all: rename package ui to unit

Package ui is now only about units except for the Config.Now method.
Remove Now and rename Config to Converter. Add layout.Config to
replace the old ui.Config.

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

app/app.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 // An UpdateEvent is generated when a Window's Update
@@ -39,7 +39,7 @@ type DestroyEvent struct {
 // system decoration such as translucent
 // system bars and software keyboards.
 type Insets struct {
-	Top, Bottom, Left, Right ui.Value
+	Top, Bottom, Left, Right unit.Value
 }
 
 // A StageEvent is generated whenever the stage of a
@@ -146,7 +146,7 @@ func Main() {
 	main()
 }
 
-// Config implements the ui.Config interface.
+// Config implements the layout.Config interface.
 type Config struct {
 	// Device pixels per dp.
 	pxPerDp float32
@@ -159,14 +159,14 @@ func (c *Config) Now() time.Time {
 	return c.now
 }
 
-func (c *Config) Px(v ui.Value) int {
+func (c *Config) Px(v unit.Value) int {
 	var r float32
 	switch v.U {
-	case ui.UnitPx:
+	case unit.UnitPx:
 		r = v.V
-	case ui.UnitDp:
+	case unit.UnitDp:
 		r = c.pxPerDp * v.V
-	case ui.UnitSp:
+	case unit.UnitSp:
 		r = c.pxPerSp * v.V
 	default:
 		panic("unknown unit")

app/doc.go

@@ -18,7 +18,7 @@ contents and state.
 
 For example:
 
-	import "gioui.org/ui"
+	import "gioui.org/unit"
 
 	w := app.NewWindow()
 	for e := range w.Events() {

app/os_android.go

@@ -27,7 +27,7 @@ import (
 	"gioui.org/f32"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 type window struct {

app/os_ios.go

@@ -25,7 +25,7 @@ import (
 	"gioui.org/f32"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 type window struct {

app/os_wayland.go

@@ -583,8 +583,7 @@ func (w *window) flushFling() {
 	w.fling.yExtrapolation = fling.Extrapolation{}
 	vel := float32(math.Sqrt(float64(estx.Velocity*estx.Velocity + esty.Velocity*esty.Velocity)))
 	_, _, c := w.config()
-	c.now = time.Now()
+	if !w.fling.anim.Start(&c, time.Now(), vel) {
-	if !w.fling.anim.Start(&c, vel) {
 		return
 	}
 	invDist := 1 / vel

app/window.go

@@ -13,7 +13,7 @@ import (
 	"gioui.org/io/event"
 	"gioui.org/io/profile"
 	"gioui.org/op"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 // WindowOption configures a Window.
@@ -22,7 +22,7 @@ type WindowOption struct {
 }
 
 type windowOptions struct {
-	Width, Height ui.Value
+	Width, Height unit.Value
 	Title         string
 }
 
@@ -86,8 +86,8 @@ var ackEvent event.Event
 // BUG: Calling NewWindow more than once is not yet supported.
 func NewWindow(options ...WindowOption) *Window {
 	opts := &windowOptions{
-		Width:  ui.Dp(800),
+		Width:  unit.Dp(800),
-		Height: ui.Dp(600),
+		Height: unit.Dp(600),
 		Title:  "Gio",
 	}
 
@@ -339,7 +339,7 @@ func WithTitle(t string) WindowOption {
 }
 
 // WithWidth returns an option that sets the window width.
-func WithWidth(w ui.Value) WindowOption {
+func WithWidth(w unit.Value) WindowOption {
 	if w.V <= 0 {
 		panic("width must be larger than or equal to 0")
 	}
@@ -351,7 +351,7 @@ func WithWidth(w ui.Value) WindowOption {
 }
 
 // WithHeight returns an option that sets the window height.
-func WithHeight(h ui.Value) WindowOption {
+func WithHeight(h unit.Value) WindowOption {
 	if h.V <= 0 {
 		panic("height must be larger than or equal to 0")
 	}

cmd/gogio/js_test.go

@@ -15,7 +15,7 @@ import (
 
 	"github.com/chromedp/chromedp"
 
