Description: Fix flickering
 - in GR_Caret::s_blink_timeout, avoid repeated calls by stopping the
   timer, it will be restarted when needed,
 .
 - in GR_Caret::s_enable, avoid extra unnecessary _blink calls when blink
   is enabled, as they serve no purpose,
 .
 - in XAP_UnixFrameImpl::_fe::expose, use the Cairo clip rectangle
   instead of the expose event area, thanks to Hubert Figuière in
   865c1dda7e13deff04573ffc42028b71fee07f9c,
 .
 - in XAP_UnixFrameImpl::_fe::expose, do not return FALSE, as other
   handlers will need to handle the draw event,
 .
 - in GR_UnixCairoGraphics::flush, fix excessive draw events;
   gtk_widget_queue_draw only marks the widget as needing redrawing,
   which causes a draw event for each call to flush, therefore every
   caret blink, so use gdk_flush instead,
Author: James Cameron <quozl@laptop.org>
Origin: other
Bug: https://bugzilla.abisource.com/show_bug.cgi?id=13791
Bug-SugarLabs: https://bugs.sugarlabs.org/ticket/4915
Bug-Ubuntu: https://pad.lv/1574278
Last-Update: 2017-09-24
--- a/src/af/gr/gtk/gr_UnixCairoGraphics.cpp
+++ b/src/af/gr/gtk/gr_UnixCairoGraphics.cpp
@@ -577,9 +577,7 @@ void GR_UnixCairoGraphics::_endPaint()
 
 void GR_UnixCairoGraphics::flush(void)
 {
-	if (m_Widget) {
-		gtk_widget_queue_draw(m_Widget);
-	}
+	gdk_flush();
 }
 
 bool GR_UnixCairoGraphics::queryProperties(GR_Graphics::Properties gp) const
--- a/src/af/gr/xp/gr_Caret.cpp
+++ b/src/af/gr/xp/gr_Caret.cpp
@@ -155,22 +155,17 @@ void GR_Caret::s_enable(UT_Worker * _w)
 {
 	GR_Caret * c = static_cast<GR_Caret *>(_w->getInstanceData());
 
+	c->m_enabler->stop();
 	c->m_worker->stop();
-	c->_blink(true);
-	if (!c->m_bCursorIsOn)
-		c->_blink(true); // blink again
-	else
-	{
-		c->_blink(true); // ?? - MARCM
-		c->_blink(true);
-	}
 	c->m_worker->start();
-	c->m_enabler->stop();
+	c->_blink(true);
 }
 
 void GR_Caret::s_blink_timeout(UT_Worker * _w)
 {
 	GR_Caret * c = static_cast<GR_Caret *>(_w->getInstanceData());
+
+	c->m_blinkTimeout->stop();
 	if (c->isEnabled())
 		c->disable();
 }
--- a/src/af/xap/gtk/xap_UnixFrameImpl.cpp
+++ b/src/af/xap/gtk/xap_UnixFrameImpl.cpp
@@ -1215,8 +1215,16 @@ gboolean XAP_UnixFrameImpl::_fe::expose(
 {
 	XAP_UnixFrameImpl * pUnixFrameImpl = static_cast<XAP_UnixFrameImpl *>(g_object_get_data(G_OBJECT(w), "user_data"));
 	FV_View * pView = static_cast<FV_View *>(pUnixFrameImpl->getFrame()->getCurrentView());
+	double x, y, width, height;
 #if GTK_CHECK_VERSION(3,0,0)
-	GdkEventExpose *pExposeEvent = reinterpret_cast<GdkEventExpose *>(gtk_get_current_event());
+	cairo_clip_extents (cr, &x, &y, &width, &height);
+	width -= x;
+	height -= y;
+#else
+	x = pExposeEvent->area.x;
+	y = pExposeEvent->area.y;
+	width = pExposeEvent->area.width;
+	height = pExposeEvent->area.height;
 #endif
 /* Jean: commenting out next lines since the zoom update code does draw only
  * part of what needs to be updated. */
@@ -1230,16 +1238,17 @@ gboolean XAP_UnixFrameImpl::_fe::expose(
 		UT_Rect rClip;
 		if (pGr->getPaintCount () > 0)
 			return TRUE;
-		xxx_UT_DEBUGMSG(("Expose area: x %d y %d width %d  height %d \n",pExposeEvent->area.x,pExposeEvent->area.y,pExposeEvent->area.width,pExposeEvent->area.height));
-		rClip.left = pGr->tlu(pExposeEvent->area.x);
-		rClip.top = pGr->tlu(pExposeEvent->area.y);
-		rClip.width = pGr->tlu(pExposeEvent->area.width)+1;
-		rClip.height = pGr->tlu(pExposeEvent->area.height)+1;
+		rClip.left = pGr->tlu(x);
+		rClip.top = pGr->tlu(y);
 #if GTK_CHECK_VERSION(3,0,0)
+		rClip.width = pGr->tlu(width);
+		rClip.height = pGr->tlu(height);
 		static_cast<GR_CairoGraphics *>(pGr)->setCairo(cr);
 		pView->draw(&rClip);
 		static_cast<GR_CairoGraphics *>(pGr)->setCairo(NULL);
 #else
+		rClip.width = pGr->tlu(width)+1;
+		rClip.height = pGr->tlu(height)+1;
 		pView->draw(&rClip);
 #endif
 	}