Improve gutter messages

internal/display/bufwindow.go

@@ -67,6 +67,10 @@ func (w *BufWindow) SetActive(b bool) {
 	w.active = b
 }
 
+func (w *BufWindow) IsActive() bool {
+	return w.active
+}
+
 func (w *BufWindow) getStartInfo(n, lineN int) ([]byte, int, int, *tcell.Style) {
 	tabsize := util.IntOpt(w.Buf.Settings["tabsize"])
 	width := 0

internal/display/infowindow.go

@@ -63,6 +63,7 @@ func (i *InfoWindow) Relocate() bool   { return false }
 func (i *InfoWindow) GetView() *View   { return i.View }
 func (i *InfoWindow) SetView(v *View)  {}
 func (i *InfoWindow) SetActive(b bool) {}
+func (i *InfoWindow) IsActive() bool   { return true }
 
 func (i *InfoWindow) GetMouseLoc(vloc buffer.Loc) buffer.Loc {
 	c := i.Buffer.GetActiveCursor()

internal/display/termwindow.go

@@ -40,6 +40,10 @@ func (w *TermWindow) SetActive(b bool) {
 	w.active = b
 }
 
+func (w *TermWindow) IsActive() bool {
+	return w.active
+}
+
 func (w *TermWindow) GetMouseLoc(vloc buffer.Loc) buffer.Loc {
 	return vloc
 }

internal/display/window.go

@@ -23,6 +23,7 @@ type Window interface {
 	GetMouseLoc(vloc buffer.Loc) buffer.Loc
 	Resize(w, h int)
 	SetActive(b bool)
+	IsActive() bool
 }
 
 type BWindow interface {