win32: Use an invisible cursor when cursor-visible is FALSE

The win32 backend now handles the WM_SETCURSOR message and sets a
fully transparent cursor if the cursor-visible property has been
cleared on the stage. The icon is stored in the library via a resource
file. The instance handle for the DLL is needed to load the resource
so there is now a DllMain function to grab the handle.

clutter/Makefile.am

@@ -20,6 +20,23 @@ DISTCLEANFILES =
 EXTRA_DIST =
 BUILT_SOURCES =
 
+if WINSYS_WIN32
+
+# Ideally this resources stuff would go in win32/ but libtool doesn't
+# seem to pass on the -Wl argument when linking a convenience library
+# so we need to do it here as part of linking the dll. libtool also
+# won't let you link against the .o directly because it wants you to
+# link against libtool objects for dynamic libraries.
+.rc.o :
+	$(WINDRES) -I$(srcdir)/win32 $< $@
+
+win32/resources.o : $(srcdir)/win32/invisible-cursor.cur
+
+win32_resources = win32/resources.o
+win32_resources_ldflag = -Wl,win32/resources.o
+
+endif # WINSYS_WIN32
+
 INCLUDES = \
 	-I$(top_srcdir) 				\
 	-I$(top_srcdir)/clutter/cogl			\
@@ -205,7 +222,8 @@ libclutter_@CLUTTER_WINSYS@_@CLUTTER_API_VERSION@_la_DEPENDENCIES = \
 	$(top_builddir)/clutter/cogl/pango/libcoglpango.la \
 	$(top_builddir)/clutter/$(CLUTTER_WINSYS)/libclutter-$(CLUTTER_WINSYS).la \
 	$(clutter_json_dep) \
-	$(CLUTTER_WINSYS_BASE_LIB)
+	$(CLUTTER_WINSYS_BASE_LIB) \
+	$(win32_resources)
 
 libclutter_@CLUTTER_WINSYS@_@CLUTTER_API_VERSION@_la_SOURCES = \
 	$(source_c) \
@@ -219,6 +237,7 @@ libclutter_@CLUTTER_WINSYS@_@CLUTTER_API_VERSION@_la_LDFLAGS = \
 	-export-dynamic \
 	-export-symbols-regex "^(clutter|cogl|json).*" \
 	-rpath $(libdir) \
+	$(win32_resources_ldflag) \
 	$(NULL)
 
 lib_LTLIBRARIES = $(CLUTTER_WINSYS_LIB)

clutter/win32/Makefile.am

@@ -33,4 +33,4 @@ libclutter_win32_la_SOURCES = \
 
 CLEANFILES = clutter-win32-$(CLUTTER_API_VERSION).pc
 
-EXTRA_DIST = clutter-win32.pc.in
+EXTRA_DIST = clutter-win32.pc.in resources.rc invisible-cursor.cur

clutter/win32/clutter-backend-win32.c

@@ -47,6 +47,8 @@ static ClutterBackendWin32 *backend_singleton = NULL;
 
 static gchar *clutter_vblank_name = NULL;
 
+static HINSTANCE clutter_hinst = NULL;
+
 gboolean
 clutter_backend_win32_pre_parse (ClutterBackend  *backend,
 				 GError         **error)
@@ -67,6 +69,18 @@ clutter_backend_win32_init_events (ClutterBackend *backend)
   _clutter_backend_win32_events_init (backend);
 }
 
+HCURSOR
+_clutter_backend_win32_get_invisible_cursor (ClutterBackend *backend)
+{
+  ClutterBackendWin32 *backend_win32 = CLUTTER_BACKEND_WIN32 (backend);
+
+  if (backend_win32->invisible_cursor == NULL)
+    backend_win32->invisible_cursor =
+      LoadCursor (clutter_hinst, MAKEINTRESOURCE (42));
+
+  return backend_win32->invisible_cursor;
+}
+
 static const GOptionEntry entries[] =
   {
     {
@@ -353,6 +367,7 @@ clutter_backend_win32_init (ClutterBackendWin32 *backend_win32)
 
   backend_win32->gl_context         = NULL;
   backend_win32->no_event_retrieval = FALSE;
+  backend_win32->invisible_cursor   = NULL;
 
   /* FIXME: get from GetSystemMetric? */
   clutter_backend_set_double_click_time (backend, 250);
@@ -370,3 +385,13 @@ _clutter_backend_impl_get_type (void)
 {
   return clutter_backend_win32_get_type ();
 }
+
+BOOL WINAPI
+DllMain (HINSTANCE hinst, DWORD reason, LPVOID reserved)
+{
+  if (reason == DLL_PROCESS_ATTACH)
+    /* Store the module handle so that we can use it to load resources */
+    clutter_hinst = hinst;
+
+  return TRUE;
+}

clutter/win32/clutter-backend-win32.h

@@ -48,6 +48,8 @@ struct _ClutterBackendWin32
   HGLRC          gl_context;
   gboolean       no_event_retrieval;
 
+  HCURSOR        invisible_cursor;
+
   GSource       *event_source;
 };
 
