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>
Allowing clients to initiate resize gestures is a waste: macOS
doesn't support them, and the only reason we added them was to
implement client-side decorations for Wayland. Now all desktop
platforms implement resize gestures as needed, and we no longer
need the system.Action actions.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Style values are ephemeral, and pointer methods can't be called in
the same expression a style value is constructed. Matches other style
types.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The unit.Value is a struct and thus more inconvenient to use than its
underlying float32 type. In addition, most uses don't need a general
value, but rather a specific unit given by the context. This change
replaces unit.Value with two float32 units, Dp and Sp. It also changes
variables and parameters of unit.Value to a specific unit type matching
the context. That is, unit.Dp everywhere except for text sizes which are
in Sp.
Switching to typed float32s has multiple advantages
- They can be constants:
const touchSlop = unit.Dp(16)
- Casting untyped constants is no longer necessary:
insets := layout.UniformInset(16)
- Calculation with values is natural:
func (s ScrollbarStyle) Width() unit.Dp {
return s.Indicator.MinorWidth + s.Track.MinorPadding + s.Track.MinorPadding
}
The main API change is that calls to gtx.Px must be replaced with either
gtx.Dp or gtx.Sp depending on the unit.
Idea by Christophe Meessen.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Like the change to op.Offset before this, clip.RRect and UniformRRect
is usually used with integer coordinates. Change to integer coordinates
to eliminate many useless conversions to float32.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
op.Offset is a convenience function most often used by layouts. Layouts
usually operate in integer coordinates, and the float32 version of op.Offset
needlessly force conversions from int to float32. This change makes op.Offset
take integer coordinates, to better match its intended use.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Most widget code operate in integer coordinates. This change makes
gesture pointer coordinates integer, to lessen the number of float32
to int conversions.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit fixes a visual-only bug in the ListStyle that could
make the scrollbar float at the edge of the maximum constraints
when the list did not occupy the full constraints. The list
would still reserve layout space for the scrollbar in the correct
position, but the scrollbar would not be displayed there.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Previously, a bug in the ListStyle could result in items being
passed a negative value in the minimum constraints.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This change makes material.Clickable propagate the constraints it is
invoked with to the widget being made clickable. Without this, the
internal use of layout.Stack resets the minimum constraints to zero.
This has the confusing effect of breaking a working layout when you
decide to wrap one element in a Clickable, which I think is sufficiently
surprising that we should eliminate the footgun.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Move Decorations to the widget package and
rename material.Decorate to material.Decorations.
This makes decorations in line with how the
other widgets are used.
Signed-off-by: Pierre Curto <pierre.curto@gmail.com>
Fix actions not processed and move the Layout method from
Decorations to DecorationsStyle.
Also clarify the comment for the app.Window.Decorated option.
Signed-off-by: Pierre Curto <pierre.curto@gmail.com>
This patch implements a mechanism for customizing window
decorations.
If a window is configured with app.Decorated(true), then
the widget/material.Decorations are applied. On Wayland,
the option is automatically set when the server does not
provide window decorations.
Server side decorations are no longer requested.
The Decorated flag is set according to the
server's requests.
Wayland is now the default driver for UNIX platforms.
References: https://todo.sr.ht/~eliasnaur/gio/318
Signed-off-by: Pierre Curto <pierre.curto@gmail.com>
Add the Decorations material widget and the related system
elements in preparation for the automatic window decoration
patch.
Signed-off-by: Pierre Curto <pierre.curto@gmail.com>
Some semantic information is automatically extracted, but some must be
provided by UI components. This change enriches the generic and material
widgets with such information.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Switch needs a semantic description, but doesn't have a text label
attached. This change adds a description argument to the constructor.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Icons have no inherent semantic meaning such as a label, so this change
adds another argument to the IconButton constructor for the client to
provide a description.
This is an API change, because it seems best to force every client to
provide semantic descriptions for icon buttons.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To make the semantic relation between the enum widget and its content,
the content must be laid out inside the enum clip rect.
This is an API change. Users of Enum.Layout must provide a content
widget.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To make the semantic relation between the editor and its content clear,
the editor clip operation must cover the content. This change adds an
explicit widget argument to editor, and lays it out inside the clip
rect.
This is an API change. Users of Editor.Layout must provide a content
widget.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To make the semantic relation between the clickable area and its
content clear, it will be important for the clickable clip operation
to cover all of the clickable content.
API change: users of widget.Clickable must now pass the clickable
content to Layout.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The click area was mistakenly offset by half the track width, but it
really should be offset by half the thumb diameter.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This comment and associated code were designed to guard against
the scrollbar failing to anchor to the proper edge of the content
when the layout.Direction was used with a zero minimum constraint.
However, they were in the wrong place to actually achieve the
desired behavior. This change simply moves the constraints
change to before the invocation of layout.Direction's Layout
method. This fixes the scrollbar appearing on the wrong edge of
content when the content is laid out with a zero minimum constraint.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
A previous change merged PassOp with AreaOp under the assumption that
the pass mode would be set on a particular area. That assumption turns
out not to hold, so this change brings back PassOp as an independent
stack operation.
This is an API change: replace AreaOp{Pass: true} with a separate
pointer.PassOp operation.
Fixes gio#288
Signed-off-by: Elias Naur <mail@eliasnaur.com>
In a discussion with Raph Levien, the author of our compute renderer
implementation, it became clear to me that it's not at all certain that
complex strokes will ever be efficiently supported by a GPU renderer.
At the same time, the machinery for converting a complex stroke to a
GPU-friendly outline has a significant maintenance cost. Further, it is
surprising to users that complex strokes are significantly slower and
allocate memory.
