Extract a private helper function preserveSelection

The operation around which the selection should be preserved is passed
in so that it can be reused for different purposes.

pkg/gui/filetree/file_tree_view_model.go

@@ -167,6 +167,25 @@ func (self *FileTreeViewModel) SetStatusFilter(filter FileTreeDisplayFilter) {
 	self.IListCursor.SetSelection(0)
 }
 
+func (self *FileTreeViewModel) preserveSelection(f func()) {
+	selectedNode := self.GetSelected()
+	var selectedPath string
+	if selectedNode != nil {
+		selectedPath = selectedNode.GetInternalPath()
+	}
+
+	f()
+
+	if selectedPath != "" {
+		self.ExpandToPath(selectedPath)
+		if idx, found := self.GetIndexForPath(selectedPath); found {
+			self.SetSelection(idx)
+			return
+		}
+	}
+	self.ClampSelection()
+}
+
 // If we're going from flat to tree we want to select the same file.
 // If we're going from tree to flat and we have a file selected we want to select that.
 // If instead we've selected a directory we need to select the first file in that directory.
@@ -233,22 +252,9 @@ func (self *FileTreeViewModel) GetFilter() string {
 }
 
 func (self *FileTreeViewModel) ClearFilter() {
-	selectedNode := self.GetSelected()
-	var selectedPath string
-	if selectedNode != nil {
-		selectedPath = selectedNode.GetInternalPath()
-	}
-
-	self.IFileTree.SetTextFilter("", false)
-
-	if selectedPath != "" {
-		self.ExpandToPath(selectedPath)
-		if idx, found := self.GetIndexForPath(selectedPath); found {
-			self.SetSelection(idx)
-			return
-		}
-	}
-	self.ClampSelection()
+	self.preserveSelection(func() {
+		self.IFileTree.SetTextFilter("", false)
+	})
 }
 
 func (self *FileTreeViewModel) ReApplyFilter(useFuzzySearch bool) {