Don't forward mouse events to nil items in Flex/Grid. Fixes #425

README.md

@@ -51,7 +51,7 @@ For a presentation highlighting this package, compile and run the program found
 
 ## Documentation
 
-Refer to https://godoc.org/github.com/rivo/tview for the package's documentation.
+Refer to https://pkg.go.dev/github.com/rivo/tview for the package's documentation.
 
 ## Dependencies
 

flex.go

@@ -211,6 +211,9 @@ func (f *Flex) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 
 		// Pass mouse events along to the first child item that takes it.
 		for _, item := range f.items {
+			if item.Item == nil {
+				continue
+			}
 			consumed, capture = item.Item.MouseHandler()(action, event, setFocus)
 			if consumed {
 				return

grid.go

@@ -670,6 +670,9 @@ func (g *Grid) MouseHandler() func(action MouseAction, event *tcell.EventMouse,
 
 		// Pass mouse events along to the first child item that takes it.
 		for _, item := range g.items {
+			if item.Item == nil {
+				continue
+			}
 			consumed, capture = item.Item.MouseHandler()(action, event, setFocus)
 			if consumed {
 				return