-	_ "gioui.org/ui" // the build tool adds it to go.mod, so keep it there
+	_ "gioui.org/unit" // the build tool adds it to go.mod, so keep it there
 )
 
 func TestJSOnChrome(t *testing.T) {

gesture/gesture.go

@@ -11,13 +11,14 @@ package gesture
 
 import (
 	"math"
+	"time"
 
 	"gioui.org/f32"
 	"gioui.org/internal/fling"
 	"gioui.org/io/event"
 	"gioui.org/io/pointer"
 	"gioui.org/op"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 // Click detects click gestures in the form
@@ -93,7 +94,7 @@ const (
 	StateFlinging
 )
 
-var touchSlop = ui.Dp(3)
+var touchSlop = unit.Dp(3)
 
 // Add the handler to the operation list to receive click events.
 func (c *Click) Add(ops *op.Ops) {
@@ -156,7 +157,7 @@ func (s *Scroll) Stop() {
 
 // Scroll detects the scrolling distance from the available events and
 // ongoing fling gestures.
-func (s *Scroll) Scroll(cfg ui.Config, q event.Queue, axis Axis) int {
+func (s *Scroll) Scroll(cfg unit.Converter, q event.Queue, t time.Time, axis Axis) int {
 	if s.axis != axis {
 		s.axis = axis
 		return 0
@@ -185,7 +186,7 @@ func (s *Scroll) Scroll(cfg ui.Config, q event.Queue, axis Axis) int {
 			}
 			fling := s.estimator.Estimate()
 			if slop, d := float32(cfg.Px(touchSlop)), fling.Distance; d < -slop || d > slop {
-				s.flinger.Start(cfg, fling.Velocity)
+				s.flinger.Start(cfg, t, fling.Velocity)
 			}
 			fallthrough
 		case pointer.Cancel:
@@ -221,7 +222,7 @@ func (s *Scroll) Scroll(cfg ui.Config, q event.Queue, axis Axis) int {
 			}
 		}
 	}
-	total += s.flinger.Tick(cfg.Now())
+	total += s.flinger.Tick(t)
 	return total
 }
 

internal/fling/animation.go

@@ -7,7 +7,7 @@ import (
 	"runtime"
 	"time"
 
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 type Animation struct {
@@ -21,8 +21,8 @@ type Animation struct {
 
 var (
 	// Pixels/second.
-	minFlingVelocity = ui.Dp(50)
+	minFlingVelocity = unit.Dp(50)
-	maxFlingVelocity = ui.Dp(8000)
+	maxFlingVelocity = unit.Dp(8000)
 )
 
 const (
@@ -31,7 +31,7 @@ const (
 
 // Start a fling given a starting velocity. Returns whether a
 // fling was started.
-func (f *Animation) Start(c ui.Config, velocity float32) bool {
+func (f *Animation) Start(c unit.Converter, now time.Time, velocity float32) bool {
 	min := float32(c.Px(minFlingVelocity))
 	v := velocity
 	if -min <= v && v <= min {
@@ -43,7 +43,7 @@ func (f *Animation) Start(c ui.Config, velocity float32) bool {
 	} else if v < -max {
 		v = -max
 	}
-	f.init(c.Now(), v)
+	f.init(now, v)
 	return true
 }
 

layout/doc.go

@@ -17,7 +17,7 @@ For example, to add space above a widget:
 	gtx.Reset(...)
 
