From 2a2d0f1d10ac5233bd429637c3867ade4381be4f Mon Sep 17 00:00:00 2001
From: Stefano Ceccherini <stefano.ceccherini@gmail.com>
Date: Fri, 14 Aug 2009 20:38:35 +0000
Subject: [PATCH] After a B_DIRECT_STOP notification, the app_server could
 trigger a B_DIRECT_MODIFY with, for example, B_CLIPPING_MODIFIED. This was
 ignored, though. Now we combine this notification with the next ones, so that
 on B_DIRECT_START, the client is informed of all the things which have
 changed. Chart was relying on receiving the B_CLIPPING_MODIFIED notification
 to exclude some stars from being erased, in case the window went offscreen.
 Anyway, the net result is that Chart doesn't crash now, and we follow more
 closely the original BDirectWindow protocol. Fixed ticket #1939.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32392 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/servers/app/ServerWindow.cpp | 49 +++++++++++++++++++++++++-------
 src/servers/app/ServerWindow.h   |  2 +-
 2 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/src/servers/app/ServerWindow.cpp b/src/servers/app/ServerWindow.cpp
index 29d94ea383..d9d75b9776 100644
--- a/src/servers/app/ServerWindow.cpp
+++ b/src/servers/app/ServerWindow.cpp
@@ -120,6 +120,24 @@ static profile sRedrawProcessingTime;
 #endif
 
 
+// TODO: Move to another file
+struct BufferState {
+	BufferState(const direct_buffer_state &state)
+		: fState(state)
+	{
+	}
+	direct_buffer_state Action() const
+	{
+		return (direct_buffer_state)(fState & B_DIRECT_MODE_MASK);
+	}
+	direct_buffer_state Reason() const
+	{
+		return (direct_buffer_state)(fState & ~B_DIRECT_MODE_MASK);
+	}	
+	direct_buffer_state fState;
+};
+
+
 class DirectWindowData {
 public:
 	DirectWindowData();
@@ -131,8 +149,8 @@ public:
 	status_t SyncronizeWithClient();
 	
 	bool SetState(const direct_buffer_state &bufferState,
-				const direct_driver_state &driverState);
-	
+					const direct_driver_state &driverState);
+		
 	BRect	old_window_frame;
 	direct_buffer_info *buffer_info;
 
@@ -140,6 +158,7 @@ private:
 	sem_id	fSem;
 	sem_id	fAcknowledgeSem;
 	area_id	fBufferArea;
+	direct_buffer_state fPreviousState;
 };
 
 
@@ -148,7 +167,8 @@ DirectWindowData::DirectWindowData()
 	buffer_info(NULL),
 	fSem(-1),
 	fAcknowledgeSem(-1),
-	fBufferArea(-1)
+	fBufferArea(-1),
+	fPreviousState(B_DIRECT_STOP)
 {
 	fBufferArea = create_area("direct area", (void **)&buffer_info,
 		B_ANY_ADDRESS, B_PAGE_SIZE, B_NO_LOCK, B_READ_WRITE);
@@ -219,22 +239,31 @@ bool
 DirectWindowData::SetState(const direct_buffer_state &bufferState,
 	const direct_driver_state &driverState)
 {
+	BufferState inputState(bufferState);
+	BufferState currentState(buffer_info->buffer_state);
 	// Don't issue a DirectConnected() notification
 	// if the connection is stopped, and we are called
-	// with bufferState == B_DIRECT_MODIFY.
-	if ((buffer_info->buffer_state & B_DIRECT_MODE_MASK) == B_DIRECT_STOP
-		&& (bufferState & B_DIRECT_MODE_MASK) != B_DIRECT_START)
+	// with bufferState == B_DIRECT_MODIFY, but save the reason
+	// and combine it for next time we are called with B_DIRECT_START	
+	if (currentState.Action() == B_DIRECT_STOP
+			&& inputState.Action() != B_DIRECT_START) {
+		fPreviousState = (direct_buffer_state)(fPreviousState 
+			| inputState.Reason());
 		return false;
-		
-	if (bufferState != -1)
-		buffer_info->buffer_state = bufferState;
+	}	
+	
+	buffer_info->buffer_state = (direct_buffer_state)(bufferState 
+		| BufferState(fPreviousState).Reason());
+	
+	fPreviousState = B_DIRECT_STOP;
+	
 	if (driverState != -1)
 		buffer_info->driver_state = driverState;
 			
 	return true;
 }
 
-
+	
 //	#pragma mark -
 
 
diff --git a/src/servers/app/ServerWindow.h b/src/servers/app/ServerWindow.h
index 0d48f65d15..50a16993e3 100644
--- a/src/servers/app/ServerWindow.h
+++ b/src/servers/app/ServerWindow.h
@@ -90,7 +90,7 @@ public:
 			// related thread/team_id(s).
 	inline	team_id				ClientTeam() const { return fClientTeam; }
 
-			void				HandleDirectConnection(int32 bufferState = -1,
+			void				HandleDirectConnection(int32 bufferState,
 									int32 driverState = -1);
 
 	inline	int32				ClientToken() const { return fClientToken; }