From 1a291ab118dab4bcf0d3df0752125583c4594911 Mon Sep 17 00:00:00 2001
From: Tudor Brindus <me@tbrindus.ca>
Date: Fri, 17 Apr 2020 13:55:44 -0400
Subject: [PATCH] wayland: add support for SDL_SetWindowGrab

---
 src/video/wayland/SDL_waylandevents.c   | 59 +++++++++++++++++++++++++
 src/video/wayland/SDL_waylandevents_c.h |  3 ++
 src/video/wayland/SDL_waylandvideo.c    |  1 +
 src/video/wayland/SDL_waylandwindow.c   | 11 +++++
 src/video/wayland/SDL_waylandwindow.h   |  1 +
 5 files changed, 75 insertions(+)

diff --git a/src/video/wayland/SDL_waylandevents.c b/src/video/wayland/SDL_waylandevents.c
index 2ec5b19a4..90486595e 100644
--- a/src/video/wayland/SDL_waylandevents.c
+++ b/src/video/wayland/SDL_waylandevents.c
@@ -65,6 +65,7 @@ struct SDL_WaylandInput {
     struct wl_keyboard *keyboard;
     SDL_WaylandDataDevice *data_device;
     struct zwp_relative_pointer_v1 *relative_pointer;
+    struct zwp_confined_pointer_v1 *confined_pointer;
     SDL_WindowData *pointer_focus;
     SDL_WindowData *keyboard_focus;
 
@@ -1263,6 +1264,64 @@ int Wayland_input_unlock_pointer(struct SDL_WaylandInput *input)
     return 0;
 }
 
+static void
+confined_pointer_confined(void *data,
+                          struct zwp_confined_pointer_v1 *confined_pointer)
+{
+}
+
+static void
+confined_pointer_unconfined(void *data,
+                            struct zwp_confined_pointer_v1 *confined_pointer)
+{
+}
+
+static const struct zwp_confined_pointer_v1_listener confined_pointer_listener = {
+    confined_pointer_confined,
+    confined_pointer_unconfined,
+};
+
+int Wayland_input_confine_pointer(SDL_Window *window, struct SDL_WaylandInput *input)
+{
+    SDL_WindowData *w = window->driverdata;
+    SDL_VideoData *d = input->display;
+    struct zwp_confined_pointer_v1 *confined_pointer;
+
+    if (!d->pointer_constraints)
+        return -1;
+
+    if (!input->pointer)
+        return -1;
+
+    /* A confine may already be active, in which case we should destroy it and
+     * create a new one. */
+    if (input->confined_pointer)
+        Wayland_input_unconfine_pointer(input);
+
+    confined_pointer =
+        zwp_pointer_constraints_v1_confine_pointer(d->pointer_constraints,
+                                                   w->surface,
+                                                   input->pointer,
+                                                   NULL,
+                                                   ZWP_POINTER_CONSTRAINTS_V1_LIFETIME_PERSISTENT);
+    zwp_confined_pointer_v1_add_listener(confined_pointer,
+                                         &confined_pointer_listener,
+                                         window);
+
+    input->confined_pointer = confined_pointer;
+    return 0;
+}
+
+int Wayland_input_unconfine_pointer(struct SDL_WaylandInput *input)
+{
+    if (input->confined_pointer) {
+        zwp_confined_pointer_v1_destroy(input->confined_pointer);
+        input->confined_pointer = NULL;
+    }
+
+    return 0;
+}
+
 #endif /* SDL_VIDEO_DRIVER_WAYLAND */
 
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/video/wayland/SDL_waylandevents_c.h b/src/video/wayland/SDL_waylandevents_c.h
index f8ba197d8..96aaa397f 100644
--- a/src/video/wayland/SDL_waylandevents_c.h
+++ b/src/video/wayland/SDL_waylandevents_c.h
@@ -43,6 +43,9 @@ extern void Wayland_display_destroy_pointer_constraints(SDL_VideoData *d);
 extern int Wayland_input_lock_pointer(struct SDL_WaylandInput *input);
 extern int Wayland_input_unlock_pointer(struct SDL_WaylandInput *input);
 
+extern int Wayland_input_confine_pointer(SDL_Window *window, struct SDL_WaylandInput *input);
+extern int Wayland_input_unconfine_pointer(struct SDL_WaylandInput *input);
+
 extern void Wayland_display_add_relative_pointer_manager(SDL_VideoData *d, uint32_t id);
 extern void Wayland_display_destroy_relative_pointer_manager(SDL_VideoData *d);
 
diff --git a/src/video/wayland/SDL_waylandvideo.c b/src/video/wayland/SDL_waylandvideo.c
index a3144b84e..68ae16e25 100644
--- a/src/video/wayland/SDL_waylandvideo.c
+++ b/src/video/wayland/SDL_waylandvideo.c
@@ -184,6 +184,7 @@ Wayland_CreateDevice(int devindex)
     device->ShowWindow = Wayland_ShowWindow;
     device->SetWindowFullscreen = Wayland_SetWindowFullscreen;
     device->MaximizeWindow = Wayland_MaximizeWindow;
+    device->SetWindowGrab = Wayland_SetWindowGrab;
     device->RestoreWindow = Wayland_RestoreWindow;
     device->SetWindowBordered = Wayland_SetWindowBordered;
     device->SetWindowSize = Wayland_SetWindowSize;
diff --git a/src/video/wayland/SDL_waylandwindow.c b/src/video/wayland/SDL_waylandwindow.c
index 193040b7d..830faba78 100644
--- a/src/video/wayland/SDL_waylandwindow.c
+++ b/src/video/wayland/SDL_waylandwindow.c
@@ -628,6 +628,17 @@ Wayland_MaximizeWindow(_THIS, SDL_Window * window)
     WAYLAND_wl_display_flush( viddata->display );
 }
 
+void
+Wayland_SetWindowGrab(_THIS, SDL_Window *window, SDL_bool grabbed)
+{
+    SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
+
+    if (grabbed)
+        Wayland_input_confine_pointer(window, data->input);
+    else
+        Wayland_input_unconfine_pointer(data->input);
+}
+
 int Wayland_CreateWindow(_THIS, SDL_Window *window)
 {
     SDL_WindowData *data;
diff --git a/src/video/wayland/SDL_waylandwindow.h b/src/video/wayland/SDL_waylandwindow.h
index 322ce6378..93ba121b8 100644
--- a/src/video/wayland/SDL_waylandwindow.h
+++ b/src/video/wayland/SDL_waylandwindow.h
@@ -88,6 +88,7 @@ extern void Wayland_SetWindowFullscreen(_THIS, SDL_Window * window,
                                         SDL_VideoDisplay * _display,
                                         SDL_bool fullscreen);
 extern void Wayland_MaximizeWindow(_THIS, SDL_Window * window);
+extern void Wayland_SetWindowGrab(_THIS, SDL_Window * window, SDL_bool grabbed);
 extern void Wayland_RestoreWindow(_THIS, SDL_Window * window);
 extern void Wayland_SetWindowBordered(_THIS, SDL_Window * window, SDL_bool bordered);
 extern int Wayland_CreateWindow(_THIS, SDL_Window *window);