Make window scroll in Go with GXUI -

i trying add scroll bars application windows in go using gxui.

say have code:

package main  import (     "fmt"      "github.com/google/gxui"     "github.com/google/gxui/drivers/gl"     "github.com/google/gxui/samples/flags"     "github.com/google/gxui/themes/dark" )  func appmain(driver gxui.driver) {     theme := dark.createtheme(driver)      window := theme.createwindow(800, 600, "grid")     window.setscale(flags.defaultscalefactor)     window.onclose(driver.terminate)      row := theme.createlinearlayout()     row.setdirection(gxui.lefttoright)     c := 0; c < 4; c++ {         col := theme.createlinearlayout()         col.setdirection(gxui.toptobottom)         r := 0; r < 100; r++ {             cell := theme.createlabel()             cell.settext(fmt.sprintf("%d", r*4+c))             col.addchild(cell)         }         row.addchild(col)     }      window.addchild(row) }  func main() {     gl.startdriver(appmain) } 

when run it, window:

how can window have scroll bar can view of lines?

i wasn't able scrolllayout, can propose variant on basis of examples github.

package main  import (     "fmt"     "github.com/google/gxui"     "github.com/google/gxui/drivers/gl"     "github.com/google/gxui/math"     "github.com/google/gxui/samples/flags"     "github.com/google/gxui/themes/dark" )  type customadapter struct {     gxui.adapterbase }  func (a *customadapter) count() int {     return 1000 }  func (a *customadapter) itemat(index int) gxui.adapteritem {     return index }  func (a *customadapter) itemindex(item gxui.adapteritem) int {     return item.(int) }  func (a *customadapter) size(theme gxui.theme) math.size {     return math.size{w: 200, h: 25} }  func (a *customadapter) create(theme gxui.theme, index int) gxui.control {      layout1 := theme.createlinearlayout()     layout1.setdirection(gxui.lefttoright)     c := 0; c < 4; c++ {         col := theme.createlinearlayout()         col.setdirection(gxui.toptobottom)         cell := theme.createlabel()         cell.settext(fmt.sprintf("%d", index*4+c))         col.addchild(cell)         layout1.addchild(col)     }     return layout1 }  func appmain(driver gxui.driver) {     theme := dark.createtheme(driver)     window := theme.createwindow(600, 400, "grid")     window.borderpen()     window.setscale(flags.defaultscalefactor)     window.onclose(driver.terminate)     adapter := &customadapter{}     list := theme.createlist()     list.setadapter(adapter)     list.setorientation(gxui.vertical)     window.addchild(list) }  func main() {     gl.startdriver(appmain) } 

each line placed in list,their number , size specified in overridden methods. advantage in list have scrollbar.