ppforge/internal/ui/flowlayout.go

package ui

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/theme"
)

type FlowLayout struct {
	LastKnownParentSize fyne.Size
	LastMinDimensions   fyne.Size
}

func NewFlowLayout(o ...fyne.CanvasObject) fyne.Layout {
	f := &FlowLayout{}
	return f
}

// MinSize is a kind of boogie function for the flow layout.
func (fl *FlowLayout) MinSize(objects []fyne.CanvasObject) fyne.Size {
	return fl.LastMinDimensions
}

func getMinHeight(objects []fyne.CanvasObject) fyne.Size {
	ret := fyne.NewSize(0, 0)
	for _, v := range objects {
		if v.MinSize().Height > ret.Height {
			ret.Height = v.MinSize().Height
		}
	}
	return ret
}

/*func getAvgWidth(objects []fyne.CanvasObject) fyne.Size {
	ret := fyne.NewSize(0, 0)
	for _, v := range objects {
		ret.Width += v.MinSize().Width
	}
	ret.Width = ret.Width / float32(len(objects))
	return ret
}*/
// Layout arranges the objects according to the flow
func (fl *FlowLayout) Layout(objects []fyne.CanvasObject, size fyne.Size) {
	fl.LastKnownParentSize = size
	i, x, y, w := 0, float32(0), float32(0), float32(0)
	lastRowEnd := 0
	for _, child := range objects {
		if !child.Visible() {
			continue
		}
		if x+child.MinSize().Width > size.Width {
			w = x
			x = 0
			y += getMinHeight(objects[lastRowEnd:i]).Height + theme.Padding()
			lastRowEnd = i
		}

		child.Move(fyne.NewPos(x, y))
		child.Resize(child.MinSize())
		x += child.MinSize().Width + theme.Padding()
		i++
	}
	y += getMinHeight(objects[lastRowEnd:i]).Height + theme.Padding()
	fl.LastMinDimensions = fyne.NewSize(w/2, y)
}