<Swing Dev> [8] Review request for 8016833: Underlines and strikethrough not rendering correctly

[anton nashatyrev]

Hello, Alexander,

     thanks for your suggestion, though I'm not sure drawing a 
background has the same semantics as drawing underline. The latter may 
be though of as a part of glyph while for background it is ok to 
'highlight' the space _reserved_ for a View. Also the taller highlight 
is almost not visible to a user comparing to incorrectly painted underline.
     I'd prefer either not to fix this at all or at least not to include 
the fix to this customer issue.

     Had fixed the EDT issue in the test.

Thanks,
Anton.

On 20.06.2013 18:57, Alexander Scherbatiy wrote:
> On 6/20/2013 2:41 PM, anton nashatyrev wrote:
>> Hello,
>>     could you please review the following fix:
>>
>> fix: http://cr.openjdk.java.net/~vkarnauk/8016833/jdk8/webrev.00/ 
>> <http://cr.openjdk.java.net/%7Evkarnauk/8016833/jdk8/webrev.00/>
>> bug: http://bugs.sun.com/view_bug.do?bug_id=8016833
>>
>     It seem that there is the same problem with the background color:
>         Style style = comp.addStyle("underlined superscript", null);
>         StyleConstants.setBackground(style, Color.BLUE);
>         ...
>             doc.insertString(doc.getLength(), "hello", style);
>
>     because paint(Graphics g, Shape a) method in GlyphView uses the 
> alloc.height in the same way.
>
>
>   Could invoke all Swing methods on EDT and remove the comments from 
> the test:
>
>  266 //        bug8016833 b = new bug8016833();
>  267 //        b.demo();
>
> Thanks,
>    Alexandr.
>
>> The reason of such behavior is that the superscripted GlyphView 
>> requested
>> increased vertical span, since the alignment of value 1.0
>> (GlyphView.getAligment(View.Y_AXIS) returns 1.0) isn't enough to 
>> paint it as
>> high as required.
>> (BTW, for subscripted text setting the alignment is enough)
>>
>> GlyphView.paintTextUsingColor() calculates the Y position of the 
>> underscore
>> as following:
>>
>>   int y = alloc.y + alloc.height - (int) painter.getDescent(this);
>>
>> but here alloc.height means the space _reserved_ for glyphs and not the
>> actual boundary of the painted text. To fix that we need to substitute
>> alloc.height with painter.getHeight(this).
>>
>> The fix looks safe since the GlyphView preferred vertical span is 
>> initially
>> requested from the GlyphPainter.
>>
>> Thanks!
>> Anton.
>
>
>