = function()
tscreen:cancelTween(menuBackground)
end
})
textGroup.tween = transition.to(textGroup, {time = inTime, transition = easing.outExpo, x = 0,
onComplete = function()
tscreen:cancelTween(textGroup)
print(getPos(textGroup), textGroup.width, textGroup.height)
end
})
end
I have the starters edition of Corona, so I don't have the recently implemented Composer API.
Maybe this isn't the most appropriate site to post this query since there already is a Corona SDK forum, but I'm trying anyway.
I'm not seeing anything wrong, but a group should not be necessary. Verify that the text can be seen ever: in the init(), do
local optionsText = {
text = "Hello World",
x = 0,
y = 100,
}
local workText = display.newText( optionsText )
workText:setFillColor( 1, 1, 1 )
If you can't see the text then something else is going on, maybe your init() is not being called or such. Once you see it, change the parameters to what you want (fill color etc), and test. If still works, add a transition, right after, in the init():
local easeXto100 = {
time = 2000,
transition = easing.outExpo,
x = 100,
onComplete = function() print('did you see text move from x=0 to 100?') end
}
transition.to(workText, easeXto100)
If you see it move, then move the relevant parts of code to your show(), if now it disappears this will give you clue.

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