SDL: wayland: Implement the popup window changes

From 233da680f08f186728fa4ea07b61f02cb3af93eb Mon Sep 17 00:00:00 2001
From: Frank Praznik <[EMAIL REDACTED]>
Date: Tue, 28 Feb 2023 13:47:40 -0500
Subject: [PATCH] wayland: Implement the popup window changes

---
 src/video/wayland/SDL_waylanddyn.h    |   1 +
 src/video/wayland/SDL_waylandsym.h    |   1 +
 src/video/wayland/SDL_waylandvideo.c  |   1 +
 src/video/wayland/SDL_waylandwindow.c | 142 ++++++++++++++++----------
 src/video/wayland/SDL_waylandwindow.h |   3 +-
 5 files changed, 90 insertions(+), 58 deletions(-)

diff --git a/src/video/wayland/SDL_waylanddyn.h b/src/video/wayland/SDL_waylanddyn.h
index a900537d8ec3..fa6b50035738 100644
--- a/src/video/wayland/SDL_waylanddyn.h
+++ b/src/video/wayland/SDL_waylanddyn.h
@@ -160,6 +160,7 @@ void SDL_WAYLAND_UnloadSymbols(void);
 #define libdecor_frame_set_parent               (*WAYLAND_libdecor_frame_set_parent)
 #define libdecor_frame_get_xdg_surface          (*WAYLAND_libdecor_frame_get_xdg_surface)
 #define libdecor_frame_get_xdg_toplevel         (*WAYLAND_libdecor_frame_get_xdg_toplevel)
+#define libdecor_frame_translate_coordinate     (*WAYLAND_libdecor_frame_translate_coordinate)
 #define libdecor_frame_map                      (*WAYLAND_libdecor_frame_map)
 #define libdecor_state_new                      (*WAYLAND_libdecor_state_new)
 #define libdecor_state_free                     (*WAYLAND_libdecor_state_free)
diff --git a/src/video/wayland/SDL_waylandsym.h b/src/video/wayland/SDL_waylandsym.h
index 481eeab27ba0..b0486a96112d 100644
--- a/src/video/wayland/SDL_waylandsym.h
+++ b/src/video/wayland/SDL_waylandsym.h
@@ -206,6 +206,7 @@ SDL_WAYLAND_SYM(void, libdecor_frame_set_parent, (struct libdecor_frame *,\
                                                   struct libdecor_frame *))
 SDL_WAYLAND_SYM(struct xdg_surface *, libdecor_frame_get_xdg_surface, (struct libdecor_frame *))
 SDL_WAYLAND_SYM(struct xdg_toplevel *, libdecor_frame_get_xdg_toplevel, (struct libdecor_frame *))
+SDL_WAYLAND_SYM(void, libdecor_frame_translate_coordinate, (struct libdecor_frame *, int, int, int *, int *))
 SDL_WAYLAND_SYM(void, libdecor_frame_map, (struct libdecor_frame *))
 SDL_WAYLAND_SYM(struct libdecor_state *, libdecor_state_new, (int, int))
 SDL_WAYLAND_SYM(void, libdecor_state_free, (struct libdecor_state *))
diff --git a/src/video/wayland/SDL_waylandvideo.c b/src/video/wayland/SDL_waylandvideo.c
index d706303053da..e3b5fc5dd20a 100644
--- a/src/video/wayland/SDL_waylandvideo.c
+++ b/src/video/wayland/SDL_waylandvideo.c
@@ -238,6 +238,7 @@ static SDL_VideoDevice *Wayland_CreateDevice(void)
     device->RestoreWindow = Wayland_RestoreWindow;
     device->SetWindowBordered = Wayland_SetWindowBordered;
     device->SetWindowResizable = Wayland_SetWindowResizable;
+    device->SetWindowPosition = Wayland_SetWindowPosition;
     device->SetWindowSize = Wayland_SetWindowSize;
     device->SetWindowMinimumSize = Wayland_SetWindowMinimumSize;
     device->SetWindowMaximumSize = Wayland_SetWindowMaximumSize;
diff --git a/src/video/wayland/SDL_waylandwindow.c b/src/video/wayland/SDL_waylandwindow.c
index c84206baf07e..b041405fd5f9 100644
--- a/src/video/wayland/SDL_waylandwindow.c
+++ b/src/video/wayland/SDL_waylandwindow.c
@@ -405,6 +405,21 @@ static void UpdateWindowFullscreen(SDL_Window *window, SDL_bool fullscreen)
     }
 }
 
