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>
Putting a string in an interface value has to (normally) heap allocate
the string header and string. However, putting the address of a local
string variable in an interface value has the same effect, as this
causes the local variable to escape to the heap.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
This commit picks up improvements in upstream go-text that (among other things)
allow the shaper to reuse a lot of information when shaping the same font face
multiple times (using an LRU cache to keep that information available). I've
tried to pick a reasonable default LRU size of 32 faces.
My simple benchmarks indicate a definitive performance gain and reduction in
memory use across the board, which is especially noticable for complex fonts
like arabic and emoji.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit combs through the logic of computing glyph sizes and positions,
attempting to remove all unnecessary rounding and truncation. This is in
an effort to help text display consistently when different-length strings
are displayed near one another.
The specific problem prompting this change was end-aligned text stacked in
rows with a common suffix. If the rows displayed different values, they
would shape such that those final glyphs were at different fractional x
coordinates, and then they would be aligned with rounding that could display
them at different x positions in spite of the fact that both suffixes are
the same glyphs.
By removing rounding from Alignment.Align, the largest problem is fixed, but
I'm also removing other unnecessary loss of precision that can circumstantially
contribute to this sort of visual issue.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Clicking on the window border or the title bar initiates resizing and
moving of the window respectively. This commit fixes a bug where this
would cause a stuck pressed primary button, as we won't receive a
release event. The fix is to only update the set of pressed buttons
after we've decided not to invoke window management.
This fixes a regression introduced by
2957d007a2.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
We panic when someone constructs a literal LabelStyle because they cannot possibly
populate the shaper field. The resulting error is cryptic, and unusual within Gio
because most style types are safe to construct literally. This commit enables
creating literal LabelStyles by exporting the Shaper field, and also documents
the purposes of all of the fields.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This change adds ViewEvent for JS/WASM, which returns the HTMLElement
which Gio is been rendered, once started.
Signed-off-by: inkeliz <inkeliz@inkeliz.com>
This commit fixes a subtle problem when trunating text widgets that contain
multiple newline-delimited paragraphs.
Paragraphs are the unit of text shaping, so we divide the text into paragraphs
and then iterate those paragraphs performing shaping and line wrapping. If we
have a maximum number of lines to fill, we stop iterating paragraphs when we
use all of the available lines. Usually, if we fill all of the lines the text
shaper will insert the truncator symbol. However, if we exactly fill all of the
lines with the end of a paragraph, the line wrapper is able to fill the line
quota without actually truncating any of the text in that paragraph. Thus it
doesn't insert a truncator even though subsequent paragraphs were truncated (it
has no way to know).
To fix this, I've taught the line wrapper about an explicit scenario in which
we always want to show the truncator symbol *if* we hit the line limit, even if
all of the text in the current paragraph fit. I've then plumbed support for
that through our text stack.
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 separates the types for interactive and non-interactive text within
package widget. widget.Selectable is used for all interactive text. widget.Label
is used for all non-interactive text. There is no longer a field on widget.Label
to provide it with a Selectable. If you want selectable text and are not relying
upon the material pacakge API, you need to create widget.Selectables instead of
widget.Labels. The material package's LabelStyle API is unchanged.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds an exported method to enable widgets to detect
when the text displayed by a Selectable has been truncated. This
can be used to implement proper show-full-text-in-an-overlay
behavior in a parent widget. I haven't attempted to implement
that in core yet, as it is a complex feature involving animation
and pointer interaction.
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 teaches the text widgets how to position their cursor according to
grapheme cluster boundaries rather than rune boundaries. While this is more work,
the results better match the expectations of users. A "grapheme cluster" is a
user-perceived character that may be composed of arbitrarily many runes.
I chose to implement this within widgets for two reasons:
- grapheme cluster boundaries would be extremely difficult to encode within the
glyph stream returned by the text shaper
- not all text needs to be segmented, only text that can be interacted with
All mutation operations exposed by widget.Editor now work in terms of grapheme
clusters instead of runes.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit allows the glyph index type to be reset and reused, preventing the
reallocation of numerous buffers when indexing glyphs.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds caching to the process of extracting bitmap images
from glyphs, ensuring that we only do so once for a given glyph so long
as it isn't evicted from our LRU.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit upgrades our version of eliasnaur.com/font to include a color
emoji font and uses that to benchmark displaying large quantities of emoji.
