From ecda86fa4f89ecdd364e5a1a22645030fe0ced6e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Camilla=20L=C3=B6wy?= <elmindreda@elmindreda.org>
Date: Wed, 1 Jan 2020 16:56:32 +0100
Subject: [PATCH] X11: Fix no window position events during resize

A window resize action that also resulting in the window being moved did
not emit any window positions events, as the position of real
ConfigureNotify events was ignored.  The real events use parent
coordinates instead of root coordinates so this adds parent tracking and
conditional translation.

Fixes #1613.

(cherry picked from commit fe57e3c2921a1901390534e1e51053df70b5644b)
---
 README.md          |  1 +
 src/x11_platform.h |  1 +
 src/x11_window.c   | 44 +++++++++++++++++++++++++++++++++-----------
 3 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index 9c6b3dc7..0a0cb660 100644
--- a/README.md
+++ b/README.md
@@ -146,6 +146,7 @@ information on what to include when reporting a bug.
  - [X11] Bugfix: Changing `GLFW_FLOATING` on a hidden window could silently fail
  - [X11] Bugfix: Disabled cursor mode was interrupted by indicator windows
  - [X11] Bugfix: Monitor physical dimensions could be reported as zero mm
+ - [X11] Bugfix: Window position events were not emitted during resizing (#1613)
  - [Wayland] Bugfix: The `GLFW_HAND_CURSOR` shape used the wrong image (#1432)
  - [NSGL] Bugfix: `GLFW_COCOA_RETINA_FRAMEBUFFER` had no effect on newer
    macOS versions (#1442)
diff --git a/src/x11_platform.h b/src/x11_platform.h
index d34bc587..7377b2c0 100644
--- a/src/x11_platform.h
+++ b/src/x11_platform.h
@@ -180,6 +180,7 @@ typedef struct _GLFWwindowX11
 {
     Colormap        colormap;
     Window          handle;
+    Window          parent;
     XIC             ic;
 
     GLFWbool        overrideRedirect;
diff --git a/src/x11_window.c b/src/x11_window.c
index 42baf5f4..522c293c 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -1258,6 +1258,18 @@ static void processEvent(XEvent *event)
 
     switch (event->type)
     {
+        case CreateNotify:
+        {
+            window->x11.parent = event->xcreatewindow.parent;
+            return;
+        }
+
+        case ReparentNotify:
+        {
+            window->x11.parent = event->xreparent.parent;
+            return;
+        }
+
         case KeyPress:
         {
             const int key = translateKey(keycode);
@@ -1542,18 +1554,28 @@ static void processEvent(XEvent *event)
                 window->x11.height = event->xconfigure.height;
             }
 
-            if (event->xconfigure.x != window->x11.xpos ||
-                event->xconfigure.y != window->x11.ypos)
-            {
-                if (window->x11.overrideRedirect || event->xany.send_event)
-                {
-                    _glfwInputWindowPos(window,
-                                        event->xconfigure.x,
-                                        event->xconfigure.y);
+            int xpos = event->xconfigure.x;
+            int ypos = event->xconfigure.y;
 
-                    window->x11.xpos = event->xconfigure.x;
-                    window->x11.ypos = event->xconfigure.y;
-                }
+            // NOTE: ConfigureNotify events from the server are in local
+            //       coordinates, so if we are reparented we need to translate
+            //       the position into root (screen) coordinates
+            if (!event->xany.send_event && window->x11.parent != _glfw.x11.root)
+            {
+                Window dummy;
+                XTranslateCoordinates(_glfw.x11.display,
+                                      window->x11.parent,
+                                      _glfw.x11.root,
+                                      xpos, ypos,
+                                      &xpos, &ypos,
+                                      &dummy);
+            }
+
+            if (xpos != window->x11.xpos || ypos != window->x11.ypos)
+            {
+                _glfwInputWindowPos(window, xpos, ypos);
+                window->x11.xpos = xpos;
+                window->x11.ypos = ypos;
             }
 
             return;