zntg/ui/stackpanel.go
Sander Schobers 67658d3bee Added key event.
Some small additions/changes.
2019-04-10 21:23:56 +02:00

86 lines
2.0 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) Arrange(ctx Context, bounds geom.RectangleF32, offset geom.PointF32) {
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))
if geom.IsNaN32(size.Y) {
stretch++
} else {
length += size.Y
}
desired[i] = size
}
var remainder = bounds.Dy() - length
var childOffset float32
for i, size := range desired {
var height = size.Y
if geom.IsNaN32(size.Y) {
if remainder < 0 {
height = 0
} else {
height = remainder / float32(stretch)
}
}
var child = geom.RectF32(bounds.Min.X, bounds.Min.Y+childOffset, bounds.Max.X, bounds.Min.Y+childOffset+height)
p.Children[i].Arrange(ctx, p.Orientation.FlipRect(child), offset)
childOffset += height
}
p.ControlBase.Arrange(ctx, p.Orientation.FlipRect(bounds), offset)
}
func (p *StackPanel) DesiredSize(ctx Context) geom.PointF32 {
var length float32
var width float32
for _, child := range p.Children {
var size = child.DesiredSize(ctx)
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 {
continue
}
child.Render(ctx)
}
}