ref: 284659d3eac9 gio/widget/label.go -rw-r--r-- 6.0 KiB
widget,widget/material: add selection to the editor

- Allow dragging to be on both horizontal and vertical axes at once.
- Split Editor.caret.pos into caret.start and caret.stop. caret.start is
  the old caret.pos, and is both the position of the caret, and also the
  start of selected text. caret.end is the end of the selected text.
  Start can be after end, e.g. after after Shift-DownArrow.
- Update caret.end after a mouse drag, and various shifted keys
  (Shift-UpArrow, Shift-DownArrow, etc).
- Change Shortcut-C to copy only the selected text, not the whole editor
- Add Shortcut-X to copy and delete selected text, and Shortcut-A to
  select all text.
- The various Insert/Delete/etc functions now overwrite or delete the
  selection, as appropriate.
- Change MoveCaret to accept a distance for selection end, as well.
  Change SetCaret to accept a selection end offset.
- Add SelectionLen to get the selection length, Selection to get
  selection offsets, SelectedText to get the selected text, and
  ClearSelection to clear the selection.
- Add a rudimentary selection unit test, and extend the deleteWord unit
  test with some text selection cases.
- Add SelectionColor to material.EditorStyle, which defaults to

Signed-off-by: Larry Clapp <larry@theclapp.org>
widget: refactoring to prep for editor selection

- Move caret from editBuffer.caret to Editor.caret.pos.ofs and related
  refactoring. Move other fields in Editor.caret into Editor.caret.pos.
- Refactor several functions to change a position passed into them,
  rather than changing e.rr.caret directly.
- Add editBuffer.Seek().
- Remove editBuffer.dump().
- Change Editor.Move to MoveCaret.
- Add Editor.SetCaret.
- Updated tests.

Signed-off-by: Larry Clapp <larry@theclapp.org>
op: rename StackOp/Push/Pop to StateOp/Save/Load

The semantics were relaxed in a previous commit; this change renames
to operations accordingly.

API change. Use gofmt to adjust your code accordingly:

gofmt -r 'op.Push(a).Pop() -> op.Save(a).Load()'
gofmt -r 'op.Push(a) -> op.Save(a)'
gofmt -r 'v.Pop() -> v.Load()'
gofmt -r 'op.StackOp -> op.StateOp'

Signed-off-by: Elias Naur <mail@eliasnaur.com>
widget: fix Editor and Label clipping

Commit gioui.org/commit/94d242d18c9245 broke Editor and Label clipping,
most visible for single-line Editors. Restore the correct clipping.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: represent laid out text as strings to facilitate caching of layouts

Commit https://gioui.org/commit/b331407e81456 added text layout and shaping
based on io.Reader and changed Editor to use it. Unfortunately, as ~inkeliz
discovered, caching of shapes were also lost.

~inkeliz suggested fix,


adds caching of shapes to Editor to regain lost performance.

This change repairs the cache to work on io.Reader API, in hope that the
already complicated Editor won't need additional caching.

Before this change, text layouts were represented as a slice of (rune, advance)
pairs. Unfortunately, this representation doesn't lend itself to caching of
shaping results, so change the representation of a line of text to be a pair
of text and advances:

	package text

	type Layout {
		Text string
		Advances []fixed.Int26_6

The Text field can then be used in a cache key, assuming Advances is
consistent with it.

The end result is that the two shaper variants of text.Shaper is reduced to
just one, and the Len field field of text.Line is no longer needed.

The changed representation adds a bit of extra work to package opentype.
Cleaning that up is left as a future TODO.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
op/paint: remove support for PaintOp.Rect

PaintOp.Rect is the wrong abstraction; it implies a clip operation
better handled by package clip, and not all paints need it (colors).
Furthermore, it's awkward to specify a PaintOp that fills up the
current clip area, regardless of its size.

Redefine PathOp to mean "fill current clip area".

API change. Replace uses of PaintOp.Rect with a TransformOp applied
before the PaintOp.

Leave a TODO for the PathOp infinity area.

Fixes gio#167

Signed-off-by: Elias Naur <mail@eliasnaur.com>
all: remove redundant op.TransformOp.Offset

Use op.Offset instead, or create and manipulate a f32.Affine2D.

API change. Update your code with a gofmt rule:

	gofmt -r 'op.TransformOp{}.Offset -> op.Offset'

Signed-off-by: Elias Naur <mail@eliasnaur.com>
ae8a377c — Thomas Bruyelle 1 year, 27 days ago
op: add op.Push and op.Record funcs

The funcs replace stack.Push and macro.Record, which become private.
This makes stack and macro faster to write, in particular for stacks
where you can just write the following line to save and restore the
state :

  defer op.Push(ops).Pop()

This usage requires Push to return a pointer (since Pop has a pointer
receiver), or else the code doesn't compile.

