lib/ui/tab: Add Replace method

Also expose a light wrapper method in aerc.go for tab replacement

Signed-off-by: Kevin Kuehler <kkuehler@brave.com>

lib/ui/tab.go

@@ -68,6 +68,22 @@ func (tabs *Tabs) Remove(content Drawable) {
 	tabs.TabStrip.Invalidate()
 }
 
+func (tabs *Tabs) Replace(contentSrc Drawable, contentTarget Drawable, name string) {
+	replaceTab := &Tab{
+		Content: contentTarget,
+		Name:    name,
+	}
+	for i, tab := range tabs.Tabs {
+		if tab.Content == contentSrc {
+			tabs.Tabs[i] = replaceTab
+			tabs.Select(i)
+			break
+		}
+	}
+	tabs.TabStrip.Invalidate()
+	contentTarget.OnInvalidate(tabs.invalidateChild)
+}
+
 func (tabs *Tabs) Select(index int) {
 	if index >= len(tabs.Tabs) {
 		panic("Tried to set tab index to a non-existing element")

widgets/aerc.go

@@ -218,6 +218,10 @@ func (aerc *Aerc) RemoveTab(tab ui.Drawable) {
 	aerc.tabs.Remove(tab)
 }
 
+func (aerc *Aerc) ReplaceTab(tabSrc ui.Drawable, tabTarget ui.Drawable, name string) {
+	aerc.tabs.Replace(tabSrc, tabTarget, name)
+}
+
 func (aerc *Aerc) NextTab() {
 	next := aerc.tabs.Selected + 1
 	if next >= len(aerc.tabs.Tabs) {