From e5a4ea71a4e6bcb9c943c81b0633d3399a4f1368 Mon Sep 17 00:00:00 2001
From: Benjamin Otte <otte@redhat.com>
Date: Tue, 15 Oct 2019 04:18:10 +0200
Subject: [PATCH] listitem: Change focus handling

Focus in the listitem now works like this:
1. If any child can take focus, do not ever attempt
   to take focus.
2. Otherwise, if this item is selectable or activatable,
   allow focusing this widget.

This makes sure every item in a list is focusable for
activation and selection handling, but no useless widgets
get focused and moving focus is as fast as possible.
---
 gtk/gtklistitem.c | 50 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/gtk/gtklistitem.c b/gtk/gtklistitem.c
index b01e7d4cfb..46d6dc09e0 100644
--- a/gtk/gtklistitem.c
+++ b/gtk/gtklistitem.c
@@ -86,6 +86,51 @@ G_DEFINE_TYPE (GtkListItem, gtk_list_item, GTK_TYPE_WIDGET)
 
 static GParamSpec *properties[N_PROPS] = { NULL, };
 
+static gboolean
+gtk_list_item_focus (GtkWidget        *widget,
+                     GtkDirectionType  direction)
+{
+  GtkListItem *self = GTK_LIST_ITEM (widget);
+
+  /* The idea of this function is the following:
+   * 1. If any child can take focus, do not ever attempt
+   *    to take focus.
+   * 2. Otherwise, if this item is selectable or activatable,
+   *    allow focusing this widget.
+   *
+   * This makes sure every item in a list is focusable for
+   * activation and selection handling, but no useless widgets
+   * get focused and moving focus is as fast as possible.
+   */
+  if (self->child)
+    {
+      if (gtk_widget_get_focus_child (widget))
+        return FALSE;
+      if (gtk_widget_child_focus (self->child, direction))
+        return TRUE;
+    }
+
+  if (gtk_widget_is_focus (widget))
+    return FALSE;
+
+  if (!gtk_widget_get_can_focus (widget) ||
+      !self->selectable)
+    return FALSE;
+
+  return gtk_widget_grab_focus (widget);
+}
+
+static gboolean
+gtk_list_item_grab_focus (GtkWidget *widget)
+{
+  GtkListItem *self = GTK_LIST_ITEM (widget);
+
+  if (self->child && gtk_widget_grab_focus (self->child))
+    return TRUE;
+
+  return GTK_WIDGET_CLASS (gtk_list_item_parent_class)->grab_focus (widget);
+}
+
 static void
 gtk_list_item_dispose (GObject *object)
 {
@@ -163,6 +208,9 @@ gtk_list_item_class_init (GtkListItemClass *klass)
   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 
+  widget_class->focus = gtk_list_item_focus;
+  widget_class->grab_focus = gtk_list_item_grab_focus;
+
   gobject_class->dispose = gtk_list_item_dispose;
   gobject_class->get_property = gtk_list_item_get_property;
   gobject_class->set_property = gtk_list_item_set_property;
@@ -550,7 +598,5 @@ gtk_list_item_set_selectable (GtkListItem *self,
 
   self->selectable = selectable;
 
-  gtk_widget_set_can_focus (GTK_WIDGET (self), self->selectable);
-
   g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTABLE]);
 }