@@ -68,6 +70,8 @@ clutter_backend_win32_add_options (ClutterBackend *backend,
 ClutterFeatureFlags
 clutter_backend_win32_get_features (ClutterBackend *backend);
 
+HCURSOR _clutter_backend_win32_get_invisible_cursor (ClutterBackend *backend);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_BACKEND_WIN32_H__ */

clutter/win32/clutter-event-win32.c

@@ -616,6 +616,20 @@ message_translate (ClutterBackend *backend,
       }
       break;
 
+    case WM_SETCURSOR:
+      /* If the cursor is in the window's client area and the stage's
+         cursor should be invisible then we'll set a blank cursor
+         instead */
+      if (LOWORD (msg->lParam) == HTCLIENT && !stage_win32->is_cursor_visible)
+        {
+          if (call_def_window_proc)
+            *call_def_window_proc = FALSE;
+          _clutter_stage_win32_update_cursor (stage_win32);
+        }
+
+      res = FALSE;
+      break;
+
     default:
       /* ignore every other message */
       res = FALSE;

clutter/win32/clutter-stage-win32.c

@@ -216,17 +216,51 @@ clutter_stage_win32_set_title (ClutterStageWindow *stage_window,
     SetWindowTextW (stage_win32->hwnd, stage_win32->wtitle);
 }
 
+void
+_clutter_stage_win32_update_cursor (ClutterStageWin32 *stage_win32)
+{
+  HCURSOR cursor;
+
+  if (stage_win32->is_cursor_visible)
+    cursor = (HCURSOR) GetClassLongPtrW (stage_win32->hwnd, GCL_HCURSOR);
+  else
+    {
+      ClutterBackend *backend = clutter_get_default_backend ();
+      /* The documentation implies that we can just use
+         SetCursor(NULL) to get rid of the cursor but apparently this
+         doesn't work very well so instead we create an invisible
+         cursor */
+      cursor = _clutter_backend_win32_get_invisible_cursor (backend);
+    }
+
+  SetCursor (cursor);
+}
+
 static void
 clutter_stage_win32_set_cursor_visible (ClutterStageWindow *stage_window,
                                         gboolean            cursor_visible)
 {
   ClutterStageWin32 *stage_win32 = CLUTTER_STAGE_WIN32 (stage_window);
 
-  if (stage_win32->is_cursor_visible != cursor_visible &&
-      stage_win32->tracking_mouse)
-    ShowCursor (cursor_visible);
+  if (stage_win32->is_cursor_visible != cursor_visible)
+    {
+      POINT cursor_pos;
+      RECT client_rect;
 
-  stage_win32->is_cursor_visible = cursor_visible;
+      stage_win32->is_cursor_visible = cursor_visible;
+
+      /* If the cursor is already over the client area of the window
+         then we need to update it immediately */
+      GetCursorPos (&cursor_pos);
+      if (WindowFromPoint (cursor_pos) == stage_win32->hwnd &&
+          ScreenToClient (stage_win32->hwnd, &cursor_pos) &&
+          GetClientRect (stage_win32->hwnd, &client_rect) &&
+          cursor_pos.x >= client_rect.left &&
+          cursor_pos.y >= client_rect.top &&
+          cursor_pos.x < client_rect.right &&
+          cursor_pos.y < client_rect.bottom)
+        _clutter_stage_win32_update_cursor (stage_win32);
+    }
 }
 
 static LONG

clutter/win32/clutter-stage-win32.h

@@ -80,6 +80,8 @@ LRESULT CALLBACK _clutter_stage_win32_window_proc (HWND hwnd,
 void _clutter_stage_win32_get_min_max_info (ClutterStageWin32 *stage_win32,
 					    MINMAXINFO *min_max_info);
 
+void _clutter_stage_win32_update_cursor (ClutterStageWin32 *stage_win32);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_STAGE_H__ */

clutter/win32/resources.rc

@@ -0,0 +1 @@
+42 CURSOR "invisible-cursor.cur"

configure.ac

@@ -364,11 +364,18 @@ AS_CASE([$CLUTTER_WINSYS],
           WIN32_CFLAGS="-D_WIN32_WINNT=0x0500"
           WIN32_LIBS="-lopengl32 -lgdi32 -lwinmm"
           CLUTTER_LT_LDFLAGS="$CLUTTER_LT_LDFLAGS -no-undefined"
+
+          AC_CHECK_TOOL(WINDRES, windres, no)
+          if test "$WINDRES" = no; then
+             AC_MSG_ERROR([*** windres is required])
+          fi
         ],
 
         [AC_MSG_ERROR([Invalid backend for Clutter: use glx, sdl, osx, win32, eglx, eglnative or fruity])]
 )
 
+AM_CONDITIONAL(WINSYS_WIN32, [test "x$CLUTTER_WINSYS" = "xwin32"])
+
 # at this point we must have a GL header to check
 AS_IF([test "x$clutter_gl_header" = "x"], [AC_MSG_ERROR([Internal error: no GL header set])])
 AC_CHECK_HEADERS([$clutter_gl_header],