SDL: X11: Implement the popup window changes

From 7af650abc98227da9869d8d8c4f84e4dba369d1b Mon Sep 17 00:00:00 2001
From: Frank Praznik <[EMAIL REDACTED]>
Date: Tue, 28 Feb 2023 13:47:47 -0500
Subject: [PATCH] X11: Implement the popup window changes

---
 src/video/x11/SDL_x11events.c |  21 ++++++-
 src/video/x11/SDL_x11sym.h    |   3 +
 src/video/x11/SDL_x11window.c | 101 ++++++++++++++++++++++++++++++----
 src/video/x11/SDL_x11window.h |   5 ++
 4 files changed, 119 insertions(+), 11 deletions(-)

diff --git a/src/video/x11/SDL_x11events.c b/src/video/x11/SDL_x11events.c
index 99014a863797..1a78a409223f 100644
--- a/src/video/x11/SDL_x11events.c
+++ b/src/video/x11/SDL_x11events.c
@@ -753,6 +753,14 @@ static int XLookupStringAsUTF8(XKeyEvent *event_struct, char *buffer_return, int
     return result;
 }
 
+static void X11_TransformPosition(SDL_Window *window, int *pos_x, int *pos_y)
+{
+    if (SDL_WINDOW_IS_POPUP(window)) {
+        *pos_x -= window->parent->driverdata->abs_x;
+        *pos_y -= window->parent->driverdata->abs_y;
+    }
+}
+
 static void X11_DispatchEvent(_THIS, XEvent *xevent)
 {
     SDL_VideoData *videodata = _this->driverdata;
@@ -1167,14 +1175,25 @@ static void X11_DispatchEvent(_THIS, XEvent *xevent)
 
         if (xevent->xconfigure.x != data->last_xconfigure.x ||
             xevent->xconfigure.y != data->last_xconfigure.y) {
+            SDL_Window *w;
+            int x = xevent->xconfigure.x;
+            int y = xevent->xconfigure.y;
+
+            data->abs_x = x;
+            data->abs_y = y;
+            X11_TransformPosition(data->window, &x, &y);
             SDL_SendWindowEvent(data->window, SDL_EVENT_WINDOW_MOVED,
-                                xevent->xconfigure.x, xevent->xconfigure.y);
+                                x, y);
+
 #ifdef SDL_USE_IME
             if (SDL_EventEnabled(SDL_EVENT_TEXT_INPUT)) {
                 /* Update IME candidate list position */
                 SDL_IME_UpdateTextRect(NULL);
             }
 #endif
+            for (w = data->window->first_child; w != NULL; w = w->next_sibling) {
+                X11_UpdateWindowPosition(w);
+            }
         }
         if (xevent->xconfigure.width != data->last_xconfigure.width ||
             xevent->xconfigure.height != data->last_xconfigure.height) {
diff --git a/src/video/x11/SDL_x11sym.h b/src/video/x11/SDL_x11sym.h
index d160eae034af..45630dd469e5 100644
--- a/src/video/x11/SDL_x11sym.h
+++ b/src/video/x11/SDL_x11sym.h
@@ -155,6 +155,9 @@ SDL_X11_SYM(void,XRefreshKeyboardMapping,(XMappingEvent *a),(a),)
 SDL_X11_SYM(int,XQueryTree,(Display* a,Window b,Window* c,Window* d,Window** e,unsigned int* f),(a,b,c,d,e,f),return)
 SDL_X11_SYM(Bool,XSupportsLocale,(void),(),return)
 SDL_X11_SYM(Status,XmbTextListToTextProperty,(Display* a,char** b,int c,XICCEncodingStyle d,XTextProperty* e),(a,b,c,d,e),return)
+SDL_X11_SYM(Region,XCreateRegion,(void),(),return)
+SDL_X11_SYM(void,XDestroyRegion,(Region),(a),)
+SDL_X11_SYM(void,XShapeCombineRegion,(Display *a,Window b,int c,int d,int e,Region f,int g),(a,b,c,d,e,f,g),)
 
 #if SDL_VIDEO_DRIVER_X11_XFIXES
 SDL_X11_MODULE(XFIXES)
diff --git a/src/video/x11/SDL_x11window.c b/src/video/x11/SDL_x11window.c
index ca94ae86065d..bc962a970e42 100644
--- a/src/video/x11/SDL_x11window.c
+++ b/src/video/x11/SDL_x11window.c
@@ -166,6 +166,36 @@ void X11_SetNetWMState(_THIS, Window xwindow, Uint32 flags)
     }
 }
 
