Thanks Andy, the new link works. I read pages 33-36. Page 35 details the two approaches: the dual caret you have described (which I had never seen before in my life), and the single "jumping" caret, which is what I advised to do. The document doesn't show, however, a direction indicator for the caret based on the selected language, and I think that that's something that should be shown.
Phil, I'm not sure how the split caret can tell a user on its own where the text will appear. The user will have to look at which language is currently selected to know which of the carets is the real indicator. That is, unless I misunderstand how the split caret works. The "why did it appear over there?" question is common in UI's that don't handle the caret indication properly, for example when there is no visual difference between the RTL and LTR carets (the direction indicator). A jumping caret with a visual direction indicator solves 100% of the ambiguity and the surprise factor without needing to look outside of the text control to check which language is selected. - Nir On Wed, Oct 18, 2023 at 10:31 PM Philip Race <philip.r...@oracle.com> wrote: > So it seems Swing never calls Java2D's TextLayout.getCaretShapes() API > which is what would provide the split carets. > > Swing's caret is an instance of javax.swing.text.DefaultCaret which has > support for rendering a "flag" that indicates > the direction of the caret bias. > > Split caret is however useful to tell a user where the text of the other > direction would appear. > Otherwise even to someone familiar with editing bi-di text I except some > cases of "oh, why did what I typed appear way over there"? > They might still wonder, but at least they'd know where it was going to be > rendered ahead of time. > > -phil > > On 10/18/23 10:47 AM, Andy Goryachev wrote: > > Thank you, Nir. > > > > Try this link: > > > https://web.archive.org/web/20120802192035/http://developer.apple.com/legacy/mac/library/documentation/Carbon/Conceptual/ATSUI_Concepts/atsui.pdf > <https://web.archive.org/web/20120802192035/http:/developer.apple.com/legacy/mac/library/documentation/Carbon/Conceptual/ATSUI_Concepts/atsui.pdf> > > > > Curiously, the dual (split) caret capability *is* present in java2d, but > apparently it is not used in Swing as far as I can tell: > > > https://docs.oracle.com/javase/tutorial/2d/text/textlayoutbidirectionaltext.html#moving_carets > > > > -andy > > > > *From: *Nir Lisker <nlis...@gmail.com> <nlis...@gmail.com> > *Date: *Wednesday, October 18, 2023 at 09:15 > *To: *Andy Goryachev <andy.goryac...@oracle.com> > <andy.goryac...@oracle.com> > *Cc: *openjfx-dev@openjdk.org <openjfx-dev@openjdk.org> > <openjfx-dev@openjdk.org> > *Subject: *Re: [External] : Re: Question: bidi navigation > > I've never seen this dual caret system. The link you gave leads to a 404 > error. > > > > I can't comment as to the plan without knowing what Prism was designed to > do, but it's rather unusual. The logical navigation choice seems correct > regardless. > > > > On Tue, Oct 17, 2023 at 7:13 PM Andy Goryachev <andy.goryac...@oracle.com> > wrote: > > Dear Nir: > > > > Thank you so much for the information. I spoke to several people none of > whom, unfortunately, use an environment configured for RTL mode (but who > have keyboard settings for RTL languages). Based on the very small sample, > it appears that logical navigation is a way to go - which means the FX > behavior (or rather lack thereof due to > https://bugs.openjdk.org/browse/JDK-8296266) needs to change relative to > jfx8. > > > > Regarding the direction indicator - FX implements a dual caret the logic > of which I am still trying to decipher: > > > > > > > > > > (*sliptCaret* in PrismTextLayout:354) > > > > The closest description I was able to find is in Apple ATSUI Programming > guide > > > http://developer.apple.com/legacy/mac/library/documentation/Carbon/Conceptual/ATSUI_Concepts/atsui.pdf > <https://urldefense.com/v3/__http:/developer.apple.com/legacy/mac/library/documentation/Carbon/Conceptual/ATSUI_Concepts/atsui.pdf__;!!ACWV5N9M2RV99hQ!LM7co48XfI4StmMZQ9TBX3emuN_Y_WM2CEdQi3PZQQ7LfjCCzhZRd1m4jTSc2n4tv6lQD49_YAhItF5cU8ZH$> > > on page 35, though I am not sure FX works as described in that document. > > > > The expectation is that the primary (high) caret is where the character > having the same directionality as the “primary line direction” is > inserted. It is possible that the text layout determines the primary line > direction based on the text as opposed to taking a hint from > NodeOrientation. > > > > Since this behavior is baked into FX prism text layout, I think it’s > unlikely to change. > > > > To summarize, I think we should switch FX TextInputControl hierarchy to > logical navigation. What do you think? > > > > -andy > > > > > > > > *From: *Nir Lisker <nlis...@gmail.com> > *Date: *Tuesday, October 17, 2023 at 03:44 > *To: *Andy Goryachev <andy.goryac...@oracle.com> > *Cc: *openjfx-dev@openjdk.org <openjfx-dev@openjdk.org> > *Subject: *Re: [External] : Re: Question: bidi navigation > > I have just tested on Win10: Notepad, Wordpad, MSWord 2021, Discord > desktop, WhatsApp desktop, Opera, Eclipse, Gimp 2, Audacity 2.1.3, and MS > VisualStudio 2022 all use logical. Edge uses logical in text areas and text > fields, but visual in the address bar (seems like a bug, but you can't have > spaces in web addresses anyway). I don't remember ever using a visual > navigation application, maybe it was very long ago. If there ever was a > decision there, it was made long ago, at least on Windows. > > > > It's very important to show the cursor direction because it resolves > ambiguities. It's available in most applications. > > > > My Windows UI is in standard English LTR. I just have an RTL language > installed. > > > > Logical navigation is a bit easier to work with I think. The behavior at > the edge of a word that changes the direction can be surprising (see the > ambiguities above), but that can be helped with the cursor direction > indication. If we can do a custom implementation, I would go a step further > and actually resolve the position ambiguities by positioning the cursor in > accordance with the selected insertion method (RTL or LTR). This means that > the cursor will jump when switching the language, but it will make life > easier because you will easily know in which direction you're about to type. > > > > On Mon, Oct 16, 2023 at 6:16 PM Andy Goryachev <andy.goryac...