Maybe, just maybe, we should implement the dual carets with
directionality indicators (highlighted here for illustration purposes
only, the actual indicator might look like a flag or a “ г”):
What do you think?
-andy
*From: *Nir Lisker <nlis...@gmail.com>
*Date: *Thursday, October 19, 2023 at 00:28
*To: *Philip Race <philip.r...@oracle.com>
*Cc: *Andy Goryachev <andy.goryac...@oracle.com>,
openjfx-dev@openjdk.org <openjfx-dev@openjdk.org>
*Subject: *Re: [External] : Re: Question: bidi navigation
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> <mailto:nlis...@gmail.com>
*Date: *Wednesday, October 18, 2023 at 09:15
*To: *Andy Goryachev <andy.goryac...@oracle.com>
<mailto:andy.goryac...@oracle.com>
*Cc: *openjfx-dev@openjdk.org <openjfx-dev@openjdk.org>
<mailto: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
