From ec2aa8e3221a7e9b3b2afae972d843215495d200 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Thu, 2 Nov 2023 12:17:33 -0700
Subject: [PATCH] apprt/gtk: maintain container pointers

---
 src/apprt/gtk/Split.zig   | 37 +++++++++++++++++++++++++++----------
 src/apprt/gtk/Surface.zig | 12 ++++++++++++
 2 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/src/apprt/gtk/Split.zig b/src/apprt/gtk/Split.zig
index fcf7f5d05..ee997af64 100644
--- a/src/apprt/gtk/Split.zig
+++ b/src/apprt/gtk/Split.zig
@@ -156,10 +156,10 @@ pub fn replaceChildInPosition(self: *Split, child: Child, position: Position) vo
 }
 
 /// Remove both children, setting *c.GtkSplit start/end children to null.
-pub fn removeChildren(self: *Split) void {
-    self.removeChildInPosition(.start);
-    self.removeChildInPosition(.end);
-}
+// pub fn removeChildren(self: *Split) void {
+//     self.removeChildInPosition(.start);
+//     self.removeChildInPosition(.end);
+//}
 
 /// Deinit the Split by deiniting its child Split, if they exist.
 pub fn deinit(self: *Split, alloc: Allocator) void {
@@ -189,6 +189,18 @@ fn removeChildInPosition(self: *Split, position: Position) void {
     }
 }
 
+/// Remove the top left child.
+pub fn removeTopLeft(self: *Split) void {
+    // Remove our children since we are going to no longer be
+    // a split anyways. This prevents widgets with multiple parents.
+    self.removeChildren();
+
+    // Our container must become whatever our bottom right is
+    self.container.replace(self.bottom_right);
+
+    // TODO: memory management of top left
+}
+
 // TODO: ehhhhhh
 pub fn replace(
     self: *Split,
@@ -203,12 +215,6 @@ pub fn replace(
     // position but we want to keep it in place so save and restore it.
     const pos = c.gtk_paned_get_position(self.paned);
     defer c.gtk_paned_set_position(self.paned, pos);
-
-    // We have to set both to null. If we overwrite the pane with
-    // the same value, then GTK bugs out (the GL area unrealizes
-    // and never rerealizes).
-    c.gtk_paned_set_start_child(@ptrCast(self.paned), null);
-    c.gtk_paned_set_end_child(@ptrCast(self.paned), null);
     self.updateChildren();
 }
 
@@ -216,6 +222,12 @@ pub fn replace(
 /// This should be called anytime the top/left or bottom/right
 /// element is changed.
 fn updateChildren(self: *const Split) void {
+    // We have to set both to null. If we overwrite the pane with
+    // the same value, then GTK bugs out (the GL area unrealizes
+    // and never rerealizes).
+    self.removeChildren();
+
+    // Set our current children
     c.gtk_paned_set_start_child(
         @ptrCast(self.paned),
         self.top_left.widget(),
@@ -226,6 +238,11 @@ fn updateChildren(self: *const Split) void {
     );
 }
 
+fn removeChildren(self: *const Split) void {
+    c.gtk_paned_set_start_child(@ptrCast(self.paned), null);
+    c.gtk_paned_set_end_child(@ptrCast(self.paned), null);
+}
+
 fn addChild1(self: *Split, child: Child) void {
     assert(self.child1 == .none);
 
diff --git a/src/apprt/gtk/Surface.zig b/src/apprt/gtk/Surface.zig
index eaf320bb4..e13871050 100644
--- a/src/apprt/gtk/Surface.zig
+++ b/src/apprt/gtk/Surface.zig
@@ -72,6 +72,13 @@ pub const Container = union(enum) {
                 .split => |s| @ptrCast(@alignCast(s.paned)),
             };
         }
+
+        pub fn containerPtr(self: Elem) *Container {
+            return switch (self) {
+                .surface => |s| &s.container,
+                .split => |s| &s.container,
+            };
+        }
     };
 
     /// Returns the window that this surface is attached to.
@@ -112,6 +119,7 @@ pub const Container = union(enum) {
     /// from a surface to a split or a split back to a surface or
     /// a split to a nested split and so on.
     pub fn replace(self: Container, elem: Elem) void {
+        // Move the element into the container
         switch (self) {
             .none => {},
             .tab_ => |t| t.replaceElem(elem),
@@ -120,6 +128,9 @@ pub const Container = union(enum) {
                 s.replace(ptr, elem);
             },
         }
+
+        // Update the reverse reference to the container
+        elem.containerPtr().* = self;
     }
 
     /// Remove ourselves from the container. This is used by
@@ -129,6 +140,7 @@ pub const Container = union(enum) {
         switch (self) {
             .none => {},
             .tab_ => |t| t.closeElem(),
+            .split_tl => self.split().?.removeTopLeft(),
             else => @panic("TOOD"),
         }
     }