layout fixes and upgrades, add list hdr sort icon

ui/layouts/hboxcustompadding.go

@@ -2,6 +2,7 @@ package layouts
 
 import (
 	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/layout"
 	"fyne.io/fyne/v2/theme"
 )
 
@@ -12,47 +13,77 @@ type HboxCustomPadding struct {
 	DisableThemePad bool
 }
 
-func (v *HboxCustomPadding) MinSize(objects []fyne.CanvasObject) fyne.Size {
+func (*HboxCustomPadding) isSpacer(obj fyne.CanvasObject) bool {
+	if !obj.Visible() {
+		return false
+	}
+	if spacer, ok := obj.(layout.SpacerObject); ok {
+		return spacer.ExpandHorizontal()
+	}
+
+	return false
+}
+
+func (h *HboxCustomPadding) MinSize(objects []fyne.CanvasObject) fyne.Size {
 	minSize := fyne.NewSize(0, 0)
+	addPadding := false
+	padding := h.themePad() + h.ExtraPad
 	for _, child := range objects {
 		if !child.Visible() {
 			continue
 		}
+		if h.isSpacer(child) {
+			continue
+		}
 
 		minSize.Height = fyne.Max(child.MinSize().Height, minSize.Height)
 		minSize.Width += child.MinSize().Width
+		if addPadding {
+			minSize.Width += padding
+		}
+		addPadding = true
 	}
-	minSize.Width += (v.themePad() + v.ExtraPad) * float32(len(objects)-1)
 	return minSize
 }
 
-func (v *HboxCustomPadding) Layout(objects []fyne.CanvasObject, size fyne.Size) {
+func (h *HboxCustomPadding) Layout(objects []fyne.CanvasObject, size fyne.Size) {
+	spacers := 0
 	total := float32(0)
 	for _, child := range objects {
 		if !child.Visible() {
 			continue
 		}
+		if h.isSpacer(child) {
+			spacers++
+			continue
+		}
 		total += child.MinSize().Width
 	}
 
 	x, y := float32(0), float32(0)
-
-	padding := v.themePad() + v.ExtraPad
-	extra := float32(0)
+	padding := h.themePad() + h.ExtraPad
+	extra := size.Width - total - (padding * float32(len(objects)-spacers-1))
+	extraCell := float32(0)
+	if spacers > 0 {
+		extraCell = extra / float32(spacers)
+	}
 	for _, child := range objects {
 		if !child.Visible() {
 			continue
 		}
+
+		if h.isSpacer(child) {
+			x += extraCell
+		}
 		width := child.MinSize().Width
-		child.Move(fyne.NewPos(x+extra, y))
-		x += width
+		child.Move(fyne.NewPos(x, y))
 		child.Resize(fyne.NewSize(width, size.Height))
-		extra += padding
+		x += padding + width
 	}
 }
 
-func (v *HboxCustomPadding) themePad() float32 {
-	if v.DisableThemePad {
+func (h *HboxCustomPadding) themePad() float32 {
+	if h.DisableThemePad {
 		return 0
 	}
 	return theme.Padding()