io/system,widget/material: add decorations

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>
This commit is contained in:
Pierre Curto
2022-01-21 17:17:18 +01:00
committed by Elias Naur
parent 0010ec1389
commit 2cf7c5b949
2 changed files with 409 additions and 0 deletions
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package system
import (
"strings"
"gioui.org/io/pointer"
)
// Action is a set of window decoration actions.
type Action uint
const (
// ActionMinimize minimizes a window.
ActionMinimize Action = 1 << iota
// ActionMaximize maximizes a window.
ActionMaximize
// ActionUnmaximize restores a maximized window.
ActionUnmaximize
// ActionFullscreen makes a window fullscreen.
ActionFullscreen
// ActionClose closes a window.
ActionClose
// ActionMove moves a window directed by the user.
ActionMove
// ActionResizeNorth resizes the top border of a window (directed by the user).
ActionResizeNorth
// ActionResizeSouth resizes the bottom border of a window (directed by the user).
ActionResizeSouth
// ActionResizeWest resizes the right border of a window (directed by the user).
ActionResizeWest
// ActionResizeEast resizes the left border of a window (directed by the user).
ActionResizeEast
// ActionResizeNorthWest resizes the top-left corner of a window (directed by the user).
ActionResizeNorthWest
// ActionResizeSouthWest resizes the bottom-left corner of a window (directed by the user).
ActionResizeSouthWest
// ActionResizeNorthEast resizes the top-right corner of a window (directed by the user).
ActionResizeNorthEast
// ActionResizeSouthEast resizes the bottom-right corner of a window (directed by the user).
ActionResizeSouthEast
)
// CursorName returns the cursor for the action.
// It must be a single action otherwise the default
// cursor is returned.
func (a Action) CursorName() pointer.CursorName {
switch a {
case ActionResizeNorthWest:
return pointer.CursorTopLeftResize
case ActionResizeSouthEast:
return pointer.CursorBottomRightResize
case ActionResizeNorthEast:
return pointer.CursorTopRightResize
case ActionResizeSouthWest:
return pointer.CursorBottomLeftResize
case ActionResizeWest:
return pointer.CursorLeftResize
case ActionResizeEast:
return pointer.CursorRightResize
case ActionResizeNorth:
return pointer.CursorTopResize
case ActionResizeSouth:
return pointer.CursorBottomResize
}
return pointer.CursorDefault
}
func (a Action) String() string {
var buf strings.Builder
for b := Action(1); a != 0; b <<= 1 {
if a&b != 0 {
if buf.Len() > 0 {
buf.WriteByte('|')
}
buf.WriteString(b.string())
a &^= b
}
}
return buf.String()
}
func (a Action) string() string {
switch a {
case ActionMinimize:
return "ActionMinimize"
case ActionMaximize:
return "ActionMaximize"
case ActionUnmaximize:
return "ActionUnmaximize"
case ActionClose:
return "ActionClose"
case ActionMove:
return "ActionMove"
case ActionResizeNorth:
return "ActionResizeNorth"
case ActionResizeSouth:
return "ActionResizeSouth"
case ActionResizeWest:
return "ActionResizeWest"
case ActionResizeEast:
return "ActionResizeEast"
case ActionResizeNorthWest:
return "ActionResizeNorthWest"
case ActionResizeSouthWest:
return "ActionResizeSouthWest"
case ActionResizeNorthEast:
return "ActionResizeNorthEast"
case ActionResizeSouthEast:
return "ActionResizeSouthEast"
}
return ""
}
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package material
import (
"image"
"image/color"
"math/bits"
"gioui.org/f32"
"gioui.org/gesture"
"gioui.org/io/pointer"
"gioui.org/io/system"
"gioui.org/layout"
"gioui.org/op"
"gioui.org/op/clip"
"gioui.org/op/paint"
"gioui.org/unit"
"gioui.org/widget"
)
// DecorationsStyle provides the style elements for Decorations.
type DecorationsStyle struct {
Actions system.Action
Title LabelStyle
Background color.NRGBA
Foreground color.NRGBA
}
// Decorate a window.
func Decorate(th *Theme, actions system.Action) DecorationsStyle {
titleStyle := Body1(th, "")
titleStyle.Color = th.Palette.ContrastFg
return DecorationsStyle{
Actions: actions,
Title: titleStyle,
Background: th.Palette.ContrastBg,
Foreground: th.Palette.ContrastFg,
}
}
// Decorations provides window decorations.
type Decorations struct {
DecorationsStyle
actions struct {
layout.List
clicks []widget.Clickable
move gesture.Drag
resize [8]struct {
gesture.Hover
gesture.Drag
}
}
actioned system.Action
path clip.Path
maximized bool
}
// Decorate a window with the title and actions defined in DecorationsStyle.
