GHOST/X11: Hotplug support for xinput

Allows to plug/unplug different tablets while Blender is running.

Also fixes crash unplugging tablet while Blender runs (T48750).

5 files changed, 146 insertions, 78 deletions

diff --git a/intern/ghost/intern/GHOST_ContextGLX.cpp b/intern/ghost/intern/GHOST_ContextGLX.cpp
index d4f67da1242..9ac61db4041 100644
--- a/intern/ghost/intern/GHOST_ContextGLX.cpp
+++ b/intern/ghost/intern/GHOST_ContextGLX.cpp
@@ -155,15 +155,7 @@ void GHOST_ContextGLX::initContextGLXEW()
 
 GHOST_TSuccess GHOST_ContextGLX::initializeDrawingContext()
 {
-#ifdef WITH_X11_XINPUT
-	/* use our own event handlers to avoid exiting blender,
-	 * this would happen for eg:
-	 * if you open blender, unplug a tablet, then open a new window. */
-	XErrorHandler   old_handler    = XSetErrorHandler  (GHOST_X11_ApplicationErrorHandler  );
-	XIOErrorHandler old_handler_io = XSetIOErrorHandler(GHOST_X11_ApplicationIOErrorHandler);
-#endif
-
-
+	GHOST_X11_ERROR_HANDLERS_OVERRIDE(handler_store);
 
 	/* -------------------------------------------------------------------- */
 	/* Begin Inline Glew  */
@@ -350,11 +342,8 @@ const bool GLXEW_ARB_create_context_robustness =
 		success = GHOST_kFailure;
 	}
 
-#ifdef WITH_X11_XINPUT
-	/* Restore handler */
-	XSetErrorHandler  (old_handler);
-	XSetIOErrorHandler(old_handler_io);
-#endif
+
+	GHOST_X11_ERROR_HANDLERS_RESTORE(handler_store);
 
 	return success;
 }
diff --git a/intern/ghost/intern/GHOST_SystemX11.cpp b/intern/ghost/intern/GHOST_SystemX11.cpp
index aeda95d5d4d..55d013f6e5f 100644
--- a/intern/ghost/intern/GHOST_SystemX11.cpp
+++ b/intern/ghost/intern/GHOST_SystemX11.cpp
@@ -73,6 +73,10 @@
 /* for debugging - so we can breakpoint X11 errors */
 // #define USE_X11_ERROR_HANDLERS
 
+#ifdef WITH_X11_XINPUT
+#  define USE_XINPUT_HOTPLUG
+#endif
+
 /* see [#34039] Fix Alt key glitch on Unity desktop */
 #define USE_UNITY_WORKAROUND
 
@@ -169,11 +173,36 @@ GHOST_SystemX11(
 	}
 	
 #ifdef WITH_X11_XINPUT
+	/* detect if we have xinput (for reuse) */
+	{
+		memset(&m_xinput_version, 0, sizeof(m_xinput_version));
+		XExtensionVersion *version = XGetExtensionVersion(m_display, INAME);
+		if (version && (version != (XExtensionVersion *)NoSuchExtension)) {
+			if (version->present) {
+				m_xinput_version = *version;
+			}
+			XFree(version);
+		}
+	}
+
+#ifdef USE_XINPUT_HOTPLUG
+	if (m_xinput_version.present) {
+		XEventClass class_presence;
+		int xi_presence;
+		DevicePresence(m_display, xi_presence, class_presence);
+		XSelectExtensionEvent(
+		        m_display,
+		        RootWindow(m_display, DefaultScreen(m_display)),
+		        &class_presence, 1);
+		(void)xi_presence;
+	}
+#endif  /* USE_XINPUT_HOTPLUG */
+
 	/* initialize incase X11 fails to load */
 	memset(&m_xtablet, 0, sizeof(m_xtablet));
 
-	initXInputDevices();
-#endif
+	refreshXInputDevices();
+#endif  /* WITH_X11_XINPUT */
 }
 
 GHOST_SystemX11::
@@ -627,8 +656,13 @@ static bool checkTabletProximity(Display *display, XDevice *device)
 		return false;
 	}
 
+	/* needed since unplugging will abort() without this */
+	GHOST_X11_ERROR_HANDLERS_OVERRIDE(handler_store);
+
 	state = XQueryDeviceState(display, device);
 
