* Introduced a new view event mask flag: B_FULL_POINTER_HISTORY which,

when set, prevents any old mouse moved message discarding.
* BWindow::DispatchMessage(B_MOUSE_MOVED) checks the event time of the
  message and discards too old events, but only if there is another event
  in the queue and the view does not specify B_FULL_POINTER_HISTORY.
* BView::GetMouse() ignores the checkHistory flag passed to the function
  in case the event mask specifies B_NO_POINTER_HISTORY.
  B_FULL_POINTER_HISTORY on the other hand prevents the dropping of old
  messages.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26341 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/View.h

@@ -43,7 +43,11 @@ enum {
 enum {
 	B_LOCK_WINDOW_FOCUS		= 0x00000001,
 	B_SUSPEND_VIEW_FOCUS	= 0x00000002,
-	B_NO_POINTER_HISTORY	= 0x00000004
+	B_NO_POINTER_HISTORY	= 0x00000004,
+	// new in Haiku (unless this flag is
+	// specified, both BWindow and BView::GetMouse()
+	// will filter out older mouse moved messages)
+	B_FULL_POINTER_HISTORY	= 0x00000008
 };
 
 enum {

src/kits/interface/View.cpp

@@ -1393,7 +1393,11 @@ BView::GetMouse(BPoint *location, uint32 *buttons, bool checkMessageQueue)
 {
 	_CheckOwnerLockAndSwitchCurrent();
 
-	if (checkMessageQueue) {
+	uint32 eventOptions = fEventOptions | fMouseEventOptions;
+	bool noHistory = eventOptions & B_NO_POINTER_HISTORY;
+	bool fullHistory = eventOptions & B_FULL_POINTER_HISTORY;
+
+	if (checkMessageQueue && !noHistory) {
 		Window()->UpdateIfNeeded();
 		BMessageQueue *queue = Window()->MessageQueue();
 		queue->Lock();
@@ -1410,7 +1414,7 @@ BView::GetMouse(BPoint *location, uint32 *buttons, bool checkMessageQueue)
 					if (!Window()->_StealMouseMessage(message, deleteMessage))
 						continue;
 
-					if (message->what == B_MOUSE_MOVED) {
+					if (!fullHistory && message->what == B_MOUSE_MOVED) {
 						// Check if the message is too old. Some applications
 						// check the message queue in such a way that mouse
 						// messages *must* pile up. This check makes them work

src/kits/interface/Window.cpp

@@ -1092,8 +1092,20 @@ FrameMoved(origin);
 		case B_MOUSE_MOVED:
 		{
 			if (BView *view = dynamic_cast<BView *>(target)) {
-				if (((view->fEventOptions | view->fMouseEventOptions)
+
-						& B_NO_POINTER_HISTORY) != 0) {
+				uint32 eventOptions = view->fEventOptions
+					| view->fMouseEventOptions;
+				bool noHistory = eventOptions & B_NO_POINTER_HISTORY;
+				bool fullHistory = eventOptions & B_FULL_POINTER_HISTORY;
+
+				bigtime_t eventTime;
+				if (noHistory
+					|| msg->FindInt64("when", (int64*)&eventTime) < B_OK) {
+					eventTime = system_time();
+				}
+
+				if (noHistory || (!fullHistory
+						&& (system_time() - eventTime > 20000))) {
 					// filter out older mouse moved messages in the queue
 					_DequeueAll();
 					BMessageQueue *queue = MessageQueue();
@@ -1102,6 +1114,9 @@ FrameMoved(origin);
 					BMessage *moved;
 					for (int32 i = 0; (moved = queue->FindMessage(i)) != NULL; i++) {
 						if (moved != msg && moved->what == B_MOUSE_MOVED) {
+							// there is a newer mouse moved message in the
+							// queue, just ignore the current one, the newer one
+							// will be handled here eventually
 							queue->Unlock();
 							return;
 						}
@@ -1116,14 +1131,6 @@ FrameMoved(origin);
 				msg->FindInt32("buttons", (int32*)&buttons);
 				msg->FindInt32("be:transit", (int32*)&transit);
 
-#if 0
-				bigtime_t when;
-				if (msg->FindInt64("when", (int64*)&when) < B_OK)
-					printf("BWindow B_MOUSE_MOVED no when\n");
-				else if (system_time() - when > 5000)
-					printf("BWindow B_MOUSE_MOVED lagging behind\n");
-#endif
-
 				BMessage* dragMessage = NULL;
 				if (msg->HasMessage("be:drag_message")) {
 					dragMessage = new BMessage();