+static void X11_ConstrainPopup(SDL_Window *window, int *offset_x, int *offset_y)
+{
+    if (SDL_WINDOW_IS_POPUP(window)) {
+        SDL_Rect bounds;
+        SDL_Window *w;
+        const int orig_offset_x = window->driverdata ? window->driverdata->offset_x : window->windowed.x;
+        const int orig_offset_y = window->driverdata ? window->driverdata->offset_y : window->windowed.y;
+        const int orig_popup_x = window->parent->driverdata->abs_x + orig_offset_x;
+        const int orig_popup_y = window->parent->driverdata->abs_y + orig_offset_y;
+        int popup_x = orig_popup_x;
+        int popup_y = orig_popup_y;
+
+        /* Find the toplevel parent */
+        for(w = window->parent; w->parent != NULL; w = w->parent);
+
+        SDL_GetDisplayBounds(SDL_GetDisplayForWindow(w), &bounds);
+        if (popup_x + window->w > bounds.x + bounds.w) {
+            popup_x -= (popup_x + window->w) - (bounds.x + bounds.w);
+        }
+        if (popup_y + window->h > bounds.y + bounds.h) {
+            popup_y -= (popup_y + window->h) - (bounds.y + bounds.h);
+        }
+        popup_x = SDL_max(popup_x, bounds.x);
+        popup_y = SDL_max(popup_y, bounds.y);
+
+        *offset_x = orig_offset_x + (popup_x - orig_popup_x);
+        *offset_y = orig_offset_y + (popup_y - orig_popup_y);
+    }
+}
+
 Uint32
 X11_GetNetWMState(_THIS, SDL_Window *window, Window xwindow)
 {
@@ -302,8 +332,10 @@ static int SetupWindowData(_THIS, SDL_Window *window, Window w, BOOL created)
         XWindowAttributes attrib;
 
         X11_XGetWindowAttributes(data->videodata->display, w, &attrib);
-        window->x = attrib.x;
-        window->y = attrib.y;
+        if (!SDL_WINDOW_IS_POPUP(window)) {
+            window->x = attrib.x;
+            window->y = attrib.y;
+        }
         window->w = attrib.width;
         window->h = attrib.height;
         if (attrib.map_state != IsUnmapped) {
@@ -392,6 +424,8 @@ int X11_CreateWindow(_THIS, SDL_Window *window)
     Atom _NET_WM_PID;
     long fevent = 0;
     const char *hint = NULL;
+    int x_pos, y_pos;
+    int popup_offset_x, popup_offset_y;
 
 #if SDL_VIDEO_OPENGL_GLX || SDL_VIDEO_OPENGL_EGL
     const char *forced_visual_id = SDL_GetHint(SDL_HINT_VIDEO_X11_WINDOW_VISUALID);
@@ -527,6 +561,15 @@ int X11_CreateWindow(_THIS, SDL_Window *window)
                                 visual, AllocNone);
     }
 
+    if (!SDL_WINDOW_IS_POPUP(window)) {
+        x_pos = window->windowed.x;
+        y_pos = window->windowed.y;
+    } else {
+        X11_ConstrainPopup(window, &popup_offset_x, &popup_offset_y);
+        x_pos = window->parent->driverdata->abs_x + popup_offset_x;
+        y_pos = window->parent->driverdata->abs_y + popup_offset_y;
+    }
+
     /* Always create this with the window->windowed.* fields; if we're
        creating a windowed mode window, that's fine. If we're creating a
        fullscreen window, the window manager will want to know these values
@@ -534,7 +577,7 @@ int X11_CreateWindow(_THIS, SDL_Window *window)
        migration to fullscreen after CreateSDLWindow returns, which will
        put all the SDL_Window fields and system state as expected. */
     w = X11_XCreateWindow(display, RootWindow(display, screen),
-                          window->windowed.x, window->windowed.y, window->windowed.w, window->windowed.h,
+                          x_pos, y_pos, window->windowed.w, window->windowed.h,
                           0, depth, InputOutput, visual,
                           (CWOverrideRedirect | CWBackPixmap | CWBorderPixel |
                            CWBackingStore | CWColormap),
@@ -554,8 +597,8 @@ int X11_CreateWindow(_THIS, SDL_Window *window)
         sizehints->min_height = sizehints->max_height = window->h;
         sizehints->flags |= (PMaxSize | PMinSize);
     }
-    sizehints->x = window->x;
-    sizehints->y = window->y;
+    sizehints->x = x_pos;
+    sizehints->y = y_pos;
     sizehints->flags |= USPosition;
 
     /* Setup the input hints so we get keyboard input */
@@ -667,6 +710,21 @@ int X11_CreateWindow(_THIS, SDL_Window *window)
     }
 #endif
 
