From 76ddda352d3dc13d16283c51a3c641a3c3c5733c Mon Sep 17 00:00:00 2001
From: Noah Petherbridge <root@kirsle.net>
Date: Sat, 19 Feb 2022 20:14:52 -0800
Subject: [PATCH] Bugfix: Window focus linked list

It used to be possible to confuse the window manager in the
CloseActiveWindow() function and the linked list got all broken. Seems
more reliable now! Added function PrintWindows() to inspect the linked
lists.
---
 supervisor.go     |  1 -
 window_manager.go | 43 ++++++++++++++++++++++++++++++++++++-------
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/supervisor.go b/supervisor.go
index 4f9733f..46f0ee4 100644
--- a/supervisor.go
+++ b/supervisor.go
@@ -87,7 +87,6 @@ type Supervisor struct {
 
 	// List of window focus history for Window Manager.
 	winFocus  *FocusedWindow
-	winTop    *FocusedWindow // pointer to top-most window
 	winBottom *FocusedWindow // pointer to bottom-most window
 }
 
diff --git a/window_manager.go b/window_manager.go
index 99a7958..e3cb676 100644
--- a/window_manager.go
+++ b/window_manager.go
@@ -66,7 +66,6 @@ func (s *Supervisor) addWindow(win *Window) {
 		s.winFocus = &FocusedWindow{
 			window: win,
 		}
-		s.winTop = s.winFocus
 		s.winBottom = s.winFocus
 		win.SetFocus(true)
 	} else {
@@ -138,7 +137,6 @@ func (s *Supervisor) FocusWindow(win *Window) error {
 		s.winFocus = target
 
 		// Fix the top and bottom pointers.
-		s.winTop = s.winFocus
 		if newBottom != nil {
 			s.winBottom = newBottom
 		}
@@ -184,13 +182,44 @@ func (s *Supervisor) CloseAllWindows() int {
 func (s *Supervisor) CloseActiveWindow() bool {
 	var node = s.winFocus
 	if node != nil {
-		node.window.Destroy()
 		node.window.Hide()
-		s.winFocus = node.next
-		s.winFocus.window.SetFocus(true)
-		return true
 	}
-	return false
+
+	// Find the next visible window to focus.
+	for node != nil {
+		if !node.window.Hidden() {
+			s.FocusWindow(node.window)
+			break
+		}
+		node = node.next
+	}
+
+	return true
+}
+
+// PrintWindows is a debug function that walks the window tree and prints them to your console.
+func (s *Supervisor) PrintWindows() {
+	var (
+		node = s.winBottom
+		i    int
+	)
+
+	fmt.Println("From the bottom:")
+	for node != nil {
+		i++
+		fmt.Printf("%d. %s  focused=%+v  hidden=%+v\n", i, node.window, node.window.Focused(), node.window.Hidden())
+		node = node.prev
+	}
+
+	node = s.winFocus
+	i = 0
+
+	fmt.Println("Focus order:")
+	for node != nil {
+		i++
+		fmt.Printf("%d. %s  focused=%+v  hidden=%+v\n", i, node.window, node.window.Focused(), node.window.Hidden())
+		node = node.next
+	}
 }
 
 // presentWindows draws the windows from bottom to top.