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Created attachment 288411 [details] A test code snippet The changes made on https://bugs.eclipse.org/bugs/show_bug.cgi?id=565526 caused RTL texts to be rendered incorrectly on TextLayout. I've attached a test code that exhibits the issue. It compares the output of Text, Label, and TextLayout.
Created attachment 288412 [details] A sample output of the test code
A user of our RCP app, Archi, has reported that RTL text is no longer rendered correctly when built on Eclipse 4.16 and later: https://github.com/archimatetool/archi/issues/796 I wonder if Bug #565526 is the cause?
I researched further why, in our RCP app, RTL is now rendered incorrectly in Draw2d figures as in the attached snippet here. When handling RTL text, Draw2d uses a class, org.eclipse.draw2d.text.BidiProcessor. and this uses the SWT TextLayout class. The TextLayout class was changed in Bug #565526 so I think this is a likely candidate.
(In reply to Phil Beauvoir from comment #2) > A user of our RCP app, Archi, has reported that RTL text is no longer > rendered correctly when built on Eclipse 4.16 and later: I mean 4.17 and later.
I tested the Snippet removing the changes to class TextLayout in Bug #565526 and the text renders correctly. I don't know how to fix this issue but it seems that RTL text is now broken for many users
I would personally disable Ligatures on TextLayout from Bug #562165 and its childbug fix Bug #565526, trading Ligatures for proper RTL rendering. Even if ligatures are disabled, the complete idea of the texts are still presented properly. It may not be visually appealing, but it would still communicate the correct information. In contrast, a sentence written backwards is not intuitive, and even if the user figured out how to "read" it, it's not something anyone would subject themselves to. combined being not characters than critical more is backwards sentence a read to forced being user A.
(In reply to Roden Roldan from comment #6) > Even if ligatures are disabled, the complete idea of the texts are still > presented properly. It may not be visually appealing, but it would still > communicate the correct information. In contrast, a sentence written > backwards is not intuitive, and even if the user figured out how to "read" > it, it's not something anyone would subject themselves to. I have to attach a disclaimer: I am not an expert on ligatures. This is just my stance based on my current understanding of the problem.
I've just had a user who uses Hebrew text in Archi confirm that Bug #565526 is indeed the cause of this: https://github.com/archimatetool/archi/issues/796#issuecomment-1094222770
In fact you don't have to do anything fancy to reproduce this. Just copy and paste the following text into an Eclipse editor (assumes UTF-8): جارِ التحميل
@Niraj: if I understand previous comments right (I'm not expert in this area neither writing in BiDi language), we should either revert this patch https://git.eclipse.org/r/c/platform/eclipse.platform.swt/+/167051 or provide an improved version for 4.24, because it seem that BiDi support is now broken in StyledText. That is much more severe issue as wrong ligatures rendering in some corner case addressed in bug 565526. WDYT?
*** Bug 566914 has been marked as a duplicate of this bug. ***
(In reply to Andrey Loskutov from comment #10) > @Niraj: if I understand previous comments right (I'm not expert in this area > neither writing in BiDi language), we should either revert this patch > https://git.eclipse.org/r/c/platform/eclipse.platform.swt/+/167051 or > provide an improved version for 4.24, because it seem that BiDi support is > now broken in StyledText. > > That is much more severe issue as wrong ligatures rendering in some corner > case addressed in bug 565526. > > WDYT? Working on this bug via below SWT github issue: https://github.com/eclipse-platform/eclipse.platform.swt/issues/37