// The space used by the decorations is returned as an inset for the window
// content.
func (d *Decorations) Decorate(gtx layout.Context, title string) layout.Inset {
rec := op.Record(gtx.Ops)
dims := d.layoutDecorations(gtx, title)
decos := rec.Stop()
r := clip.Rect{Max: dims.Size}
paint.FillShape(gtx.Ops, d.DecorationsStyle.Background, r.Op())
decos.Add(gtx.Ops)
d.layoutResizing(gtx)
return layout.Inset{
Top: unit.Px(float32(dims.Size.Y)),
}
}
func (d *Decorations) layoutResizing(gtx layout.Context) {
cs := gtx.Constraints.Min
wh := gtx.Px(unit.Dp(10))
s := []struct {
system.Action
image.Rectangle
}{
{system.ActionResizeNorth, image.Rect(0, 0, cs.X, wh)},
{system.ActionResizeSouth, image.Rect(0, cs.Y-wh, cs.X, cs.Y)},
{system.ActionResizeWest, image.Rect(cs.X-wh, 0, cs.X, cs.Y)},
{system.ActionResizeEast, image.Rect(0, 0, wh, cs.Y)},
{system.ActionResizeNorthWest, image.Rect(0, 0, wh, wh)},
{system.ActionResizeSouthWest, image.Rect(cs.X-wh, 0, cs.X, wh)},
{system.ActionResizeNorthEast, image.Rect(0, cs.Y-wh, wh, cs.Y)},
{system.ActionResizeSouthEast, image.Rect(cs.X-wh, cs.Y-wh, cs.X, cs.Y)},
}
for i, data := range s {
action := data.Action
if d.DecorationsStyle.Actions&action == 0 {
continue
}
rsz := &d.actions.resize[i]
rsz.Events(gtx.Metric, gtx, gesture.Both)
if rsz.Drag.Dragging() {
d.actioned |= action
}
st := clip.Rect(data.Rectangle).Push(gtx.Ops)
if rsz.Hover.Hovered(gtx) {
pointer.CursorNameOp{Name: action.CursorName()}.Add(gtx.Ops)
}
rsz.Drag.Add(gtx.Ops)
pass := pointer.PassOp{}.Push(gtx.Ops)
rsz.Hover.Add(gtx.Ops)
pass.Pop()
st.Pop()
}
}
func (d *Decorations) layoutDecorations(gtx layout.Context, title string) layout.Dimensions {
gtx.Constraints.Min.Y = 0
inset := layout.UniformInset(unit.Dp(10))
return layout.Flex{
Axis: layout.Horizontal,
Alignment: layout.Middle,
Spacing: layout.SpaceBetween,
}.Layout(gtx,
layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
d.DecorationsStyle.Title.Text = title
dims := inset.Layout(gtx, d.DecorationsStyle.Title.Layout)
if d.DecorationsStyle.Actions&system.ActionMove != 0 {
d.actions.move.Events(gtx.Metric, gtx, gesture.Both)
st := clip.Rect{Max: dims.Size}.Push(gtx.Ops)
d.actions.move.Add(gtx.Ops)
if d.actions.move.Pressed() {
d.actioned |= system.ActionMove
}
st.Pop()
}
return dims
}),
layout.Rigid(func(gtx layout.Context) layout.Dimensions {
// Remove the unmaximize action as it is taken care of by maximize.
actions := d.DecorationsStyle.Actions &^ system.ActionUnmaximize
an := bits.OnesCount(uint(actions))
if n := len(d.actions.clicks); n < an {
d.actions.clicks = append(d.actions.clicks, make([]widget.Clickable, an-n)...)
}
return d.actions.Layout(gtx, an, func(gtx layout.Context, idx int) layout.Dimensions {
action := system.Action(1 << idx)
var w layout.Widget
switch actions & action {
case system.ActionMinimize:
w = d.minimizeWindow
case system.ActionMaximize:
if d.maximized {
w = d.maximizedWindow
} else {
w = d.maximizeWindow
}
case system.ActionClose:
w = d.closeWindow
default:
return layout.Dimensions{}
}
click := &d.actions.clicks[idx]
if click.Clicked() {
if action == system.ActionMaximize {
if d.maximized {
d.maximized = false
d.actioned |= system.ActionUnmaximize
} else {
d.maximized = true
d.actioned |= system.ActionMaximize
}
} else {
d.actioned |= action
}
}
return Clickable(gtx, click, func(gtx layout.Context) layout.Dimensions {
return inset.Layout(gtx, w)
})
})
}),
)
}
// Perform updates the decorations as if the specified actions were
// performed by the user.
