On Thu, 11 Feb 2021 21:33:44 GMT, Alexey Ivanov <aiva...@openjdk.org> wrote:
>> I think the test does something wrong. Now I see how `uiScale` affects >> rendering. The test does not paint JLabel directly to the image but rather >> in its overridden `paintComponent`. So `uiScale` controls the size of the >> component or rather where the break occurs. >> >> For me on Windows with 200% scaling, in the first image ‘…’ is painted over >> the transparent background whereas in the second image ‘…’ is over the >> components opaque background. >> >> The test passes with `uiScale=1` but I see no ‘…’ at all. Both images are >> clipped at “.1”. >> >> As far as I understand, the purpose of the test is to make sure combining >> diacritics does not affect string clipping, and it occurs at the same >> position whether a composite character is used of a decomposed one. Yet no >> clipping occurs at all with `uiScale=1`. This looks wrong even though the >> test passes successfully. And when the test fails with `uiScale=2`, the >> images suggest there's a product bug because the string is clipped >> differently. > >> For me on Windows with 200% scaling, in the first image ‘…’ is painted over >> the transparent background whereas in the second image ‘…’ is over the >> components opaque background. >> >> The test passes with `uiScale=1` but I see no ‘…’ at all. Both images are >> clipped at “.1”. > > As you can see on the screenshots below, the strings are clipped differently. > In the case where `uiScale=1`, the string is not clipped, it's displayed > completely in the frame. >  >  > > Shall the test be modified to do some text measurement to ensure the JLabel > cannot fit the text completely? And then paint it to the image of the > calculated size? > > As for the clipping itself, I think the first frame, the bottom one, looks > correctly: the text is clipped right to the edge of the client area whereas > the second frame, the upper one, leaves some whitespace. The rendering of the test may be affected by the uiScale, but when this test is executed, it uses only one-same scale for both use cases(different strings), and both of them should produce the same result. ------------- PR: https://git.openjdk.java.net/jdk/pull/2502
