<Swing Dev> [10] RFR JDK-8191428: Regression: Swing button label wrapping with hidpi

[Sergey Bylokhov]

Hi, Prasanta.
Is it possible to create an automated test for this issue?
(I think that we were just lucky that Phil found this problem by the demo)

On 20/11/2017 03:26, Prasanta Sadhukhan wrote:
> Hi All,
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8191428
> 
> It is seen that with
> 8172025: HiDPI with non-integer scale factor - SPANs in HTML are 
> rendered overlapping each other
> fix, the html text in button is rendered in different lines even though 
> it is specified as a one word.
> 
> This is because with getSpan() returning float value (say 29.9996)
> FlowView.layoutRow() calculates "spanLeft" using getFlowSpan() method 
> which uses "int" calculation (so get 29]
> whereas "chunkSpan" got from GlyphView#getTabbedPane (using 
> GlyphPainter1.getSpan) gets "float" value [ie 29.9996]
> so this calculation (chunkSpan > spanLeft) is satisfied  [ex, 29.996 > 
> 29] and so it calls breakView() to break the text.
> 
> In the proposed fix, I have reverted the getSpan() value to return "int" 
> so as to prevent this regression.
> This fix also does not cause any problem with 8172025 issue which 
> renders fine.
> 
> webrev: 
> http://cr.openjdk.java.net/~psadhukhan/8191428/webrev-1stapproach/webrev.00/ 
> 
> 
> 
> Another approach is to use "float" calculation for all "spans" 
> calculation but that will cause many changes, including changing 
> public/protected method signature
> which I believe is risky at this point of time for jdk10, as it might 
> potentially cause more regressions.
> Sneak peek of 2nd approach changes are:  [work in progress]
> http://cr.openjdk.java.net/~psadhukhan/8191428/webrev-2ndapproach/
> 
> Regards
> Prasanta


-- 
Best regards, Sergey.