As expected, this is very slow when the strings change frequently, and uses
silly amounts of memory. Future commits will work to improve this.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit supports rendering opentype glyphs containing bitmap data instead of
color data. In order to support returning the shaped bitmap glyphs from the Shaper's
Shape() method, it has gained a second return parameter, an op.CallOp. Adding
that CallOp immediately after or immediately before painting the returned path
will display the bitmap glyphs.
The consequences of supporting colored glyphs forced changes upon the widget APIs
for widgets that display text. Previously text always had a fixed paint material,
so we could rely upon the caller setting the material (e.g. adding a paint.ColorOp)
before painting the glyphs and everything would work. Now that we display image-
based glyphs, we end up changing the painting material to an image midway through
displaying text. This is an awkward consequence of how we currently manage the
painting material, and to work around it widgets now accept an op.CallOp that
is expected to set the proper paint material. Text widgets will use that op.CallOp
before painting text (or other paint operations) to ensure that they are painting
with the proper materials.
This, in turn, changed the APIs for laying out widget.Editor, widget.Label, and
widget.Selectable, and eliminated the need for them to accept a callback (the
callback was only really to set the colors). Dropping that callback function
allowed me to consolidate widget.Label to only need one exported Layout method,
and allowed me to unexport the PaintText, PaintCaret, and PaintSelection methods
from widget.Editor and widget.Selectable. Those methods are useless in the public
API now that they don't need to be invoked after applying a color operation.
Callers of the raw text shaper API will need to make the following changes:
- Where before you used:
var ops *op.Ops // Assume we have an operation list.
var shaper *text.Shaper // Assume we have a shaper.
var col color.NRGBA // Assume we have a text color.
var glyphs []text.Glyph // Assume we have already filled a slice of glyphs.
shape := shaper.Shape(glyphs)
paint.FillShape(ops, col, clip.Outline{Path:shape}.Op())
- Now you should do:
shape, call := shaper.Shape(glyphs)
paint.FillShape(ops, col, clip.Outline{Path:shape}.Op())
call.Add(ops)
Callers of the widget.{Label,Selectable,Editor} APIs will need to make the
following changes:
- Where before you used:
var gtx layout.Context // Assume we have an operation list.
var shaper *text.Shaper // Assume we have a shaper.
var textCol color.NRGBA // Assume we have a text color.
var selectCol color.NRGBA // Assume we have a selection color.
var ed widget.Editor // Assume we have an editor.
var sel widget.Selectable // Assume we have a selectable.
// Lay out an editor.
ed.Layout(gtx, shaper, text.Font{}, unit.Sp(30), func(layout.Context) layout.Dimensions {
// Paint the editor.
})
// Lay out a selectable.
sel.Layout(gtx, shaper, text.Font{}, unit.Sp(30), func(layout.Context) layout.Dimensions {
// Paint the selectable.
})
// Lay out an interactive label.
widget.Label{}.LayoutSelectable(gtx, shaper, text.Font{}, unit.Sp(30), "hello", func(layout.Context) layout.Dimensions {
// Paint the label.
})
// Lay out a non-interactive label.
widget.Label{}.Layout(gtx, shaper, text.Font{}, unit.Sp(30), "hello")
- Now you should do:
// Capture setting the text paint material in a macro.
textColMacro := op.Record(gtx.Ops)
paint.ColorOp{Color: textCol}.Add(gtx.Ops)
textMaterial := textColMacro.Stop()
// Capture setting the selection paint material in a macro.
selectColMacro := op.Record(gtx.Ops)
paint.ColorOp{Color: selectCol}.Add(gtx.Ops)
selectMaterial := selectColMacro.Stop()
// Lay out an editor.
ed.Layout(gtx, shaper, text.Font{}, unit.Sp(30), textMaterial, selectMaterial)
// Lay out a selectable.
sel.Layout(gtx, shaper, text.Font{}, unit.Sp(30), textMaterial, selectMaterial)
// Lay out a label (no difference between interactive and non-interactive)
widget.Label{}.Layout(gtx, shaper, text.Font{}, unit.Sp(30), "hello", textMaterial, selectMaterial)
Callers of the material package API do not need to make any changes.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit upgrades our go-text version to the latest one which internalizes
harfbuzz and supports text truncators. This allows us to drop our dependency
upon Benoit's textlayout package.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit ensures that the Spacer type doesn't break layouts
by ignoring when its min constraints require it to be larger or
its max constraints require it to be smaller.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
When no scale factor is set, scale by 1.0, mapping one image pixel to
one device-independent pixel. This matches the behavior of CSS and other
frameworks.
