From b0f2cd02ad39f3078c26c0dcf187bb5709167f3a Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Tue, 21 Apr 2020 18:14:40 -0400
Subject: [PATCH] window: Tweak visible focus behavior

Only turn on visible focus when a key event actually leads
to a change in focus location (ie, 'keynav').

Make the visible focus disappear after 5 seconds of no
keyboard interaction, to avoid permanent focus ring
distraction.

As an extra bonus, make it so that we make the focus
visible while the Alt key is pressed. This gives us
a 'find my focus!' shortcut, and goes well with the
prexisting use of Alt for finding mnemonics.

Discussed in: #2644
---
 gtk/gtkwindow.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 81 insertions(+), 5 deletions(-)

diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 9d87e68d35..194d0ef0c4 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -191,12 +191,15 @@ typedef struct
 
   guint    mnemonics_display_timeout_id;
 
+  guint    focus_visible_timeout;
+
   gint     scale;
 
   gint title_height;
   GtkWidget *title_box;
   GtkWidget *titlebar;
   GtkWidget *popup_menu;
+  GtkWidget *key_press_focus;
 
   GdkMonitor *initial_fullscreen_monitor;
   guint      edge_constraints;
@@ -4068,6 +4071,12 @@ gtk_window_finalize (GObject *object)
       priv->mnemonics_display_timeout_id = 0;
     }
 
+  if (priv->focus_visible_timeout)
+    {
+      g_source_remove (priv->focus_visible_timeout);
+      priv->focus_visible_timeout = 0;
+    }
+
   g_clear_object (&priv->constraint_solver);
   g_clear_object (&priv->renderer);
   g_clear_object (&priv->resize_cursor);
@@ -5362,6 +5371,36 @@ update_mnemonics_visible (GtkWindow       *window,
     }
 }
 
+static void
+update_focus_visible (GtkWindow       *window,
+                      guint            keyval,
+                      GdkModifierType  state,
+                      gboolean         visible)
+{
+  GtkWindowPrivate *priv = gtk_window_get_instance_private (window);
+
+  if (visible)
+    {
+      if (priv->focus_visible)
+        priv->key_press_focus = NULL;
+      else
+        priv->key_press_focus = priv->focus_widget;
+
+      if ((keyval == GDK_KEY_Alt_L || keyval == GDK_KEY_Alt_R) &&
+               ((state & (gtk_accelerator_get_default_mod_mask ()) & ~(GDK_ALT_MASK)) == 0))
+        gtk_window_set_focus_visible (window, TRUE);
+    }
+  else
+    {
+      if (priv->key_press_focus == priv->focus_widget)
+        gtk_window_set_focus_visible (window, FALSE);
+      else
+        gtk_window_set_focus_visible (window, TRUE);
+
+      priv->key_press_focus = NULL;
+    }
+}
+
 static gboolean
 gtk_window_key_pressed (GtkWidget       *widget,
                         guint            keyval,
@@ -5371,8 +5410,7 @@ gtk_window_key_pressed (GtkWidget       *widget,
 {
   GtkWindow *window = GTK_WINDOW (widget);
 
-  gtk_window_set_focus_visible (window, TRUE);
-
+  update_focus_visible (window, keyval, state, TRUE);
   update_mnemonics_visible (window, keyval, state, TRUE);
 
   return FALSE;
@@ -5387,6 +5425,7 @@ gtk_window_key_released (GtkWidget       *widget,
 {
   GtkWindow *window = GTK_WINDOW (widget);
 
+  update_focus_visible (window, keyval, state, FALSE);
   update_mnemonics_visible (window, keyval, state, FALSE);
 
   return FALSE;
@@ -7406,6 +7445,19 @@ gtk_window_get_focus_visible (GtkWindow *window)
   return priv->focus_visible;
 }
 
+static gboolean
+unset_focus_visible (gpointer data)
+{
+  GtkWindow *window = data;
+  GtkWindowPrivate *priv = gtk_window_get_instance_private (window);
+
+  priv->focus_visible_timeout = 0;
+
+  gtk_window_set_focus_visible (window, FALSE);
+
+  return G_SOURCE_REMOVE;
+}
+
 /**
  * gtk_window_set_focus_visible:
  * @window: a #GtkWindow
@@ -7417,15 +7469,39 @@ void
 gtk_window_set_focus_visible (GtkWindow *window,
                               gboolean   setting)
 {
+  gboolean changed;
+
   GtkWindowPrivate *priv = gtk_window_get_instance_private (window);
 
   g_return_if_fail (GTK_IS_WINDOW (window));
 
-  setting = setting != FALSE;
+  changed = priv->focus_visible != setting;
 
-  if (priv->focus_visible != setting)
+  priv->focus_visible = setting;
+
+  if (priv->focus_visible_timeout)
+    {
+      g_source_remove (priv->focus_visible_timeout);
+      priv->focus_visible_timeout = 0;
+    }
+
+  if (priv->focus_visible)
+    priv->focus_visible_timeout = g_timeout_add_seconds (5, unset_focus_visible, window);
+
+  if (changed)
     {
-      priv->focus_visible = setting;
+      if (priv->focus_widget)
+        {
+          GtkWidget *widget;
+
+          for (widget = priv->focus_widget; widget; widget = gtk_widget_get_parent (widget))
+            {
+              if (priv->focus_visible)
+                gtk_widget_set_state_flags (widget, GTK_STATE_FLAG_FOCUS_VISIBLE, FALSE);
+              else
+                gtk_widget_unset_state_flags (widget, GTK_STATE_FLAG_FOCUS_VISIBLE);
+            }
+        }
       g_object_notify_by_pspec (G_OBJECT (window), window_props[PROP_FOCUS_VISIBLE]);
     }
 }
-- 
2.30.2