This should also be moved from the top-level

It's a simple type wrapped around a tree-walker, and this lets me
shorten the name I use to refer to it, too.

noroot.go → pkg/noroot/noroot.go

@@ -2,7 +2,7 @@
 // code is governed by the MIT license that can be found in the LICENSE
 // file.
 
-package termshark
+package noroot
 
 import (
 	"github.com/gcla/gowid/widgets/list"
@@ -11,22 +11,22 @@ import (
 
 //======================================================================
 
-type NoRootWalker struct {
+type Walker struct {
 	*tree.TreeWalker
 }
 
-func NewNoRootWalker(w *tree.TreeWalker) *NoRootWalker {
-	return &NoRootWalker{
+func NewWalker(w *tree.TreeWalker) *Walker {
+	return &Walker{
 		TreeWalker: w,
 	}
 }
 
 // for omitting top level node
-func (f *NoRootWalker) Next(pos list.IWalkerPosition) list.IWalkerPosition {
+func (f *Walker) Next(pos list.IWalkerPosition) list.IWalkerPosition {
 	return tree.WalkerNext(f, pos)
 }
 
-func (f *NoRootWalker) Previous(pos list.IWalkerPosition) list.IWalkerPosition {
+func (f *Walker) Previous(pos list.IWalkerPosition) list.IWalkerPosition {
 	fc := pos.(tree.IPos)
 	pp := tree.PreviousPosition(fc, f.Tree())
 	if pp.Equal(tree.NewPos()) {

ui/ui.go

@@ -48,6 +48,7 @@ import (
 	"github.com/gcla/termshark/v2"
 	"github.com/gcla/termshark/v2/configs/profiles"
 	"github.com/gcla/termshark/v2/pkg/fields"
+	"github.com/gcla/termshark/v2/pkg/noroot"
 	"github.com/gcla/termshark/v2/pkg/pcap"
 	"github.com/gcla/termshark/v2/pkg/pdmltree"
 	"github.com/gcla/termshark/v2/pkg/psmlmodel"
@@ -2630,7 +2631,7 @@ func setPacketListWidgets(psml iPsmlInfo, app gowid.IApp) {
 
 func expandStructWidgetAtPosition(row int, pos int, app gowid.IApp) {
 	if curPacketStructWidget != nil {
-		walker := curPacketStructWidget.Walker().(*termshark.NoRootWalker)
+		walker := curPacketStructWidget.Walker().(*noroot.Walker)
 		curTree := walker.Tree().(*pdmltree.Model)
 
 		finalPos := make([]int, 0)
@@ -2812,7 +2813,7 @@ func getStructWidgetToDisplay(row int, app gowid.IApp) gowid.IWidget {
 			tree.NewCachingMaker(tree.WidgetMakerFunction(makeStructNodeWidget)),
 			tree.NewCachingDecorator(tree.DecoratorFunction(makeStructNodeDecoration)))
 		// Without the caching layer, clicking on a button has no effect
-		walker := termshark.NewNoRootWalker(rwalker)
+		walker := noroot.NewWalker(rwalker)
 
 		// Send the layers represents the tree expansion to hex.
 		// This could be the user clicking inside the tree. Or it might be the position changing