zntg/ui/stackpanel.go

129 lines
3.1 KiB
Go

package ui
import (
"opslag.de/schobers/geom"
)
type StackPanel struct {
ContainerBase
Orientation Orientation
}
func BuildStackPanel(o Orientation, fn func(*StackPanel)) *StackPanel {
var p = &StackPanel{Orientation: o}
if fn != nil {
fn(p)
}
return p
}
func (p *StackPanel) preArrange(ctx Context, bounds geom.RectangleF32, clip bool) []geom.RectangleF32 {
bounds = p.Orientation.FlipRect(bounds)
var length float32
var stretch int
var desired = make([]geom.PointF32, len(p.Children))
for i, child := range p.Children {
var size = p.Orientation.FlipPt(child.DesiredSize(ctx, p.Orientation.FlipPt(bounds.Size())))
if geom.IsNaN32(size.Y) {
stretch++
} else {
length += size.Y
}
desired[i] = size
}
var remainder = bounds.Dy() - length
var childOffset float32
childBounds := make([]geom.RectangleF32, 0, len(p.Children))
for _, size := range desired {
var height = size.Y
if geom.IsNaN32(size.Y) {
if remainder < 0 {
height = 0
} else {
height = remainder / float32(stretch)
}
}
minY := bounds.Min.Y + childOffset
maxY := minY + height
if clip {
if minY > bounds.Max.Y {
minY = bounds.Max.Y
}
if maxY > bounds.Max.Y {
maxY = bounds.Max.Y
}
}
var child = geom.RectF32(bounds.Min.X, minY, bounds.Max.X, maxY)
childBounds = append(childBounds, p.Orientation.FlipRect(child))
childOffset += height
}
return childBounds
}
func (p *StackPanel) Arrange(ctx Context, bounds geom.RectangleF32, offset geom.PointF32, parent Control) {
childBounds := p.preArrange(ctx, bounds, true)
for i := range p.Children {
p.Children[i].Arrange(ctx, p.Orientation.FlipRect(childBounds[i]), offset, p)
}
p.ControlBase.Arrange(ctx, p.Orientation.FlipRect(bounds), offset, parent)
}
func (p *StackPanel) BoundsUnclipped(ctx Context, path ControlPath) geom.RectangleF32 {
if len(path) == 0 {
return p.bounds
}
next := path[0]
childBounds := p.preArrange(ctx, p.bounds, false)
for i, child := range p.Children {
if child != next && next.Self() != child.Self() {
continue
}
return childBounds[i]
}
panic("child not found in path")
}
func (p *StackPanel) DesiredSize(ctx Context, size geom.PointF32) geom.PointF32 {
var length float32
var width float32
for _, child := range p.Children {
var size = child.DesiredSize(ctx, size)
var l, w = p.Orientation.LengthParallel(size), p.Orientation.LengthPerpendicular(size)
if geom.IsNaN32(l) {
length = l
} else {
if !geom.IsNaN32(length) {
length += l
}
}
if geom.IsNaN32(w) {
width = w
} else {
if !geom.IsNaN32(width) {
width = geom.Max32(width, w)
}
}
}
return p.Orientation.Pt(length, width)
}
func (p *StackPanel) Render(ctx Context) {
p.RenderBackground(ctx)
var bounds = p.Bounds()
for _, child := range p.Children {
var childB = child.Bounds()
if childB.Min.X >= bounds.Max.X || childB.Min.Y >= bounds.Max.Y || childB.Max.X < bounds.Min.X || childB.Max.Y < bounds.Min.Y || childB.Max.X < 0 || childB.Max.Y < 0 {
continue
}
child.Render(ctx)
}
}
func (p *StackPanel) ScrollIntoView(ctx Context, path ControlPath) {
if p.parent == nil {
return
}
p.parent.ScrollIntoView(ctx, path.Prepend(p))
}