This commit fixes the association of diacritical marks with the proper script
during text segmentation, as well as fixing the visual position of diacritical
marks. The prior code inverted the Y axis positioning for diacritics, which made
them frequently overlap the glyph they were meant to appear above or below.
Signed-off-by: runitclean <runitclean@disroot.org>
We've migrated the processing of bidi run ordering into the upstream typesetting
package, so now we can just consume the already-ordered runs instead of computing
their ordering ourselves.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit updates the shaper fuzzer to try truncating the text, exposing
new edge cases.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit removes the logic that calculates the bounding box of a line.
We don't actually use this information anywhere, so computing it is just
a waste of CPU and memory. Widgets arrive at their own bounding boxes from
consuming the glyph stream anyway.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit updates the text package to be able to load system fonts. As a consequence,
application authors may choose to provide no fonts manually, and it's
also possible that the system provides none (WASM, for instance, currently provides no
system fonts). As such, the text stack needed some minor tweaks to handle this case by
displaying blank spaces where text should be rather than crashing when no faces are
available.
Internally, we are dropping the old method of choosing faces and instead relying solely
on the new font matching logic in go-text. I chose to do this because maintaining two
different sets of logic with a hierarchical relationship proved to be really complex,
and also the go-text logic seems to produce higher-quality choices.
The breaking API change from this commit is the new way of constructing a text shaper
using text.ShaperOptions. Providing no options will result in a shaper that uses solely
system fonts. The various options can be used to disable system font loading and to
provide an already-parsed collection of fonts as per Gio's old API.
The material.NewTheme function now accepts no arguments instead of a font collection.
Users wanting to provide a collection can simply provide a new shaper configured how
they would like:
theme := material.NewTheme()
theme.Shaper = text.NewShaper(text.NoSystemFonts(), text.WithCollection(gofont.Regular()))
This commit touches many packages to fix up their construction of text shapers, mostly in
test code. The changes to the tests in package widget deserve special note:
Changing our font resolution logic caused the tofu characters within the
test strings to use a different font's tofu. This isn't a problem, but shifted
the layout of the shaped text a little bit. I've updated the numbers to expect
the new glyph positions.
Fixes: https://todo.sr.ht/~eliasnaur/gio/309
Fixes: https://todo.sr.ht/~eliasnaur/gio/184
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit enables consumers of the text shaper to select a policy for how
line breaking candidates will be chosen. The new default policy can break lines
within "words" (UAX#14 segments) when words do not fit by themselves on a line.
This ensures that text does not horizontally overflow its bounding box unless
the available width is insufficient to display a single UAX#29 grapheme cluster.
Fixes: https://todo.sr.ht/~eliasnaur/gio/467
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit fixes a problem in the unpacking of text.GlyphID on 32 bit architectures.
Incorrectly casting to an `int` on those platforms resulted in truncating the faceIndex
to always be zero. To catch mistakes like this in the future, I've added tests for this
problem that should be run by our new 32-bit CI testing.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds back support for loading font collections, which we
lost when switching to the harfbuzz-based shaper last January. In
addition, this commit takes advantage of our new font loading library's
metadata facilities to automatically construct text.FontFaces for all
fonts within a collection. This is significantly more ergonomic for
users, and can be used to load single fonts with automatic metadata
detection as well.
I've exposed a opentype.Face.Font() method that can be used to get the
font metadata for a given face as well, though you have to type assert to
see it:
var myFace text.Face
if asOpentype, ok := myFace.(opentype.Face); ok {
myFont := asOpentype.Font()
}
The one problem with this approach is that the font variant field always
be automatically populated. Mono font detection is supported, but
other variants like SmallCaps are more complicated and may need to be
expressed differently in the future (smallcaps is a feature that any font
file can have, not necessarily a separate font file). See this [0] upstream
issue for details.
Additionally, in order to avoid import cycles, I've moved the declarations
of font attributes to package font. You can fix your code automatically to
refer to the new definitions by running the following:
gofmt -w -r 'text.FontFace -> font.FontFace' .
gofmt -w -r 'text.Variant -> font.Variant' .
gofmt -w -r 'text.Style -> font.Style' .
gofmt -w -r 'text.Typeface -> font.Typeface' .
gofmt -w -r 'text.Font -> font.Font' .
gofmt -w -r 'text.Regular -> font.Regular' .
gofmt -w -r 'text.Italic -> font.Italic' .
gofmt -w -r 'text.Thin -> font.Thin' .
gofmt -w -r 'text.ExtraLight -> font.ExtraLight' .
gofmt -w -r 'text.Light -> font.Light' .
gofmt -w -r 'text.Normal -> font.Normal' .
gofmt -w -r 'text.Medium -> font.Medium' .
gofmt -w -r 'text.SemiBold -> font.SemiBold' .
gofmt -w -r 'text.Bold -> font.Bold' .
gofmt -w -r 'text.ExtraBold -> font.ExtraBold' .
gofmt -w -r 'text.Black -> font.Black' .
gofmt -w -r 'text.Hairline -> font.Thin' .
gofmt -w -r 'text.UltraLight -> font.ExtraLight' .
gofmt -w -r 'text.DemiBold -> font.SemiBold' .
gofmt -w -r 'text.UltraBold -> font.ExtraBold' .
gofmt -w -r 'text.Heavy -> font.Black' .
gofmt -w -r 'text.ExtraBlack -> font.Black+50' .
gofmt -w -r 'text.UltraBlack -> font.ExtraBlack' .