+static void GetPopupPosition(SDL_Window *popup, int x, int y, int *adj_x, int *adj_y)
+{
+    /* Adjust the popup positioning, if necessary */
+#ifdef HAVE_LIBDECOR_H
+    if (popup->parent->driverdata->shell_surface_type == WAYLAND_SURFACE_LIBDECOR) {
+        libdecor_frame_translate_coordinate(popup->parent->driverdata->shell_surface.libdecor.frame,
+                                            x, y, adj_x, adj_y);
+    } else
+#endif
+    {
+        *adj_x = x;
+        *adj_y = y;
+    }
+}
+
 static const struct wl_callback_listener surface_damage_frame_listener;
 
 static void surface_damage_frame_done(void *data, struct wl_callback *cb, uint32_t time)
@@ -590,7 +605,17 @@ static void handle_configure_xdg_popup(void *data,
                                        int32_t width,
                                        int32_t height)
 {
-    /* No-op, we don't use x/y and width/height are fixed-size */
+    /* Popups can't be resized, so only position data is sent. */
+    SDL_WindowData *wind = (SDL_WindowData *)data;
+    int offset_x, offset_y;
+
+    /* Adjust the position if it was offset for libdecor */
+    GetPopupPosition(wind->sdlwindow, 0, 0, &offset_x, &offset_y);
+    x -= offset_x;
+    y -= offset_y;
+    
+    SDL_SendWindowEvent(wind->sdlwindow, SDL_EVENT_WINDOW_RESIZED, width, height);
+    SDL_SendWindowEvent(wind->sdlwindow, SDL_EVENT_WINDOW_MOVED, x, y);
 }
 
 static void handle_done_xdg_popup(void *data, struct xdg_popup *xdg_popup)
@@ -612,27 +637,6 @@ static const struct xdg_popup_listener popup_listener_xdg = {
     handle_repositioned_xdg_popup
 };
 
-#define TOOLTIP_CURSOR_OFFSET 8 /* FIXME: Arbitrary, eyeballed from X tooltip */
-
-static int Wayland_PopupWatch(void *data, SDL_Event *event)
-{
-    if (event->type == SDL_EVENT_MOUSE_MOTION) {
-        SDL_Window *window = (SDL_Window *)data;
-        SDL_WindowData *wind = window->driverdata;
-
-        /* Coordinates might be relative to the popup, which we don't want */
-        if (event->motion.windowID == wind->shell_surface.xdg.roleobj.popup.parentID) {
-            xdg_positioner_set_offset(wind->shell_surface.xdg.roleobj.popup.positioner,
-                                      event->motion.x + TOOLTIP_CURSOR_OFFSET,
-                                      event->motion.y + TOOLTIP_CURSOR_OFFSET);
-            xdg_popup_reposition(wind->shell_surface.xdg.roleobj.popup.popup,
-                                 wind->shell_surface.xdg.roleobj.popup.positioner,
-                                 0);
-        }
-    }
-    return 1;
-}
-
 static void handle_configure_zxdg_decoration(void *data,
                                              struct zxdg_toplevel_decoration_v1 *zxdg_toplevel_decoration_v1,
                                              uint32_t mode)
@@ -1152,41 +1156,55 @@ void Wayland_ShowWindow(_THIS, SDL_Window *window)
         }
     } else
 #endif
-        if (c->shell.xdg) {
+        if ((data->shell_surface_type == WAYLAND_SURFACE_XDG_TOPLEVEL || data->shell_surface_type == WAYLAND_SURFACE_XDG_POPUP) && c->shell.xdg) {
         data->shell_surface.xdg.surface = xdg_wm_base_get_xdg_surface(c->shell.xdg, data->surface);
         xdg_surface_set_user_data(data->shell_surface.xdg.surface, data);
         xdg_surface_add_listener(data->shell_surface.xdg.surface, &shell_surface_listener_xdg, data);
 