+	GHOST_X11_ERROR_HANDLERS_RESTORE(handler_store);
+
 	if (state) {
 		XInputClass *cls = state->data;
 		// printf("%d class%s :\n", state->num_classes,
@@ -661,6 +695,41 @@ GHOST_SystemX11::processEvent(XEvent *xe)
 	GHOST_WindowX11 *window = findGhostWindow(xe->xany.window);
 	GHOST_Event *g_event = NULL;
 
+#ifdef USE_XINPUT_HOTPLUG
+	/* Hot-Plug support */
+	if (m_xinput_version.present) {
+		XEventClass class_presence;
+		int xi_presence;
+
+		DevicePresence(m_display, xi_presence, class_presence);
+		(void)class_presence;
+
+		if (xe->type == xi_presence) {
+			XDevicePresenceNotifyEvent *notify_event = (XDevicePresenceNotifyEvent *)xe;
+			if ((notify_event->devchange == DeviceEnabled) ||
+			    (notify_event->devchange == DeviceDisabled) ||
+			    (notify_event->devchange == DeviceAdded) ||
+			    (notify_event->devchange == DeviceRemoved))
+			{
+				refreshXInputDevices();
+
+				/* update all window events */
+				{
+					vector<GHOST_IWindow *> & win_vec = m_windowManager->getWindows();
+					vector<GHOST_IWindow *>::iterator win_it = win_vec.begin();
+					vector<GHOST_IWindow *>::const_iterator win_end = win_vec.end();
+
+					for (; win_it != win_end; ++win_it) {
+						GHOST_WindowX11 *window = static_cast<GHOST_WindowX11 *>(*win_it);
+						window->refreshXInputDevices();
+					}
+				}
+			}
+		}
+	}
+#endif  /* USE_XINPUT_HOTPLUG */
+
+
 	if (!window) {
 		return;
 	}
@@ -680,7 +749,6 @@ GHOST_SystemX11::processEvent(XEvent *xe)
 		}
 	}
 #endif /* WITH_X11_XINPUT */
-
 	switch (xe->type) {
 		case Expose:
 		{
@@ -1917,8 +1985,6 @@ GHOST_TSuccess GHOST_SystemX11::pushDragDropEvent(GHOST_TEventType eventType,
 	                         );
 }
 #endif
-
-#if defined(USE_X11_ERROR_HANDLERS) || defined(WITH_X11_XINPUT)
 /*
  * These callbacks can be used for debugging, so we can breakpoint on an X11 error.
 
@@ -1952,7 +2018,6 @@ int GHOST_X11_ApplicationIOErrorHandler(Display * /*display*/)
 	/* No exit! - but keep lint happy */
 	return 0;
 }
-#endif
 
 #ifdef WITH_X11_XINPUT
 /* These C functions are copied from Wine 1.1.13's wintab.c */
@@ -2049,23 +2114,27 @@ static BOOL is_eraser(const char *name, const char *type)
 #undef FALSE
 /* end code copied from wine */
 
-void GHOST_SystemX11::initXInputDevices()
+void GHOST_SystemX11::refreshXInputDevices()
 {
-	static XErrorHandler   old_handler = (XErrorHandler) 0;
-	static XIOErrorHandler old_handler_io = (XIOErrorHandler) 0;
+	if (m_xinput_version.present) {
 
-	XExtensionVersion *version = XGetExtensionVersion(m_display, INAME);
+		if (m_xtablet.StylusDevice) {
+			XCloseDevice(m_display, m_xtablet.StylusDevice);
+			m_xtablet.StylusDevice = NULL;
+		}
 
-	if (version && (version != (XExtensionVersion *)NoSuchExtension)) {
-		if (version->present) {
+		if (m_xtablet.EraserDevice) {
+			XCloseDevice(m_display, m_xtablet.EraserDevice);
+			m_xtablet.EraserDevice = NULL;
+		}
+
+		/* Install our error handler to override Xlib's termination behavior */
+		GHOST_X11_ERROR_HANDLERS_OVERRIDE(handler_store);
+
+		{
 			int device_count;
 			XDeviceInfo *device_info = XListInputDevices(m_display, &device_count);
-			m_xtablet.StylusDevice = NULL;
-			m_xtablet.EraserDevice = NULL;
 
