joejulian/gio
1
0
Fork 1
mirror of https://git.sr.ht/~eliasnaur/gio synced 2026-07-05 17:35:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

ui/layout: introduce Context

Browse Source 
Context keeps the current Constraints and Dimensions so the layout
function scopes don't have to.

With

	ctx := new(layout.Context)

a label with margins and alignment goes from

	return al.Layout(ops, cs, func(cs layout.Constraints) layout.Dimensions {
		in := layout.Inset{...}
		return in.Layout(c, ops, cs, func(cs layout.Constraints) layout.Dimensions {
			return text.Label{...}.Layout(ops, cs)
		})
	})

to

	al.Layout(ops, ctx, func() {
		in := layout.Inset{...}
		in.Layout(c, ops, ctx, func() {
		       text.Label{...}.Layout(ops, ctx)
		})
	})

It was a difficult trade-off between the verbose functional approach
and the shorter but more complex Context.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit is contained in:
Elias Naur
2019-09-24 19:06:07 +02:00
parent 64add13d28
commit ce9bcee62b
9 changed files with 126 additions and 89 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ui/layout/flex.go
+18 -13
View File
@@ -20,9 +20,9 @@ type Flex struct {
// Alignment is the alignment in the cross axis.
Alignment Alignment
ctx *Context
macro ui.MacroOp
ops *ui.Ops
cs Constraints
mode flexMode
size int
rigidSize int
@@ -69,13 +69,13 @@ const (
)
// Init must be called before Rigid or Flexible.
func (f *Flex) Init(ops *ui.Ops, cs Constraints) *Flex {
func (f *Flex) Init(ops *ui.Ops, ctx *Context) *Flex {
if f.mode > modeBegun {
panic("must End the current child before calling Init again")
}
f.mode = modeBegun
f.ops = ops
f.cs = cs
f.ctx = ctx
f.size = 0
f.rigidSize = 0
f.maxCross = 0
@@ -98,20 +98,23 @@ func (f *Flex) begin(mode flexMode) {
// from 0 to the remaining space.
func (f *Flex) Rigid(w Widget) FlexChild {
f.begin(modeRigid)
mainc := axisMainConstraint(f.Axis, f.cs)
cs := f.ctx.Constraints
mainc := axisMainConstraint(f.Axis, cs)
mainMax := mainc.Max - f.size
if mainMax < 0 {
mainMax = 0
}
cs := axisConstraints(f.Axis, Constraint{Max: mainMax}, axisCrossConstraint(f.Axis, f.cs))
return f.end(w(cs))
cs = axisConstraints(f.Axis, Constraint{Max: mainMax}, axisCrossConstraint(f.Axis, cs))
dims := f.ctx.Layout(cs, w)
return f.end(dims)
}
// Flexible is like Rigid, where the main axis size is also constrained to a
// fraction of the space not taken up by Rigid children.
func (f *Flex) Flexible(weight float32, w Widget) FlexChild {
f.begin(modeFlex)
mainc := axisMainConstraint(f.Axis, f.cs)
cs := f.ctx.Constraints
mainc := axisMainConstraint(f.Axis, cs)
var flexSize int
if mainc.Max > f.size {
flexSize = mainc.Max - f.rigidSize
@@ -125,8 +128,9 @@ func (f *Flex) Flexible(weight float32, w Widget) FlexChild {
}
}
submainc := Constraint{Max: flexSize}
cs := axisConstraints(f.Axis, submainc, axisCrossConstraint(f.Axis, f.cs))
return f.end(w(cs))
cs = axisConstraints(f.Axis, submainc, axisCrossConstraint(f.Axis, cs))
dims := f.ctx.Layout(cs, w)
return f.end(dims)
}
// End a child by specifying its dimensions. Pass the returned layout result
@@ -153,9 +157,10 @@ func (f *Flex) end(dims Dimensions) FlexChild {
// Layout a list of children. The order of the children determines their laid
// out order.
func (f *Flex) Layout(children ...FlexChild) Dimensions {
mainc := axisMainConstraint(f.Axis, f.cs)
crossSize := axisCrossConstraint(f.Axis, f.cs).Constrain(f.maxCross)
func (f *Flex) Layout(children ...FlexChild) {
cs := f.ctx.Constraints
mainc := axisMainConstraint(f.Axis, cs)
crossSize := axisCrossConstraint(f.Axis, cs).Constrain(f.maxCross)
var space int
if mainc.Min > f.size {
space = mainc.Min - f.size
@@ -220,7 +225,7 @@ func (f *Flex) Layout(children ...FlexChild) Dimensions {
if baseline == 0 {
baseline = sz.Y
}
return Dimensions{Size: sz, Baseline: baseline}
f.ctx.Dimensions = Dimensions{Size: sz, Baseline: baseline}
}
func axisPoint(a Axis, main, cross int) image.Point {