 	// Configure a top inset.
-	inset := layout.Inset{Top: ui.Dp(8), ...}
+	inset := layout.Inset{Top: unit.Dp(8), ...}
 	// Use the inset to lay out a widget.
 	inset.Layout(gtx, func() {
 		// Lay out widget and determine its size given the constraints.

layout/layout.go

@@ -4,10 +4,11 @@ package layout
 
 import (
 	"image"
+	"time"
 
 	"gioui.org/io/event"
 	"gioui.org/op"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 // Constraints represent a set of acceptable ranges for
@@ -52,11 +53,20 @@ type Context struct {
 	// operation.
 	Dimensions Dimensions
 
-	ui.Config
+	Config
 	event.Queue
 	*op.Ops
 }
 
+// Config define the essential properties of
+// the environment.
+type Config interface {
+	// Now returns the current animation time.
+	Now() time.Time
+
+	unit.Converter
+}
+
 const (
 	Start Alignment = iota
 	End
@@ -93,7 +103,7 @@ func (s *Context) Layout(cs Constraints, w Widget) Dimensions {
 }
 
 // Reset the context.
-func (c *Context) Reset(cfg ui.Config, cs Constraints) {
+func (c *Context) Reset(cfg Config, cs Constraints) {
 	c.Constraints = cs
 	c.Dimensions = Dimensions{}
 	c.Config = cfg
@@ -129,7 +139,7 @@ func RigidConstraints(size image.Point) Constraints {
 
 // Inset adds space around a widget.
 type Inset struct {
-	Top, Right, Bottom, Left ui.Value
+	Top, Right, Bottom, Left unit.Value
 }
 
 // Align aligns a widget in the available space.
@@ -171,7 +181,7 @@ func (in Inset) Layout(gtx *Context, w Widget) {
 
 // UniformInset returns an Inset with a single inset applied to all
 // edges.
-func UniformInset(v ui.Value) Inset {
+func UniformInset(v unit.Value) Inset {
 	return Inset{Top: v, Right: v, Bottom: v, Left: v}
 }
 

layout/layout_test.go

@@ -7,7 +7,7 @@ import (
 
 	"gioui.org/io/event"
 	"gioui.org/layout"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 type queue struct{}
@@ -26,7 +26,7 @@ func ExampleInset() {
 	gtx.Reset(cfg, cs)
 
 	// Inset all edges by 10.
-	inset := layout.UniformInset(ui.Dp(10))
+	inset := layout.UniformInset(unit.Dp(10))
 	inset.Layout(gtx, func() {
 		// Lay out a 50x50 sized widget.
 		layoutWidget(gtx, 50, 50)
@@ -146,7 +146,7 @@ func (config) Now() time.Time {
 	return time.Now()
 }
 
-func (config) Px(v ui.Value) int {
+func (config) Px(v unit.Value) int {
 	return int(v.V + .5)
 }
 

layout/list.go

@@ -110,7 +110,7 @@ func (l *List) Dragging() bool {
 }
 
 func (l *List) update() {
-	d := l.scroll.Scroll(l.ctx.Config, l.ctx.Queue, gesture.Axis(l.Axis))
+	d := l.scroll.Scroll(l.ctx.Config, l.ctx.Queue, l.ctx.Now(), gesture.Axis(l.Axis))
 	l.scrollDelta = d
 	l.offset += d
 }

op/op.go

@@ -15,7 +15,7 @@ to a ui/app.Window's Update method.
 
 Drawing a colored square:
 
-	import "gioui.org/ui"
+	import "gioui.org/unit"
 	import "gioui.org/app"
 	import "gioui.org/op/paint"
 

text/editor.go

@@ -16,7 +16,7 @@ import (
 	"gioui.org/layout"
 	"gioui.org/op"
 	"gioui.org/op/paint"
-	"gioui.org/ui"
+	"gioui.org/unit"
 
