input: Add support for keyboard shortcuts inhibit

Adding support for the keyboard shortcuts inhibit protocol allows remote
desktop and virtualisation software to receive all keyboard input in
order to pass it through to their clients so users can fully interact
the their remote/virtual session. The software usually provides its own
key combination to release its "grab" to all keyboard input. The
inhibitor can be deactivated by the user by removing focus from the
surface using another input device such as the pointer.

Use support for the procotol in wlroots to add support to sway. Extend
the input manager with handlers for inhibitor creation and destruction
and appropriate bookkeeping. Attach the inhibitors to the seats they
apply to to avoid having to search the list of all currently existing
inhibitors on every keystroke and passing the inhibitor manager around.
Add a helper function to retrieve the inhibitor applying to the
currently focused surface of a seat, if one exists.

Extend bindsym with a flag for bindings that should be processed even if
an inhibitor is active. Conversely this disables all normal shortcuts if
an inhibitor is found for the currently focused surface in
keyboard::handle_key_event() since they don't have that flag set. Use
above helper function to determine if an inhibitor exists for the
surface that would eventually receive input.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>

3 files changed, 22 insertions, 0 deletions

diff --git a/include/sway/config.h b/include/sway/config.h
index 5f02e44f..fdd65efd 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -40,6 +40,7 @@ enum binding_flags {
         BINDING_TITLEBAR=16, // mouse only; trigger on container titlebar
         BINDING_CODE=32,     // keyboard only; convert keysyms into keycodes
         BINDING_RELOAD=64,   // switch only; (re)trigger binding on reload
+        BINDING_INHIBITED=128,  // keyboard only: ignore shortcut inhibitor
 };
 
 /**
diff --git a/include/sway/input/input-manager.h b/include/sway/input/input-manager.h
index a5392c6b..410d17a8 100644
--- a/include/sway/input/input-manager.h
+++ b/include/sway/input/input-manager.h
@@ -2,6 +2,7 @@
 #define _SWAY_INPUT_INPUT_MANAGER_H
 #include <libinput.h>
 #include <wlr/types/wlr_input_inhibitor.h>
+#include <wlr/types/wlr_keyboard_shortcuts_inhibit_v1.h>
 #include <wlr/types/wlr_virtual_keyboard_v1.h>
 #include <wlr/types/wlr_virtual_pointer_v1.h>
 #include "sway/server.h"
@@ -20,12 +21,14 @@ struct sway_input_manager {
         struct wl_list seats;
 
         struct wlr_input_inhibit_manager *inhibit;
+        struct wlr_keyboard_shortcuts_inhibit_manager_v1 *keyboard_shortcuts_inhibit;
         struct wlr_virtual_keyboard_manager_v1 *virtual_keyboard;
         struct wlr_virtual_pointer_manager_v1 *virtual_pointer;
 
         struct wl_listener new_input;
         struct wl_listener inhibit_activate;
         struct wl_listener inhibit_deactivate;
+        struct wl_listener keyboard_shortcuts_inhibit_new_inhibitor;
         struct wl_listener virtual_keyboard_new;
         struct wl_listener virtual_pointer_new;
 };
diff --git a/include/sway/input/seat.h b/include/sway/input/seat.h
index 9c3028c5..49b9d09b 100644
--- a/include/sway/input/seat.h
+++ b/include/sway/input/seat.h
@@ -1,6 +1,7 @@
 #ifndef _SWAY_INPUT_SEAT_H
 #define _SWAY_INPUT_SEAT_H
 
+#include <wlr/types/wlr_keyboard_shortcuts_inhibit_v1.h>
 #include <wlr/types/wlr_layer_shell_v1.h>
 #include <wlr/types/wlr_seat.h>
 #include <wlr/util/edges.h>
@@ -94,6 +95,8 @@ struct sway_seat {
 
         struct wl_list devices; // sway_seat_device::link
         struct wl_list keyboard_groups; // sway_keyboard_group::link
+        struct wl_list keyboard_shortcuts_inhibitors;
+                                // sway_keyboard_shortcuts_inhibitor::link
 
         struct wl_list link; // input_manager::seats
 };
@@ -104,6 +107,14 @@ struct sway_pointer_constraint {
         struct wl_listener destroy;
 };
 
+struct sway_keyboard_shortcuts_inhibitor {
+        struct wlr_keyboard_shortcuts_inhibitor_v1 *inhibitor;
+
+        struct wl_listener destroy;
+
+        struct wl_list link; // sway_seat::keyboard_shortcuts_inhibitors
+};
+
 struct sway_seat *seat_create(const char *seat_name);
 
 void seat_destroy(struct sway_seat *seat);
@@ -269,4 +280,11 @@ void seatop_render(struct sway_seat *seat, struct sway_output *output,
 
 bool seatop_allows_set_cursor(struct sway_seat *seat);
 
+/**
+ * Returns the keyboard shortcuts inhibitor that applies to the currently
+ * focused surface of a seat or NULL if none exists.
+ */
+struct sway_keyboard_shortcuts_inhibitor *
+keyboard_shortcuts_inhibitor_get_for_focused_surface(const struct sway_seat *seat);
+
 #endif