@oracle.com> > wrote: > > Nir, thank you for responding! > > > > The behavior you describe (“logical” navigation) is what can be seen in > many, but not all applications, and that is what puzzles me. What’s more > interesting, the applications that use a “visual” kind of navigation, that > is the RIGHT ARROW key always moving the cursor right regardless of the > text, is used by javafx8 (it’s totally broken in jfx17, but it looks from > the code that it is supposed to be the same as in javafx8), java swing, MS > Word 2007 on Windows 10, macOS Notes app, macOS TextEdit, and Mozilla > Thunderbird. Also, this is the kind of navigation that some users prefer > (based on a very, very limited sample I was able to contact). > > > > What puzzles me is that there is no apparent standard even among the > modern applications (bundled macOS apps), although the transition from > visual to logical navigation in MS Word might indicate that the logical > navigation is winning. > > > > The appearance of caret is another aspect that seem to have no standard. > In many apps the caret does not change at all, very rarely we see a flag > indicating direction (java swing), and only javafx8 and some obsolete mac > Carbon reference doc shows a split caret. > > > > More questions for you: > > 1. it looks like you are on Windows, and are you using (or have you > seen) a fully localized version of Windows with all the UI set to RTL mode? > 2. Have you seen any native applications that use the visual > navigation model? > > > > Getting back to the problem at hand: if we were to retain the backward > compatibility in FX, we would need to fix the “visual” navigation. FX uses > the split caret which some users find confusing but we probably are stuck > with it. If we were to assume that the “logical” navigation is a standard > everyone is slowly converging to, then my fix for > https://bugs.openjdk.org/browse/JDK-8296266 is the right one and we > should declare a change in behavior. > > > > What do you think? > > > > P.S. I wonder if the logical navigation was chosen because of ease of > implementation, or is there a deeper reason? > > > > > > > > > > *From: *Nir Lisker <nlis...@gmail.com> > *Date: *Monday, October 16, 2023 at 04:52 > *To: *Andy Goryachev <andy.goryac...@oracle.com> > *Cc: *openjfx-dev@openjdk.org <openjfx-dev@openjdk.org> > *Subject: *[External] : Re: Question: bidi navigation > > This is a tricky one. All applications I have seen, and I think that's > what people expect, is that the cursor changes direction during traversal. > > > > A key point is where the paragraph is aligned to (in Windows adjusted with > left CTRL+SHIFT and right CTRL+SHIFT). This sets the forward and backward > direction: if the paragraph is left-aligned, pressing the right arrow moves > the cursor forward, and for a right aligned, the right arrow moves the > cursor backward. Then the actual movement of the cursor is relative to the > paragraph alignment: in RTL alignment, traversing RTL text moves the > cursor forward, while traversing LTR moves the cursor backward. > > > > Examples > > In a left-aligned paragraph, pressing the right arrow will move the cursor > (|) like this: > > |ab אבג cd > > a|b אבג cd > > ab| אבג cd > > ab |אבג cd OR ab אבג| cd (there is ambiguity because the space > character can be both RTL or LTR) > > ab א|בג cd > > ab אב|ג cd > > ab אבג| cd OR ab |אבג cd > > ab אבג |cd > > ab אבג c|d > > ab אבג cd| > > > > To help with navigation, the cursor has a line attached to its top showing > which direction it's facing. > > > > Hope this helps. > > > > On Thu, Oct 12, 2023 at 3:42 AM Andy Goryachev <andy.goryac...@oracle.com> > wrote: > > Hi. > > > > I have a question for people who routinely use right-to-left RTL languages > (Arabic, Hebrew, etc.): > > > > *What is your expectation for navigating text using left/right arrow keys > when the text contains a mixture of RTL and LTR?* > > > > It looks like there is no standard when it comes to modern applications – > see a small sample: > > > https://gist.github.com/andy-goryachev-oracle/4802f9380fb03ec2be7ac36bd98a2059 > <https://urldefense.com/v3/__https:/gist.github.com/andy-goryachev-oracle/4802f9380fb03ec2be7ac36bd98a2059__;!!ACWV5N9M2RV99hQ!P_TgGd02CrA1gNF2bW5yHBRJHFkdDqluPJmHDwIcAQ-DR_NWNd-JMkTn0x9d1m5azgCucompGMSgi7PqR7TS$> > > > > In javafx, the navigation of bidirectional (bidi) text might have been > broken sometime after jfx8, and even jfx8 might have issues, see > > https://bugs.openjdk.org/browse/JDK-8296266 > > > > It looks like the most modern applications use logical navigation and > logical selection (that is, when navigating using left/right arrow keys, > the cursor position reflects previous/next insertion indexes in the text, > rather than visual position). This causes the cursor to change the > direction of movement when it crosses the bidi boundary. Would you say > this is the expected behavior? > > > > Thank you > > -andy > > >