 	"golang.org/x/image/math/fixed"
 )
@@ -88,7 +88,7 @@ const (
 // Event returns the next available editor event, or false if none are available.
 func (e *Editor) Event(gtx *layout.Context) (EditorEvent, bool) {
 	// Crude configuration change detection.
-	if scale := gtx.Px(ui.Sp(100)); scale != e.oldScale {
+	if scale := gtx.Px(unit.Sp(100)); scale != e.oldScale {
 		e.invalidate()
 		e.oldScale = scale
 	}
@@ -102,7 +102,7 @@ func (e *Editor) Event(gtx *layout.Context) (EditorEvent, bool) {
 		axis = gesture.Vertical
 		smin, smax = sbounds.Min.Y, sbounds.Max.Y
 	}
-	sdist := e.scroller.Scroll(gtx.Config, gtx.Queue, axis)
+	sdist := e.scroller.Scroll(gtx.Config, gtx.Queue, gtx.Now(), axis)
 	var soff int
 	if e.SingleLine {
 		e.scrollOff.X += sdist
@@ -167,8 +167,8 @@ func (e *Editor) editorEvent(gtx *layout.Context) (EditorEvent, bool) {
 	return nil, false
 }
 
-func (e *Editor) caretWidth(c ui.Config) fixed.Int26_6 {
+func (e *Editor) caretWidth(c unit.Converter) fixed.Int26_6 {
-	oneDp := c.Px(ui.Dp(1))
+	oneDp := c.Px(unit.Dp(1))
 	return fixed.Int26_6(oneDp * 64)
 }
 
@@ -182,7 +182,7 @@ func (e *Editor) Layout(gtx *layout.Context) {
 	cs := gtx.Constraints
 	for _, ok := e.Event(gtx); ok; _, ok = e.Event(gtx) {
 	}
-	twoDp := gtx.Px(ui.Dp(2))
+	twoDp := gtx.Px(unit.Dp(2))
 	e.padLeft, e.padRight = twoDp, twoDp
 	maxWidth := cs.Width.Max
 	if e.SingleLine {
@@ -275,7 +275,7 @@ func (e *Editor) Layout(gtx *layout.Context) {
 	stack.Pop()
 
 	baseline := e.padTop + e.dims.Baseline
-	pointerPadding := gtx.Px(ui.Dp(4))
+	pointerPadding := gtx.Px(unit.Dp(4))
 	r := image.Rectangle{Max: e.viewSize}
 	r.Min.X -= pointerPadding
 	r.Min.Y -= pointerPadding
@@ -563,7 +563,7 @@ func (e *Editor) moveEnd() {
 	e.carXOff = l.Width + a - x
 }
 
-func (e *Editor) scrollToCaret(c ui.Config) {
+func (e *Editor) scrollToCaret(c unit.Converter) {
 	carWidth := e.caretWidth(c)
 	carLine, _, x, y := e.layoutCaret()
 	l := e.lines[carLine]

text/shape/measure.go

@@ -14,7 +14,7 @@ import (
 	"gioui.org/op"
 	"gioui.org/op/paint"
 	"gioui.org/text"
-	"gioui.org/ui"
+	"gioui.org/unit"
 	"golang.org/x/image/font"
 	"golang.org/x/image/font/sfnt"
 	"golang.org/x/image/math/fixed"
@@ -22,7 +22,7 @@ import (
 
 // Faces is a cache of text layouts and paths.
 type Faces struct {
-	config      ui.Config
+	config      unit.Converter
 	faceCache   map[faceKey]*Face
 	layoutCache map[layoutKey]cachedLayout
 	pathCache   map[pathKey]cachedPath
@@ -53,19 +53,19 @@ type pathKey struct {
 
 type faceKey struct {
 	font *sfnt.Font
-	size ui.Value
+	size unit.Value
 }
 
 // Face is a cached implementation of text.Face.
 type Face struct {
 	faces *Faces
-	size  ui.Value
+	size  unit.Value
 	font  *opentype
 }
 
 // Reset the cache, discarding any measures or paths that
 // haven't been used since the last call to Reset.
-func (f *Faces) Reset(c ui.Config) {
+func (f *Faces) Reset(c unit.Converter) {
 	f.config = c
 	f.init()
 	for pk, p := range f.pathCache {
@@ -87,7 +87,7 @@ func (f *Faces) Reset(c ui.Config) {
 }
 