func (d *Decorations) Perform(actions system.Action) {
if actions&system.ActionMaximize != 0 {
d.maximized = true
}
if actions&(system.ActionUnmaximize|system.ActionMinimize|system.ActionFullscreen) != 0 {
d.maximized = false
}
}
// Actions returns the set of actions activated by the user.
func (d *Decorations) Actions() system.Action {
a := d.actioned
d.actioned = 0
return a
}
var (
winIconSize = unit.Dp(20)
winIconMargin = unit.Dp(4)
winIconStroke = unit.Dp(2)
)
// minimizeWindows draws a line icon representing the minimize action.
func (d *Decorations) minimizeWindow(gtx layout.Context) layout.Dimensions {
paint.ColorOp{Color: d.DecorationsStyle.Foreground}.Add(gtx.Ops)
size := gtx.Px(winIconSize)
size32 := float32(size)
margin := float32(gtx.Px(winIconMargin))
width := float32(gtx.Px(winIconStroke))
p := &d.path
p.Begin(gtx.Ops)
p.MoveTo(f32.Point{X: margin, Y: size32 - margin})
p.LineTo(f32.Point{X: size32 - 2*margin, Y: size32 - margin})
st := clip.Stroke{
Path: p.End(),
Width: width,
}.Op().Push(gtx.Ops)
paint.PaintOp{}.Add(gtx.Ops)
st.Pop()
return layout.Dimensions{Size: image.Pt(size, size)}
}
// maximizeWindow draws a rectangle representing the maximize action.
func (d *Decorations) maximizeWindow(gtx layout.Context) layout.Dimensions {
paint.ColorOp{Color: d.DecorationsStyle.Foreground}.Add(gtx.Ops)
size := gtx.Px(winIconSize)
size32 := float32(size)
margin := float32(gtx.Px(winIconMargin))
width := float32(gtx.Px(winIconStroke))
r := clip.RRect{
Rect: f32.Rect(margin, margin, size32-margin, size32-margin),
}
st := clip.Stroke{
Path: r.Path(gtx.Ops),
Width: width,
}.Op().Push(gtx.Ops)
paint.PaintOp{}.Add(gtx.Ops)
st.Pop()
r.Rect.Max = f32.Pt(size32-margin, 2*margin)
st = clip.Outline{
Path: r.Path(gtx.Ops),
}.Op().Push(gtx.Ops)
paint.PaintOp{}.Add(gtx.Ops)
st.Pop()
return layout.Dimensions{Size: image.Pt(size, size)}
}
// maximizedWindow draws interleaved rectangles representing the un-maximize action.
func (d *Decorations) maximizedWindow(gtx layout.Context) layout.Dimensions {
paint.ColorOp{Color: d.DecorationsStyle.Foreground}.Add(gtx.Ops)
size := gtx.Px(winIconSize)
size32 := float32(size)
margin := float32(gtx.Px(winIconMargin))
width := float32(gtx.Px(winIconStroke))
r := clip.RRect{
Rect: f32.Rect(margin, margin, size32-2*margin, size32-2*margin),
}
st := clip.Stroke{
Path: r.Path(gtx.Ops),
Width: width,
}.Op().Push(gtx.Ops)
paint.PaintOp{}.Add(gtx.Ops)
st.Pop()
r = clip.RRect{
Rect: f32.Rect(2*margin, 2*margin, size32-margin, size32-margin),
}
st = clip.Stroke{
Path: r.Path(gtx.Ops),
Width: width,
}.Op().Push(gtx.Ops)
paint.PaintOp{}.Add(gtx.Ops)
st.Pop()
return layout.Dimensions{Size: image.Pt(size, size)}
}
// closeWindow draws a cross representing the close action.
func (d *Decorations) closeWindow(gtx layout.Context) layout.Dimensions {
paint.ColorOp{Color: d.DecorationsStyle.Foreground}.Add(gtx.Ops)
size := gtx.Px(winIconSize)
size32 := float32(size)
margin := float32(gtx.Px(winIconMargin))
width := float32(gtx.Px(winIconStroke))
p := &d.path
p.Begin(gtx.Ops)
p.MoveTo(f32.Point{X: margin, Y: margin})
p.LineTo(f32.Point{X: size32 - margin, Y: size32 - margin})
p.MoveTo(f32.Point{X: size32 - margin, Y: margin})
p.LineTo(f32.Point{X: margin, Y: size32 - margin})
st := clip.Stroke{
Path: p.End(),
Width: width,
}.Op().Push(gtx.Ops)
paint.PaintOp{}.Add(gtx.Ops)
st.Pop()
return layout.Dimensions{Size: image.Pt(size, size)}
}