Method CreateLayoutItem

scrollview.go:304–369

(ctx *LayoutContext)

}

func (sv *ScrollView) CreateLayoutItem(ctx *LayoutContext) LayoutItem {
	svli := new(scrollViewLayoutItem)
	svli.ctx = ctx
	cli := CreateLayoutItemsForContainerWithContext(sv.composite, ctx)
	cli.AsLayoutItemBase().parent = svli
	svli.children = append(svli.children, cli)

	if box, ok := cli.(*boxLayoutItem); ok {
		if len(box.children) > 0 {
			if _, ok := box.children[len(box.children)-1].(*spacerLayoutItem); !ok {
				// To retain the previous behavior with box layouts, we add a fake spacer at the end.
				// Maybe this should just be an option.
				box.children = append(box.children, &spacerLayoutItem{
					LayoutItemBase: LayoutItemBase{ctx: ctx},
					layoutFlags:    ShrinkableHorz | ShrinkableVert | GrowableVert | GreedyVert,
				})
			}
		}
	}

	svli.idealSize = cli.MinSize()

	h, v := sv.Scrollbars()

	if h {
		svli.layoutFlags |= ShrinkableHorz | GrowableHorz | GreedyHorz

		if !v {
			maxSize := SizeFrom96DPI(sv.maxSize96dpi, ctx.dpi)
			if svli.idealSize.Width > sv.geometry.ClientSize.Width && sv.geometry.ClientSize.Width > 0 && maxSize.Width == 0 ||
				svli.idealSize.Width > maxSize.Width && maxSize.Width > 0 {
				svli.sbSize.Height = int(win.GetSystemMetricsForDpi(win.SM_CYHSCROLL, uint32(ctx.dpi)))
				svli.idealSize.Height += svli.sbSize.Height
			}

			svli.minSize.Height = svli.idealSize.Height
		}
	}

	if v {
		svli.layoutFlags |= GreedyVert | GrowableVert | ShrinkableVert

		if !h {
			maxSize := SizeFrom96DPI(sv.maxSize96dpi, ctx.dpi)
			if svli.idealSize.Height > sv.geometry.ClientSize.Height && sv.geometry.ClientSize.Height > 0 && maxSize.Height == 0 ||
				svli.idealSize.Height > maxSize.Height && maxSize.Height > 0 {
				svli.sbSize.Width = int(win.GetSystemMetricsForDpi(win.SM_CXVSCROLL, uint32(ctx.dpi)))
				svli.idealSize.Width += svli.sbSize.Width
			}

			svli.minSize.Width = svli.idealSize.Width
		}
	}

	var si win.SCROLLINFO
	si.CbSize = uint32(unsafe.Sizeof(si))
	si.FMask = win.SIF_POS | win.SIF_RANGE