         if (data->shell_surface_type == WAYLAND_SURFACE_XDG_POPUP) {
-            SDL_Mouse *mouse = SDL_GetMouse();
-            SDL_Window *focused = SDL_GetMouseFocus();
-            SDL_WindowData *focuseddata = focused->driverdata;
-
-            /* This popup may be a child of another popup! */
-            data->shell_surface.xdg.roleobj.popup.parentID = SDL_GetWindowID(focused);
-            data->shell_surface.xdg.roleobj.popup.child = NULL;
-            if (focuseddata->shell_surface_type == WAYLAND_SURFACE_XDG_POPUP) {
-                SDL_assert(focuseddata->shell_surface.xdg.roleobj.popup.child == NULL);
-                focuseddata->shell_surface.xdg.roleobj.popup.child = window;
+            SDL_Window *parent = window->parent;
+            SDL_WindowData *parent_data = parent->driverdata;
+            struct xdg_surface *parent_xdg_surface = NULL;
+            int position_x = 0, position_y = 0;
+
+            /* Configure the popup parameters */
+#ifdef HAVE_LIBDECOR_H
+            if (parent_data->shell_surface_type == WAYLAND_SURFACE_LIBDECOR) {
+                parent_xdg_surface = libdecor_frame_get_xdg_surface(parent_data->shell_surface.libdecor.frame);
+            } else
+#endif
+            if (parent_data->shell_surface_type == WAYLAND_SURFACE_XDG_TOPLEVEL ||
+                    parent_data->shell_surface_type == WAYLAND_SURFACE_XDG_POPUP) {
+                parent_xdg_surface = parent_data->shell_surface.xdg.surface;
             }
 
-            /* Set up the positioner for the popup */
+            /* Set up the positioner for the popup and configure the constraints */
             data->shell_surface.xdg.roleobj.popup.positioner = xdg_wm_base_create_positioner(c->shell.xdg);
-            xdg_positioner_set_offset(data->shell_surface.xdg.roleobj.popup.positioner,
-                                      mouse->x + TOOLTIP_CURSOR_OFFSET,
-                                      mouse->y + TOOLTIP_CURSOR_OFFSET);
+            xdg_positioner_set_anchor(data->shell_surface.xdg.roleobj.popup.positioner, XDG_POSITIONER_ANCHOR_TOP_LEFT);
+            xdg_positioner_set_anchor_rect(data->shell_surface.xdg.roleobj.popup.positioner, 0, 0, parent->w, parent->h);
+            xdg_positioner_set_constraint_adjustment(data->shell_surface.xdg.roleobj.popup.positioner,
+                                                     XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_X | XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_Y);
+            xdg_positioner_set_gravity(data->shell_surface.xdg.roleobj.popup.positioner, XDG_POSITIONER_GRAVITY_BOTTOM_RIGHT);
+            xdg_positioner_set_size(data->shell_surface.xdg.roleobj.popup.positioner, window->w, window->h);
+
+            /* Set the popup initial position */
+            GetPopupPosition(window, window->x, window->y, &position_x, &position_y);
+            xdg_positioner_set_offset(data->shell_surface.xdg.roleobj.popup.positioner, position_x, position_y);
 
             /* Assign the popup role */
             data->shell_surface.xdg.roleobj.popup.popup = xdg_surface_get_popup(data->shell_surface.xdg.surface,
-                                                                                focuseddata->shell_surface.xdg.surface,
+                                                                                parent_xdg_surface,
                                                                                 data->shell_surface.xdg.roleobj.popup.positioner);
             xdg_popup_add_listener(data->shell_surface.xdg.roleobj.popup.popup, &popup_listener_xdg, data);
 
-            /* For tooltips, track mouse motion so it follows the cursor */
             if (window->flags & SDL_WINDOW_TOOLTIP) {
-                if (xdg_popup_get_version(data->shell_surface.xdg.roleobj.popup.popup) >= 3) {
-                    SDL_AddEventWatch(Wayland_PopupWatch, window);
-                }
+                struct wl_region *region;
+
+                /* Tooltips can't be interacted with, so turn off the input region to avoid blocking anything behind them */
+                region = wl_compositor_create_region(c->compositor);
+                wl_region_add(region, 0, 0, 0, 0);
+                wl_surface_set_input_region(data->surface, region);
+                wl_region_destroy(region);
             }
         } else {
             data->shell_surface.xdg.roleobj.toplevel = xdg_surface_get_toplevel(data->shell_surface.xdg.surface);
@@ -1318,17 +1336,6 @@ static void Wayland_ReleasePopup(_THIS, SDL_Window *popup)
         return;
     }
 
-    /* Release the child _first_, otherwise a protocol error triggers */
-    if (popupdata->shell_surface.xdg.roleobj.popup.child != NULL) {
-        Wayland_ReleasePopup(_this, popupdata->shell_surface.xdg.roleobj.popup.child);
-        popupdata->shell_surface.xdg.roleobj.popup.child = NULL;
-    }
-
-    if (popup->flags & SDL_WINDOW_TOOLTIP) {
-        if (xdg_popup_get_version(popupdata->shell_surface.xdg.roleobj.popup.popup) >= 3) {
-            SDL_DelEventWatch(Wayland_PopupWatch, popup);
-        }
-    }
     xdg_popup_destroy(popupdata->shell_surface.xdg.roleobj.popup.popup);
     xdg_positioner_destroy(popupdata->shell_surface.xdg.roleobj.popup.positioner);
     popupdata->shell_surface.xdg.roleobj.popup.popup = NULL;
@@ -1806,11 +1813,19 @@ void Wayland_SetWindowKeyboardGrab(_THIS, SDL_Window *window, SDL_bool grabbed)
     }
 }
 
