Q: missing APIs needed for implementation of a rich text control

[Scott Palmer]

When I was experimenting with a program to generate titles for videos the
ability to control the spacing between letters (not kerning, but tracking)
would have been helpful.
E.g. animating something like this:
Title
T i t l e
T  i  t  l  e
T   i   t   l   e
I don't recall everything I encountered in that project, but I believe all
the basic font metrics about baseline and ascenders/descenders would help.

A FontChooser would be useful.  Applications can always code their own, but
the same can be said for ColorPicker.  It doesn't look like there is one
available even from 3rd-party libraries like ControlsFX.
Going from a Font object to CSS -fx-font-size, -fx-font-family, -fx-
font-weight, -fx-font-style doesn't always work as I've already mentioned.
The Font object doesn't have a method to get the font weight and there is
no -fx-font-name style.  Setting -fx-font-family doesn't always result in
CSS that successfully selects the desired font if used in combination with
-fx-font-style and/or -fx-font-weight.  Sometimes adding CSS for weight or
style will cause a completely different family to be used which can look
quite drastic when a variable width font is substituted for a fixed-width
font just because you tried to make something bold.
Also FontPosture only has ITALIC and NORMAL, but CSS -fx-font-style has
'normal',  'italic' and 'oblique' - There is no way to ask for 'oblique'
from code and the FontStyleConverter will convert "oblique" to REGULAR,
even though "oblique" works in CSS to get a slanted font.

Asking about caretBlinkRate, I'm not sure. I imagine only one caret
should ever be visible, with the exception of a rich text control that
supports multiple simultaneous insertion points, like many code editors.
In that case there would still only be one rate at a time even though there
are multiple carets.  My point being there should never be a need for
multiple rates to be active at the same time, so maybe you could get away
with a global rate.  I can't think of a need for multiple rates, but maybe
someone else can.

Regards,

Scott

On Fri, Jan 27, 2023 at 12:31 PM Andy Goryachev <andy.goryachev at oracle.com>
wrote:

> >  More control of kerning and general spacing might be nice.
>
>
>
> What properties, besides kerning, are you referring to?
>
>
>
> Also, a question for the wider audience: is there a need to have
> caretBlinkRate property for each control, or a single global one would
> suffice?  In other words, are there use cases when two or more controls
> might need a different blink rate?
>
>
>
> Thank you.
>
>
>
> -andy
>
>
>
>
>
> *From: *openjfx-dev <openjfx-dev-retn at openjdk.org> on behalf of Scott
> Palmer <swpalmer at gmail.com>
> *Date: *Thursday, January 26, 2023 at 12:33
> *To: *openjfx-dev <openjfx-dev at openjdk.org>
> *Subject: *Re: Q: missing APIs needed for implementation of a rich text
> control
>
> [dupe of private message, now including the mailing list]
>
>
>
> I've been using RichTextFX to make my own code editor/IDE.  I see that you
> have asked that project specifically on GitHub, excellent.
>
> One thing that I wanted to do was to use a font like Fira Code that
> combines characters such as != or >= into a single glyph, but there are no
> APIs to request that JavaFX render those optional ligatures. Swing APIs
> automatically do.  In fact just implementing some basic font selection has
> been tedious.  Getting the font family from a Font object and trying to use
> it in CSS to specify -fx-font-family simply doesn't work sometimes.  Trying
> to filter the list of available fonts to show only those that are
> fixed-width is tedious.  I tried to hack something by measuring a couple
> different characters from the font that would normally be different widths,
> but this is an unreliable hack. Allowing the user to choose a preferred
> font and then configuring components to use it via a CSS stylesheet is
> simply more difficult than it should be.
>
> A few years ago I contributed the changes to make the tab-width
> configurable, which helped with my project a little bit.  Other APIs are
> needed to better control line spacing and measure font baseline offsets and
> that sort of thing.  I see there is an issue for caretBlinkRate, what about
> changing the caret shape? E.g. block, underscore, vertical bar, etc.
> Should the block be solid or an outline? Why is caretShape read-only? Why
> does it return an array of PathElements instead of simply a Shape which by
> default would be a Path?  More control of kerning and general spacing might
> be nice. I've wanted that in the past, not for a rich text control, but for
> doing video titles.  I can see how the two needs overlap though.  I
> recently asked here about rendering emojis.  That's currently very
> unreliable and broken.  Getting something to work consistently
> cross-platform is not easy.  Sometimes emojis are rendered in color, other
> times not.  Mac renders color emojis in gray and at the wrong size (since
>  the sub-pixel rendering was turned off to match macOS).  On Windows the
> emojis are never in color.
>
>
>
> Regards,
>
>
>
> Scott
>
>
>
> On Wed, Jan 25, 2023 at 10:41 PM Scott Palmer <swpalmer at gmail.com> wrote:
>
> I've been using RichTextFX to make my own code editor/IDE.  I see that you
> have asked that project specifically on GitHub, excellent.
>
> One thing that I wanted to do was to use a font like Fira Code that
> combines characters such as != or >= into a single glyph, but there are no
> APIs to request that JavaFX render those optional ligatures. Swing APIs
> automatically do.  In fact just implementing some basic font selection has
> been tedious.  Getting the font family from a Font object and trying to use
> it in CSS to specify -fx-font-family simply doesn't work sometimes.  Trying
> to filter the list of available fonts to show only those that are
> fixed-width is tedious.  I tried to hack something by measuring a couple
> different characters from the font that would normally be different widths,
> but this is an unreliable hack. Allowing the user to choose a preferred
> font and then configuring components to use it via a CSS stylesheet is
> simply more difficult than it should be.
>
> A few years ago I contributed the changes to make the tab-width
> configurable, which helped with my project a little bit.  Other APIs are
> needed to better control line spacing and measure font baseline offsets and
> that sort of thing.  I see there is an issue for caretBlinkRate, what about
> changing the caret shape? E.g. block, underscore, vertical bar, etc.
> Should the block be solid or an outline? Why is caretShape read-only? Why
> does it return an array of PathElements instead of simply a Shape which by
> default would be a Path?  More control of kerning and general spacing might
> be nice. I've wanted that in the past, not for a rich text control, but for
> doing video title.  I can see how the two needs overlap though.  I recently
> asked here about rendering emojis.  That's currently very unreliable and
> broken.  Getting something to work consistently cross-platform is not
> easy.  Sometimes emojis are rendered in color, other times not.  Mac
> renders color emojis in gray and at the wrong size (since  the sub-pixel
> rendering was turned off to match macOS).  On Windows the emojis are never
> in color.
>
>
>
> Regards,
>
>
>
> Scott
>
>
>
> On Wed, Jan 25, 2023 at 5:38 PM Andy Goryachev <andy.goryachev at oracle.com>
> wrote:
>
> Dear colleagues:
>
>
>
> I am trying to identify missing public APIs needed to support a rich text
> control.  There is a number of tickets created already against various
> parts of JavaFX, collected in https://bugs.openjdk.org/browse/JDK-8300569
> , though I suspect this list may not be complete.
>
>
>
> If anyone has any suggestions or requests related to the new APIs, I would
> be very interested to learn the context, the reason these APIs are needed,
> and whether a workaround exists.
>
>
>
> Thank you in advance.
>
>
>
> Cheers,
>
> -andy
>
>
>
>
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