Fix monitor notifications on X11

Fixes #288.

README.md

@@ -69,6 +69,7 @@ used by the tests and examples and are not required to build the library.
  - Added `GLFW_TRUE` and `GLFW_FALSE` as client API independent boolean values
  - Removed dependency on external OpenGL or OpenGL ES headers
  - [Cocoa] Removed support for OS X 10.6
+ - [X11] Bugfix: Monitor connection and disconnection events were not reported
  - [WGL] Removed dependency on external WGL headers
  - [GLX] Removed dependency on external GLX headers
  - [EGL] Removed dependency on external EGL headers

include/GLFW/glfw3.h

@@ -1374,9 +1374,6 @@ GLFWAPI const char* glfwGetMonitorName(GLFWmonitor* monitor);
  *  @return The previously set callback, or `NULL` if no callback was set or the
  *  library had not been [initialized](@ref intro_init).
  *
- *  @bug __X11:__ This callback is not yet called on monitor configuration
- *  changes.
- *
  *  @par Thread Safety
  *  This function may only be called from the main thread.
  *

src/x11_init.c

@@ -486,29 +486,29 @@ static GLFWbool initExtensions(void)
 #endif /*_GLFW_HAS_XF86VM*/
 
     // Check for RandR extension
-    _glfw.x11.randr.available =
-        XRRQueryExtension(_glfw.x11.display,
+    if (XRRQueryExtension(_glfw.x11.display,
                           &_glfw.x11.randr.eventBase,
-                          &_glfw.x11.randr.errorBase);
-
-    if (_glfw.x11.randr.available)
+                          &_glfw.x11.randr.errorBase))
     {
-        XRRScreenResources* sr;
-
-        if (!XRRQueryVersion(_glfw.x11.display,
-                             &_glfw.x11.randr.major,
-                             &_glfw.x11.randr.minor))
+        if (XRRQueryVersion(_glfw.x11.display,
+                            &_glfw.x11.randr.major,
+                            &_glfw.x11.randr.minor))
+        {
+            // The GLFW RandR path requires at least version 1.3
+            if (_glfw.x11.randr.major > 1 || _glfw.x11.randr.minor >= 3)
+                _glfw.x11.randr.available = GLFW_TRUE;
+        }
+        else
         {
             _glfwInputError(GLFW_PLATFORM_ERROR,
                             "X11: Failed to query RandR version");
-            return GLFW_FALSE;
         }
+    }
 
-        // The GLFW RandR path requires at least version 1.3
-        if (_glfw.x11.randr.major == 1 && _glfw.x11.randr.minor < 3)
-            _glfw.x11.randr.available = GLFW_FALSE;
-
-        sr = XRRGetScreenResources(_glfw.x11.display, _glfw.x11.root);
+    if (_glfw.x11.randr.available)
+    {
+        XRRScreenResources* sr = XRRGetScreenResources(_glfw.x11.display,
+                                                       _glfw.x11.root);
 
         if (!sr->ncrtc || !XRRGetCrtcGammaSize(_glfw.x11.display, sr->crtcs[0]))
         {
@@ -522,6 +522,9 @@ static GLFWbool initExtensions(void)
         }
 
         XRRFreeScreenResources(sr);
+
+        XRRSelectInput(_glfw.x11.display, _glfw.x11.root,
+                       RROutputChangeNotifyMask);
     }
 
     if (XineramaQueryExtension(_glfw.x11.display,

src/x11_window.c

@@ -480,9 +480,6 @@ static GLFWbool createWindow(_GLFWwindow* window,
 
     _glfwPlatformSetWindowTitle(window, wndconfig->title);
 
-    XRRSelectInput(_glfw.x11.display, window->x11.handle,
-                   RRScreenChangeNotifyMask);
-
     if (_glfw.x11.im)
     {
         window->x11.ic = XCreateIC(_glfw.x11.im,
@@ -852,6 +849,16 @@ static void processEvent(XEvent *event)
     if (_glfw.x11.im)
         filtered = XFilterEvent(event, None);
 
+    if (_glfw.x11.randr.available)
+    {
+        if (event->type == _glfw.x11.randr.eventBase + RRNotify)
+        {
+            XRRUpdateConfiguration(event);
+            _glfwInputMonitorChange();
+            return;
+        }
+    }
+
     if (event->type != GenericEvent)
     {
         window = findWindowByHandle(event->xany.window);
@@ -1412,12 +1419,6 @@ static void processEvent(XEvent *event)
         }
 #endif /*_GLFW_HAS_XINPUT*/
     }
-
-    if (event->type - _glfw.x11.randr.eventBase == RRScreenChangeNotify)
-    {
-        XRRUpdateConfiguration(event);
-        return;
-    }
 }