+#define IS_POPUP(window) \
+    (window->flags & (SDL_WINDOW_TOOLTIP | SDL_WINDOW_POPUP_MENU))
+
 int Wayland_CreateWindow(_THIS, SDL_Window *window)
 {
     SDL_WindowData *data;
     SDL_VideoData *c;
 
+    /* Popups must have a parent window */
+    if (IS_POPUP(window) && !SDL_GetMouseFocus()) {
+        return -1;
+    }
+
     data = SDL_calloc(1, sizeof *data);
     if (data == NULL) {
         return SDL_OutOfMemory();
@@ -1927,8 +1942,6 @@ int Wayland_CreateWindow(_THIS, SDL_Window *window)
     /* We may need to create an idle inhibitor for this new window */
     Wayland_SuspendScreenSaver(_this);
 
-#define IS_POPUP(window) \
-    (window->flags & (SDL_WINDOW_TOOLTIP | SDL_WINDOW_POPUP_MENU))
 #ifdef HAVE_LIBDECOR_H
     if (c->shell.libdecor && !IS_POPUP(window)) {
         data->shell_surface_type = WAYLAND_SURFACE_LIBDECOR;
@@ -1956,6 +1969,23 @@ void Wayland_SetWindowMaximumSize(_THIS, SDL_Window *window)
     SetMinMaxDimensions(window, SDL_TRUE);
 }
 
+void Wayland_SetWindowPosition(_THIS, SDL_Window *window)
+{
+    SDL_WindowData *wind = window->driverdata;
+
+    /* Only popup windows can be positioned relative to the parent. */
+    if (wind->shell_surface_type == WAYLAND_SURFACE_XDG_POPUP && !(window->flags & SDL_WINDOW_HIDDEN) &&
+        xdg_popup_get_version(wind->shell_surface.xdg.roleobj.popup.popup) >= XDG_POPUP_REPOSITION_SINCE_VERSION) {
+        int x, y;
+
+        GetPopupPosition(window, window->x, window->y, &x, &y);
+        xdg_positioner_set_offset(wind->shell_surface.xdg.roleobj.popup.positioner, x, y);
+        xdg_popup_reposition(wind->shell_surface.xdg.roleobj.popup.popup,
+                             wind->shell_surface.xdg.roleobj.popup.positioner,
+                             0);
+    }
+}
+
 void Wayland_SetWindowSize(_THIS, SDL_Window *window)
 {
     SDL_WindowData *wind = window->driverdata;
@@ -2059,7 +2089,7 @@ void Wayland_DestroyWindow(_THIS, SDL_Window *window)
     SDL_VideoData *data = _this->driverdata;
     SDL_WindowData *wind = window->driverdata;
 
-    if (data) {
+    if (data && wind) {
 #if SDL_VIDEO_OPENGL_EGL
         if (wind->egl_surface) {
             SDL_EGL_DestroySurface(_this, wind->egl_surface);
diff --git a/src/video/wayland/SDL_waylandwindow.h b/src/video/wayland/SDL_waylandwindow.h
index 9a7cc1321383..fe0238d0a249 100644
--- a/src/video/wayland/SDL_waylandwindow.h
+++ b/src/video/wayland/SDL_waylandwindow.h
@@ -62,8 +62,6 @@ struct SDL_WindowData
                 {
                     struct xdg_popup *popup;
                     struct xdg_positioner *positioner;
-                    Uint32 parentID;
-                    SDL_Window *child;
                 } popup;
             } roleobj;
             SDL_bool initial_configure_seen;
@@ -133,6 +131,7 @@ extern void Wayland_RestoreWindow(_THIS, SDL_Window *window);
 extern void Wayland_SetWindowBordered(_THIS, SDL_Window *window, SDL_bool bordered);
 extern void Wayland_SetWindowResizable(_THIS, SDL_Window *window, SDL_bool resizable);
 extern int Wayland_CreateWindow(_THIS, SDL_Window *window);
+extern void Wayland_SetWindowPosition(_THIS, SDL_Window *window);
 extern void Wayland_SetWindowSize(_THIS, SDL_Window *window);
 extern void Wayland_SetWindowMinimumSize(_THIS, SDL_Window *window);
 extern void Wayland_SetWindowMaximumSize(_THIS, SDL_Window *window);