This change removes support for complex strokes, leaving only
round-capped, round-joined strokes supported by the compute renderer.
The default renderer still converts all strokes to outline, but it also
caches the result.
This is an API change. The complex stroke conversion code has been moved
to the external gioui.org/x/stroke package, with a similar API.
Updats gio#282 (Inkeliz brought up the allocation issue)
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The op.Save and Load methods exist to support the need for
transformation, clip, pointer area state to behave as stacks. For
example, layout needs to apply an offset to its children but not
subsequent operations.
Before this change, op.Save and Load were used to save and restore the
state:
ops := new(op.Ops)
// Save state.
state := op.Save(ops)
// Apply offset.
op.Offset(...).Add(ops)
// Draw with offset applied.
draw(ops)
// Restore state.
state.Load()
A drawback with the op.Save mechanism is that there is no direct
connection between the state change and the saving and loading of state.
This causes confusion as to when a Save/Load is needed and who is
responsible for performing them, which leads to subtle bugs and over-use
of Save/Loads.
This change gets rid of the general state stack and replaces it with
per-state stacks. There is now a stack for transformation, clip, pointer
areas, and they can only be restored by the code pushing state to them.
The example above now becomes:
ops := new(op.Ops)
// Push offset to the transformation stack.
stack := op.Offset(...).Push(ops)
// Draw with offset applied.
draw(ops)
// Restore state.
stack.Pop()
For convenience, transformation also be Add'ed if the stack operation is
not required.
Simple state such as the current material no longer has a way to be
restored; it is assumed the client of a PaintOp adds their desired
material operation before it.
API change: replace op.Save/Load with explicit Push/Pop scopes for
op.TransformOps, pointer.AreaOps, clip.Ops.
To ease porting, this change retains a version of op.Save/Load that
saves and restores the transformation and clip stacks. It also retains
an Add method for clip.Op.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We're about to make operation scopes explicit, which would result in
both AreaOp and PassOp be scoped. However, PassOp seems to light to have
its separate stack, so this change instead makes pass-through a property
of an area. We're assuming that clients that want pass-through are also
aware of the affected hit area.
API change: replace PassOps with the AreaOp.PassThrough field.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit is based on a patch by Elias that improved drag scrolling
on the scrollbar by locking some parameters of the math at the start
of the scroll event.
I discovered while playing with that implementation that there was
an even simpler approach within his changeset. You can actually
use no information other than the delta between the current and
previous frame's scroll position to compute the scroll distance.
By simplifying the math to rely on no other inputs, the jitter that
we've been fighting simply disappears (it came from other inputs).
Turns out my attempts to make the logic smart were the problem.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit fixes a problem that could force the scroll indicator to
lay itself out outside of its configured bounds. This occurred when
the scroll indicator size was increased to meet the minimum size
configured on the style type while the scrollbar was near the end
of the list. The increased size did not take the start position
of the scroll indicator into account, which made the indicator begin
in the correct place, but extend beyond the end of its track.
This commit alters the logic to ensure that the scroll indicator can
never extend beyond the end of its track.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Previously, it was possible for fromListPosition to return
an end coordinate greater than 1, which would make scroll
indicators using those coordinates render beyond the
boundaries of their scroll tracks. One could argue that
this is a bug in the scroll indicator, but I don't think
this method should return data outside of its documented
range.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Icons are meant to be shared among multiple widgets, but their Color
state may end up with unexpected values after use. Replace the state
with and explicit argument to Layout.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit ensures that the dimensions returned by material.List
include the size of the scrollbar when the scrollbar is set to
the Occupy AnchorStrategy.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This change ensures that the scrollbar anchors to the proper edge of the
content even when the list was drawn with a zero minimum constraint.
Without this, the layout.Direction used to anchor the scrollbar will choose
to use the minimum size and anchor it to the opposite edge of the content.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
The scrollbar implementation prior to this change only adjusted
list.Position.Offset. This works in all circumstances except when
list.Position.BeforeEnd=false. If the position indicates that the
scroll position is at the end of the list, the offset is ignored.
This change ensures that manually dragging the scrollbar always
causes BeforeEnd to be set to true. If the drag ends with the
scrollbar at the end of the list, BeforeEnd will be set
automatically by the next list.Layout call, so this doesn't
prevent the list from optimizing for that case in general.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
To use these lists instead of layout.List, callers simply need to
change declarations of layout.List to widget.List, and to change
calls to layout.List.Layout to material.List(th,&list).Layout.
So this:
var list layout.List
list.Layout(gtx, 10, func(gtx C, index int) D {
return material.Body1(th, fmt.Sprintf("%d", index)).Layout(gtx)
})
Becomes:
var list widget.List
material.List(th, &list).Layout(gtx, 10, func(gtx C, index int) D {
return material.Body1(th, fmt.Sprintf("%d", index)).Layout(gtx)
})
Naturally, the material.ListStyle type supports tweaking the scrollbar's
appearance and behavior.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This is a breaking change as Icon.Layout no longer requests a size.
Before:
sz := unit.Dp(20)
ic.Layout(gtx, sz)
After:
sz := gtx.Metric.Px(unit.Dp(20))
gtx.Constraints.Min = image.Pt(sz, 0)
ic.Layout(gtx)
Fixes gio#240
Signed-off-by: pierre <pierre.curto@gmail.com>
Before this change, a radio button with the empty key ("") would be
displayed as hovering if no other button were.
It's still not possible to have no radio buttons selected when one of
them is the empty key. If that's becomes necessary, Enum.Value can be
converted to a *string.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Chris Waldon