From eda0018fc5aa24a7d2a381cab2046f460aed84f1 Mon Sep 17 00:00:00 2001
From: Nick Bolton <nick@synergy-project.org>
Date: Mon, 29 Oct 2012 13:43:08 +0000
Subject: [PATCH] attempted fix to 'cursor does not show' bug, though i don't
 think the issue is solved, it appears to be more stable (but it's so hard to
 tell, since the bug is so random)

---
 src/lib/platform/COSXScreen.cpp | 59 ++++++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 12 deletions(-)

diff --git a/src/lib/platform/COSXScreen.cpp b/src/lib/platform/COSXScreen.cpp
index 28af27a0..ee3aa95e 100644
--- a/src/lib/platform/COSXScreen.cpp
+++ b/src/lib/platform/COSXScreen.cpp
@@ -650,18 +650,30 @@ COSXScreen::showCursor()
 {
 	LOG((CLOG_DEBUG "showing cursor"));
 
+	CFStringRef propertyString = CFStringCreateWithCString(
+		NULL, "SetsCursorInBackground", kCFStringEncodingMacRoman);
+
+	// it looks like from around 2010 (os x 10.6 or 10.7) the behavior of
+	// CGDisplayHideCursor changed so that the cursor could only be hidden by
+	// the program which owned it. ed's solution in r820 was to send the
+	// cursor to the background before trying to hide it. however, this
+	// intermittently caused the cursor to remain hidden when we try to
+	// show it again. to solve this bug, we return the cursor to the
+	// background.
+	CGSSetConnectionProperty(
+		_CGSDefaultConnection(), _CGSDefaultConnection(),
+		propertyString, kCFBooleanTrue);
+
 	CGError error = CGDisplayShowCursor(m_displayID);
 	if (error != kCGErrorSuccess) {
 		LOG((CLOG_ERR "failed to show cursor, error=%d", error));
 	}
 
-	CFStringRef propertyString = CFStringCreateWithCString(NULL, "SetsCursorInBackground", kCFStringEncodingMacRoman);
-	CGSSetConnectionProperty(_CGSDefaultConnection(), _CGSDefaultConnection(), propertyString, kCFBooleanFalse);
-	CFRelease(propertyString);
+	CGSSetConnectionProperty(
+		_CGSDefaultConnection(), _CGSDefaultConnection(),
+		propertyString, kCFBooleanFalse);
 
-	if (!CGCursorIsVisible()) {
-		LOG((CLOG_WARN "cursor is not visible"));
-	}
+	CFRelease(propertyString);
 
 	m_cursorHidden = false;
 }
@@ -671,18 +683,41 @@ COSXScreen::hideCursor()
 {
 	LOG((CLOG_DEBUG "hiding cursor"));
 
-	CFStringRef propertyString = CFStringCreateWithCString(NULL, "SetsCursorInBackground", kCFStringEncodingMacRoman);
-	CGSSetConnectionProperty(_CGSDefaultConnection(), _CGSDefaultConnection(), propertyString, kCFBooleanTrue);
-	CFRelease(propertyString);
+	CFStringRef propertyString = CFStringCreateWithCString(
+		NULL, "SetsCursorInBackground", kCFStringEncodingMacRoman);
+
+	CGSSetConnectionProperty(
+		_CGSDefaultConnection(), _CGSDefaultConnection(),
+		propertyString, kCFBooleanTrue);
 
 	CGError error = CGDisplayHideCursor(m_displayID);
 	if (error != kCGErrorSuccess) {
 		LOG((CLOG_ERR "failed to hide cursor, error=%d", error));
 	}
 
+	// ed's solution to send the cursor to the background before hiding
+	// fixed the bug caused by the new behavior of CGDisplayHideCursor,
+	// which is to only allow cursor to be shown/hidden by the program
+	// that has focus.
+	// however, this does not always work, and the cursor remains hidden,
+	// often when leaving the screen immediately after using the dock.
+	// to work around this, we send the mouse to the corner of the screen
+	// when the cursor is still visible, where it is less noticeable than
+	// at the center.
 	if (CGCursorIsVisible()) {
-		LOG((CLOG_WARN "cursor is still visible"));
+		LOG((CLOG_WARN "cursor is still visible (warping to corner)"));
+		warpCursor(0, m_h);
 	}
+	else {
+		LOG((CLOG_DEBUG "cursor is hidden, warping to center"));
+		warpCursor(m_xCenter, m_yCenter);
+	}
+
+	CGSSetConnectionProperty(
+		_CGSDefaultConnection(), _CGSDefaultConnection(),
+		propertyString, kCFBooleanFalse);
+
+	CFRelease(propertyString);
 
 	m_cursorHidden = true;
 }
@@ -807,7 +842,7 @@ COSXScreen::leave()
     
 	if (m_isPrimary) {
 		// warp to center
-		warpCursor(m_xCenter, m_yCenter);
+		//warpCursor(m_xCenter, m_yCenter);
 		
 		// This used to be necessary to get smooth mouse motion on other screens,
 		// but now is just to avoid a hesitating cursor when transitioning to
@@ -819,7 +854,7 @@ COSXScreen::leave()
 	}
 	else {
 		// warp the mouse to the cursor center
-		fakeMouseMove(m_xCenter, m_yCenter);
+		//fakeMouseMove(m_xCenter, m_yCenter);
 
 		// FIXME -- prepare to show cursor if it moves