From 920e6dd004ea34055139202ee3e81d53ec38624d Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Tue, 29 Mar 2022 17:30:23 +0200
Subject: [PATCH] io/router,app: move Tab-to-focus conversion to app.Window

This is a refactor to make it easier to add higher level logic to
focus moves. A follow-up will add automatic scrolling to bring
focused widgets into view.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 app/window.go         | 19 +++++++++++++++----
 io/router/key.go      | 42 ++++++++++++++++++++----------------------
 io/router/key_test.go | 26 +++++---------------------
 3 files changed, 40 insertions(+), 47 deletions(-)

diff --git a/app/window.go b/app/window.go
index 4702958b..af2349af 100644
--- a/app/window.go
+++ b/app/window.go
@@ -498,9 +498,13 @@ func (c *callbacks) SetEditorSnippet(r key.Range) {
 }
 
 func (c *callbacks) MoveFocus(dir router.FocusDirection) {
-	c.w.queue.q.MoveFocus(dir)
-	c.w.setNextFrame(time.Time{})
-	c.w.updateAnimation(c.d)
+	c.w.moveFocus(dir, c.d)
+}
+
+func (w *Window) moveFocus(dir router.FocusDirection, d driver) {
+	w.queue.q.MoveFocus(dir)
+	w.setNextFrame(time.Time{})
+	w.updateAnimation(d)
 }
 
 func (c *callbacks) ClickFocus() {
@@ -793,7 +797,14 @@ func (w *Window) processEvent(d driver, e event.Event) {
 		e2.Config.Size = e2.Config.Size.Sub(w.decorations.size)
 		w.out <- e2
 	case event.Event:
-		if w.queue.q.Queue(e2) {
+		// Convert tab or shift+tab presses to focus moves.
+		if e, ok := e.(key.Event); ok && e.State == key.Press && e.Name == key.NameTab && e.Modifiers&^key.ModShift == 0 {
+			dir := router.FocusForward
+			if e.Modifiers.Contain(key.ModShift) {
+				dir = router.FocusBackward
+			}
+			w.moveFocus(dir, d)
+		} else if w.queue.q.Queue(e2) {
 			w.setNextFrame(time.Time{})
 			w.updateAnimation(d)
 		}
diff --git a/io/router/key.go b/io/router/key.go
index 8266c1c1..8482c5b0 100644
--- a/io/router/key.go
+++ b/io/router/key.go
@@ -70,6 +70,8 @@ const (
 	FocusLeft
 	FocusUp
 	FocusDown
+	FocusForward
+	FocusBackward
 )
 
 // InputState returns the last text input state as
@@ -173,6 +175,24 @@ func (q *keyQueue) MoveFocus(dir FocusDirection, events *handlerEvents) {
 	}
 	focus := q.dirOrder[order]
 	switch dir {
+	case FocusForward, FocusBackward:
+		if len(q.order) == 0 {
+			break
+		}
+		order := 0
+		if dir == FocusBackward {
+			order = -1
+		}
+		if q.focus != nil {
+			order = q.handlers[q.focus].order
+			if dir == FocusForward {
+				order++
+			} else {
+				order--
+			}
+		}
+		order = (order + len(q.order)) % len(q.order)
+		q.setFocus(q.order[order], events)
 	case FocusRight, FocusLeft:
 		next := order
 		if q.focus != nil {
@@ -226,28 +246,6 @@ func (q *keyQueue) MoveFocus(dir FocusDirection, events *handlerEvents) {
 }
 
 func (q *keyQueue) Push(e event.Event, events *handlerEvents) {
-	// Convert tab or shift+tab presses to focus moves.
-	if e, ok := e.(key.Event); ok && e.Name == key.NameTab && e.Modifiers&^key.ModShift == 0 {
-		if e.State == key.Release || len(q.order) == 0 {
-			return
-		}
-		forward := !e.Modifiers.Contain(key.ModShift)
-		order := 0
-		if !forward {
-			order = -1
-		}
-		if q.focus != nil {
-			order = q.handlers[q.focus].order
-			if forward {
-				order++
-			} else {
-				order--
-			}
-		}
-		order = (order + len(q.order)) % len(q.order)
-		q.setFocus(q.order[order], events)
-		return
-	}
 	if q.focus != nil {
 		events.Add(q.focus, e)
 	}
diff --git a/io/router/key_test.go b/io/router/key_test.go
index 41183037..fd048d76 100644
--- a/io/router/key_test.go
+++ b/io/router/key_test.go
@@ -227,27 +227,6 @@ func TestNoOps(t *testing.T) {
 	r.Frame(nil)
 }
 
-func TestTabFocus(t *testing.T) {
-	handlers := make([]int, 3)
-	ops := new(op.Ops)
-	r := new(Router)
-
-	for i := range handlers {
-		key.InputOp{Tag: &handlers[i]}.Add(ops)
-	}
-	r.Frame(ops)
-
-	tab := func(mod key.Modifiers) {
-		r.Queue(
-			key.Event{Name: key.NameTab, State: key.Press, Modifiers: mod},
-			key.Event{Name: key.NameTab, State: key.Release, Modifiers: mod},
-		)
-	}
-	tab(0)
-	tab(key.ModShift)
-	assertFocus(t, r, &handlers[2])
-}
-
 func TestDirectionalFocus(t *testing.T) {
 	ops := new(op.Ops)
 	r := new(Router)
@@ -281,6 +260,11 @@ func TestDirectionalFocus(t *testing.T) {
 	assertFocus(t, r, &handlers[3])
 	r.MoveFocus(FocusUp)
 	assertFocus(t, r, &handlers[0])
+
+	r.MoveFocus(FocusForward)
+	assertFocus(t, r, &handlers[1])
+	r.MoveFocus(FocusBackward)
+	assertFocus(t, r, &handlers[0])
 }
 
 func assertKeyEvent(t *testing.T, events []event.Event, expected bool, expectedInputs ...event.Event) {