tabs: use template for compose tabs

Use a template for compose tabs.

Other available values:

	Account      string
	Subject      string
	To           []*mail.Address
	From         []*mail.Address
	Cc           []*mail.Address
	Bcc          []*mail.Address
	OriginalFrom []*mail.Address

When you use To, From, CC, BCC, or OriginalFrom the title will only be
updated when an editing field has lost focus. This is so we don't end up
calling "PrepareHeader" on every keystroke, which will likely error out
anyways since it will be an invalid header.

Subject still updates every keystroke.

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Robin Jarry <robin@jarry.cc>

2 files changed, 55 insertions, 9 deletions

diff --git a/widgets/aerc.go b/widgets/aerc.go
index e8d65539..8eec8823 100644
--- a/widgets/aerc.go
+++ b/widgets/aerc.go
@@ -748,15 +748,7 @@ func (aerc *Aerc) Mailto(addr *url.URL) error {
 	if to == nil {
 		composer.FocusEditor("to")
 	}
-	tab := aerc.NewTab(composer, title)
-	composer.OnHeaderChange("Subject", func(subject string) {
-		if subject == "" {
-			tab.Name = "New email"
-		} else {
-			tab.Name = subject
-		}
-		ui.Invalidate()
-	})
+	composer.Tab = aerc.NewTab(composer, title)
 
 	for _, file := range attachments {
 		composer.AddAttachment(file)
diff --git a/widgets/compose.go b/widgets/compose.go
index 5795ccba..94fd79d5 100644
--- a/widgets/compose.go
+++ b/widgets/compose.go
@@ -63,6 +63,7 @@ type Composer struct {
 	width int
 
 	textParts []*lib.Part
+	Tab       *ui.Tab
 }
 
 func NewComposer(
@@ -235,6 +236,15 @@ func (c *Composer) buildComposeHeader(aerc *Aerc, cmpl *completer.Completer) {
 			default:
 				c.focusable = append(c.focusable, e)
 			}
+			e.OnChange(func() {
+				c.setTitle()
+				ui.Invalidate()
+			})
+			e.OnFocusLost(func() {
+				c.PrepareHeader() //nolint:errcheck // tab title only, fine if it's not valid yet
+				c.setTitle()
+				ui.Invalidate()
+			})
 		}
 	}
 
@@ -606,6 +616,7 @@ func (c *Composer) OnClose(fn func(composer *Composer)) {
 }
 
 func (c *Composer) Draw(ctx *ui.Context) {
+	c.setTitle()
 	c.width = ctx.Width()
 	c.grid.Draw(ctx)
 }
@@ -1517,3 +1528,46 @@ func (c *Composer) checkEncryptionKeys(_ string) bool {
 	}
 	return true
 }
+
+// setTitle executes the title template and sets the tab title
+func (c *Composer) setTitle() {
+	if c.Tab == nil {
+		return
+	}
+	data := struct {
+		Account      string
+		Subject      string
+		To           []*mail.Address
+		From         []*mail.Address
+		Cc           []*mail.Address
+		Bcc          []*mail.Address
+		OriginalFrom []*mail.Address
+	}{}
+	data.Account = c.acct.Name()
+	// Get subject direct from the textinput
+	subject, ok := c.editors["subject"]
+	if ok {
+		data.Subject = subject.input.String()
+	}
+	if data.Subject == "" {
+		data.Subject = "New Email"
+	}
+	// Get address fields from header, which gets updated on focus lost of
+	// any headerEditor field
+	data.From, _ = c.header.AddressList("from")
+	data.To, _ = c.header.AddressList("to")
+	data.Cc, _ = c.header.AddressList("cc")
+	data.Bcc, _ = c.header.AddressList("bcc")
+
+	if c.parent != nil && c.parent.RFC822Headers != nil {
+		data.OriginalFrom, _ = c.parent.RFC822Headers.AddressList("from")
+	}
+
+	buf := bytes.NewBuffer(nil)
+	err := c.acct.UiConfig().TabTitleComposer.Execute(buf, data)
+	if err != nil {
+		c.acct.PushError(err)
+		return
+	}
+	c.Tab.SetTitle(buf.String())
+}