simplify SearchEntry and extract a debouncer util func

ui/widgets/searchentry.go

@@ -0,0 +1,73 @@
+package widgets
+
+import (
+	"time"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/theme"
+	"fyne.io/fyne/v2/widget"
+	"github.com/dweymouth/supersonic/ui/util"
+)
+
+// SearchEntry is a search entry widget that will issue a search command
+// (aka call OnSearched) when a short span of time has elapsed since
+// the user typed into the widget.
+type SearchEntry struct {
+	widget.Entry
+
+	OnSearched func(string)
+}
+
+func NewSearchEntry() *SearchEntry {
+	sf := &SearchEntry{}
+	sf.ExtendBaseWidget(sf)
+	sf.PlaceHolder = "Search"
+	sf.ActionItem = NewClearTextButton(func() {
+		sf.SetText("")
+	})
+	debounceFunc := util.NewDebouncer(200*time.Millisecond, func() {
+		sf.sendSearch(sf.Entry.Text)
+	})
+	sf.Entry.OnChanged = func(_ string) { debounceFunc() }
+	return sf
+}
+
+func (s *SearchEntry) Refresh() {
+	if s.Text == "" {
+		s.ActionItem.(*clearTextButton).Resource = theme.SearchIcon()
+	} else {
+		s.ActionItem.(*clearTextButton).Resource = theme.ContentClearIcon()
+	}
+	s.Entry.Refresh()
+}
+
+func (s *SearchEntry) MinSize() fyne.Size {
+	return fyne.NewSize(200, s.Entry.MinSize().Height)
+}
+
+var _ fyne.Tappable = (*clearTextButton)(nil)
+
+type clearTextButton struct {
+	widget.Icon
+
+	OnTapped func()
+}
+
+func (s *SearchEntry) sendSearch(text string) {
+	if s.OnSearched != nil {
+		s.OnSearched(text)
+	}
+}
+
+func NewClearTextButton(onTapped func()) *clearTextButton {
+	c := &clearTextButton{OnTapped: onTapped}
+	c.ExtendBaseWidget(c)
+	c.Resource = theme.SearchIcon()
+	return c
+}
+
+func (c *clearTextButton) Tapped(*fyne.PointEvent) {
+	if c.OnTapped != nil {
+		c.OnTapped()
+	}
+}