<Swing Dev> [10] RFR JDK-8178025:HiDPI with non-integer scale factor - SPANs in HTML are rendered overlapping each other

[Prasanta Sadhukhan]

Hi All,

Please review a fix for an issue whereby, when using a non-integer 
resolution (e.g. 225%) for a HiDPI display,
the Swing HTML rendering incorrectly calculates the width of SPAN 
elements which results in SPANs being
incorrectly positioned and overlapping with each other.

Issue was, when a JLabel with an html text is created, the 
GlyphPainter1.getSpan() uses a FontrenderedContext with transform scale 1
and also the obtained width is converted to int and not to float.

Proposed fix is to use correct transform while calculating the string 
width and also use floating point API to get floating point width.

webrev:http://cr.openjdk.java.net/~psadhukhan/8178025/webrev.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8178025

Regards
Prasanta