Cannot set scrollView's Height

Solar2D General Questions/Discussion
#1

Hi

I used the ScrollView sample code from Corona installation, and I found I cannot fixed the hegith of ScrollViewl

The following source is same as Corona default installation, and I just set backgroup color to see what happend for the height of Scrollview after I set height=display.contentHeight*0.5.

display.setDefault( “background”, 0,255, 0 )
display.setStatusBar( display.HiddenStatusBar )
local widget = require( “widget” )
 
local scrollView = widget.newScrollView
{
    left = 0,
    top = 0,
    width = display.contentWidth,
     height = display.contentHeight*0.5 ,
    bottomPadding = 50,
    id = “onBottom”,
    horizontalScrollDisabled = true,
    verticalScrollDisabled = false,
    listener = scrollListener,
}

–Create a large text string
local lotsOfText = "Lorem ipsum dolor sit amet, …  "

–Create a text object containing the large text string and insert it into the scrollView
local lotsOfTextObject = display.newText( lotsOfText, 0, 0, 300, 0, “Helvetica”, 14)
lotsOfTextObject:setTextColor( 0 )
lotsOfTextObject:setReferencePoint( display.TopCenterReferencePoint )
lotsOfTextObject.x = display.contentCenterX
lotsOfTextObject.y = titleText.y + titleText.contentHeight + 10
scrollView:insert( lotsOfTextObject )

The screen result is as following pic:

The above source code set the background color of screen is green and the background color of screen is white.

And you can find even I set _ height = display.contentHeight*0.5, _ actually the text out of scrollview is still in the screen (green area).

How to set exactly scrollview size thus the text is only shown in scrollview area ?

Thanks

#2

You need to create a bitmap mask, and apply that onto the scrollview:

http://www.coronalabs.com/blog/2012/05/29/how-to-use-bitmap-masks/

Also see the “Gotchas” section here:

http://docs.coronalabs.com/api/library/widget/newScrollView.html

It’s annoying, I would much rather that it was able to automask based on the height + width we supply, but for now this is the only way to have non-fullscreen scrollviews / tableviews (as far as I know - feel free to correct me if I’m wrong).

#3

Thanks for your help.

Yes, setMask is workable, but not so convenient. We have to make different pre-defined mask bitmap file for different app if we don’t use same resolution.

The best way to do this is as you mentioned, an automask function based on the height + width. Looking forward Corona next update for this function.

Another suggestion, Corona also may create a new TextBox widget component which can put a very long string into that TextBox, then add this TextBox into a scrollView.

#4

There’s a new blog post about ‘containers’ which seem to be auto-masking display groups. They’re part of graphics 2.0, hopefully they’ll work with scroll views too. Not an immediate fix, but hopefully not too far away now.

#5

That new blog post looks great and which is exactly what I am looking for. Hope it can be released as soon as posibile.

Thanks for your great information.

#6

You need to create a bitmap mask, and apply that onto the scrollview:

http://www.coronalabs.com/blog/2012/05/29/how-to-use-bitmap-masks/

Also see the “Gotchas” section here:

http://docs.coronalabs.com/api/library/widget/newScrollView.html

It’s annoying, I would much rather that it was able to automask based on the height + width we supply, but for now this is the only way to have non-fullscreen scrollviews / tableviews (as far as I know - feel free to correct me if I’m wrong).

#7

Thanks for your help.

Yes, setMask is workable, but not so convenient. We have to make different pre-defined mask bitmap file for different app if we don’t use same resolution.

The best way to do this is as you mentioned, an automask function based on the height + width. Looking forward Corona next update for this function.

Another suggestion, Corona also may create a new TextBox widget component which can put a very long string into that TextBox, then add this TextBox into a scrollView.

#8

There’s a new blog post about ‘containers’ which seem to be auto-masking display groups. They’re part of graphics 2.0, hopefully they’ll work with scroll views too. Not an immediate fix, but hopefully not too far away now.

#9

That new blog post looks great and which is exactly what I am looking for. Hope it can be released as soon as posibile.

Thanks for your great information.