>I agree that the logic may need fixing.  It may not have been tested at large 
>font sizes

Yes.  In fact, for small enough fonts, the measuring/layout computations 
approximations were somehow compensated by big enough paddings.

I have seen that useTightTextBound=true is for regural text and 
useTightTextBound=false for editable text (TextArea, TextInput).

So I will focus on the case where useTightTextBound = true, to minimize the 
impact.

This will probably break some Mustella mobile tests.

Maurice 

-----Message d'origine-----
De : Alex Harui [mailto:aha...@adobe.com] 
Envoyé : dimanche 23 février 2014 20:10
À : dev@flex.apache.org
Objet : RE: Need your help on problem with opaqueBackground

I agree that the logic may need fixing.  It may not have been tested at large 
font sizes.

IIRC, tight text bounds tries to ignore the "gutter" around the textfield.  
There is always a few more pixels in the TextField around the actual text.

-Alex
________________________________________
From: Maurice Amsellem [maurice.amsel...@systar.com]
Sent: Sunday, February 23, 2014 10:25 AM
To: dev@flex.apache.org
Subject: RE: Need your help on problem with opaqueBackground

The 15% was an empirical finding based on comparing "unscaledHeight" and the 
apparent physical height in pixels of the renderered item.
So let's forget this for a moment, as I don't know where it comes from.

Searching more, I found something else:
StylableTextField has "useTightTextBounds=true", which is logical, as we want 
precise measurement.

In the measure() function of IconItemRenderer, the preferred height of the text 
is retrieved by calling :
STF.getPreferredBoundHeight() which returns, in this case , tightTextHeight 
(let's say 36 in our example).

So one would think that when the STF is sized in layoutContents(), using the 
same value, the text will get the same height:
layoutContents()
   labelDisplay. setLayoutBoundsSize ( width, 36).

But in StylableTextField. setLayoutBoundsSize(),  there is some logic regarding 
useTightTextBounds

And at the end it set text.height = 63 !! (instead of 36).

I don't know if   SFT. setLayoutBoundSize (STF.getPreferredWidth() , 
STF.getPreferredBoundHeight)  should be a no-op,

I wonder if this logic needs to be reviewed ??

 Line 1687 and follows:

     if (useTightTextBounds)
        {
            if (newHeight > 0)
            {
                var bottomOffset:Number = measuredTextSize.y - 
tightTextTopOffset - tightTextHeight;

                // when clipping, allow gutter to be outside of height
                // use 2x gutter (actual gutter is not part of tight text 
height)
                // when newHeight==1, actual visible height==3 (1px + 1x gutter)
                if (newHeight < tightTextHeight)
                    bottomOffset = StyleableTextField.TEXT_HEIGHT_PADDING;

                // re-add the top and bottom offsets.  (measuredTextSize.y - 
tightTextHeight) gives us
                // the sum of top and bottom offsets
                newHeight += (tightTextTopOffset + bottomOffset);
            }
        }
   this.height = newHeight;


Maurice

-----Message d'origine-----
De : Alex Harui [mailto:aha...@adobe.com] Envoyé : dimanche 23 février 2014 
17:45 À : dev@flex.apache.org Objet : RE: Need your help on problem with 
opaqueBackground

The TextField extent is surprising to me.  What does it mean to be 15% larger?  
What does transform.pixelbounds show?  Does it have to do with the border or 
background property?

-Alex
________________________________________
From: Maurice Amsellem [maurice.amsel...@systar.com]
Sent: Sunday, February 23, 2014 5:20 AM
To: dev@flex.apache.org
Subject: Need your help on problem with opaqueBackground

Hi team,

Piotr has raised an interesting issue in mobile apps:
https://issues.apache.org/jira/browse/FLEX-34107

When using a large font (size > 40) with IconItemRenderer on spark List, the 
bottom separators between items are not displayed.

After some hours of debugging, I finally found the cause, but don't know how to 
fix it, because it's related to AIR.

Here is the story, in short (details in the ticket):


-          Mobile item renderers "opaqueBackground=color" property draws an 
opaque background behind item renderers, to make scrolling faster (no 
transparency).

-          When StyleableTextField (text used in mobile renderers, inheriting 
from TextField) is given WxH size in flex, its actual extent will be around 15% 
larger

-          the opaqueBackground extent of a renderer (DisplayObject) is 
computed based on the cumulated extents of its children, not of its own width 
and height



In LabelItemRenderer, the padding around the renderer is big enough (16 px at 
160 DPI) to compensate for this excess size for fonts not too large

However, in IconItemRender, the padding is set to 8px, so when the font size > 
50, opaqueBackgorund overflows the item render size, and separator lines are 
masked.



There are many ways of fixing this :

-          increase the padding in IconItemRenderer, for 'reasonable' font sizes

-          modify the measure() to account for the excess size, so that 
opaqueBackground never overflows.

-          etc...


What do you think ?

Maurice


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