[External] : Re: Question: bidi navigation

Wed Oct 18 16:14:29 UTC 2023

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.goryachev at 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
>
> 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 <nlisker at gmail.com>
> *Date: *Tuesday, October 17, 2023 at 03:44
> *To: *Andy Goryachev <andy.goryachev at oracle.com>
> *Cc: *openjfx-dev at openjdk.org <openjfx-dev at 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.goryachev at 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 <nlisker at gmail.com>
> *Date: *Monday, October 16, 2023 at 04:52
> *To: *Andy Goryachev <andy.goryachev at oracle.com>
> *Cc: *openjfx-dev at openjdk.org <openjfx-dev at 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.goryachev at 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
>
>
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