Fix for continuous grab on X11.

Need to stop accumulating warp coordinates after the first cursor warp (store time of new generated event and skip warp for events time smaller).

There's some interesting X11 code in there, if people are curious.

2 files changed, 79 insertions, 5 deletions

diff --git a/intern/ghost/intern/GHOST_SystemX11.cpp b/intern/ghost/intern/GHOST_SystemX11.cpp
index ff4a5956a12..3f5f52aa2ed 100644
--- a/intern/ghost/intern/GHOST_SystemX11.cpp
+++ b/intern/ghost/intern/GHOST_SystemX11.cpp
@@ -23,6 +23,9 @@
  *
  * Contributor(s): none yet.
  *
+ * Part of this code has been taken from Qt, under LGPL license
+ * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+ *
  * ***** END GPL LICENSE BLOCK *****
  */
 
@@ -126,6 +129,8 @@ GHOST_SystemX11(
 	m_xclip_out= XInternAtom(m_display, "XCLIP_OUT", False);
 	m_incr= XInternAtom(m_display, "INCR", False);
 	m_utf8_string= XInternAtom(m_display, "UTF8_STRING", False);
+	m_last_warp = 0;
+
 
 	// compute the initial time
 	timeval tv;
@@ -310,6 +315,61 @@ static void SleepTillEvent(Display *display, GHOST_TInt64 maxSleep) {
 	}
 }
 
+/* This function borrowed from Qt's X11 support
+ * qclipboard_x11.cpp
+ *  */
+struct init_timestamp_data
+{
+    Time timestamp;
+};
+
+static Bool init_timestamp_scanner(Display*, XEvent *event, XPointer arg)
+{
+	init_timestamp_data *data =
+        reinterpret_cast<init_timestamp_data*>(arg);
+    switch(event->type)
+    {
+    case ButtonPress:
+    case ButtonRelease:
+        data->timestamp = event->xbutton.time;
+        break;
+    case MotionNotify:
+        data->timestamp = event->xmotion.time;
+        break;
+    case KeyPress:
+    case KeyRelease:
+        data->timestamp = event->xkey.time;
+        break;
+    case PropertyNotify:
+        data->timestamp = event->xproperty.time;
+        break;
+    case EnterNotify:
+    case LeaveNotify:
+        data->timestamp = event->xcrossing.time;
+        break;
+    case SelectionClear:
+        data->timestamp = event->xselectionclear.time;
+        break;
+    default:
+        break;
+    }
+
+    return false;
+}
+
+Time
+GHOST_SystemX11::
+lastEventTime(Time default_time) {
+    init_timestamp_data data;
+    data.timestamp = default_time;
+    XEvent ev;
+    XCheckIfEvent(m_display, &ev, &init_timestamp_scanner, (XPointer)&data);
+
+    return data.timestamp;
+}
+
+
+
 	bool 
 GHOST_SystemX11::
 processEvents(
@@ -405,10 +465,15 @@ GHOST_SystemX11::processEvent(XEvent *xe)
 				window->getCursorGrabAccum(x_accum, y_accum);
 
 				if(x_new != xme.x_root || y_new != xme.y_root) {
-					/* when wrapping we don't need to add an event because the
-					 * setCursorPosition call will cause a new event after */
-					setCursorPosition(x_new, y_new); /* wrap */
-					window->setCursorGrabAccum(x_accum + (xme.x_root - x_new), y_accum + (xme.y_root - y_new));
+					if (xme.time > m_last_warp) {
+						/* when wrapping we don't need to add an event because the
+						 * setCursorPosition call will cause a new event after */
+						setCursorPosition(x_new, y_new); /* wrap */
+						window->setCursorGrabAccum(x_accum + (xme.x_root - x_new), y_accum + (xme.y_root - y_new));
+						m_last_warp = lastEventTime(xme.time);
+					} else {
+						setCursorPosition(x_new, y_new); /* wrap but don't accumulate */
+					}
 				}
 				else {
 					g_event = new
@@ -907,7 +972,7 @@ setCursorPosition(
 	int rely = y-cy;
 
 	XWarpPointer(m_display,None,None,0,0,0,0,relx,rely);
-	XFlush(m_display);
+	XSync(m_display, 0); /* Sync to process all requests */
 	
 	return GHOST_kSuccess;
 }
diff --git a/intern/ghost/intern/GHOST_SystemX11.h b/intern/ghost/intern/GHOST_SystemX11.h
index 782f08f6737..d76c3991beb 100644
--- a/intern/ghost/intern/GHOST_SystemX11.h
+++ b/intern/ghost/intern/GHOST_SystemX11.h
@@ -266,6 +266,10 @@ private :
 	/// A vector of keyboard key masks
 	char m_keyboard_vector[32];
 
+	/* to prevent multiple warp, we store the time of the last warp event
+	 *  and stop accumulating all events generated before that */
+	Time m_last_warp;
+
 	/**
 	 * Return the ghost window associated with the
 	 * X11 window xwind
@@ -281,6 +285,11 @@ private :
 		XEvent *xe
  	);
 
+		Time
+	lastEventTime(
+		Time default_time
+	);
+
 		bool
 	generateWindowExposeEvents(
  	);