Turns out the whole "active app" mechanism in the registrar wasn't used at all; the

Switcher now works as expected.
* Renamed TRoster::ActivateApp() to UpdateActiveApp(), as the app is already activated
  at that point (the registrar only keeps track of it).
* BWindow::DispatchMessage() now calls the new BRoster::Private::UpdateActiveApp()
  method when it receives a B_WINDOW_ACTIVATED message.
* Added BRoster::_UpdateActiveApp() which calls the new B_REG_UPDATE_ACTIVE_APP.
* Removed now unused B_REG_ACTIVATE_APP.
* Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19857 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/Window.cpp

@@ -29,6 +29,7 @@
 #include <MenuPrivate.h>
 #include <MessagePrivate.h>
 #include <PortLink.h>
+#include <RosterPrivate.h>
 #include <ServerProtocol.h>
 #include <TokenSpace.h>
 #include <tracker_private.h>
@@ -905,12 +906,18 @@ FrameMoved(origin);
 				if (msg->FindBool("active", &active) == B_OK
 					&& active != fActive) {
 					fActive = active;
+					if (active) {
+						// notify registrar about the active app
+						BRoster::Private roster;
+						roster.UpdateActiveApp(be_app->Team());
+					}
+
 					WindowActivated(active);
-	
+
 					// call hook function 'WindowActivated(bool)' for all
 					// views attached to this window.
 					fTopView->_Activate(active);
-	
+
 					// we notify the input server if we are gaining or losing focus
 					// from a view which has the B_INPUT_METHOD_AWARE on a window 
 					// (de)activation