-			/* Install our error handler to override Xlib's termination behavior */
-			old_handler = XSetErrorHandler(GHOST_X11_ApplicationErrorHandler);
-			old_handler_io = XSetIOErrorHandler(GHOST_X11_ApplicationIOErrorHandler);
 
 			for (int i = 0; i < device_count; ++i) {
 				char *device_type = device_info[i].type ? XGetAtomName(m_display, device_info[i].type) : NULL;
@@ -2124,13 +2193,10 @@ void GHOST_SystemX11::initXInputDevices()
 				}
 			}
 
-			/* Restore handler */
-			(void) XSetErrorHandler(old_handler);
-			(void) XSetIOErrorHandler(old_handler_io);
-
 			XFreeDeviceList(device_info);
 		}
-		XFree(version);
+
+		GHOST_X11_ERROR_HANDLERS_RESTORE(handler_store);
 	}
 }
 
diff --git a/intern/ghost/intern/GHOST_SystemX11.h b/intern/ghost/intern/GHOST_SystemX11.h
index a0088dbe8f0..e60cab6a194 100644
--- a/intern/ghost/intern/GHOST_SystemX11.h
+++ b/intern/ghost/intern/GHOST_SystemX11.h
@@ -52,6 +52,20 @@
 int GHOST_X11_ApplicationErrorHandler(Display *display, XErrorEvent *theEvent);
 int GHOST_X11_ApplicationIOErrorHandler(Display *display);
 
+#define GHOST_X11_ERROR_HANDLERS_OVERRIDE(var) \
+	struct { \
+		XErrorHandler handler; \
+		XIOErrorHandler handler_io; \
+	} var = { \
+		XSetErrorHandler(GHOST_X11_ApplicationErrorHandler), \
+		XSetIOErrorHandler(GHOST_X11_ApplicationIOErrorHandler), \
+	}
+
+#define GHOST_X11_ERROR_HANDLERS_RESTORE(var) \
+	{ \
+		(void)XSetErrorHandler(var.handler); \
+		(void)XSetIOErrorHandler(var.handler_io); \
+	} ((void)0)
 
 class GHOST_WindowX11;
 
@@ -328,6 +342,10 @@ public:
 #endif
 	} m_atom;
 
+#ifdef WITH_X11_XINPUT
+	XExtensionVersion m_xinput_version;
+#endif
+
 private:
 
 	Display *m_display;
@@ -367,7 +385,7 @@ private:
 #endif
 
 #ifdef WITH_X11_XINPUT
-	void initXInputDevices();
+	void refreshXInputDevices();
 #endif
 
 	GHOST_WindowX11 *
diff --git a/intern/ghost/intern/GHOST_WindowX11.cpp b/intern/ghost/intern/GHOST_WindowX11.cpp
index a12ecec6371..fd002cec80c 100644
--- a/intern/ghost/intern/GHOST_WindowX11.cpp
+++ b/intern/ghost/intern/GHOST_WindowX11.cpp
@@ -566,7 +566,7 @@ GHOST_WindowX11(GHOST_SystemX11 *system,
 	}
 
 #ifdef WITH_X11_XINPUT
-	initXInputDevices();
+	refreshXInputDevices();
 
 	m_tabletData.Active = GHOST_kTabletModeNone;
 #endif
@@ -633,45 +633,40 @@ bool GHOST_WindowX11::createX11_XIC()
 #endif
 
