From f6e3527767fffe81fa05073ae73893bb89a45d4f Mon Sep 17 00:00:00 2001
From: John Lindgren <john@jlindgren.net>
Date: Sat, 14 Oct 2023 16:29:13 -0400
Subject: [PATCH] desktop: allow re-focus between "globally active" views of
 the same PID

Commit 7e72bf975fb6 changed behavior to not automatically focus xwayland
views using the "Globally Active" input model (WM_HINTS.inputs = false
but WM_TAKE_FOCUS listed in WM_PROTOCOLS).

One undesired side effect of this change is that when a dialog is
closed, the parent window is not re-focused if "Globally Active". This
issue is seen for example with JDownloader. It can be solved taking a
similar approach to what is done for unmanaged xwayland views: allow
automatic re-focus between views sharing the same PID.

Note that it's difficult to completely solve all of the focus issues
with Globally Active views without proper WM_TAKE_FOCUS support.
Implementing proper support is difficult since it requires wlroots
changes and would also mean waiting for a message round-trip in
desktop_focus_topmost_view().

Fixes (partially): 7e72bf975fb65c8290b398d21b2ad9d87a22880f
("view/xwayland: avoid focusing views that don't want focus")
---
 include/view.h | 13 ++++++++++++-
 src/desktop.c  |  4 +++-
 src/view.c     | 18 +++++++++++++++---
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/include/view.h b/include/view.h
index 12b5d109..b3cc0368 100644
--- a/include/view.h
+++ b/include/view.h
@@ -290,6 +290,14 @@ void view_array_append(struct server *server, struct wl_array *views,
 
 enum view_wants_focus view_wants_focus(struct view *view);
 
+/**
+ * view_is_focusable_from() - variant of view_is_focusable()
+ * that takes into account the previously focused surface
+ * @view: view to be checked
+ * @prev_surface: previously focused surface
+ */
+bool view_is_focusable_from(struct view *view, struct wlr_surface *prev);
+
 /**
  * view_is_focusable() - Check whether or not a view can be focused
  * @view: view to be checked
@@ -302,7 +310,10 @@ enum view_wants_focus view_wants_focus(struct view *view);
  * The only views that are allowed to be focusd are those that have a surface
  * and have been mapped at some point since creation.
  */
-bool view_is_focusable(struct view *view);
+static inline bool
+view_is_focusable(struct view *view) {
+	return view_is_focusable_from(view, NULL);
+}
 
 void view_toggle_keybinds(struct view *view);
 
diff --git a/src/desktop.c b/src/desktop.c
index 607da49c..ab057fbe 100644
--- a/src/desktop.c
+++ b/src/desktop.c
@@ -192,6 +192,8 @@ desktop_cycle_view(struct server *server, struct view *start_view,
 struct view *
 desktop_topmost_focusable_view(struct server *server)
 {
+	struct wlr_surface *prev =
+		server->seat.seat->keyboard_state.focused_surface;
 	struct view *view;
 	struct wl_list *node_list;
 	struct wlr_scene_node *node;
@@ -202,7 +204,7 @@ desktop_topmost_focusable_view(struct server *server)
 			continue;
 		}
 		view = node_view_from_node(node);
-		if (view->mapped && view_is_focusable(view)) {
+		if (view->mapped && view_is_focusable_from(view, prev)) {
 			return view;
 		}
 	}
diff --git a/src/view.c b/src/view.c
index dcca4bcd..813566bd 100644
--- a/src/view.c
+++ b/src/view.c
@@ -154,16 +154,28 @@ view_wants_focus(struct view *view)
 }
 
 bool
-view_is_focusable(struct view *view)
+view_is_focusable_from(struct view *view, struct wlr_surface *prev)
 {
 	assert(view);
 	if (!view->surface) {
 		return false;
 	}
-	if (view_wants_focus(view) != VIEW_WANTS_FOCUS_ALWAYS) {
+	if (!view->mapped && !view->minimized) {
 		return false;
 	}
-	return (view->mapped || view->minimized);
+	enum view_wants_focus wants_focus = view_wants_focus(view);
+	/*
+	 * Consider "offer focus" (Globally Active) views as focusable
+	 * only if another surface from the same application already had
+	 * focus. The goal is to allow focusing a parent window when a
+	 * dialog/popup is closed, but still avoid focusing standalone
+	 * panels/toolbars/notifications. Note that we are basically
+	 * guessing whether Globally Active views want focus, and will
+	 * probably be wrong some of the time.
+	 */
+	return (wants_focus == VIEW_WANTS_FOCUS_ALWAYS
+		|| (wants_focus == VIEW_WANTS_FOCUS_OFFER
+			&& prev && view_is_related(view, prev)));
 }
 
 /**