For consistancy, I tried to do the same for op.Record, but this implied
to turn all the MacroOp fields into pointers, and this caused some
panics. As a result, op.Record doesn't return a pointer.

An other side effect pointed by Larry Clapp: StackOp and MacroOp are not
re-usable any more, you have to allocate a new one for each usage, using
the described funcs above.

Signed-off-by: Thomas Bruyelle <thomas.bruyelle@gmail.com>
layout: change Widget to take explicit Context and return explicit Dimensions

Change the definition of Widget from the implicit

        type Widget func()

to the explicit functional

        type Widget func(gtx layout.Context) layout.Dimensions

The advantages are numerous:

- Clearer connection between the incoming context and the output dimensions.
- Returning the Dimensions are impossible to omit.
- Contexts passed by value, so its fields can be exported
and freely mutated by the program.

The only disadvantage is the longer function literals and the many "returns".
What tipped the scales in favour of the explicit Widget variant is that type
aliases can dramatically shorten the literals:

	type (
		C = layout.Context
		D = layout.Dimensions

	widget := func(gtx C) D {

Note that the aliases are not part of the Gio API and it is up to each user
whether they want to use them.

Finally the Go proposal for lightweight function literals,
https://github.com/golang/go/issues/21498, may remove the disadvantage
completely in future.

Context becomes a plain struct with only public fields, and its Reset is
replaced by a NewContext convenience constructor.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
all: use new rectangle and point convenience functions

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout,widget: transpose Constraints to use image.Points for limits

Instead of

    type Contraints struct {
	    Width, Height Constraint


    type Constraints struct {
	    Min, Max image.Point

which leads to simpler use. For example, the Min method is trivally replaced by
the field, and the RigidConstraints constructor is no longer a net win.

API Change. Rewrites:

    gofmt -r 'gtx.Constraints.Min() -> gtx.Constraints.Min'
    gofmt -r 'gtx.Constraints.Width.Min -> gtx.Constraints.Min.X'
    gofmt -r 'gtx.Constraints.Height.Min -> gtx.Constraints.Min.Y'
    gofmt -r 'gtx.Constraints.Height.Max -> gtx.Constraints.Max.Y'
    gofmt -r 'gtx.Constraints.Width.Max -> gtx.Constraints.Max.X'

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: simplify text layout and shaping API

First, replace LayoutOptions with an explicit maximum width parameter.  The
single-field option struct doesn't carry its weight, and I don't think we'll
see more global layout options in the future. Rather, I expect options to cover
spans of text or be part of a Font.

Second, replace the unit.Converter with an scaled text size. It's simpler and
allow the Editor and similar widgets to easily detect whether their cached
layouts are stale. Package text no longer depends on package unit, which is
now dealt with at the widget-level only.

Finally, remove the Size field from Font. It was a design mistake: a Font is
assumed to cover all sizes, as evidenced by the FontRegistry disregarding
Size when looking up fonts.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: add io.Reader Layout method to Shaper

use them for Editor, which is no longer required to construct a string
for laying out its content.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: remove String, Layout and add Glyph

In preparation for using Shaper with an io.Reader, rework the API to not refer
to strings. In particular, introduce Glyph for holding the rune in addition to
the advance. For fast traversing of the underlying text, add Len to Line with
the UTF8 length.

Layout is a useless wrapper around []Line; remove it while we're

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: make Shaper an interface

And rename out the caching implementation to FontRegistry.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
layout: invert baseline to measure positive distance from bottom

With an inverted baseline, the zero value results in the widget
baseline aligned to its bottom.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
widget,text: move Label and Editor from text to widget package

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: remove themable properties from Editor and Label

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: tighten clip bounds for Editor and Label

We're about to remove the extra padding from Editor. To do that, the
clipping must account for text drawing that lie outside the viewport.

With accurate clip bounds, use it for Label as well.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
text: replace Family with Shaper, add Font, Face

There is now a single shaping implementation, Shaper, for all fonts, replacing
Family that only covered a single typeface.

A typeface is identified by a name, where the empty string denotes the
default typeface.

Font is introduced to specify a particular font from the typeface, style,
weight and size.

Face is changed to an interface for a particular layout and shaping method.
The text/shape package is renamed to text/opentype and contains a Face
implementation based on golang.org/x/image/font/sfnt.

Signed-off-by: Elias Naur <mail@eliasnaur.com>