 // For returns a Face for the given font and size.
-func (f *Faces) For(fnt *sfnt.Font, size ui.Value) *Face {
+func (f *Faces) For(fnt *sfnt.Font, size unit.Value) *Face {
 	f.init()
 	fk := faceKey{fnt, size}
 	if f, exist := f.faceCache[fk]; exist {

ui/doc.go

@@ -1,25 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-/*
-Package ui defines operations buffers, units and common operations
-for GUI programs written with the Gio module.
-
-Units
-
-A Value is a value with a Unit attached.
-
-Device independent pixel, or dp, is the unit for sizes independent of
-the underlying display device.
-
-Scaled pixels, or sp, is the unit for text sizes. An sp is like dp with
-text scaling applied.
-
-Finally, pixels, or px, is the unit for display dependent pixels. Their
-size vary between platforms and displays.
-
-To maintain a constant visual size across platforms and displays, always
-use dps or sps to define user interfaces. Only use pixels for derived
-values.
-
-*/
-package ui

ui/ui.go

@@ -1,16 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-package ui
-
-import (
-	"time"
-)
-
-// Config define the essential properties of
-// the environment.
-type Config interface {
-	// Now returns the current animation time.
-	Now() time.Time
-	// Px converts a Value to pixels.
-	Px(v Value) int
-}

unit/unit.go

@@ -1,6 +1,26 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package ui
+/*
+
+Package unit implements device independent units and values.
+
+A Value is a value with a Unit attached.
+
+Device independent pixel, or dp, is the unit for sizes independent of
+the underlying display device.
+
+Scaled pixels, or sp, is the unit for text sizes. An sp is like dp with
+text scaling applied.
+
+Finally, pixels, or px, is the unit for display dependent pixels. Their
+size vary between platforms and displays.
+
+To maintain a constant visual size across platforms and displays, always
+use dps or sps to define user interfaces. Only use pixels for derived
+values.
+
+*/
+package unit
 
 import "fmt"
 
@@ -13,6 +33,11 @@ type Value struct {
 // Unit represents a unit for a Value.
 type Unit uint8
 
+// Converter converts Values to pixels.
+type Converter interface {
+	Px(v Value) int
+}
+
 const (
 	// UnitPx represent device pixels in the resolution of
 	// the underlying display.
@@ -59,7 +84,7 @@ func (u Unit) String() string {
 }
 
 // Add a list of Values.
-func Add(c Config, values ...Value) Value {
+func Add(c Converter, values ...Value) Value {
 	var sum Value
 	for _, v := range values {
 		sum, v = compatible(c, sum, v)
@@ -69,7 +94,7 @@ func Add(c Config, values ...Value) Value {
 }
 
 // Max returns the maximum of a list of Values.
-func Max(c Config, values ...Value) Value {
+func Max(c Converter, values ...Value) Value {
 	var max Value
 	for _, v := range values {
 		max, v = compatible(c, max, v)
@@ -80,7 +105,7 @@ func Max(c Config, values ...Value) Value {
 	return max
 }
 
-func compatible(c Config, v1, v2 Value) (Value, Value) {
+func compatible(c Converter, v1, v2 Value) (Value, Value) {
 	if v1.U == v2.U {
 		return v1, v2
 	}

widget/image.go

@@ -9,7 +9,7 @@ import (
 	"gioui.org/f32"
 	"gioui.org/layout"
 	"gioui.org/op/paint"
-	"gioui.org/ui"
+	"gioui.org/unit"
 )
 
 // Image is a widget that displays an image.
@@ -31,7 +31,7 @@ func (im Image) Layout(gtx *layout.Context) {
 	var w, h int
 	if im.Scale == 0 {
 		const dpPrPx = 160 / 72
-		w, h = gtx.Px(ui.Dp(wf*dpPrPx)), gtx.Px(ui.Dp(hf*dpPrPx))
+		w, h = gtx.Px(unit.Dp(wf*dpPrPx)), gtx.Px(unit.Dp(hf*dpPrPx))
 	} else {
 		w, h = int(wf*im.Scale+.5), int(hf*im.Scale+.5)
 	}