 #ifdef WITH_X11_XINPUT
-void GHOST_WindowX11::initXInputDevices()
+void GHOST_WindowX11::refreshXInputDevices()
 {
-	XExtensionVersion *version = XGetExtensionVersion(m_display, INAME);
-
-	if (version && (version != (XExtensionVersion *)NoSuchExtension)) {
-		if (version->present) {
-			GHOST_SystemX11::GHOST_TabletX11 &xtablet = m_system->GetXTablet();
-			XEventClass xevents[8], ev;
-			int dcount = 0;
-
-			/* With modern XInput (xlib 1.6.2 at least and/or evdev 2.9.0) and some 'no-name' tablets
-			 * like 'UC-LOGIC Tablet WP5540U', we also need to 'select' ButtonPress for motion event,
-			 * otherwise we do not get any tablet motion event once pen is pressed... See T43367.
-			 */
-
-			if (xtablet.StylusDevice) {
-				DeviceMotionNotify(xtablet.StylusDevice, xtablet.MotionEvent, ev);
-				if (ev) xevents[dcount++] = ev;
-				DeviceButtonPress(xtablet.StylusDevice, xtablet.PressEvent, ev);
-				if (ev) xevents[dcount++] = ev;
-				ProximityIn(xtablet.StylusDevice, xtablet.ProxInEvent, ev);
-				if (ev) xevents[dcount++] = ev;
-				ProximityOut(xtablet.StylusDevice, xtablet.ProxOutEvent, ev);
-				if (ev) xevents[dcount++] = ev;
-			}
-			if (xtablet.EraserDevice) {
-				DeviceMotionNotify(xtablet.EraserDevice, xtablet.MotionEventEraser, ev);
-				if (ev) xevents[dcount++] = ev;
-				DeviceButtonPress(xtablet.EraserDevice, xtablet.PressEventEraser, ev);
-				if (ev) xevents[dcount++] = ev;
-				ProximityIn(xtablet.EraserDevice, xtablet.ProxInEventEraser, ev);
-				if (ev) xevents[dcount++] = ev;
-				ProximityOut(xtablet.EraserDevice, xtablet.ProxOutEventEraser, ev);
-				if (ev) xevents[dcount++] = ev;
-			}
+	if (m_system->m_xinput_version.present) {
+		GHOST_SystemX11::GHOST_TabletX11 &xtablet = m_system->GetXTablet();
+		XEventClass xevents[8], ev;
+		int dcount = 0;
+
+		/* With modern XInput (xlib 1.6.2 at least and/or evdev 2.9.0) and some 'no-name' tablets
+		 * like 'UC-LOGIC Tablet WP5540U', we also need to 'select' ButtonPress for motion event,
+		 * otherwise we do not get any tablet motion event once pen is pressed... See T43367.
+		 */
 
-			XSelectExtensionEvent(m_display, m_window, xevents, dcount);
+		if (xtablet.StylusDevice) {
+			DeviceMotionNotify(xtablet.StylusDevice, xtablet.MotionEvent, ev);
+			if (ev) xevents[dcount++] = ev;
+			DeviceButtonPress(xtablet.StylusDevice, xtablet.PressEvent, ev);
+			if (ev) xevents[dcount++] = ev;
+			ProximityIn(xtablet.StylusDevice, xtablet.ProxInEvent, ev);
+			if (ev) xevents[dcount++] = ev;
+			ProximityOut(xtablet.StylusDevice, xtablet.ProxOutEvent, ev);
+			if (ev) xevents[dcount++] = ev;
 		}
-		XFree(version);
+		if (xtablet.EraserDevice) {
+			DeviceMotionNotify(xtablet.EraserDevice, xtablet.MotionEventEraser, ev);
+			if (ev) xevents[dcount++] = ev;
+			DeviceButtonPress(xtablet.EraserDevice, xtablet.PressEventEraser, ev);
+			if (ev) xevents[dcount++] = ev;
+			ProximityIn(xtablet.EraserDevice, xtablet.ProxInEventEraser, ev);
+			if (ev) xevents[dcount++] = ev;
+			ProximityOut(xtablet.EraserDevice, xtablet.ProxOutEventEraser, ev);
+			if (ev) xevents[dcount++] = ev;
+		}
+
+		XSelectExtensionEvent(m_display, m_window, xevents, dcount);
 	}
 }
 
diff --git a/intern/ghost/intern/GHOST_WindowX11.h b/intern/ghost/intern/GHOST_WindowX11.h
index 0738e3d47b8..9380aa9d631 100644
--- a/intern/ghost/intern/GHOST_WindowX11.h
+++ b/intern/ghost/intern/GHOST_WindowX11.h
@@ -212,6 +212,10 @@ public:
 	bool createX11_XIC();
 #endif
 
+#ifdef WITH_X11_XINPUT
+	void refreshXInputDevices();
+#endif
+
 #ifdef WITH_XDND
 	GHOST_DropTargetX11 *getDropTarget()
 	{
@@ -315,10 +319,6 @@ private:
 	Cursor
 	getEmptyCursor(
 	    );
-
-#ifdef WITH_X11_XINPUT
-	void initXInputDevices();
-#endif
 	
 	Window m_window;
 	Display *m_display;