+    windowdata->abs_x = x_pos;
+    windowdata->abs_y = y_pos;
+
+    if (SDL_WINDOW_IS_POPUP(window)) {
+        windowdata->offset_x = popup_offset_x;
+        windowdata->offset_y = popup_offset_y;
+    }
+
+    /* Tooltips do not receive input */
+    if (window->flags & SDL_WINDOW_TOOLTIP) {
+        Region region = X11_XCreateRegion();
+        X11_XShapeCombineRegion(display, w, ShapeInput, 0, 0, region, ShapeSet);
+        X11_XDestroyRegion(region);
+    }
+
     X11_Xinput2SelectTouch(_this, window);
 
     X11_XSelectInput(display, w,
@@ -806,8 +864,9 @@ int X11_SetWindowIcon(_THIS, SDL_Window *window, SDL_Surface *icon)
     return rc;
 }
 
-void X11_SetWindowPosition(_THIS, SDL_Window *window)
+void X11_UpdateWindowPosition(SDL_Window *window)
 {
+    SDL_Window *w;
     SDL_WindowData *data = window->driverdata;
     Display *display = data->videodata->display;
     int (*prev_handler)(Display *, XErrorEvent *) = NULL;
@@ -824,8 +883,16 @@ void X11_SetWindowPosition(_THIS, SDL_Window *window)
     X11_XTranslateCoordinates(display, parent, DefaultRootWindow(display),
                               attrs.x, attrs.y, &orig_x, &orig_y, &childReturn);
 
+    if (!SDL_WINDOW_IS_POPUP(window)) {
+        data->abs_x = window->x - data->border_left;
+        data->abs_y = window->y - data->border_top;
+    } else {
+        data->abs_x = window->parent->driverdata->abs_x + data->offset_x;
+        data->abs_y = window->parent->driverdata->abs_y + data->offset_y;
+    }
+
     /*Attempt to move the window*/
-    X11_XMoveWindow(display, data->xwindow, window->x - data->border_left, window->y - data->border_top);
+    X11_XMoveWindow(display, data->xwindow, data->abs_x, data->abs_y);
 
     /* Wait a brief time to see if the window manager decided to let this move happen.
        If the window changes at all, even to an unexpected value, we break out. */
@@ -844,10 +911,10 @@ void X11_SetWindowPosition(_THIS, SDL_Window *window)
 
         if (!caught_x11_error) {
             if ((x != orig_x) || (y != orig_y)) {
-                window->x = x;
-                window->y = y;
+                data->abs_x = x;
+                data->abs_y = y;
                 break; /* window moved, time to go. */
-            } else if ((x == window->x) && (y == window->y)) {
+            } else if ((x == data->abs_x) && (y == data->abs_y)) {
                 break; /* we're at the place we wanted to be anyhow, drop out. */
             }
         }
@@ -861,6 +928,20 @@ void X11_SetWindowPosition(_THIS, SDL_Window *window)
 
     X11_XSetErrorHandler(prev_handler);
     caught_x11_error = SDL_FALSE;
+
+    for (w = window->first_child; w != NULL; w = w->next_sibling) {
+        X11_UpdateWindowPosition(w);
+    }
+}
+
+void X11_SetWindowPosition(_THIS, SDL_Window *window)
+{
+    if (SDL_WINDOW_IS_POPUP(window)) {
+        window->driverdata->offset_x = window->x;
+        window->driverdata->offset_y = window->y;
+        X11_ConstrainPopup(window, &window->driverdata->offset_x, &window->driverdata->offset_y);
+    }
+    X11_UpdateWindowPosition(window);
 }
 
 void X11_SetWindowMinimumSize(_THIS, SDL_Window *window)
diff --git a/src/video/x11/SDL_x11window.h b/src/video/x11/SDL_x11window.h
index fe1321849f55..f2c41a782063 100644
--- a/src/video/x11/SDL_x11window.h
+++ b/src/video/x11/SDL_x11window.h
@@ -59,6 +59,10 @@ struct SDL_WindowData
     int border_right;
     int border_top;
     int border_bottom;
+    int offset_x;
+    int offset_y;
+    int abs_x;
+    int abs_y;
     SDL_bool mouse_grabbed;
     Uint64 last_focus_event_time;
     PendingFocusEnum pending_focus;
@@ -116,5 +120,6 @@ extern void X11_AcceptDragAndDrop(SDL_Window *window, SDL_bool accept);
 extern int X11_FlashWindow(_THIS, SDL_Window *window, SDL_FlashOperation operation);
 
 int SDL_X11_SetWindowTitle(Display *display, Window xwindow, char *title);
+void X11_UpdateWindowPosition(SDL_Window *window);
 
 #endif /* SDL_x11window_h_ */