The old code attempted to convert to Dp while taking the image's DPI
into account. This was wrong in two ways:
- It assumed that the default display DPI is 160, but this is only true
for Android. Other platforms use 96, 162, or leave it undefined. Thus
image.Layout's idea of a dp didn't match that of Gio on most
platforms.
- It tried to account for image DPI, and assumed a default of 72. This
was wrong in that DPI in images is merely metadata meant for printing,
not display. The vast majority of software such as image viewers and
image editors do not take DPI into account, mapping one image pixel
either to one physical pixel or to one device-independent pixel. That
is, users would expect their images to either display 1 to 1, or scaled
based on PxPerDp, but not scaled based on the image's DPI.
We default to a scale of 1 to stay consistent with other parts of Gio
that scale by default. Users who don't want any scaling can continue to
set the scale to the inverse of PxPerDp.
While we're here we clarify the documentation of the Scale field.
This change is backwards incompatible for users that relied on the
default scale.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
faceOrderer.sorted tried to put the "primary" font first by tweaking the
"less" function in sort.Slice, but it didn't work correctly.
If item i equaled the "primary" font, less() always returned true. This
did not take into account if item j was the "primary" font, in which
case it could easily be sorted differently.
Rather than adding another special case for that, which I couldn't
convince myself was actually correct in every case, I just searched for
the "primary" font and moved it to the front of the slice, and then
omitted the first item of the slice from the rest of the sorting.
Signed-off-by: Larry Clapp <larry@theclapp.org>
This commit extends the key event handling for text widgets to always check for
appropriate modifier keys. Previously this wasn't necessary, as the text widgets
would only ever receive key events it registered for, but now it may be the top-level
key event handler and thus receive all key events that aren't handled elsewhere.
Fixes: https://todo.sr.ht/~eliasnaur/gio/487
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
The majority of scrolling happens by manipulating the index of the first
displayed item instead of by just manipulating the offset. This lets us
avoid having to render all items that were scrolled past.
Instead of numbers of items we could've accepted a ratio in [0, 1] to
scroll by or to, to match the data we get from scrollbars. However,
there are more use cases for scrolling by items, such as keyboard
shortcuts, go-to dialogs, etc. And converting from [0, 1] to items is
trivial for the user as long as they know the number of items, and will
usually be handled for them by a theme.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
When the line overlaps itself backtracking exactly, e.g.
path.MoveTo(0, 100)
path.LineTo(100, 0)
path.LineTo(0, 100)
then acos calculation is relatively unstable. By using atan2 it avoids
some of such problems in the calculation. Additionally, it simpliflies
the round join calculation.
Fixes: https://todo.sr.ht/~eliasnaur/gio/474
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
Apparently, alphaClose has been overflowing and giving the wrong answer
for a while and hence some of the tests are broken. I currently disabled
those tests, because I'm not quite sure where and how they broke.
Also, bumped alpha tolerance to 8, to ignore false positives.
Signed-off-by: Egon Elbre <egonelbre@gmail.com>
Setting Float.Invert=true not only inverts the order of values (which was already easily done by swapping min and max), it also draws the widget inverted so that the track is darkened on the opposite side from usual.
This patch also fixes a bug wherein a vertical slider was drawn inverted by default.
Signed-off-by: Gordon Klaus <gordon.klaus@gmail.com>
This commit alters the textView API to give callers the option to provide
their own buffers for reading text. This enables some widget usecases to
be zero-allocation if a widget simply needs to examine the contents of the
text without returning it as a string.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit updates the textView to better describe the expectations
and behaviors of the Update and Paint* methods.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Chris Waldon