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

[Scott Palmer]

[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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