Make sure each affected file imports gioui.org/font.
[0] https://github.com/go-text/typesetting/issues/57
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit moves the min/max width of shaped text and the text's Locale into
text.Parameters. They were previously passed as separate function parameters to
the shaper, but this made little sense and added visual noise. This is a breaking
change, but only if you previously invoked the shaping API directly.
Callers of text.(*Shaper).LayoutString should change:
shaper.LayoutString(params, minWidth, maxWidth, locale, "string")
to
params.MinWidth=minWidth
params.MaxWidth=maxWidth
params.Locale=locale
shaper.LayoutString(params, "string")
Callers of text.(*Shaper).Layout should do likewise.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds support for the idea of a text "Truncator", a string
that is shown at the end of truncated text to indicate that it has been
shortened because it would not fit within the requested number of lines.
When specifying a maximum number of lines, a truncator symbol is always
used. If the user does not provide one, the rune `…` is used. This
requirement results in a better user experience and significantly simpler
code, as we can rely upon the presence of one or more truncator glyphs in
the output glyph stream when truncation has occurred.
When interacting with truncated text, the truncator glyphs all act as
a single, indivisible unit. They can be selected or not, and if selected
they act as the entire contents of the truncated portion of the text.
This means that copying all of a truncated label will copy the entire
label text content, with the truncator symbol not appearing at all.
Concretely, the exposed text API now accepts a Truncator string in
text.Parameters, and there is a new glyph flag FlagTruncator which indicates
that the glyph is part of the truncator run. The truncator run will only
have a single FlagClusterBreak (even if the run would usually have many),
and the glyph with both FlagClusterBreak and FlagTruncator will have the
quantity of truncated runes in its Runes field. This necessitated increasing
the size of the Runes field from a byte to an int, as it's theoretically possible
for quite a lot of text to be truncated.
This commit necessarily bumps our go-text/typesetting dependency to the version
exposing truncation in the exported API.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit unifies and fixes the shaper's handling of the alignment
minimum width. Previously it was only considered when the text was
a single line, but in hindsight that was clearly a mistake. Now the
maximum width of all shaped lines and the minimum width is used to
set the text alignment.
This commit also fixes an index test in package widget that was
relying on the old (incorrect) alignment behavior.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit pushes limiting the maximum number of lines of text into
the shaper implementation. This is more efficient than doing it in
widgets, and also opens the door for future use of the shaper to
insert ellipsis and other truncating characters as appropriate.
I realized that we lost the implementation of limiting the number of
lines of text in my text stack overhaul, so this fixes a regression
from that work.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit restructures the entire text shaping stack to enable lines of shaped text to
have non-homogeneous properties like which font face they belong to and which direction
a segment of text is going.
The text package now provides a concrete type text.Shaper which can be used to convert
strings into sequences of renderable text.Glyphs. At a high level, the API is used
like this:
// Prepare some fonts.
var collection []text.FontFace
// Make a shaper with those fonts loaded.
shaper := text.NewShaper(collection)
// Shape a string.
shaper.LayoutString(text.Parameters{
PxPerEm: fixed.I(12),
}, 0, 100, system.Locale{}, "Hello")
// Iterate the glyphs from that string.
for glyph, ok := shaper.NextGlyph(); ok; glyph, ok = shaper.NextGlyph() {
// Convert the glyph data into a path. In real uses, convert batches of glyphs
// rather than single glyphs to reduce the number of individual paths and offsets
// required to display your text.
shape := shaper.Shape([]text.Glyph{glyph})
// Offset the glyph to the position it declares within its fields. This will
// automatically handle correct bidirectional text glyph positioning.
offset := op.Offset(image.Pt(glyph.X.Floor(), int(glyph.Y))).Push(gtx.Ops)
// Create a clip area from the shape of the glyph.
area := clip.Outline{Path: shape}.Push(gtx.Ops)
// Paint whatever the current color is within the glyph's shape.
paint.PaintOp{}.Add(gtx.Ops)
area.Pop()
offset.Pop()
}
This API will transparently handle both font fallback (choosing appropriate fonts
from those loaded when the primary font doesn't contain a required glyph) and
bidirectional text (mixed left-to-right and right-to-left text). Glyphs are
iterated in order of the input runes, not their visual order, but proper use
of the provided offsets will ensure that text always displays correctly.
Thanks to Elias Naur for suggesting this glyph iterator strategy. It let us cut
through a lot of accumulated complexity from trying to match our old text APIs,
meaning that this change actually is a net negative change in lines of code.
This commit consumes the upstream github.com/go-text/typesetting/shaping API
now that my prior work is merged there, removing the need for the font/opentype/internal
package entirely.
As part of my efforts, I fuzzed both the low-level text shaping stack and the
editor widget extensively. I've committed regression tests found that way into
the appropriate testdata files to ensure the fuzzer re-checks them.
Fixes: https://todo.sr.ht/~eliasnaur/gio/425
Fixes: https://todo.sr.ht/~eliasnaur/gio/211
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Elias Naur